feat(experiments): target rollouts by guild and premium status (#3012 )

feat(profile): move profile timezone from staff to an experiment (#3011 )
fix(app): react at once when picking a +: autocomplete emoji (#3010 )
2026-10-09 04:02:41 +09:00 · 2026-09-28 14:34:19 +02:00 · 2026-09-28 12:57:26 +02:00 · 2026-09-28 12:30:45 +02:00 · 2026-09-28 02:07:47 +02:00 · 2026-09-28 01:56:08 +02:00
665 changed files with 77315 additions and 39586 deletions
@@ -32,6 +32,7 @@
 /fluxer_docs/.astro/
 /fluxer_app/.devserver-cache.json
 /fluxer_app/pkgs/libfluxcore/
+/fluxer_app/pkgs/libfluxwebp/
 /fluxer_app/src/features/i18n/locales/*/messages.mjs
 /fluxer_app/src/features/messaging/utils/markdown/parser/MarkdownParserWasmBytes.ts
 /fluxer_app/src/features/theme/styles/generated/
@@ -28,6 +28,9 @@ f:media_proxy:
 f:messages:
  - changed-files:
    - any-glob-to-any-file: fluxer_messages/**/*
+f:push:
+  - changed-files:
+    - any-glob-to-any-file: fluxer_push/**/*
 f:snowflakes:
  - changed-files:
    - any-glob-to-any-file: fluxer_snowflakes/**/*
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+name: build push
+
+on:
+  workflow_dispatch:
+    inputs:
+      build-version:
+        description: "Explicit Fluxer CalVer build version (YYYY.MDD.MICRO, UTC HHMMSS without leading zeroes) to use instead of automatic UTC clock allocation"
+        type: string
+        required: false
+        default: ""
+
+permissions:
+  actions: read
+  contents: write
+  packages: write
+
+jobs:
+  approve:
+    name: approve build release
+    permissions: {}
+    runs-on: ubuntu-24.04
+    environment: builds
+    timeout-minutes: 5
+    steps:
+      - name: approved
+        run: echo "Build release approved."
+
+  image:
+    needs: approve
+    uses: ./.github/workflows/_build-image.yaml
+    secrets: inherit
+    with:
+      image: fluxer-push
+      dockerfile: fluxer_push/Dockerfile
+      build-version: ${{ inputs['build-version'] }}
@@ -123,12 +123,16 @@ jobs:
        with:
          path: |
            fluxer_app/pkgs/libfluxcore
+            fluxer_app/pkgs/libfluxwebp
            fluxer_app/src/features/messaging/utils/markdown/parser/MarkdownParserWasmBytes.ts
          key: >-
            app-wasm-${{ runner.os }}-1.98.1-${{ hashFiles('Cargo.lock', 'tools/ci/src/app_wasm.rs',
            'tools/ci/templates/libfluxcore_wrapper.js', 'tools/ci/templates/libfluxcore_wrapper.d.ts',
            'fluxer_app/rust/libfluxcore/Cargo.toml', 'fluxer_app/rust/libfluxcore/Cargo.lock',
            'fluxer_app/rust/libfluxcore/.cargo/config.toml', 'fluxer_app/rust/libfluxcore/src/**',
+            'fluxer_app/rust/libfluxwebp/Cargo.toml', 'fluxer_app/rust/libfluxwebp/Cargo.lock',
+            'fluxer_app/rust/libfluxwebp/src/**', 'fluxer_app/rust/libfluxwebp/shim/**',
+            'fluxer_app/rust/libfluxwebp/simd/**',
            'packages/markdown_parser/rust/Cargo.toml', 'packages/markdown_parser/rust/.cargo/config.toml',
            'packages/markdown_parser/rust/src/**') }}

@@ -142,12 +146,16 @@ jobs:
        with:
          path: |
            fluxer_app/pkgs/libfluxcore
+            fluxer_app/pkgs/libfluxwebp
            fluxer_app/src/features/messaging/utils/markdown/parser/MarkdownParserWasmBytes.ts
          key: >-
            app-wasm-${{ runner.os }}-1.98.1-${{ hashFiles('Cargo.lock', 'tools/ci/src/app_wasm.rs',
            'tools/ci/templates/libfluxcore_wrapper.js', 'tools/ci/templates/libfluxcore_wrapper.d.ts',
            'fluxer_app/rust/libfluxcore/Cargo.toml', 'fluxer_app/rust/libfluxcore/Cargo.lock',
            'fluxer_app/rust/libfluxcore/.cargo/config.toml', 'fluxer_app/rust/libfluxcore/src/**',
+            'fluxer_app/rust/libfluxwebp/Cargo.toml', 'fluxer_app/rust/libfluxwebp/Cargo.lock',
+            'fluxer_app/rust/libfluxwebp/src/**', 'fluxer_app/rust/libfluxwebp/shim/**',
+            'fluxer_app/rust/libfluxwebp/simd/**',
            'packages/markdown_parser/rust/Cargo.toml', 'packages/markdown_parser/rust/.cargo/config.toml',
            'packages/markdown_parser/rust/src/**') }}

@@ -190,6 +198,9 @@ jobs:
      - name: Check Rust dependencies
        run: cargo deny --locked check -D warnings

+      - name: Check libfluxwebp dependencies
+        run: cargo deny --manifest-path fluxer_app/rust/libfluxwebp/Cargo.toml --config deny.toml --locked check licenses bans sources
+
      - name: Check desktop native dependencies
        run: tools/ci/check-desktop-native-workspaces.sh dependencies

@@ -242,6 +253,9 @@ jobs:
      - name: Check formatting
        run: cargo fmt --all -- --check

+      - name: Check formatting (libfluxwebp)
+        run: cargo fmt --manifest-path fluxer_app/rust/libfluxwebp/Cargo.toml -- --check
+
      - name: Check formatting (desktop native workspaces)
        run: tools/ci/check-desktop-native-workspaces.sh fmt

@@ -322,6 +336,9 @@ jobs:
          restore-keys: |
            rebar3-${{ runner.os }}-otp28-rebar3.27.0-

+      - name: Drop restored gateway build output
+        run: rm -rf fluxer_gateway/_build/default/lib/fluxer_gateway fluxer_gateway/_build/test/lib/fluxer_gateway
+
      - name: Check formatting
        run: |
          "$FLUXER_CI_BIN" ci --step gateway_fmt
@@ -398,12 +415,16 @@ jobs:
        with:
          path: |
            fluxer_app/pkgs/libfluxcore
+            fluxer_app/pkgs/libfluxwebp
            fluxer_app/src/features/messaging/utils/markdown/parser/MarkdownParserWasmBytes.ts
          key: >-
            app-wasm-${{ runner.os }}-1.98.1-${{ hashFiles('Cargo.lock', 'tools/ci/src/app_wasm.rs',
            'tools/ci/templates/libfluxcore_wrapper.js', 'tools/ci/templates/libfluxcore_wrapper.d.ts',
            'fluxer_app/rust/libfluxcore/Cargo.toml', 'fluxer_app/rust/libfluxcore/Cargo.lock',
            'fluxer_app/rust/libfluxcore/.cargo/config.toml', 'fluxer_app/rust/libfluxcore/src/**',
+            'fluxer_app/rust/libfluxwebp/Cargo.toml', 'fluxer_app/rust/libfluxwebp/Cargo.lock',
+            'fluxer_app/rust/libfluxwebp/src/**', 'fluxer_app/rust/libfluxwebp/shim/**',
+            'fluxer_app/rust/libfluxwebp/simd/**',
            'packages/markdown_parser/rust/Cargo.toml', 'packages/markdown_parser/rust/.cargo/config.toml',
            'packages/markdown_parser/rust/src/**') }}

@@ -417,12 +438,16 @@ jobs:
        with:
          path: |
            fluxer_app/pkgs/libfluxcore
+            fluxer_app/pkgs/libfluxwebp
            fluxer_app/src/features/messaging/utils/markdown/parser/MarkdownParserWasmBytes.ts
          key: >-
            app-wasm-${{ runner.os }}-1.98.1-${{ hashFiles('Cargo.lock', 'tools/ci/src/app_wasm.rs',
            'tools/ci/templates/libfluxcore_wrapper.js', 'tools/ci/templates/libfluxcore_wrapper.d.ts',
            'fluxer_app/rust/libfluxcore/Cargo.toml', 'fluxer_app/rust/libfluxcore/Cargo.lock',
            'fluxer_app/rust/libfluxcore/.cargo/config.toml', 'fluxer_app/rust/libfluxcore/src/**',
+            'fluxer_app/rust/libfluxwebp/Cargo.toml', 'fluxer_app/rust/libfluxwebp/Cargo.lock',
+            'fluxer_app/rust/libfluxwebp/src/**', 'fluxer_app/rust/libfluxwebp/shim/**',
+            'fluxer_app/rust/libfluxwebp/simd/**',
            'packages/markdown_parser/rust/Cargo.toml', 'packages/markdown_parser/rust/.cargo/config.toml',
            'packages/markdown_parser/rust/src/**') }}

@@ -26,6 +26,7 @@

 /fluxer_app/.devserver-cache.json
 /fluxer_app/pkgs/libfluxcore/
+/fluxer_app/pkgs/libfluxwebp/
 /fluxer_app/src/features/i18n/locales/*/messages.mjs
 /fluxer_app/src/features/messaging/utils/markdown/parser/MarkdownParserWasmBytes.ts
 /fluxer_app/src/features/theme/styles/generated/
@@ -1607,6 +1607,7 @@ dependencies = [
 "ff",
 "generic-array",
 "group",
+ "hkdf",
 "pem-rfc7468",
 "pkcs8",
 "rand_core 0.6.4",
@@ -1881,6 +1882,32 @@ dependencies = [
 "url",
 ]

+[[package]]
+name = "fluxer-push"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "axum",
+ "base64 0.23.1",
+ "clap",
+ "fluxer-svc",
+ "futures",
+ "hmac 0.13.0",
+ "p256",
+ "percent-encoding",
+ "rand 0.10.2",
+ "reqwest",
+ "ring",
+ "serde",
+ "serde_json",
+ "sha2 0.11.0",
+ "thiserror",
+ "tokio",
+ "tracing",
+ "tracing-subscriber",
+ "url",
+]
+
 [[package]]
 name = "fluxer-snowflakes"
 version = "0.1.0"
@@ -2308,6 +2335,15 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"

+[[package]]
+name = "hkdf"
+version = "0.12.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b5f8eb2ad728638ea2c7d47a21db23b7b58a72ed6a38256b8a1849f15fbbdf7"
+dependencies = [
+ "hmac 0.12.1",
+]
+
 [[package]]
 name = "hmac"
 version = "0.12.1"
@@ -3893,6 +3929,7 @@ dependencies = [
 "futures-channel",
 "futures-core",
 "futures-util",
+ "h2",
 "http 1.5.0",
 "http-body 1.1.0",
 "http-body-util",
@@ -7,6 +7,7 @@ members = [
 	"fluxer_gifs",
 	"fluxer_svc",
 	"fluxer_messages",
+	"fluxer_push",
 	"fluxer_snowflakes",
 	"tools/ci",
 	"tools/dev",
@@ -16,6 +16,11 @@
    <img src="https://img.shields.io/badge/License-AGPLv3-purple" alt="AGPLv3 License" /></a>
 </p>

+<p align="center">
+  <a href="https://flathub.org/apps/app.fluxer.Fluxer">
+    <img src="https://dl.flathub.org/assets/badges/flathub-badge-en.svg" alt="Get it on Flathub" height="60" /></a>
+</p>
+
 # Fluxer

 Fluxer is a free and open source instant messaging and VoIP chat app built for friends, groups, and communities.
@@ -28,9 +33,9 @@ Fluxer is a free and open source instant messaging and VoIP chat app built for f

 | Windows | macOS | Linux | Android | iOS |
 | --- | --- | --- | --- | --- |
-| [Installer (x64)][win-setup-x64] | [Disk image][mac-dmg] | [Flatpak][flatpak-ref] | [APK][android-apk] | [TestFlight][ios-testflight] |
-| [Installer (ARM64)][win-setup-arm64] | | [deb (x64)][linux-deb-x64] | [Obtainium][obtainium] | |
-| [Portable (x64)][win-portable-x64] | | [deb (ARM64)][linux-deb-arm64] | | |
+| [Installer (x64)][win-setup-x64] | [Disk image][mac-dmg] | [Flathub][flathub] | [Google Play (beta)][android-play] | [TestFlight][ios-testflight] |
+| [Installer (ARM64)][win-setup-arm64] | | [deb (x64)][linux-deb-x64] | [APK (beta)][android-apk] | |
+| [Portable (x64)][win-portable-x64] | | [deb (ARM64)][linux-deb-arm64] | [Obtainium (beta)][obtainium] | |
 | [Portable (ARM64)][win-portable-arm64] | | [rpm (x64)][linux-rpm-x64] | | |
 | | | [rpm (ARM64)][linux-rpm-arm64] | | |
 | | | [AppImage (x64)][linux-appimage-x64] | | |
@@ -38,17 +43,23 @@ Fluxer is a free and open source instant messaging and VoIP chat app built for f
 | | | [tar.gz (x64)][linux-targz-x64] | | |
 | | | [tar.gz (ARM64)][linux-targz-arm64] | | |

-The macOS disk image is universal and runs on both Apple silicon and Intel. Windows and Linux need the build that matches your processor.
+The macOS disk image runs on both Apple silicon and Intel. Windows and Linux need the build matching your processor.

-On Linux, prefer a package repository over a file. Fluxer then updates with the rest of your system.
+On Linux, prefer a repository over a single file so Fluxer updates with the rest of your system.

 ## Linux package repositories

-All four repositories serve stable and canary. The package is `fluxer` for stable and `fluxer-canary` for canary.
+The package is `fluxer` for stable and `fluxer-canary` for canary. apt and dnf subscribe to one channel per entry file. pacman and Flatpak serve both from one repository.

 ### Flatpak

-Opening [this reference file][flatpak-ref] hands the install to your desktop software manager. Some desktops also accept `flatpak+https://pkgs.fluxer.com/flatpak/fluxer.flatpakref` pasted into the address bar.
+Stable is on [Flathub][flathub], the easiest route on most desktops:
+
+```sh
+flatpak install flathub app.fluxer.Fluxer
+```
+
+Flathub has stable only. To use Fluxer's own repository, open [the stable][flatpak-ref] or [the canary][flatpak-canary-ref] reference file and your software manager takes over. Some desktops also accept `flatpak+https://pkgs.fluxer.com/flatpak/fluxer.flatpakref` in the address bar.

 From a terminal:

@@ -65,6 +76,15 @@ sudo curl -fsSL -o /etc/apt/sources.list.d/fluxer.sources https://pkgs.fluxer.co
 sudo apt update && sudo apt install fluxer
 ```

+For canary, use the canary entry file and package.
+
+```sh
+sudo curl -fsSL -o /etc/apt/sources.list.d/fluxer-canary.sources https://pkgs.fluxer.com/deb/fluxer-canary.sources
+sudo apt update && sudo apt install fluxer-canary
+```
+
+A `.deb` installed from a download only updates once its channel's entry is added.
+
 ### Fedora and RHEL

 ```sh
@@ -72,11 +92,18 @@ sudo curl -fsSL -o /etc/yum.repos.d/fluxer.repo https://pkgs.fluxer.com/rpm/flux
 sudo dnf install fluxer
 ```

-RHEL, Rocky, Alma and CentOS Stream need `sudo dnf install epel-release` first, because the base repositories do not ship `libXScrnSaver`. Fedora does not need this.
+For canary, use the canary entry file and package.
+
+```sh
+sudo curl -fsSL -o /etc/yum.repos.d/fluxer-canary.repo https://pkgs.fluxer.com/rpm/fluxer-canary.repo
+sudo dnf install fluxer-canary
+```
+
+RHEL, Rocky, Alma and CentOS Stream need `sudo dnf install epel-release` first, because their base repositories lack `libXScrnSaver`. Fedora does not.

 ### Arch Linux

-The repository is signed, so pacman needs the key in its own keyring once:
+The repository is signed, so pacman needs the key once:

 ```sh
 sudo pacman-key --init
@@ -85,7 +112,7 @@ sudo pacman-key --add /tmp/fluxer-archive-keyring.asc
 sudo pacman-key --lsign-key 09D01339EE128925F75E675C855C5BDE34D205D2
 ```

-`--lsign-key` is the step that makes pacman trust the key. Then add the repository:
+`--lsign-key` is what makes pacman trust it. Then add the repository:

 ```sh
 sudo tee -a /etc/pacman.conf >/dev/null <<'REPO'
@@ -97,13 +124,13 @@ REPO
 sudo pacman -Syu fluxer
 ```

-Write `$repo` and `$arch` literally. Both are pacman variables, not shell ones, which is why the heredoc above is quoted.
+Write `$repo` and `$arch` literally. Both are pacman variables, not shell ones, hence the quoted heredoc.

-Full setup notes, including the canary channel, live in the [Linux repositories documentation][docs-linux].
+Full setup notes, including canary, are in the [Linux repositories documentation][docs-linux].

 ## Other ways to run it

- [Open Fluxer in a browser](https://web.fluxer.app) with no install at all.
+- [Open Fluxer in a browser](https://web.fluxer.app), no install needed.
 - [Host your own instance][docs-selfhost] from this repository.

 ## Documentation
@@ -117,9 +144,9 @@ Full setup notes, including the canary channel, live in the [Linux repositories
 The source is licensed under the [AGPL-3.0-or-later](./LICENSE) license.

 Fluxer branding, icons, default avatars, badge artwork, screenshots and marketing
-imagery are copyright Fluxer and all rights reserved, as set out in
-[fluxer_static/LICENSE](./fluxer_static/LICENSE). Third-party material keeps its
-own terms, listed in
+imagery are copyright Fluxer, all rights reserved, as set out in
+[fluxer_static/LICENSE](./fluxer_static/LICENSE). Third-party material keeps its own
+terms, listed in
 [fluxer_static/THIRD_PARTY_LICENSES.md](./fluxer_static/THIRD_PARTY_LICENSES.md).

 Public availability of this repository does not grant trademark, brand, or
@@ -139,6 +166,9 @@ endorsement rights.
 [linux-targz-x64]: https://pkgs.fluxer.com/desktop/stable/linux/x64/latest/tar_gz
 [linux-targz-arm64]: https://pkgs.fluxer.com/desktop/stable/linux/arm64/latest/tar_gz
 [flatpak-ref]: https://pkgs.fluxer.com/flatpak/fluxer.flatpakref
+[flatpak-canary-ref]: https://pkgs.fluxer.com/flatpak/fluxer-canary.flatpakref
+[flathub]: https://flathub.org/apps/app.fluxer.Fluxer
+[android-play]: https://play.google.com/store/apps/details?id=com.fluxer
 [android-apk]: https://github.com/fluxerapp/flutter_client/releases
 [obtainium]: https://obtainium.imranr.dev/
 [ios-testflight]: https://testflight.apple.com/join/PKZR6pK9
@@ -147,6 +147,12 @@ FLUXER_VAPID_PRIVATE_KEY=CHANGE_ME
 #FLUXER_PASSKEY_ADDITIONAL_ALLOWED_ORIGINS=https://chat.example.com
 #FLUXER_PASSKEY_ADDITIONAL_ALLOWED_ORIGINS=http://chat.example.com:19080

+# Notification jobs the push container holds at once, 1 to 1000000.
+#FLUXER_PUSH_SERVICE_QUEUE_CAPACITY=10000
+# Provider requests the push container sends at once, 1 to 65536.
+#FLUXER_PUSH_SERVICE_SEND_CONCURRENCY=256
+
+
 # Optional media policies, both off by default. See the operator docs.
 #
 # CORS limits which web origins may read media. A request with no Origin is
@@ -245,6 +251,7 @@ FLUXER_DISCOVERY_ENABLED=true
 #FLUXER_GATEWAY_MEMORY_LIMIT=1gb
 #FLUXER_GATEWAY_MEMORY_RESERVATION=384mb
 #FLUXER_MEDIA_PROXY_MEMORY_LIMIT=512mb
+#FLUXER_PUSH_MEMORY_LIMIT=256mb
 #FLUXER_STATIC_PROXY_MEMORY_LIMIT=256mb
 #FLUXER_APP_PROXY_MEMORY_LIMIT=256mb
 #FLUXER_SNOWFLAKES_MEMORY_LIMIT=128mb
@@ -482,6 +482,30 @@ services:
      seaweedfs-init: {condition: service_completed_successfully}
      nats: {condition: service_healthy}

+  push:
+    <<: *fluxer-service
+    image: ${FLUXER_REGISTRY:-ghcr.io/${FLUXER_REGISTRY_OWNER:-fluxerapp}}/fluxer-push:${FLUXER_IMAGE_TAG:-v1}
+    deploy:
+      resources:
+        limits:
+          memory: ${FLUXER_PUSH_MEMORY_LIMIT:-256mb}
+    environment:
+      <<: *fluxer-env
+      FLUXER_PUSH_SERVICE_HOST: 0.0.0.0
+      FLUXER_PUSH_SERVICE_PORT: "8126"
+      FLUXER_PUSH_SERVICE_QUEUE_CAPACITY: "${FLUXER_PUSH_SERVICE_QUEUE_CAPACITY:-}"
+      FLUXER_PUSH_SERVICE_SEND_CONCURRENCY: "${FLUXER_PUSH_SERVICE_SEND_CONCURRENCY:-}"
+    healthcheck:
+      test: ["CMD", "/usr/local/bin/fluxer-push", "healthcheck"]
+      interval: 10s
+      timeout: 5s
+      retries: 30
+      start_period: 60s
+      start_interval: 1s
+    depends_on:
+      nats: {condition: service_healthy}
+      api: {condition: service_healthy}
+
  static-proxy:
    <<: *fluxer-service
    image: ${FLUXER_REGISTRY:-ghcr.io/${FLUXER_REGISTRY_OWNER:-fluxerapp}}/fluxer-static:${FLUXER_IMAGE_TAG:-v1}
@@ -10524,7 +10524,10 @@
 					},
 					"gateway_rollout": {"$ref": "#/components/schemas/GatewayRolloutConfigResponse"},
 					"voice_noise_suppression": {"$ref": "#/components/schemas/VoiceNoiseSuppressionConfigResponse"},
-					"screen_share_delivery": {"$ref": "#/components/schemas/ScreenShareDeliveryConfigResponse"},
+					"push_relay": {"$ref": "#/components/schemas/PushRelayConfigResponse"},
+					"domain_migration": {"$ref": "#/components/schemas/DomainMigrationConfigResponse"},
+					"altcha_captcha": {"$ref": "#/components/schemas/AltchaCaptchaConfigResponse"},
+					"profile_timezone": {"$ref": "#/components/schemas/ProfileTimezoneConfigResponse"},
 					"experiment_delivery": {"$ref": "#/components/schemas/ExperimentDeliveryConfigResponse"},
 					"registration": {
 						"type": "object",
@@ -10952,7 +10955,10 @@
 					"sso",
 					"gateway_rollout",
 					"voice_noise_suppression",
-					"screen_share_delivery",
+					"push_relay",
+					"domain_migration",
+					"altcha_captcha",
+					"profile_timezone",
 					"experiment_delivery",
 					"registration",
 					"self_hosted",
@@ -11087,9 +11093,18 @@
 						"nullable": true,
 						"allOf": [{"$ref": "#/components/schemas/VoiceNoiseSuppressionConfigUpdateRequest"}]
 					},
-					"screen_share_delivery": {
+					"push_relay": {"nullable": true, "allOf": [{"$ref": "#/components/schemas/PushRelayConfigUpdateRequest"}]},
+					"domain_migration": {
 						"nullable": true,
-						"allOf": [{"$ref": "#/components/schemas/ScreenShareDeliveryConfigUpdateRequest"}]
+						"allOf": [{"$ref": "#/components/schemas/DomainMigrationConfigUpdateRequest"}]
+					},
+					"altcha_captcha": {
+						"nullable": true,
+						"allOf": [{"$ref": "#/components/schemas/AltchaCaptchaConfigUpdateRequest"}]
+					},
+					"profile_timezone": {
+						"nullable": true,
+						"allOf": [{"$ref": "#/components/schemas/ProfileTimezoneConfigUpdateRequest"}]
 					},
 					"experiment_delivery": {
 						"nullable": true,
@@ -15184,17 +15199,23 @@
 					"poll_jitter_percent": {"type": "integer", "minimum": 0, "maximum": 50}
 				}
 			},
-			"ScreenShareDeliveryConfigUpdateRequest": {
+			"ProfileTimezoneConfigUpdateRequest": {
 				"type": "object",
 				"properties": {
 					"enabled": {"type": "boolean"},
 					"rollout_basis_points": {"type": "integer", "minimum": 0, "maximum": 10000},
-					"rollout_salt": {"type": "string", "minLength": 1, "maxLength": 64},
+					"rollout_salt": {"type": "string", "minLength": 1, "maxLength": 64, "pattern": "^[\\x20-\\x7e]+$"},
 					"included_user_ids": {
 						"maxItems": 1000,
 						"type": "array",
 						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
 					},
+					"included_guild_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"type": "boolean"},
 					"excluded_user_ids": {
 						"maxItems": 1000,
 						"type": "array",
@@ -15202,6 +15223,60 @@
 					}
 				}
 			},
+			"AltchaCaptchaConfigUpdateRequest": {
+				"type": "object",
+				"properties": {
+					"enabled": {"type": "boolean"},
+					"rollout_basis_points": {"type": "integer", "minimum": 0, "maximum": 10000},
+					"rollout_salt": {"type": "string", "minLength": 1, "maxLength": 64, "pattern": "^[\\x20-\\x7e]+$"},
+					"included_user_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"included_guild_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"type": "boolean"},
+					"excluded_user_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"anonymous_enabled": {"type": "boolean"},
+					"cost": {"type": "integer", "minimum": 1000, "maximum": 100000},
+					"max_counter": {"type": "integer", "minimum": 100, "maximum": 1000000}
+				}
+			},
+			"DomainMigrationConfigUpdateRequest": {
+				"type": "object",
+				"properties": {
+					"enabled": {"type": "boolean"},
+					"rollout_basis_points": {"type": "integer", "minimum": 0, "maximum": 10000},
+					"rollout_salt": {"type": "string", "minLength": 1, "maxLength": 64, "pattern": "^[\\x20-\\x7e]+$"},
+					"included_user_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"included_guild_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"type": "boolean"},
+					"excluded_user_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"anonymous_rollout_basis_points": {"type": "integer", "minimum": 0, "maximum": 10000},
+					"standalone_forwarding": {"type": "boolean"}
+				}
+			},
+			"PushRelayConfigUpdateRequest": {"type": "object", "properties": {"relay_consent_accepted": {"type": "boolean"}}},
 			"VoiceNoiseSuppressionConfigUpdateRequest": {
 				"type": "object",
 				"properties": {
@@ -15220,6 +15295,12 @@
 						"type": "array",
 						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
 					},
+					"included_guild_ids": {
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"type": "boolean"},
 					"excluded_user_ids": {
 						"maxItems": 1000,
 						"type": "array",
@@ -15267,19 +15348,32 @@
 				"required": ["poll_interval_seconds", "poll_jitter_percent"],
 				"additionalProperties": false
 			},
-			"ScreenShareDeliveryConfigResponse": {
+			"ProfileTimezoneConfigResponse": {
 				"type": "object",
 				"properties": {
 					"enabled": {"default": false, "type": "boolean"},
 					"config_version": {"default": 0, "type": "integer", "minimum": 0, "maximum": 9007199254740991},
 					"rollout_basis_points": {"default": 0, "type": "integer", "minimum": 0, "maximum": 10000},
-					"rollout_salt": {"default": "screen-share-delivery-v1", "type": "string", "minLength": 1, "maxLength": 64},
+					"rollout_salt": {
+						"default": "profile-timezone-v1",
+						"type": "string",
+						"minLength": 1,
+						"maxLength": 64,
+						"pattern": "^[\\x20-\\x7e]+$"
+					},
 					"included_user_ids": {
 						"default": [],
 						"maxItems": 1000,
 						"type": "array",
 						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
 					},
+					"included_guild_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"default": false, "type": "boolean"},
 					"excluded_user_ids": {
 						"default": [],
 						"maxItems": 1000,
@@ -15293,10 +15387,128 @@
 					"rollout_basis_points",
 					"rollout_salt",
 					"included_user_ids",
+					"included_guild_ids",
+					"include_premium_users",
 					"excluded_user_ids"
 				],
 				"additionalProperties": false
 			},
+			"AltchaCaptchaConfigResponse": {
+				"type": "object",
+				"properties": {
+					"enabled": {"default": false, "type": "boolean"},
+					"config_version": {"default": 0, "type": "integer", "minimum": 0, "maximum": 9007199254740991},
+					"rollout_basis_points": {"default": 0, "type": "integer", "minimum": 0, "maximum": 10000},
+					"rollout_salt": {
+						"default": "altcha-captcha-v1",
+						"type": "string",
+						"minLength": 1,
+						"maxLength": 64,
+						"pattern": "^[\\x20-\\x7e]+$"
+					},
+					"included_user_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"included_guild_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"default": false, "type": "boolean"},
+					"excluded_user_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"anonymous_enabled": {"default": false, "type": "boolean"},
+					"cost": {"default": 5000, "type": "integer", "minimum": 1000, "maximum": 100000},
+					"max_counter": {"default": 10000, "type": "integer", "minimum": 100, "maximum": 1000000}
+				},
+				"required": [
+					"enabled",
+					"config_version",
+					"rollout_basis_points",
+					"rollout_salt",
+					"included_user_ids",
+					"included_guild_ids",
+					"include_premium_users",
+					"excluded_user_ids",
+					"anonymous_enabled",
+					"cost",
+					"max_counter"
+				],
+				"additionalProperties": false
+			},
+			"DomainMigrationConfigResponse": {
+				"type": "object",
+				"properties": {
+					"enabled": {"default": false, "type": "boolean"},
+					"config_version": {"default": 0, "type": "integer", "minimum": 0, "maximum": 9007199254740991},
+					"rollout_basis_points": {"default": 0, "type": "integer", "minimum": 0, "maximum": 10000},
+					"rollout_salt": {
+						"default": "domain-migration-v1",
+						"type": "string",
+						"minLength": 1,
+						"maxLength": 64,
+						"pattern": "^[\\x20-\\x7e]+$"
+					},
+					"included_user_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"included_guild_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"default": false, "type": "boolean"},
+					"excluded_user_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"anonymous_rollout_basis_points": {"default": 0, "type": "integer", "minimum": 0, "maximum": 10000},
+					"standalone_forwarding": {"default": false, "type": "boolean"}
+				},
+				"required": [
+					"enabled",
+					"config_version",
+					"rollout_basis_points",
+					"rollout_salt",
+					"included_user_ids",
+					"included_guild_ids",
+					"include_premium_users",
+					"excluded_user_ids",
+					"anonymous_rollout_basis_points",
+					"standalone_forwarding"
+				],
+				"additionalProperties": false
+			},
+			"PushRelayConfigResponse": {
+				"type": "object",
+				"properties": {
+					"relay_consent_accepted": {"default": false, "type": "boolean"},
+					"relay_consent_accepted_at": {
+						"default": null,
+						"nullable": true,
+						"type": "string",
+						"format": "date-time",
+						"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
+					},
+					"relay_consent_accepted_by": {"default": null, "nullable": true, "type": "string", "pattern": "^\\d{1,20}$"}
+				},
+				"required": ["relay_consent_accepted", "relay_consent_accepted_at", "relay_consent_accepted_by"],
+				"additionalProperties": false
+			},
 			"VoiceNoiseSuppressionConfigResponse": {
 				"type": "object",
 				"properties": {
@@ -15321,6 +15533,13 @@
 						"type": "array",
 						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
 					},
+					"included_guild_ids": {
+						"default": [],
+						"maxItems": 1000,
+						"type": "array",
+						"items": {"type": "string", "pattern": "^\\d{1,20}$"}
+					},
+					"include_premium_users": {"default": false, "type": "boolean"},
 					"excluded_user_ids": {
 						"default": [],
 						"maxItems": 1000,
@@ -15352,6 +15571,8 @@
 					"rollout_basis_points",
 					"rollout_salt",
 					"included_user_ids",
+					"included_guild_ids",
+					"include_premium_users",
 					"excluded_user_ids",
 					"guild_overrides",
 					"suppression_strength"
@@ -15639,9 +15860,10 @@
 					"id": {"type": "string", "description": "The credential ID"},
 					"name": {"type": "string", "description": "User-assigned name for the credential"},
 					"created_at": {"type": "string", "description": "When the credential was registered"},
-					"last_used_at": {"nullable": true, "description": "When the credential was last used", "type": "string"}
+					"last_used_at": {"nullable": true, "description": "When the credential was last used", "type": "string"},
+					"rp_id": {"type": "string", "description": "Relying party ID the passkey belongs to"}
 				},
-				"required": ["id", "name", "created_at", "last_used_at"],
+				"required": ["id", "name", "created_at", "last_used_at", "rp_id"],
 				"additionalProperties": false
 			},
 			"VoiceServerAdminResponse": {
@@ -23,7 +23,13 @@ pub struct InstanceConfigResponse {
    #[serde(default)]
    pub voice_noise_suppression: VoiceNoiseSuppressionConfigResponse,
    #[serde(default)]
-    pub screen_share_delivery: ScreenShareDeliveryConfigResponse,
+    pub push_relay: PushRelayConfigResponse,
+    #[serde(default)]
+    pub domain_migration: DomainMigrationConfigResponse,
+    #[serde(default)]
+    pub altcha_captcha: AltchaCaptchaConfigResponse,
+    #[serde(default)]
+    pub profile_timezone: ProfileTimezoneConfigResponse,
    #[serde(default)]
    pub experiment_delivery: ExperimentDeliveryConfigResponse,
 }
@@ -449,7 +455,11 @@ impl VoiceE2eeScope {
 }

 pub const EXPERIMENT_MAX_TARGETED_USERS: usize = 1_000;
-pub const SCREEN_SHARE_DELIVERY_DEFAULT_SALT: &str = "screen-share-delivery-v1";
+pub const DOMAIN_MIGRATION_DEFAULT_SALT: &str = "domain-migration-v1";
+pub const ALTCHA_CAPTCHA_DEFAULT_SALT: &str = "altcha-captcha-v1";
+pub const ALTCHA_CAPTCHA_COST_RANGE: std::ops::RangeInclusive<u32> = 1_000..=100_000;
+pub const ALTCHA_CAPTCHA_MAX_COUNTER_RANGE: std::ops::RangeInclusive<u32> = 100..=1_000_000;
+pub const PROFILE_TIMEZONE_DEFAULT_SALT: &str = "profile-timezone-v1";
 pub const VOICE_NS_MAX_GUILD_OVERRIDES: usize = 200;

 impl NoiseSuppressionBackend {
@@ -493,6 +503,8 @@ pub struct VoiceNoiseSuppressionConfigResponse {
    pub rollout_basis_points: u32,
    pub rollout_salt: String,
    pub included_user_ids: Vec<String>,
+    pub included_guild_ids: Vec<String>,
+    pub include_premium_users: bool,
    pub excluded_user_ids: Vec<String>,
    pub guild_overrides: Vec<VoiceNoiseSuppressionGuildOverride>,
    pub suppression_strength: u32,
@@ -509,6 +521,8 @@ impl Default for VoiceNoiseSuppressionConfigResponse {
            rollout_basis_points: 0,
            rollout_salt: "voice-ns-v1".to_owned(),
            included_user_ids: Vec::new(),
+            included_guild_ids: Vec::new(),
+            include_premium_users: false,
            excluded_user_ids: Vec::new(),
            guild_overrides: Vec::new(),
            suppression_strength: 80,
@@ -533,6 +547,10 @@ pub struct VoiceNoiseSuppressionConfigUpdateRequest {
    #[serde(skip_serializing_if = "Option::is_none")]
    pub included_user_ids: Option<Vec<String>>,
    #[serde(skip_serializing_if = "Option::is_none")]
+    pub included_guild_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub include_premium_users: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
    pub excluded_user_ids: Option<Vec<String>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub guild_overrides: Option<Vec<VoiceNoiseSuppressionGuildOverride>>,
@@ -540,32 +558,54 @@ pub struct VoiceNoiseSuppressionConfigUpdateRequest {
    pub suppression_strength: Option<u32>,
 }

+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+#[serde(default)]
+pub struct PushRelayConfigResponse {
+    pub relay_consent_accepted: bool,
+    pub relay_consent_accepted_at: Option<String>,
+    pub relay_consent_accepted_by: Option<String>,
+}
+
+#[derive(Clone, Debug, Default, Serialize)]
+pub struct PushRelayConfigUpdateRequest {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub relay_consent_accepted: Option<bool>,
+}
+
 #[derive(Clone, Debug, Deserialize, Serialize)]
 #[serde(default)]
-pub struct ScreenShareDeliveryConfigResponse {
+pub struct DomainMigrationConfigResponse {
    pub enabled: bool,
    pub config_version: u64,
    pub rollout_basis_points: u32,
    pub rollout_salt: String,
    pub included_user_ids: Vec<String>,
+    pub included_guild_ids: Vec<String>,
+    pub include_premium_users: bool,
    pub excluded_user_ids: Vec<String>,
+    pub anonymous_rollout_basis_points: u32,
+    pub standalone_forwarding: bool,
 }

-impl Default for ScreenShareDeliveryConfigResponse {
+impl Default for DomainMigrationConfigResponse {
    fn default() -> Self {
        Self {
            enabled: false,
            config_version: 0,
            rollout_basis_points: 0,
-            rollout_salt: SCREEN_SHARE_DELIVERY_DEFAULT_SALT.to_owned(),
+            rollout_salt: DOMAIN_MIGRATION_DEFAULT_SALT.to_owned(),
            included_user_ids: Vec::new(),
+            included_guild_ids: Vec::new(),
+            include_premium_users: false,
            excluded_user_ids: Vec::new(),
+            anonymous_rollout_basis_points: 0,
+            standalone_forwarding: false,
        }
    }
 }

 #[derive(Clone, Debug, Default, Serialize)]
-pub struct ScreenShareDeliveryConfigUpdateRequest {
+pub struct DomainMigrationConfigUpdateRequest {
    #[serde(skip_serializing_if = "Option::is_none")]
    pub enabled: Option<bool>,
    #[serde(skip_serializing_if = "Option::is_none")]
@@ -575,6 +615,118 @@ pub struct ScreenShareDeliveryConfigUpdateRequest {
    #[serde(skip_serializing_if = "Option::is_none")]
    pub included_user_ids: Option<Vec<String>>,
    #[serde(skip_serializing_if = "Option::is_none")]
+    pub included_guild_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub include_premium_users: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub excluded_user_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub anonymous_rollout_basis_points: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub standalone_forwarding: Option<bool>,
+}
+
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[serde(default)]
+pub struct AltchaCaptchaConfigResponse {
+    pub enabled: bool,
+    pub config_version: u64,
+    pub rollout_basis_points: u32,
+    pub rollout_salt: String,
+    pub included_user_ids: Vec<String>,
+    pub included_guild_ids: Vec<String>,
+    pub include_premium_users: bool,
+    pub excluded_user_ids: Vec<String>,
+    pub anonymous_enabled: bool,
+    pub cost: u32,
+    pub max_counter: u32,
+}
+
+impl Default for AltchaCaptchaConfigResponse {
+    fn default() -> Self {
+        Self {
+            enabled: false,
+            config_version: 0,
+            rollout_basis_points: 0,
+            rollout_salt: ALTCHA_CAPTCHA_DEFAULT_SALT.to_owned(),
+            included_user_ids: Vec::new(),
+            included_guild_ids: Vec::new(),
+            include_premium_users: false,
+            excluded_user_ids: Vec::new(),
+            anonymous_enabled: false,
+            cost: 5_000,
+            max_counter: 10_000,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, Serialize)]
+pub struct AltchaCaptchaConfigUpdateRequest {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub enabled: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub rollout_basis_points: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub rollout_salt: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub included_user_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub included_guild_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub include_premium_users: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub excluded_user_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub anonymous_enabled: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub cost: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub max_counter: Option<u32>,
+}
+
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[serde(default)]
+pub struct ProfileTimezoneConfigResponse {
+    pub enabled: bool,
+    pub config_version: u64,
+    pub rollout_basis_points: u32,
+    pub rollout_salt: String,
+    pub included_user_ids: Vec<String>,
+    pub included_guild_ids: Vec<String>,
+    pub include_premium_users: bool,
+    pub excluded_user_ids: Vec<String>,
+}
+
+impl Default for ProfileTimezoneConfigResponse {
+    fn default() -> Self {
+        Self {
+            enabled: false,
+            config_version: 0,
+            rollout_basis_points: 0,
+            rollout_salt: PROFILE_TIMEZONE_DEFAULT_SALT.to_owned(),
+            included_user_ids: Vec::new(),
+            included_guild_ids: Vec::new(),
+            include_premium_users: false,
+            excluded_user_ids: Vec::new(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, Serialize)]
+pub struct ProfileTimezoneConfigUpdateRequest {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub enabled: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub rollout_basis_points: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub rollout_salt: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub included_user_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub included_guild_ids: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub include_premium_users: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
    pub excluded_user_ids: Option<Vec<String>>,
 }

@@ -694,7 +846,13 @@ pub struct InstanceConfigUpdateRequest {
    #[serde(skip_serializing_if = "Option::is_none")]
    pub voice_noise_suppression: Option<VoiceNoiseSuppressionConfigUpdateRequest>,
    #[serde(skip_serializing_if = "Option::is_none")]
-    pub screen_share_delivery: Option<ScreenShareDeliveryConfigUpdateRequest>,
+    pub push_relay: Option<PushRelayConfigUpdateRequest>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub domain_migration: Option<DomainMigrationConfigUpdateRequest>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub altcha_captcha: Option<AltchaCaptchaConfigUpdateRequest>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub profile_timezone: Option<ProfileTimezoneConfigUpdateRequest>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub experiment_delivery: Option<ExperimentDeliveryConfigUpdateRequest>,
 }
@@ -1033,19 +1191,33 @@ mod tests {
                .expect("admin schema");
        let noise = serde_json::from_value::<VoiceNoiseSuppressionConfigResponse>(json!({}))
            .expect("default noise config");
-        let screen_share = serde_json::from_value::<ScreenShareDeliveryConfigResponse>(json!({}))
-            .expect("default screen share config");
+        let domain_migration = serde_json::from_value::<DomainMigrationConfigResponse>(json!({}))
+            .expect("default domain migration config");
+        let altcha_captcha = serde_json::from_value::<AltchaCaptchaConfigResponse>(json!({}))
+            .expect("default altcha captcha config");
+        let profile_timezone = serde_json::from_value::<ProfileTimezoneConfigResponse>(json!({}))
+            .expect("default profile timezone config");
        let delivery = serde_json::from_value::<ExperimentDeliveryConfigResponse>(json!({}))
            .expect("default delivery config");
        let noise = serde_json::to_value(noise).expect("serializable noise config");
-        let screen_share =
-            serde_json::to_value(screen_share).expect("serializable screen share config");
+        let domain_migration =
+            serde_json::to_value(domain_migration).expect("serializable domain migration config");
+        let altcha_captcha =
+            serde_json::to_value(altcha_captcha).expect("serializable altcha captcha config");
+        let profile_timezone =
+            serde_json::to_value(profile_timezone).expect("serializable profile timezone config");
        let delivery = serde_json::to_value(delivery).expect("serializable delivery config");
        let generated_noise: generated_types::VoiceNoiseSuppressionConfigResponse =
            serde_json::from_value(noise.clone()).expect("generated noise config contract");
-        let generated_screen_share: generated_types::ScreenShareDeliveryConfigResponse =
-            serde_json::from_value(screen_share.clone())
-                .expect("generated screen share config contract");
+        let generated_domain_migration: generated_types::DomainMigrationConfigResponse =
+            serde_json::from_value(domain_migration.clone())
+                .expect("generated domain migration config contract");
+        let generated_altcha_captcha: generated_types::AltchaCaptchaConfigResponse =
+            serde_json::from_value(altcha_captcha.clone())
+                .expect("generated altcha captcha config contract");
+        let generated_profile_timezone: generated_types::ProfileTimezoneConfigResponse =
+            serde_json::from_value(profile_timezone.clone())
+                .expect("generated profile timezone config contract");
        let generated_delivery: generated_types::ExperimentDeliveryConfigResponse =
            serde_json::from_value(delivery.clone()).expect("generated delivery config contract");
        assert_eq!(
@@ -1053,9 +1225,19 @@ mod tests {
            noise
        );
        assert_eq!(
-            serde_json::to_value(generated_screen_share)
-                .expect("serializable generated screen share config"),
-            screen_share
+            serde_json::to_value(generated_domain_migration)
+                .expect("serializable generated domain migration config"),
+            domain_migration
+        );
+        assert_eq!(
+            serde_json::to_value(generated_altcha_captcha)
+                .expect("serializable generated altcha captcha config"),
+            altcha_captcha
+        );
+        assert_eq!(
+            serde_json::to_value(generated_profile_timezone)
+                .expect("serializable generated profile timezone config"),
+            profile_timezone
        );
        assert_eq!(
            serde_json::to_value(generated_delivery)
@@ -1064,7 +1246,9 @@ mod tests {
        );
        for (name, value) in [
            ("VoiceNoiseSuppressionConfigResponse", noise),
-            ("ScreenShareDeliveryConfigResponse", screen_share),
+            ("DomainMigrationConfigResponse", domain_migration),
+            ("AltchaCaptchaConfigResponse", altcha_captcha),
+            ("ProfileTimezoneConfigResponse", profile_timezone),
            ("ExperimentDeliveryConfigResponse", delivery),
        ] {
            for (field, value) in value.as_object().expect("config object") {
@@ -1076,29 +1260,6 @@ mod tests {
        }
    }

-    #[test]
-    fn screen_share_delivery_update_preserves_empty_lists_and_omitted_fields() {
-        let update = ScreenShareDeliveryConfigUpdateRequest {
-            included_user_ids: Some(Vec::new()),
-            excluded_user_ids: Some(Vec::new()),
-            ..Default::default()
-        };
-        let value = serde_json::to_value(update).expect("serializable update");
-        serde_json::from_value::<generated_types::ScreenShareDeliveryConfigUpdateRequest>(
-            value.clone(),
-        )
-        .expect("generated update contract");
-        assert_eq!(
-            value,
-            json!({"included_user_ids": [], "excluded_user_ids": []})
-        );
-        assert_eq!(
-            serde_json::to_value(ScreenShareDeliveryConfigUpdateRequest::default())
-                .expect("serializable update"),
-            json!({})
-        );
-    }
-
    #[test]
    fn noise_suppression_update_preserves_empty_lists_and_omitted_fields() {
        let update = VoiceNoiseSuppressionConfigUpdateRequest {
@@ -1123,4 +1284,27 @@ mod tests {
            json!({})
        );
    }
+
+    #[test]
+    fn domain_migration_update_preserves_empty_lists_and_omitted_fields() {
+        let update = DomainMigrationConfigUpdateRequest {
+            included_user_ids: Some(Vec::new()),
+            excluded_user_ids: Some(Vec::new()),
+            ..Default::default()
+        };
+        let value = serde_json::to_value(update).expect("serializable update");
+        serde_json::from_value::<generated_types::DomainMigrationConfigUpdateRequest>(
+            value.clone(),
+        )
+        .expect("generated update contract");
+        assert_eq!(
+            value,
+            json!({"included_user_ids": [], "excluded_user_ids": []})
+        );
+        assert_eq!(
+            serde_json::to_value(DomainMigrationConfigUpdateRequest::default())
+                .expect("serializable update"),
+            json!({})
+        );
+    }
 }
@@ -80,7 +80,7 @@ async fn reports_list(
        return reports_error_page(
            config,
            &auth.0,
-            "That page is out of range. The reports search returns at most the first 10000 reports, so narrow the filters and start again.",
+            "That page is out of range. The reports search returns at most the first 10000 reports. Narrow the filters and start again.",
        );
    }
    let search_query = query.q.as_deref().and_then(clean_string);
@@ -4,10 +4,12 @@ use crate::{
    api::{
        client::AdminApiClient,
        types::{
-            AppBrandingConfigUpdateRequest, AppLegalConfigUpdateRequest,
-            AppPublicConfigUpdateRequest, AppRegistrationConfigUpdateRequest,
-            AppSetupConfigUpdateRequest, CreateRegistrationUrlRequest,
-            DeferredPhoneGateUpdateRequest, EXPERIMENT_MAX_TARGETED_USERS,
+            ALTCHA_CAPTCHA_COST_RANGE, ALTCHA_CAPTCHA_MAX_COUNTER_RANGE,
+            AltchaCaptchaConfigUpdateRequest, AppBrandingConfigUpdateRequest,
+            AppLegalConfigUpdateRequest, AppPublicConfigUpdateRequest,
+            AppRegistrationConfigUpdateRequest, AppSetupConfigUpdateRequest,
+            CreateRegistrationUrlRequest, DeferredPhoneGateUpdateRequest,
+            DomainMigrationConfigUpdateRequest, EXPERIMENT_MAX_TARGETED_USERS,
            ExperimentDeliveryConfigUpdateRequest, GatewayRolloutConfigUpdateRequest,
            GatewayRolloutMode, InstanceAttachmentDecayUpdateRequest,
            InstanceBlueskyIntegrationUpdateRequest, InstanceBlueskyKeyIntegrationUpdateRequest,
@@ -18,8 +20,8 @@ use crate::{
            InstancePolicyUpdateRequest, InstanceRegistrationConfigUpdateRequest,
            InstanceServicesUpdateRequest, InstanceYoutubeIntegrationUpdateRequest,
            LimitConfigUpdateRequest, LimitRule, LimitRuleFilters, NoiseSuppressionBackend,
-            PremiumMode, RegistrationMode, ScreenShareDeliveryConfigUpdateRequest,
-            SsoConfigUpdateRequest, VOICE_NS_MAX_GUILD_OVERRIDES, VoiceE2eeScope,
+            PremiumMode, ProfileTimezoneConfigUpdateRequest, PushRelayConfigUpdateRequest,
+            RegistrationMode, SsoConfigUpdateRequest, VOICE_NS_MAX_GUILD_OVERRIDES, VoiceE2eeScope,
            VoiceNoiseSuppressionConfigUpdateRequest, VoiceNoiseSuppressionGuildOverride,
        },
    },
@@ -207,7 +209,19 @@ pub async fn instance_config_post(
            Ok(update) => instance_config_result(client.update_instance_config(&update).await),
            Err(message) => FlashData::error(message),
        },
-        "update_screen_share_delivery" => match build_screen_share_delivery_update(&form) {
+        "update_push_relay" => {
+            let update = build_push_relay_update(&form);
+            instance_config_result(client.update_instance_config(&update).await)
+        }
+        "update_domain_migration" => match build_domain_migration_update(&form) {
+            Ok(update) => instance_config_result(client.update_instance_config(&update).await),
+            Err(message) => FlashData::error(message),
+        },
+        "update_altcha_captcha" => match build_altcha_captcha_update(&form) {
+            Ok(update) => instance_config_result(client.update_instance_config(&update).await),
+            Err(message) => FlashData::error(message),
+        },
+        "update_profile_timezone" => match build_profile_timezone_update(&form) {
            Ok(update) => instance_config_result(client.update_instance_config(&update).await),
            Err(message) => FlashData::error(message),
        },
@@ -496,6 +510,21 @@ fn parse_experiment_rollout_salt(
    Ok(Some(salt.to_owned()))
 }

+fn parse_ascii_experiment_rollout_salt(
+    form: &MultiValueForm,
+    key: &str,
+) -> Result<Option<String>, String> {
+    let salt = parse_experiment_rollout_salt(form, key)?;
+    if let Some(value) = salt.as_deref()
+        && !value
+            .bytes()
+            .all(|byte| byte.is_ascii_graphic() || byte == b' ')
+    {
+        return Err("Rollout salt must use printable ASCII".to_owned());
+    }
+    Ok(salt)
+}
+
 fn is_experiment_snowflake(value: &str) -> bool {
    !value.is_empty()
        && value.len() <= EXPERIMENT_MAX_SNOWFLAKE_LENGTH
@@ -614,6 +643,12 @@ fn build_voice_noise_suppression_update(
                form.first("voice_ns_included_user_ids").unwrap_or_default(),
                "Included user IDs",
            )?),
+            included_guild_ids: Some(parse_experiment_user_ids(
+                form.first("voice_ns_included_guild_ids")
+                    .unwrap_or_default(),
+                "Included guild IDs",
+            )?),
+            include_premium_users: Some(form.bool_value("voice_ns_include_premium_users")),
            excluded_user_ids: Some(parse_experiment_user_ids(
                form.first("voice_ns_excluded_user_ids").unwrap_or_default(),
                "Excluded user IDs",
@@ -633,30 +668,141 @@ fn build_voice_noise_suppression_update(
    })
 }

-fn build_screen_share_delivery_update(
+fn build_push_relay_update(form: &MultiValueForm) -> InstanceConfigUpdateRequest {
+    InstanceConfigUpdateRequest {
+        push_relay: Some(PushRelayConfigUpdateRequest {
+            relay_consent_accepted: Some(form.bool_value("push_relay_consent_accepted")),
+        }),
+        ..Default::default()
+    }
+}
+
+fn build_domain_migration_update(
    form: &MultiValueForm,
 ) -> Result<InstanceConfigUpdateRequest, String> {
    Ok(InstanceConfigUpdateRequest {
-        screen_share_delivery: Some(ScreenShareDeliveryConfigUpdateRequest {
-            enabled: Some(form.bool_value("screen_share_delivery_enabled")),
+        domain_migration: Some(DomainMigrationConfigUpdateRequest {
+            enabled: Some(form.bool_value("domain_migration_enabled")),
            rollout_basis_points: parse_form_number(
                form,
-                "screen_share_delivery_rollout_basis_points",
+                "domain_migration_rollout_basis_points",
                "Rollout basis points",
                0,
                EXPERIMENT_ROLLOUT_BASIS_POINTS_MAX,
            )?,
-            rollout_salt: parse_experiment_rollout_salt(
+            rollout_salt: parse_ascii_experiment_rollout_salt(
                form,
-                "screen_share_delivery_rollout_salt",
+                "domain_migration_rollout_salt",
            )?,
            included_user_ids: Some(parse_experiment_user_ids(
-                form.first("screen_share_delivery_included_user_ids")
+                form.first("domain_migration_included_user_ids")
                    .unwrap_or_default(),
                "Included user IDs",
            )?),
+            included_guild_ids: Some(parse_experiment_user_ids(
+                form.first("domain_migration_included_guild_ids")
+                    .unwrap_or_default(),
+                "Included guild IDs",
+            )?),
+            include_premium_users: Some(form.bool_value("domain_migration_include_premium_users")),
            excluded_user_ids: Some(parse_experiment_user_ids(
-                form.first("screen_share_delivery_excluded_user_ids")
+                form.first("domain_migration_excluded_user_ids")
+                    .unwrap_or_default(),
+                "Excluded user IDs",
+            )?),
+            anonymous_rollout_basis_points: parse_form_number(
+                form,
+                "domain_migration_anonymous_rollout_basis_points",
+                "Anonymous rollout basis points",
+                0,
+                EXPERIMENT_ROLLOUT_BASIS_POINTS_MAX,
+            )?,
+            standalone_forwarding: Some(form.bool_value("domain_migration_standalone_forwarding")),
+        }),
+        ..Default::default()
+    })
+}
+
+fn build_altcha_captcha_update(
+    form: &MultiValueForm,
+) -> Result<InstanceConfigUpdateRequest, String> {
+    Ok(InstanceConfigUpdateRequest {
+        altcha_captcha: Some(AltchaCaptchaConfigUpdateRequest {
+            enabled: Some(form.bool_value("altcha_captcha_enabled")),
+            rollout_basis_points: parse_form_number(
+                form,
+                "altcha_captcha_rollout_basis_points",
+                "Rollout basis points",
+                0,
+                EXPERIMENT_ROLLOUT_BASIS_POINTS_MAX,
+            )?,
+            rollout_salt: parse_ascii_experiment_rollout_salt(form, "altcha_captcha_rollout_salt")?,
+            included_user_ids: Some(parse_experiment_user_ids(
+                form.first("altcha_captcha_included_user_ids")
+                    .unwrap_or_default(),
+                "Included user IDs",
+            )?),
+            included_guild_ids: Some(parse_experiment_user_ids(
+                form.first("altcha_captcha_included_guild_ids")
+                    .unwrap_or_default(),
+                "Included guild IDs",
+            )?),
+            include_premium_users: Some(form.bool_value("altcha_captcha_include_premium_users")),
+            excluded_user_ids: Some(parse_experiment_user_ids(
+                form.first("altcha_captcha_excluded_user_ids")
+                    .unwrap_or_default(),
+                "Excluded user IDs",
+            )?),
+            anonymous_enabled: Some(form.bool_value("altcha_captcha_anonymous_enabled")),
+            cost: parse_form_number(
+                form,
+                "altcha_captcha_cost",
+                "Cost",
+                *ALTCHA_CAPTCHA_COST_RANGE.start(),
+                *ALTCHA_CAPTCHA_COST_RANGE.end(),
+            )?,
+            max_counter: parse_form_number(
+                form,
+                "altcha_captcha_max_counter",
+                "Maximum counter",
+                *ALTCHA_CAPTCHA_MAX_COUNTER_RANGE.start(),
+                *ALTCHA_CAPTCHA_MAX_COUNTER_RANGE.end(),
+            )?,
+        }),
+        ..Default::default()
+    })
+}
+
+fn build_profile_timezone_update(
+    form: &MultiValueForm,
+) -> Result<InstanceConfigUpdateRequest, String> {
+    Ok(InstanceConfigUpdateRequest {
+        profile_timezone: Some(ProfileTimezoneConfigUpdateRequest {
+            enabled: Some(form.bool_value("profile_timezone_enabled")),
+            rollout_basis_points: parse_form_number(
+                form,
+                "profile_timezone_rollout_basis_points",
+                "Rollout basis points",
+                0,
+                EXPERIMENT_ROLLOUT_BASIS_POINTS_MAX,
+            )?,
+            rollout_salt: parse_ascii_experiment_rollout_salt(
+                form,
+                "profile_timezone_rollout_salt",
+            )?,
+            included_user_ids: Some(parse_experiment_user_ids(
+                form.first("profile_timezone_included_user_ids")
+                    .unwrap_or_default(),
+                "Included user IDs",
+            )?),
+            included_guild_ids: Some(parse_experiment_user_ids(
+                form.first("profile_timezone_included_guild_ids")
+                    .unwrap_or_default(),
+                "Included guild IDs",
+            )?),
+            include_premium_users: Some(form.bool_value("profile_timezone_include_premium_users")),
+            excluded_user_ids: Some(parse_experiment_user_ids(
+                form.first("profile_timezone_excluded_user_ids")
                    .unwrap_or_default(),
                "Excluded user IDs",
            )?),
@@ -1309,6 +1455,8 @@ mod tests {
                "allow_user_override": false,
                "enabled_backends": [],
                "included_user_ids": [],
+                "included_guild_ids": [],
+                "include_premium_users": false,
                "excluded_user_ids": [],
                "guild_overrides": [],
            }})
@@ -1587,20 +1735,17 @@ mod tests {
    }

    #[test]
-    fn build_screen_share_delivery_update_reads_the_rollout_fields() {
+    fn build_domain_migration_update_reads_the_rollout_fields() {
        let form = MultiValueForm::parse(
-            b"screen_share_delivery_enabled=true&screen_share_delivery_rollout_basis_points=%20250%20&screen_share_delivery_rollout_salt=%20screen-share-delivery-v2%20&screen_share_delivery_included_user_ids=1500000000000000001%0A1500000000000000002&screen_share_delivery_excluded_user_ids=1500000000000000003%2C%201500000000000000004",
+            b"domain_migration_enabled=true&domain_migration_rollout_basis_points=%20250%20&domain_migration_rollout_salt=%20domain-migration-v2%20&domain_migration_included_user_ids=1500000000000000001%0A1500000000000000002&domain_migration_excluded_user_ids=1500000000000000003%2C%201500000000000000004&domain_migration_anonymous_rollout_basis_points=%20100%20&domain_migration_standalone_forwarding=true",
        );
-        let update = build_screen_share_delivery_update(&form)
+        let update = build_domain_migration_update(&form)
            .expect("valid form")
-            .screen_share_delivery
-            .expect("screen share delivery update");
+            .domain_migration
+            .expect("domain migration update");
        assert_eq!(update.enabled, Some(true));
        assert_eq!(update.rollout_basis_points, Some(250));
-        assert_eq!(
-            update.rollout_salt,
-            Some("screen-share-delivery-v2".to_owned())
-        );
+        assert_eq!(update.rollout_salt, Some("domain-migration-v2".to_owned()));
        assert_eq!(
            update.included_user_ids,
            Some(vec![
@@ -1615,54 +1760,228 @@ mod tests {
                "1500000000000000004".to_owned()
            ])
        );
+        assert_eq!(update.anonymous_rollout_basis_points, Some(100));
+        assert_eq!(update.standalone_forwarding, Some(true));
    }

    #[test]
-    fn build_screen_share_delivery_update_leaves_the_feature_inert_when_nothing_is_submitted() {
+    fn build_domain_migration_update_leaves_the_feature_inert_when_nothing_is_submitted() {
        let form = MultiValueForm::parse(b"_csrf=token");
-        let request = build_screen_share_delivery_update(&form).expect("valid form");
+        let request = build_domain_migration_update(&form).expect("valid form");
        assert_eq!(
            serde_json::to_value(request).expect("serializable update"),
-            serde_json::json!({"screen_share_delivery": {
+            serde_json::json!({"domain_migration": {
                "enabled": false,
                "included_user_ids": [],
+                "included_guild_ids": [],
+                "include_premium_users": false,
+                "excluded_user_ids": [],
+                "standalone_forwarding": false,
+            }})
+        );
+    }
+
+    #[test]
+    fn build_domain_migration_update_rejects_invalid_rollout_fields() {
+        for (form, message) in [
+            (
+                "domain_migration_rollout_basis_points=10001",
+                "Rollout basis points must be a whole number between 0 and 10000",
+            ),
+            (
+                "domain_migration_anonymous_rollout_basis_points=10001",
+                "Anonymous rollout basis points must be a whole number between 0 and 10000",
+            ),
+            (
+                "domain_migration_anonymous_rollout_basis_points=abc",
+                "Anonymous rollout basis points must be a whole number between 0 and 10000",
+            ),
+            (
+                "domain_migration_rollout_salt=%20%20",
+                "Rollout salt must be between 1 and 64 characters",
+            ),
+            (
+                "domain_migration_rollout_salt=caf%C3%A9",
+                "Rollout salt must use printable ASCII",
+            ),
+            (
+                "domain_migration_included_user_ids=123%2Cinvalid",
+                "Included user IDs entry 2 must contain 1 to 20 decimal digits",
+            ),
+            (
+                "domain_migration_excluded_user_ids=123%2Cinvalid",
+                "Excluded user IDs entry 2 must contain 1 to 20 decimal digits",
+            ),
+        ] {
+            let form = MultiValueForm::parse(form.as_bytes());
+            assert_eq!(
+                build_domain_migration_update(&form).expect_err("invalid rollout field"),
+                message
+            );
+        }
+    }
+
+    #[test]
+    fn build_push_relay_update_reads_the_consent_checkbox() {
+        let unchecked = build_push_relay_update(&MultiValueForm::parse(b"_csrf=token"));
+        assert_eq!(
+            serde_json::to_value(&unchecked).expect("serialize update"),
+            serde_json::json!({"push_relay": {"relay_consent_accepted": false}})
+        );
+
+        let checked = build_push_relay_update(&MultiValueForm::parse(
+            b"_csrf=token&push_relay_consent_accepted=true",
+        ));
+        assert_eq!(
+            serde_json::to_value(&checked).expect("serialize update"),
+            serde_json::json!({"push_relay": {"relay_consent_accepted": true}})
+        );
+    }
+
+    #[test]
+    fn build_altcha_captcha_update_reads_the_rollout_and_difficulty_fields() {
+        let form = MultiValueForm::parse(
+            b"altcha_captcha_enabled=true&altcha_captcha_rollout_basis_points=%20500%20&altcha_captcha_rollout_salt=%20altcha-captcha-v2%20&altcha_captcha_included_user_ids=1500000000000000001&altcha_captcha_excluded_user_ids=1500000000000000002&altcha_captcha_anonymous_enabled=true&altcha_captcha_cost=2000&altcha_captcha_max_counter=%20400%20",
+        );
+        let update = build_altcha_captcha_update(&form)
+            .expect("valid form")
+            .altcha_captcha
+            .expect("altcha captcha update");
+        assert_eq!(update.enabled, Some(true));
+        assert_eq!(update.rollout_basis_points, Some(500));
+        assert_eq!(update.rollout_salt, Some("altcha-captcha-v2".to_owned()));
+        assert_eq!(
+            update.included_user_ids,
+            Some(vec!["1500000000000000001".to_owned()])
+        );
+        assert_eq!(
+            update.excluded_user_ids,
+            Some(vec!["1500000000000000002".to_owned()])
+        );
+        assert_eq!(update.anonymous_enabled, Some(true));
+        assert_eq!(update.cost, Some(2000));
+        assert_eq!(update.max_counter, Some(400));
+    }
+
+    #[test]
+    fn build_altcha_captcha_update_leaves_the_feature_inert_when_nothing_is_submitted() {
+        let form = MultiValueForm::parse(b"_csrf=token");
+        let request = build_altcha_captcha_update(&form).expect("valid form");
+        assert_eq!(
+            serde_json::to_value(request).expect("serializable update"),
+            serde_json::json!({"altcha_captcha": {
+                "enabled": false,
+                "included_user_ids": [],
+                "included_guild_ids": [],
+                "include_premium_users": false,
+                "excluded_user_ids": [],
+                "anonymous_enabled": false,
+            }})
+        );
+    }
+
+    #[test]
+    fn build_altcha_captcha_update_rejects_difficulty_outside_the_supported_range() {
+        for (form, message) in [
+            (
+                "altcha_captcha_cost=999",
+                "Cost must be a whole number between 1000 and 100000",
+            ),
+            (
+                "altcha_captcha_max_counter=1000001",
+                "Maximum counter must be a whole number between 100 and 1000000",
+            ),
+            (
+                "altcha_captcha_rollout_basis_points=10001",
+                "Rollout basis points must be a whole number between 0 and 10000",
+            ),
+        ] {
+            let form = MultiValueForm::parse(form.as_bytes());
+            assert_eq!(
+                build_altcha_captcha_update(&form).expect_err("invalid field"),
+                message
+            );
+        }
+    }
+
+    #[test]
+    fn build_profile_timezone_update_reads_the_rollout_fields() {
+        let form = MultiValueForm::parse(
+            b"profile_timezone_enabled=true&profile_timezone_rollout_basis_points=%20500%20&profile_timezone_rollout_salt=%20profile-timezone-v2%20&profile_timezone_included_user_ids=1500000000000000001&profile_timezone_excluded_user_ids=1500000000000000002&profile_timezone_included_guild_ids=1500000000000000005%0A1500000000000000006%2C1500000000000000005&profile_timezone_include_premium_users=true",
+        );
+        let update = build_profile_timezone_update(&form)
+            .expect("valid form")
+            .profile_timezone
+            .expect("profile timezone update");
+        assert_eq!(update.enabled, Some(true));
+        assert_eq!(update.rollout_basis_points, Some(500));
+        assert_eq!(update.rollout_salt, Some("profile-timezone-v2".to_owned()));
+        assert_eq!(update.include_premium_users, Some(true));
+        assert_eq!(
+            update.included_guild_ids,
+            Some(vec![
+                "1500000000000000005".to_owned(),
+                "1500000000000000006".to_owned()
+            ])
+        );
+        assert_eq!(
+            update.included_user_ids,
+            Some(vec!["1500000000000000001".to_owned()])
+        );
+        assert_eq!(
+            update.excluded_user_ids,
+            Some(vec!["1500000000000000002".to_owned()])
+        );
+    }
+
+    #[test]
+    fn build_profile_timezone_update_leaves_the_feature_inert_when_nothing_is_submitted() {
+        let form = MultiValueForm::parse(b"_csrf=token");
+        let request = build_profile_timezone_update(&form).expect("valid form");
+        assert_eq!(
+            serde_json::to_value(request).expect("serializable update"),
+            serde_json::json!({"profile_timezone": {
+                "enabled": false,
+                "included_user_ids": [],
+                "included_guild_ids": [],
+                "include_premium_users": false,
                "excluded_user_ids": [],
            }})
        );
    }

    #[test]
-    fn build_screen_share_delivery_update_rejects_invalid_rollout_fields() {
-        for (form, message) in [
+    fn every_experiment_update_rejects_an_invalid_included_guild_id() {
+        for (prefix, build) in [
            (
-                "screen_share_delivery_rollout_basis_points=10001",
-                "Rollout basis points must be a whole number between 0 and 10000",
-            ),
-            (
-                "screen_share_delivery_rollout_basis_points=abc",
-                "Rollout basis points must be a whole number between 0 and 10000",
-            ),
-            (
-                "screen_share_delivery_rollout_salt=%20%20",
-                "Rollout salt must be between 1 and 64 characters",
-            ),
-            (
-                "screen_share_delivery_included_user_ids=123%2Cinvalid",
-                "Included user IDs entry 2 must contain 1 to 20 decimal digits",
-            ),
-            (
-                "screen_share_delivery_excluded_user_ids=123%2Cinvalid",
-                "Excluded user IDs entry 2 must contain 1 to 20 decimal digits",
+                "voice_ns",
+                build_voice_noise_suppression_update
+                    as fn(&MultiValueForm) -> Result<InstanceConfigUpdateRequest, String>,
            ),
+            ("domain_migration", build_domain_migration_update),
+            ("altcha_captcha", build_altcha_captcha_update),
+            ("profile_timezone", build_profile_timezone_update),
        ] {
-            let form = MultiValueForm::parse(form.as_bytes());
+            let form = MultiValueForm::parse(
+                format!("{prefix}_included_guild_ids=1500000000000000005%0Anot-a-guild").as_bytes(),
+            );
            assert_eq!(
-                build_screen_share_delivery_update(&form).expect_err("invalid rollout field"),
-                message
+                build(&form).expect_err("invalid guild id"),
+                "Included guild IDs entry 2 must contain 1 to 20 decimal digits",
+                "{prefix}"
            );
        }
    }

+    #[test]
+    fn build_profile_timezone_update_rejects_a_rollout_above_everybody() {
+        let form = MultiValueForm::parse(b"profile_timezone_rollout_basis_points=10001");
+        assert_eq!(
+            build_profile_timezone_update(&form).expect_err("invalid field"),
+            "Rollout basis points must be a whole number between 0 and 10000"
+        );
+    }
+
    #[test]
    fn build_experiment_delivery_update_leaves_both_fields_unchanged_when_absent() {
        let form = MultiValueForm::parse(b"_csrf=token");
@@ -2,13 +2,15 @@

 use crate::{
    api::types::{
-        AppPublicConfigResponse, EXPERIMENT_MAX_TARGETED_USERS, ExperimentDeliveryConfigResponse,
-        GatewayRolloutConfigResponse, InstanceConfigResponse, InstanceIntegrationsResponse,
-        InstanceMediaResponse, InstancePolicyResponse, InstanceRegistrationResponse,
-        LimitConfigResponse, NoiseSuppressionBackend, PendingRegistrationResponse,
-        RegistrationUrlResponse, SCREEN_SHARE_DELIVERY_DEFAULT_SALT,
-        ScreenShareDeliveryConfigResponse, SsoConfigResponse, VOICE_NS_MAX_GUILD_OVERRIDES,
-        VoiceNoiseSuppressionConfigResponse,
+        ALTCHA_CAPTCHA_COST_RANGE, ALTCHA_CAPTCHA_DEFAULT_SALT, ALTCHA_CAPTCHA_MAX_COUNTER_RANGE,
+        AltchaCaptchaConfigResponse, AppPublicConfigResponse, DOMAIN_MIGRATION_DEFAULT_SALT,
+        DomainMigrationConfigResponse, EXPERIMENT_MAX_TARGETED_USERS,
+        ExperimentDeliveryConfigResponse, GatewayRolloutConfigResponse, InstanceConfigResponse,
+        InstanceIntegrationsResponse, InstanceMediaResponse, InstancePolicyResponse,
+        InstanceRegistrationResponse, LimitConfigResponse, NoiseSuppressionBackend,
+        PROFILE_TIMEZONE_DEFAULT_SALT, PendingRegistrationResponse, ProfileTimezoneConfigResponse,
+        PushRelayConfigResponse, RegistrationUrlResponse, SsoConfigResponse,
+        VOICE_NS_MAX_GUILD_OVERRIDES, VoiceNoiseSuppressionConfigResponse,
    },
    config::AdminConfig,
    middleware::auth::AuthContext,
@@ -136,6 +138,13 @@ pub fn instance_config_page(
                        (integrations_config_section(base, csrf_token, &instance_config.integrations))
                    },
                ))
+                (config_group(
+                    "Push notifications",
+                    "Consent for the relay that delivers official mobile app notifications.",
+                    html! {
+                        (push_relay_section(base, csrf_token, &instance_config.push_relay))
+                    },
+                ))
                (config_group(
                    "Media & retention",
                    "Attachment expiry rules that can be changed without editing environment variables.",
@@ -149,7 +158,9 @@ pub fn instance_config_page(
                    html! {
                        (gateway_rollout_section(base, csrf_token, &instance_config.gateway_rollout))
                        (voice_noise_suppression_section(base, csrf_token, &instance_config.voice_noise_suppression))
-                        (screen_share_delivery_section(base, csrf_token, &instance_config.screen_share_delivery))
+                        (domain_migration_section(base, csrf_token, &instance_config.domain_migration))
+                        (altcha_captcha_section(base, csrf_token, &instance_config.altcha_captcha))
+                        (profile_timezone_section(base, csrf_token, &instance_config.profile_timezone))
                        (experiment_delivery_section(base, csrf_token, &instance_config.experiment_delivery))
                        @if let Some(limit_config) = limit_config {
                            (limit_config_section(base, limit_config))
@@ -1112,10 +1123,42 @@ fn voice_noise_suppression_section(
                        p class="text-xs text-neutral-500" {
                            "One snowflake per line, or comma separated. These users are targeted \
                             regardless of the percentage above. IDs must contain 1 to 20 decimal \
-                             digits. Invalid entries prevent the save; blank entries and duplicate \
+                             digits. Invalid entries prevent the save. Blank entries and duplicate \
                             IDs are ignored."
                        }
                    }
+                    div class="flex flex-col gap-2" {
+                        (checkbox(
+                            "voice_ns_include_premium_users",
+                            "true",
+                            "Include premium users",
+                            voice_noise_suppression.include_premium_users,
+                            true,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Includes every account with active premium perks, regardless of the \
+                             percentage above. The never-on list still wins."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "voice_ns_included_guild_ids",
+                            "Always-on Guild IDs",
+                            "1500000000000000005\n1500000000000000006",
+                            &voice_noise_suppression.included_guild_ids.join("\n"),
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            voice_noise_suppression.included_guild_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format, with guild IDs. Every member of a listed guild is \
+                             included regardless of the percentage above, unless the user is \
+                             in the never-on list."
+                        }
+                    }
                    div class="flex flex-col gap-2" {
                        (textarea_input(
                            "voice_ns_excluded_user_ids",
@@ -1131,7 +1174,7 @@ fn voice_noise_suppression_section(
                        ))
                        p class="text-xs text-neutral-500" {
                            "Same format. Exclusion wins over both the always-on list and the \
-                             percentage, so this is the per-user kill switch."
+                             percentage. This is the per-user kill switch."
                        }
                    }

@@ -1178,72 +1221,163 @@ fn voice_noise_suppression_section(
    )
 }

-fn screen_share_delivery_section(
+fn push_relay_section(
    base: &str,
    csrf_token: &str,
-    screen_share_delivery: &ScreenShareDeliveryConfigResponse,
+    push_relay: &PushRelayConfigResponse,
 ) -> Markup {
-    let status = if screen_share_delivery.enabled {
+    let status = if push_relay.relay_consent_accepted {
+        ("Accepted", BadgeVariant::Success)
+    } else {
+        ("Not accepted", BadgeVariant::Default)
+    };
+    let accepted_at =
+        format_optional_admin_timestamp(push_relay.relay_consent_accepted_at.as_deref(), "Never");
+    let accepted_by = push_relay
+        .relay_consent_accepted_by
+        .as_deref()
+        .unwrap_or("Nobody");
+    section_card_with_description(
+        "Push Relay",
+        "Official mobile app notifications travel through Fluxer's relay to Apple and Google. \
+         The relay delivers them only after an operator accepts its privacy notice.",
+        html! {
+            form method="post" action={(base) "/instance-config?action=update_push_relay"} {
+                (csrf_input(csrf_token))
+                div class="space-y-6" {
+                    div class="flex flex-wrap items-center gap-2" {
+                        h3 class="text-sm font-semibold text-neutral-900" { "Relay consent" }
+                        (badge(status.0, status.1))
+                    }
+                    (checkbox(
+                        "push_relay_consent_accepted",
+                        "true",
+                        "Accept the push relay supplemental privacy notice",
+                        push_relay.relay_consent_accepted,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Until this is accepted official mobile app notifications are dropped. \
+                         Self-hosted UnifiedPush and ntfy endpoints never reach the relay and are \
+                         unaffected. "
+                        a href="https://fluxer.com/push-relay" target="_blank" rel="noreferrer"
+                            class="text-neutral-900 underline decoration-neutral-300 hover:text-neutral-600 hover:decoration-neutral-500" {
+                            "Read the notice"
+                        }
+                    }
+                    div class="grid grid-cols-1 gap-4 sm:grid-cols-2" {
+                        (form_field_group("Accepted at", "push_relay_consent_accepted_at", false, None, None,
+                            html! {
+                                input type="text" id="push_relay_consent_accepted_at"
+                                    value=(accepted_at)
+                                    disabled class=(FORM_INPUT_CLASS);
+                            },
+                        ))
+                        (form_field_group("Accepted by user ID", "push_relay_consent_accepted_by", false, None, None,
+                            html! {
+                                input type="text" id="push_relay_consent_accepted_by"
+                                    value=(accepted_by)
+                                    disabled class=(FORM_INPUT_CLASS);
+                            },
+                        ))
+                    }
+
+                    (form_actions(html! {
+                        (submit_button("Save Push Relay Settings"))
+                    }))
+                }
+            }
+        },
+    )
+}
+
+fn domain_migration_section(
+    base: &str,
+    csrf_token: &str,
+    domain_migration: &DomainMigrationConfigResponse,
+) -> Markup {
+    let status = if domain_migration.enabled {
        ("Live", BadgeVariant::Success)
    } else {
        ("Inert", BadgeVariant::Default)
    };
-    let included_user_ids = screen_share_delivery.included_user_ids.join("\n");
-    let excluded_user_ids = screen_share_delivery.excluded_user_ids.join("\n");
+    let included_user_ids = domain_migration.included_user_ids.join("\n");
+    let excluded_user_ids = domain_migration.excluded_user_ids.join("\n");
    section_card_with_description(
-        "Screen Share Delivery",
-        "Pick how many clients publish screen shares through the reworked delivery path. While \
-         the master switch below is off nothing on this form reaches any client: every user \
-         keeps the screen share pipeline they have today, whatever the rest of these fields say. \
-         A client that is already sharing keeps the path it started on until the share ends.",
+        "Domain Migration",
+        "Moves web clients of the official instance from the legacy web app origin to the new \
+         one. Selected accounts copy their local data across and continue on the new origin. \
+         Clients of other instances read this configuration and ignore it.",
        html! {
-            form method="post" action={(base) "/instance-config?action=update_screen_share_delivery"} {
+            form method="post" action={(base) "/instance-config?action=update_domain_migration"} {
                (csrf_input(csrf_token))
                div class="space-y-6" {
                    div class="flex flex-wrap items-center gap-2" {
                        h3 class="text-sm font-semibold text-neutral-900" { "Master switch" }
                        (badge(status.0, status.1))
                        span class="text-xs text-neutral-500" {
-                            "Config version " (screen_share_delivery.config_version)
+                            "Config version " (domain_migration.config_version)
                        }
                    }
                    (checkbox(
-                        "screen_share_delivery_enabled",
+                        "domain_migration_enabled",
                        "true",
-                        "Serve screen share delivery assignments to clients",
-                        screen_share_delivery.enabled,
+                        "Move selected web clients to the new origin",
+                        domain_migration.enabled,
                        true,
                    ))
                    p class="text-xs text-neutral-500" {
-                        "Off is the safe state. With this unchecked every client is told the \
-                         feature is inert and keeps its current behavior, so the rollout and \
-                         targeting fields below have no effect at all."
+                        "Off is the safe state and the kill switch. With this unchecked no client \
+                         starts a migration and clients that already migrated stop forwarding the \
+                         legacy origin, so the rollout and targeting fields below have no effect at all."
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Installed apps" }
+                    (checkbox(
+                        "domain_migration_standalone_forwarding",
+                        "true",
+                        "Forward installed desktop web apps to the new origin",
+                        domain_migration.standalone_forwarding,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Leave this off until the manifest scope extension and the association file \
+                         are live and verified. While it is off, installed Chromium desktop apps copy \
+                         their data across but stay on the legacy origin and offer to install the new \
+                         app. Installed mobile and Safari apps never forward either way."
                    }

                    h3 class="text-sm font-semibold text-neutral-900" { "Rollout" }
                    (number_field(
-                        "screen_share_delivery_rollout_basis_points",
+                        "domain_migration_rollout_basis_points",
                        "Rollout (basis points)",
-                        &screen_share_delivery.rollout_basis_points.to_string(),
+                        &domain_migration.rollout_basis_points.to_string(),
                        Some(0), Some(10000), "1",
-                        Some("Share of users bucketed into the canary, in basis points: 0 is nobody, 100 is 1%, 10000 is everybody."),
+                        Some("Share of logged-in users bucketed into the migration, in basis points: 0 is nobody, 100 is 1%, 10000 is everybody."),
+                    ))
+                    (number_field(
+                        "domain_migration_anonymous_rollout_basis_points",
+                        "Anonymous rollout (basis points)",
+                        &domain_migration.anonymous_rollout_basis_points.to_string(),
+                        Some(0), Some(10000), "1",
+                        Some("Share of logged-out devices sent to the new origin, in basis points. Each device is bucketed on its own random ID."),
                    ))
                    div class="flex flex-col gap-2" {
                        (text_input(
-                            "screen_share_delivery_rollout_salt",
+                            "domain_migration_rollout_salt",
                            "Rollout Salt",
-                            &screen_share_delivery.rollout_salt,
-                            SCREEN_SHARE_DELIVERY_DEFAULT_SALT,
+                            &domain_migration.rollout_salt,
+                            DOMAIN_MIGRATION_DEFAULT_SALT,
                        ))
                        p class="text-xs text-neutral-500" {
-                            "Seeds the bucketing hash. Changing it reshuffles which users fall \
-                             inside the percentage above. Leave it alone to keep the current \
-                             cohort stable."
+                            "Seeds the bucketing hash for users and devices. Changing it reshuffles \
+                             which users and devices fall inside the percentages above. Leave it \
+                             alone to keep the current cohort stable."
                        }
                    }
                    div class="flex flex-col gap-2" {
                        (textarea_input(
-                            "screen_share_delivery_included_user_ids",
+                            "domain_migration_included_user_ids",
                            "Always-on User IDs",
                            "1500000000000000001\n1500000000000000002",
                            &included_user_ids,
@@ -1251,19 +1385,51 @@ fn screen_share_delivery_section(
                            false,
                        ))
                        (entry_count_hint(
-                            screen_share_delivery.included_user_ids.len(),
+                            domain_migration.included_user_ids.len(),
                            EXPERIMENT_MAX_TARGETED_USERS,
                        ))
                        p class="text-xs text-neutral-500" {
                            "One snowflake per line, or comma separated. These users are targeted \
                             regardless of the percentage above. IDs must contain 1 to 20 decimal \
-                             digits. Invalid entries prevent the save; blank entries and duplicate \
+                             digits. Invalid entries prevent the save. Blank entries and duplicate \
                             IDs are ignored."
                        }
                    }
+                    div class="flex flex-col gap-2" {
+                        (checkbox(
+                            "domain_migration_include_premium_users",
+                            "true",
+                            "Include premium users",
+                            domain_migration.include_premium_users,
+                            true,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Includes every account with active premium perks, regardless of the \
+                             percentage above. The never-on list still wins."
+                        }
+                    }
                    div class="flex flex-col gap-2" {
                        (textarea_input(
-                            "screen_share_delivery_excluded_user_ids",
+                            "domain_migration_included_guild_ids",
+                            "Always-on Guild IDs",
+                            "1500000000000000005\n1500000000000000006",
+                            &domain_migration.included_guild_ids.join("\n"),
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            domain_migration.included_guild_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format, with guild IDs. Every member of a listed guild is \
+                             included regardless of the percentage above, unless the user is \
+                             in the never-on list."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "domain_migration_excluded_user_ids",
                            "Never-on User IDs",
                            "1500000000000000003\n1500000000000000004",
                            &excluded_user_ids,
@@ -1271,17 +1437,326 @@ fn screen_share_delivery_section(
                            false,
                        ))
                        (entry_count_hint(
-                            screen_share_delivery.excluded_user_ids.len(),
+                            domain_migration.excluded_user_ids.len(),
                            EXPERIMENT_MAX_TARGETED_USERS,
                        ))
                        p class="text-xs text-neutral-500" {
                            "Same format. Exclusion wins over both the always-on list and the \
-                             percentage, so this is the per-user kill switch."
+                             percentage. It stops new migrations only. A user who already moved \
+                             stays on the new origin."
                        }
                    }

                    (form_actions(html! {
-                        (submit_button("Save Screen Share Delivery Configuration"))
+                        (submit_button("Save Domain Migration Configuration"))
+                    }))
+                }
+            }
+        },
+    )
+}
+
+fn altcha_captcha_section(
+    base: &str,
+    csrf_token: &str,
+    altcha_captcha: &AltchaCaptchaConfigResponse,
+) -> Markup {
+    let status = if altcha_captcha.enabled {
+        ("Live", BadgeVariant::Success)
+    } else {
+        ("Inert", BadgeVariant::Default)
+    };
+    let included_user_ids = altcha_captcha.included_user_ids.join("\n");
+    let excluded_user_ids = altcha_captcha.excluded_user_ids.join("\n");
+    section_card_with_description(
+        "ALTCHA Captcha",
+        "Replaces the configured captcha provider with an ALTCHA proof-of-work check for the \
+         selected requesters. The API issues and verifies every challenge itself, so no third \
+         party is involved. Requests only need a captcha where one is already required, so this \
+         does nothing while captcha is off for the instance.",
+        html! {
+            form method="post" action={(base) "/instance-config?action=update_altcha_captcha"} {
+                (csrf_input(csrf_token))
+                div class="space-y-6" {
+                    div class="flex flex-wrap items-center gap-2" {
+                        h3 class="text-sm font-semibold text-neutral-900" { "Master switch" }
+                        (badge(status.0, status.1))
+                        span class="text-xs text-neutral-500" {
+                            "Config version " (altcha_captcha.config_version)
+                        }
+                    }
+                    (checkbox(
+                        "altcha_captcha_enabled",
+                        "true",
+                        "Serve ALTCHA to the selected requesters",
+                        altcha_captcha.enabled,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Off is the safe state and the kill switch. With this unchecked every \
+                         requester gets the configured provider and ALTCHA answers are rejected."
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Logged-out requests" }
+                    (checkbox(
+                        "altcha_captcha_anonymous_enabled",
+                        "true",
+                        "Serve ALTCHA to logged-out requests",
+                        altcha_captcha.anonymous_enabled,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Covers registration, login and password reset. These requests have no \
+                         account to bucket, so this switch applies to all of them at once."
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Rollout" }
+                    (number_field(
+                        "altcha_captcha_rollout_basis_points",
+                        "Rollout (basis points)",
+                        &altcha_captcha.rollout_basis_points.to_string(),
+                        Some(0), Some(10000), "1",
+                        Some("Share of logged-in users bucketed into ALTCHA, in basis points: 0 is nobody, 100 is 1%, 10000 is everybody."),
+                    ))
+                    div class="flex flex-col gap-2" {
+                        (text_input(
+                            "altcha_captcha_rollout_salt",
+                            "Rollout Salt",
+                            &altcha_captcha.rollout_salt,
+                            ALTCHA_CAPTCHA_DEFAULT_SALT,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Seeds the bucketing hash. Changing it reshuffles which users fall \
+                             inside the percentage above."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "altcha_captcha_included_user_ids",
+                            "Always-on User IDs",
+                            "1500000000000000001\n1500000000000000002",
+                            &included_user_ids,
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            altcha_captcha.included_user_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "One snowflake per line, or comma separated. These users get ALTCHA \
+                             regardless of the percentage above. Invalid entries prevent the save."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (checkbox(
+                            "altcha_captcha_include_premium_users",
+                            "true",
+                            "Include premium users",
+                            altcha_captcha.include_premium_users,
+                            true,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Includes every account with active premium perks, regardless of the \
+                             percentage above. The never-on list still wins."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "altcha_captcha_included_guild_ids",
+                            "Always-on Guild IDs",
+                            "1500000000000000005\n1500000000000000006",
+                            &altcha_captcha.included_guild_ids.join("\n"),
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            altcha_captcha.included_guild_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format, with guild IDs. Every member of a listed guild is \
+                             included regardless of the percentage above, unless the user is \
+                             in the never-on list."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "altcha_captcha_excluded_user_ids",
+                            "Never-on User IDs",
+                            "1500000000000000003\n1500000000000000004",
+                            &excluded_user_ids,
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            altcha_captcha.excluded_user_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format. Exclusion wins over both the always-on list and the percentage."
+                        }
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Difficulty" }
+                    (number_field(
+                        "altcha_captcha_cost",
+                        "Cost (PBKDF2 iterations per attempt)",
+                        &altcha_captcha.cost.to_string(),
+                        Some(*ALTCHA_CAPTCHA_COST_RANGE.start()),
+                        Some(*ALTCHA_CAPTCHA_COST_RANGE.end()),
+                        "1",
+                        Some("The API spends one attempt at this cost to issue each challenge."),
+                    ))
+                    (number_field(
+                        "altcha_captcha_max_counter",
+                        "Maximum counter",
+                        &altcha_captcha.max_counter.to_string(),
+                        Some(*ALTCHA_CAPTCHA_MAX_COUNTER_RANGE.start()),
+                        Some(*ALTCHA_CAPTCHA_MAX_COUNTER_RANGE.end()),
+                        "1",
+                        Some("Each challenge hides its answer between half this value and this value. The client tries counters from 0 until it finds it, so solve time grows with cost times this value. At the defaults a recent laptop takes about 3 seconds."),
+                    ))
+
+                    (form_actions(html! {
+                        (submit_button("Save ALTCHA Configuration"))
+                    }))
+                }
+            }
+        },
+    )
+}
+
+fn profile_timezone_section(
+    base: &str,
+    csrf_token: &str,
+    profile_timezone: &ProfileTimezoneConfigResponse,
+) -> Markup {
+    let status = if profile_timezone.enabled {
+        ("Live", BadgeVariant::Success)
+    } else {
+        ("Inert", BadgeVariant::Default)
+    };
+    let included_user_ids = profile_timezone.included_user_ids.join("\n");
+    let excluded_user_ids = profile_timezone.excluded_user_ids.join("\n");
+    section_card_with_description(
+        "Profile Timezone",
+        "Lets the selected users save a time zone in profile settings and show their local time \
+         on their profile. Users outside the rollout cannot change it, and a saved time zone \
+         stays hidden from everyone while its owner is outside the rollout.",
+        html! {
+            form method="post" action={(base) "/instance-config?action=update_profile_timezone"} {
+                (csrf_input(csrf_token))
+                div class="space-y-6" {
+                    div class="flex flex-wrap items-center gap-2" {
+                        h3 class="text-sm font-semibold text-neutral-900" { "Master switch" }
+                        (badge(status.0, status.1))
+                        span class="text-xs text-neutral-500" {
+                            "Config version " (profile_timezone.config_version)
+                        }
+                    }
+                    (checkbox(
+                        "profile_timezone_enabled",
+                        "true",
+                        "Serve profile timezone to the selected users",
+                        profile_timezone.enabled,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Off is the safe state and the kill switch. With this unchecked nobody \
+                         sees the setting and every saved time zone is hidden."
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Rollout" }
+                    (number_field(
+                        "profile_timezone_rollout_basis_points",
+                        "Rollout (basis points)",
+                        &profile_timezone.rollout_basis_points.to_string(),
+                        Some(0), Some(10000), "1",
+                        Some("Share of users bucketed into profile timezone, in basis points: 0 is nobody, 100 is 1%, 10000 is everybody."),
+                    ))
+                    div class="flex flex-col gap-2" {
+                        (text_input(
+                            "profile_timezone_rollout_salt",
+                            "Rollout Salt",
+                            &profile_timezone.rollout_salt,
+                            PROFILE_TIMEZONE_DEFAULT_SALT,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Seeds the bucketing hash. Changing it reshuffles which users fall \
+                             inside the percentage above."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "profile_timezone_included_user_ids",
+                            "Always-on User IDs",
+                            "1500000000000000001\n1500000000000000002",
+                            &included_user_ids,
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            profile_timezone.included_user_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "One snowflake per line, or comma separated. These users get profile \
+                             timezone regardless of the percentage above. Invalid entries prevent the save."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (checkbox(
+                            "profile_timezone_include_premium_users",
+                            "true",
+                            "Include premium users",
+                            profile_timezone.include_premium_users,
+                            true,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Includes every account with active premium perks, regardless of the \
+                             percentage above. The never-on list still wins."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "profile_timezone_included_guild_ids",
+                            "Always-on Guild IDs",
+                            "1500000000000000005\n1500000000000000006",
+                            &profile_timezone.included_guild_ids.join("\n"),
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            profile_timezone.included_guild_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format, with guild IDs. Every member of a listed guild is \
+                             included regardless of the percentage above, unless the user is \
+                             in the never-on list."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "profile_timezone_excluded_user_ids",
+                            "Never-on User IDs",
+                            "1500000000000000003\n1500000000000000004",
+                            &excluded_user_ids,
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            profile_timezone.excluded_user_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format. Exclusion wins over both the always-on list and the percentage."
+                        }
+                    }
+
+                    (form_actions(html! {
+                        (submit_button("Save Profile Timezone Configuration"))
                    }))
                }
            }
@@ -1933,24 +2408,52 @@ mod tests {
    }

    #[test]
-    fn screen_share_delivery_section_shows_list_counts_and_the_master_switch() {
-        let screen_share_delivery = ScreenShareDeliveryConfigResponse {
+    fn domain_migration_section_shows_both_rollouts_and_list_counts() {
+        let domain_migration = DomainMigrationConfigResponse {
+            anonymous_rollout_basis_points: 250,
            included_user_ids: vec!["1500000000000000001".to_owned()],
            excluded_user_ids: vec![
                "1500000000000000002".to_owned(),
                "1500000000000000003".to_owned(),
            ],
-            ..ScreenShareDeliveryConfigResponse::default()
+            ..DomainMigrationConfigResponse::default()
        };
-        let markup =
-            screen_share_delivery_section("/admin", "csrf", &screen_share_delivery).into_string();
-        assert!(markup.contains("action=update_screen_share_delivery"));
-        assert!(markup.contains("screen_share_delivery_enabled"));
+        let markup = domain_migration_section("/admin", "csrf", &domain_migration).into_string();
+        assert!(markup.contains("action=update_domain_migration"));
+        assert!(markup.contains("domain_migration_enabled"));
+        assert!(markup.contains("name=\"domain_migration_anonymous_rollout_basis_points\""));
+        assert!(markup.contains("value=\"250\""));
+        assert!(markup.contains("name=\"domain_migration_standalone_forwarding\""));
        assert!(markup.contains("1 of 1000 stored"));
        assert!(markup.contains("2 of 1000 stored"));
        assert!(!markup.contains("at the cap"));
    }

+    #[test]
+    fn push_relay_section_shows_the_consent_toggle() {
+        let accepted = PushRelayConfigResponse {
+            relay_consent_accepted: true,
+            relay_consent_accepted_at: Some("2026-09-27T10:11:12.000Z".to_owned()),
+            relay_consent_accepted_by: Some("1130650140672000000".to_owned()),
+        };
+        let markup = push_relay_section("/admin", "csrf", &accepted).into_string();
+        assert!(markup.contains("action=update_push_relay"));
+        assert!(markup.contains("name=\"push_relay_consent_accepted\""));
+        assert!(markup.contains("https://fluxer.com/push-relay"));
+        assert!(markup.contains("value=\"Sep 27, 2026, 10:11 AM UTC\""));
+        assert!(markup.contains("value=\"1130650140672000000\""));
+        assert!(!markup.contains("name=\"push_relay_consent_accepted_at\""));
+        assert!(!markup.contains("name=\"push_relay_consent_accepted_by\""));
+        assert!(!markup.to_lowercase().contains("rollout"));
+
+        let unaccepted =
+            push_relay_section("/admin", "csrf", &PushRelayConfigResponse::default()).into_string();
+        assert!(unaccepted.contains("name=\"push_relay_consent_accepted\""));
+        assert!(unaccepted.contains("Not accepted"));
+        assert!(unaccepted.contains("value=\"Never\""));
+        assert!(unaccepted.contains("value=\"Nobody\""));
+    }
+
    #[test]
    fn voice_noise_suppression_section_flags_a_list_at_its_cap() {
        let voice_noise_suppression = VoiceNoiseSuppressionConfigResponse {
@@ -114,7 +114,10 @@ pub fn users_list_page(
    let content = html! {
        div class="space-y-6" {
            (page_header("Users", None))
-            div class="rounded-lg bg-white transition-all border border-neutral-200 p-4" {
+            div class="rounded-lg bg-white transition-all border border-neutral-200 p-3" {
+                p class="mb-1 text-xs text-neutral-500" {
+                    "For example, type " span class="font-mono" { "*" } " in to search for all users."
+                }
                (search_form(base, params))
            }
            (results_markup)
@@ -403,20 +403,56 @@ fn deserialize_instance_config_response_with_unknown_keys() {
            "included_user_ids": [],
            "excluded_user_ids": [],
            "guild_overrides": [],
+            "included_guild_ids": ["1500000000000000005"],
+            "include_premium_users": true,
            "suppression_strength": 80,
            "future_presentation_knob": "verbose",
            "future_knob": 7,
            "future_object_knob": {"nested": true},
            "future_list_knob": ["a", "b"]
        },
-        "screen_share_delivery": {
+        "push_relay": {
+            "relay_consent_accepted": true,
+            "relay_consent_accepted_at": "2026-09-27T10:11:12.000Z",
+            "relay_consent_accepted_by": "1130650140672000000"
+        },
+        "domain_migration": {
            "enabled": true,
            "config_version": 2,
            "rollout_basis_points": 2500,
-            "rollout_salt": "screen-share-delivery-v1",
+            "rollout_salt": "domain-migration-v1",
            "included_user_ids": ["1500000000000000001"],
-            "future_delivery_knob": 9,
-            "excluded_user_ids": []
+            "excluded_user_ids": [],
+            "included_guild_ids": [],
+            "include_premium_users": false,
+            "future_migration_knob": 9,
+            "anonymous_rollout_basis_points": 100,
+            "standalone_forwarding": true
+        },
+        "altcha_captcha": {
+            "enabled": true,
+            "config_version": 3,
+            "rollout_basis_points": 500,
+            "rollout_salt": "altcha-captcha-v1",
+            "included_user_ids": [],
+            "excluded_user_ids": ["1500000000000000003"],
+            "anonymous_enabled": true,
+            "cost": 5000,
+            "max_counter": 10000,
+            "included_guild_ids": [],
+            "include_premium_users": false,
+            "future_altcha_knob": "argon2id"
+        },
+        "profile_timezone": {
+            "enabled": true,
+            "config_version": 2,
+            "rollout_basis_points": 0,
+            "rollout_salt": "profile-timezone-v1",
+            "included_user_ids": ["1500000000000000001"],
+            "excluded_user_ids": [],
+            "included_guild_ids": ["1500000000000000005"],
+            "include_premium_users": true,
+            "future_profile_timezone_knob": true
        },
        "experiment_delivery": {"poll_interval_seconds": 300, "poll_jitter_percent": 15},
        "registration": {
@@ -547,14 +583,25 @@ fn deserialize_instance_config_response_with_unknown_keys() {
    assert_eq!(resp.voice_noise_suppression.rollout_basis_points, 10000);
    assert_eq!(*resp.voice_noise_suppression.rollout_salt, "voice-ns-v1");
    assert_eq!(resp.voice_noise_suppression.enabled_backends.len(), 3);
-    assert!(resp.screen_share_delivery.enabled);
-    assert_eq!(resp.screen_share_delivery.config_version, 2);
-    assert_eq!(resp.screen_share_delivery.rollout_basis_points, 2500);
-    assert_eq!(
-        *resp.screen_share_delivery.rollout_salt,
-        "screen-share-delivery-v1"
-    );
-    assert_eq!(resp.screen_share_delivery.included_user_ids.len(), 1);
+    assert!(resp.domain_migration.enabled);
+    assert_eq!(resp.domain_migration.config_version, 2);
+    assert_eq!(resp.domain_migration.rollout_basis_points, 2500);
+    assert_eq!(*resp.domain_migration.rollout_salt, "domain-migration-v1");
+    assert_eq!(resp.domain_migration.included_user_ids.len(), 1);
+    assert_eq!(resp.domain_migration.anonymous_rollout_basis_points, 100);
+    assert!(resp.domain_migration.standalone_forwarding);
+    assert!(resp.push_relay.relay_consent_accepted);
+    assert!(resp.altcha_captcha.enabled);
+    assert_eq!(resp.altcha_captcha.config_version, 3);
+    assert!(resp.altcha_captcha.anonymous_enabled);
+    assert_eq!(resp.altcha_captcha.excluded_user_ids.len(), 1);
+    assert_eq!(resp.altcha_captcha.max_counter, 10000);
+    assert!(resp.profile_timezone.enabled);
+    assert_eq!(resp.profile_timezone.config_version, 2);
+    assert_eq!(resp.profile_timezone.included_user_ids.len(), 1);
+    assert_eq!(resp.profile_timezone.included_guild_ids.len(), 1);
+    assert!(resp.profile_timezone.include_premium_users);
+    assert!(resp.voice_noise_suppression.include_premium_users);
    assert_eq!(resp.experiment_delivery.poll_interval_seconds, 300);
    assert!(resp.policy.single_community_guild_id.is_none());
    assert_eq!(resp.policy.services.gif_enabled, Some(true));
@@ -565,7 +612,7 @@ fn deserialize_instance_config_response_with_unknown_keys() {
        .replace("\"future_rollout_knob\": 3,", "")
        .replace("\"future_presentation_knob\": \"verbose\",", "")
        .replace("\"future_knob\": 7,", "")
-        .replace("\"future_delivery_knob\": 9,", "")
+        .replace("\"future_migration_knob\": 9,", "")
        .replace("\"future_object_knob\": {\"nested\": true},", "")
        .replace("\"future_list_knob\": [\"a\", \"b\"],", "")
        .replace(
@@ -587,6 +634,51 @@ fn deserialize_instance_config_response_with_unknown_keys() {
    );
 }

+#[test]
+fn deserialize_push_relay_config() {
+    let accepted: types::PushRelayConfigResponse = serde_json::from_str(
+        r#"{
+        "relay_consent_accepted": true,
+        "relay_consent_accepted_at": "2026-09-27T10:11:12.000Z",
+        "relay_consent_accepted_by": "1130650140672000000"
+    }"#,
+    )
+    .expect("an accepted relay consent must deserialize");
+
+    assert!(accepted.relay_consent_accepted);
+    assert_eq!(
+        accepted.relay_consent_accepted_at.as_deref(),
+        Some("2026-09-27T10:11:12.000Z")
+    );
+    assert_eq!(
+        accepted.relay_consent_accepted_by.as_deref(),
+        Some("1130650140672000000")
+    );
+
+    let empty: types::PushRelayConfigResponse =
+        serde_json::from_str("{}").expect("an empty push relay config must deserialize");
+
+    assert!(!empty.relay_consent_accepted);
+    assert!(empty.relay_consent_accepted_at.is_none());
+    assert!(empty.relay_consent_accepted_by.is_none());
+}
+
+#[test]
+fn serialize_push_relay_update_omits_an_unset_consent() {
+    assert_eq!(
+        serde_json::to_value(types::PushRelayConfigUpdateRequest::default()).unwrap(),
+        serde_json::json!({})
+    );
+
+    let with = types::PushRelayConfigUpdateRequest {
+        relay_consent_accepted: Some(true),
+    };
+    assert_eq!(
+        serde_json::to_value(&with).unwrap(),
+        serde_json::json!({"relay_consent_accepted": true})
+    );
+}
+
 #[test]
 fn deserialize_search_reports_response() {
    let json = r#"{
@@ -861,7 +953,8 @@ fn deserialize_webauthn_credentials_response() {
            "id": "credential-a",
            "name": "YubiKey",
            "created_at": "2026-05-26T12:00:00.000Z",
-            "last_used_at": null
+            "last_used_at": null,
+            "rp_id": "fluxer.com"
        },
        {
            "id": "credential-b",
@@ -465,7 +465,7 @@ async fn mutating_admin_pages_render_usable_csrf_tokens() {
                "/instance-config?action=update_gateway_rollout",
                "/instance-config?action=update_sso",
                "/instance-config?action=update_voice_noise_suppression",
-                "/instance-config?action=update_screen_share_delivery",
+                "/instance-config?action=update_domain_migration",
                "/instance-config?action=update_experiment_delivery",
            ][..],
        ),
@@ -817,6 +817,9 @@ async fn spawn_mock_api() -> String {

 async fn mock_api(method: Method, uri: Uri) -> Response {
    let path = uri.path().to_owned();
+    if method == Method::PATCH && path == "/admin/instance/config" {
+        return json_response(instance_config());
+    }
    match (method, path.as_str()) {
        (Method::GET, "/admin/users/@me") => json_response(json!({ "user": admin_user() })),
        (Method::GET, "/admin/api-keys") => json_response(json!([])),
@@ -1197,13 +1200,15 @@ fn instance_config() -> Value {
            "guild_overrides": [],
            "suppression_strength": 80
        },
-        "screen_share_delivery": {
+        "domain_migration": {
            "enabled": false,
            "config_version": 0,
            "rollout_basis_points": 0,
-            "rollout_salt": "screen-share-delivery-v1",
+            "rollout_salt": "domain-migration-v1",
            "included_user_ids": [],
-            "excluded_user_ids": []
+            "excluded_user_ids": [],
+            "anonymous_rollout_basis_points": 0,
+            "standalone_forwarding": false
        },
        "experiment_delivery": {
            "poll_interval_seconds": 300,
@@ -56,6 +56,7 @@
 		"@simplewebauthn/server": "catalog:",
 		"@types/node": "catalog:",
 		"@vvo/tzdb": "catalog:",
+		"altcha-lib": "catalog:",
 		"archiver": "catalog:",
 		"argon2": "catalog:",
 		"bowser": "catalog:",
@@ -11,7 +11,9 @@
 	},
 	"dependencies": {
 		"@fluxer/logger": "workspace:*",
-		"itty-time": "catalog:"
+		"altcha-lib": "catalog:",
+		"itty-time": "catalog:",
+		"zod": "catalog:"
 	},
 	"devDependencies": {
 		"@types/node": "catalog:",
@@ -5,7 +5,7 @@ export interface VerifyCaptchaParams {
 	remoteIp?: string;
 }

-export type CaptchaProviderType = 'hcaptcha' | 'recaptcha' | 'turnstile' | 'test' | 'unavailable';
+export type CaptchaProviderType = 'hcaptcha' | 'recaptcha' | 'turnstile' | 'altcha' | 'test' | 'unavailable';

 export interface ICaptchaProvider {
 	readonly type: CaptchaProviderType;
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {LoggerInterface} from '@fluxer/logger/src/LoggerInterface';
+import type {CaptchaProviderType, ICaptchaProvider, VerifyCaptchaParams} from '@pkgs/captcha/src/ICaptchaProvider';
+import {createChallenge, randomInt, verifySolution} from 'altcha-lib';
+import {deriveKey} from 'altcha-lib/algorithms/pbkdf2';
+import type {Challenge} from 'altcha-lib/types';
+import {ms} from 'itty-time';
+import {z} from 'zod';
+
+export const ALTCHA_ALGORITHM = 'PBKDF2/SHA-256';
+const ALTCHA_CHALLENGE_TTL_MS = ms('10 minutes');
+const ALTCHA_MAX_TOKEN_LENGTH = 4096;
+const HEX_PATTERN = /^[0-9a-f]+$/u;
+
+const AltchaPayloadSchema = z.object({
+	challenge: z.object({
+		parameters: z.looseObject({
+			algorithm: z.literal(ALTCHA_ALGORITHM),
+			nonce: z.string().regex(HEX_PATTERN),
+			salt: z.string().regex(HEX_PATTERN),
+			cost: z.number().int().positive(),
+			keyLength: z.number().int().positive(),
+			keyPrefix: z.string().regex(HEX_PATTERN),
+			keySignature: z.string().regex(HEX_PATTERN),
+			expiresAt: z.number().int().positive(),
+		}),
+		signature: z.string().regex(HEX_PATTERN),
+	}),
+	solution: z.object({
+		counter: z.number().int().min(0),
+		derivedKey: z.string().regex(HEX_PATTERN),
+		time: z.number().optional(),
+	}),
+});
+
+type AltchaPayload = z.infer<typeof AltchaPayloadSchema>;
+
+export interface AltchaProviderOptions {
+	hmacSignatureSecret: string;
+	hmacKeySignatureSecret: string;
+	cost: number;
+	maxCounter: number;
+	claimChallenge: (signature: string, ttlSeconds: number) => Promise<boolean>;
+	logger?: LoggerInterface;
+	now?: () => number;
+}
+
+function decodePayload(token: string): AltchaPayload | null {
+	if (token.length > ALTCHA_MAX_TOKEN_LENGTH) return null;
+	try {
+		const parsed = AltchaPayloadSchema.safeParse(JSON.parse(Buffer.from(token, 'base64').toString('utf8')));
+		return parsed.success ? parsed.data : null;
+	} catch {
+		return null;
+	}
+}
+
+export class AltchaProvider implements ICaptchaProvider {
+	readonly type: CaptchaProviderType = 'altcha';
+	private readonly options: AltchaProviderOptions;
+	private readonly now: () => number;
+
+	constructor(options: AltchaProviderOptions) {
+		this.options = options;
+		this.now = options.now ?? Date.now;
+	}
+
+	async createChallenge(): Promise<Challenge> {
+		const {cost, maxCounter, hmacSignatureSecret, hmacKeySignatureSecret} = this.options;
+		return await createChallenge({
+			algorithm: ALTCHA_ALGORITHM,
+			cost,
+			counter: randomInt(maxCounter, Math.ceil(maxCounter / 2)),
+			deriveKey,
+			expiresAt: new Date(this.now() + ALTCHA_CHALLENGE_TTL_MS),
+			hmacSignatureSecret,
+			hmacKeySignatureSecret,
+		});
+	}
+
+	async verify({token}: VerifyCaptchaParams): Promise<boolean> {
+		const payload = decodePayload(token);
+		if (!payload) return false;
+		try {
+			const result = await verifySolution({
+				challenge: payload.challenge,
+				solution: payload.solution,
+				deriveKey,
+				hmacSignatureSecret: this.options.hmacSignatureSecret,
+				hmacKeySignatureSecret: this.options.hmacKeySignatureSecret,
+			});
+			if (!result.verified) {
+				this.options.logger?.warn(
+					{expired: result.expired, invalidSignature: result.invalidSignature, invalidSolution: result.invalidSolution},
+					'ALTCHA verification failed',
+				);
+				return false;
+			}
+		} catch (error) {
+			this.options.logger?.error({error}, 'Error verifying ALTCHA payload');
+			return false;
+		}
+		const ttlSeconds = Math.max(1, payload.challenge.parameters.expiresAt - Math.floor(this.now() / 1000));
+		return await this.options.claimChallenge(payload.challenge.signature, ttlSeconds);
+	}
+}
@@ -45,7 +45,7 @@ export async function createAPIApp(options: CreateAPIAppOptions): Promise<APIApp
 	configureMiddleware(routes, {
 		logger,
 		nodeEnv: config.nodeEnv,
-		corsOrigins: [config.endpoints.webApp, config.endpoints.marketing],
+		corsOrigins: [...config.endpoints.webAppOrigins, config.endpoints.marketing],
 		trustClientIpHeader: config.proxy.trust_client_ip_header,
 		clientIpHeaderName: config.proxy.client_ip_header,
 		maxInflightRequests: config.maxInflightRequests,
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

 import type {APIConfig, BlueskyOAuthConfig} from '@app/api/config/APIConfig';
+import {parseIpBanEntry} from '@app/api/utils/IpRangeUtils';
 import type {WorkerTaskName} from '@app/api/worker/WorkerLaneConfig';
 import type {MasterConfig} from '@fluxer/config/src/MasterConfig';
 import {parseIpAddress} from '@fluxer/ip_utils/src/IpAddress';
@@ -82,6 +83,14 @@ function resolveTrustClientIpHeader(proxyConfig: object): boolean {
 function normalizeIpBanExemptIps(values: Array<string>): Array<string> {
 	const normalized = new Set<string>();
 	for (const value of values) {
+		if (value.includes('/')) {
+			const range = parseIpBanEntry(value);
+			if (range?.type !== 'range') {
+				throw new Error(`FLUXER_API_IP_BAN_EXEMPT_IPS contains an invalid CIDR range: ${value}`);
+			}
+			normalized.add(range.canonical);
+			continue;
+		}
 		const parsed = parseIpAddress(value);
 		if (!parsed) {
 			throw new Error(`FLUXER_API_IP_BAN_EXEMPT_IPS contains an invalid IP address: ${value}`);
@@ -258,6 +267,7 @@ export function buildAPIConfigFromMaster(master: MasterConfig): APIConfig {
 			apiPublic: master.endpoints.api,
 			apiClient: master.endpoints.api_client,
 			webApp: master.endpoints.app,
+			webAppOrigins: [...new Set([new URL(master.endpoints.app).origin, ...master.services.api.app_origin_aliases])],
 			gateway: master.endpoints.gateway,
 			media: master.endpoints.media,
 			marketing: master.endpoints.marketing,
@@ -272,8 +282,6 @@ export function buildAPIConfigFromMaster(master: MasterConfig): APIConfig {
 			donationProxyKey,
 		},
 		hosts: {
-			invite: extractHostname(master.endpoints.invite),
-			gift: extractHostname(master.endpoints.gift),
 			marketing: extractHostname(master.endpoints.marketing),
 			unfurlIgnored: master.services.api.unfurl_ignored_hosts,
 		},
@@ -478,6 +486,10 @@ export function buildAPIConfigFromMaster(master: MasterConfig): APIConfig {
 		},
 		abusePolicy: {
 			inboundPhoneCountryCodes: master.instance.abuse_policy.inbound_phone_country_codes,
+			phoneFlagging: {
+				enabled: master.instance.abuse_policy.phone_flagging.enabled,
+				exemptCountryCodes: master.instance.abuse_policy.phone_flagging.exempt_country_codes,
+			},
 			phoneVerification: {
 				inboundRequiredPrefixes: master.instance.abuse_policy.phone_verification.inbound_required_prefixes,
 			},
@@ -13,7 +13,11 @@ import {deriveSsoRedirectUri, normalizeAndValidateSsoConfig} from '@app/api/inst
 import {requireAdminACL} from '@app/api/middleware/AdminMiddleware';
 import {RateLimitMiddleware} from '@app/api/middleware/RateLimitMiddleware';
 import {OpenAPI} from '@app/api/middleware/ResponseTypeMiddleware';
-import {getGatewayRolloutConfigPublisher, getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import {
+	getGatewayRolloutConfigPublisher,
+	getInstanceConfigRepository,
+	getPushRelayConfigPublisher,
+} from '@app/api/middleware/ServiceSingletons';
 import {RateLimitConfigs} from '@app/api/RateLimitConfig';
 import type {HonoApp, HonoEnv} from '@app/api/types/HonoEnv';
 import {Validator} from '@app/api/Validator';
@@ -30,8 +34,11 @@ import {
 	PendingRegistrationActionRequest,
 	RegistrationUrlIdParam,
 } from '@fluxer/schema/src/domains/admin/AdminSchemas';
+import {AltchaCaptchaConfigSchema} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
+import {DomainMigrationConfigSchema} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
 import {GatewayRolloutConfigSchema} from '@fluxer/schema/src/domains/admin/GatewayRolloutSchemas';
-import {ScreenShareDeliveryConfigSchema} from '@fluxer/schema/src/domains/admin/ScreenShareDeliverySchemas';
+import {ProfileTimezoneConfigSchema} from '@fluxer/schema/src/domains/admin/ProfileTimezoneSchemas';
+import type {PushRelayConfig, PushRelayConfigUpdateRequest} from '@fluxer/schema/src/domains/admin/PushRelaySchemas';
 import {VoiceNoiseSuppressionConfigSchema} from '@fluxer/schema/src/domains/admin/VoiceNoiseSuppressionSchemas';
 import {UserIdParam} from '@fluxer/schema/src/domains/common/CommonParamSchemas';
 import {ExperimentDeliveryConfigSchema} from '@fluxer/schema/src/domains/experiment/ExperimentSchemas';
@@ -60,7 +67,10 @@ async function buildInstanceConfigResponse(): Promise<InstanceConfigResponse> {
 		ssoConfig,
 		gatewayRollout,
 		voiceNoiseSuppression,
-		screenShareDelivery,
+		pushRelay,
+		domainMigration,
+		altchaCaptcha,
+		profileTimezone,
 		experimentDelivery,
 		registrationConfig,
 		registrationUrls,
@@ -69,7 +79,10 @@ async function buildInstanceConfigResponse(): Promise<InstanceConfigResponse> {
 		instanceConfigRepository.getSsoConfig(),
 		instanceConfigRepository.getGatewayRolloutConfig(),
 		instanceConfigRepository.getVoiceNoiseSuppressionConfig(),
-		instanceConfigRepository.getScreenShareDeliveryConfig(),
+		instanceConfigRepository.getPushRelayConfig(),
+		instanceConfigRepository.getDomainMigrationConfig(),
+		instanceConfigRepository.getAltchaCaptchaConfig(),
+		instanceConfigRepository.getProfileTimezoneConfig(),
 		instanceConfigRepository.getExperimentDeliveryConfig(),
 		instanceConfigRepository.getRegistrationConfig(),
 		instanceConfigRepository.getRegistrationUrlsForAdmin(),
@@ -101,7 +114,10 @@ async function buildInstanceConfigResponse(): Promise<InstanceConfigResponse> {
 		},
 		gateway_rollout: gatewayRollout,
 		voice_noise_suppression: voiceNoiseSuppression,
-		screen_share_delivery: screenShareDelivery,
+		push_relay: pushRelay,
+		domain_migration: domainMigration,
+		altcha_captcha: altchaCaptcha,
+		profile_timezone: profileTimezone,
 		experiment_delivery: experimentDelivery,
 		registration: {
 			...registrationConfig,
@@ -186,6 +202,20 @@ async function grantSetupCompleterAdminACL(ctx: Context<HonoEnv>): Promise<boole
 	return true;
 }

+function relayConsentStamp(
+	current: PushRelayConfig,
+	patch: PushRelayConfigUpdateRequest,
+	adminUserId: string,
+): Partial<PushRelayConfig> {
+	const accepted = patch.relay_consent_accepted;
+	if (accepted === undefined || accepted === current.relay_consent_accepted) {
+		return {};
+	}
+	return accepted
+		? {relay_consent_accepted_at: new Date().toISOString(), relay_consent_accepted_by: adminUserId}
+		: {relay_consent_accepted_at: null, relay_consent_accepted_by: null};
+}
+
 function listSuppliedSections(data: InstanceConfigUpdateRequest): string | undefined {
 	const sections = Object.entries(data)
 		.filter(([, value]) => value != null)
@@ -247,43 +277,77 @@ export function InstanceConfigAdminController(app: HonoApp) {
 			const shouldGrantSetupCompleterAdmin =
 				appPublicBeforeUpdate !== null && completesInitialSetup(data, appPublicBeforeUpdate.setup.configured);
 			if (data.gateway_rollout) {
-				const currentRollout = await instanceConfigRepository.getGatewayRolloutConfig();
-				const merged = {...currentRollout, ...data.gateway_rollout};
-				const validated = GatewayRolloutConfigSchema.parse(merged);
-				await instanceConfigRepository.setGatewayRolloutConfig(validated);
-				await getGatewayRolloutConfigPublisher().publish(validated);
+				const patch = data.gateway_rollout;
+				const landed = await instanceConfigRepository.updateGatewayRolloutConfig((current) =>
+					GatewayRolloutConfigSchema.parse({...current, ...patch}),
+				);
+				await getGatewayRolloutConfigPublisher().publish(landed);
 			}
 			if (data.voice_noise_suppression) {
 				const patch = omitUndefinedFields(data.voice_noise_suppression);
 				if (Object.keys(patch).length > 0) {
-					const currentNoiseSuppression = await instanceConfigRepository.getVoiceNoiseSuppressionConfig();
-					const validated = VoiceNoiseSuppressionConfigSchema.parse({
-						...currentNoiseSuppression,
-						...patch,
-						config_version: currentNoiseSuppression.config_version + 1,
-					});
-					await instanceConfigRepository.setVoiceNoiseSuppressionConfig(validated);
+					await instanceConfigRepository.updateVoiceNoiseSuppressionConfig((current) =>
+						VoiceNoiseSuppressionConfigSchema.parse({
+							...current,
+							...patch,
+							config_version: current.config_version + 1,
+						}),
+					);
 				}
 			}
-			if (data.screen_share_delivery) {
-				const patch = omitUndefinedFields(data.screen_share_delivery);
+			if (data.push_relay) {
+				const patch = omitUndefinedFields(data.push_relay);
 				if (Object.keys(patch).length > 0) {
-					const currentScreenShareDelivery = await instanceConfigRepository.getScreenShareDeliveryConfig();
-					const validated = ScreenShareDeliveryConfigSchema.parse({
-						...currentScreenShareDelivery,
+					const adminUserId = ctx.get('adminUserId').toString();
+					const landed = await instanceConfigRepository.updatePushRelayConfig((current) => ({
+						...current,
 						...patch,
-						config_version: currentScreenShareDelivery.config_version + 1,
-					});
-					await instanceConfigRepository.setScreenShareDeliveryConfig(validated);
+						...relayConsentStamp(current, patch, adminUserId),
+					}));
+					await getPushRelayConfigPublisher().publish(landed);
+				}
+			}
+			if (data.domain_migration) {
+				const patch = omitUndefinedFields(data.domain_migration);
+				if (Object.keys(patch).length > 0) {
+					await instanceConfigRepository.updateDomainMigrationConfig((current) =>
+						DomainMigrationConfigSchema.parse({
+							...current,
+							...patch,
+							config_version: current.config_version + 1,
+						}),
+					);
+				}
+			}
+			if (data.altcha_captcha) {
+				const patch = omitUndefinedFields(data.altcha_captcha);
+				if (Object.keys(patch).length > 0) {
+					await instanceConfigRepository.updateAltchaCaptchaConfig((current) =>
+						AltchaCaptchaConfigSchema.parse({
+							...current,
+							...patch,
+							config_version: current.config_version + 1,
+						}),
+					);
+				}
+			}
+			if (data.profile_timezone) {
+				const patch = omitUndefinedFields(data.profile_timezone);
+				if (Object.keys(patch).length > 0) {
+					await instanceConfigRepository.updateProfileTimezoneConfig((current) =>
+						ProfileTimezoneConfigSchema.parse({
+							...current,
+							...patch,
+							config_version: current.config_version + 1,
+						}),
+					);
 				}
 			}
 			if (data.experiment_delivery) {
-				const currentExperimentDelivery = await instanceConfigRepository.getExperimentDeliveryConfig();
-				const validated = ExperimentDeliveryConfigSchema.parse({
-					...currentExperimentDelivery,
-					...data.experiment_delivery,
-				});
-				await instanceConfigRepository.setExperimentDeliveryConfig(validated);
+				const patch = data.experiment_delivery;
+				await instanceConfigRepository.updateExperimentDeliveryConfig((current) =>
+					ExperimentDeliveryConfigSchema.parse({...current, ...patch}),
+				);
 			}
 			if (data.sso) {
 				const sso = data.sso;
@@ -308,21 +372,22 @@ export function InstanceConfigAdminController(app: HonoApp) {
 				const validated = await normalizeAndValidateSsoConfig(next, {
 					testModeEnabled: Config.dev.testModeEnabled,
 				});
+				const supplied = <T>(field: keyof typeof sso, value: T): T | undefined =>
+					readOptionalField(sso, field) === undefined ? undefined : value;
 				await instanceConfigRepository.setSsoConfig({
-					enabled: validated.enabled,
-					enforced: validated.enforced,
-					displayName: next.displayName,
-					issuer: validated.issuer,
-					authorizationUrl: validated.authorizationUrl,
-					tokenUrl: validated.tokenUrl,
-					userInfoUrl: validated.userInfoUrl,
-					jwksUrl: validated.jwksUrl,
-					clientId: validated.clientId,
+					enabled: supplied('enabled', validated.enabled),
+					enforced: supplied('enforced', validated.enforced),
+					displayName: supplied('display_name', next.displayName),
+					issuer: supplied('issuer', validated.issuer),
+					authorizationUrl: supplied('authorization_url', validated.authorizationUrl),
+					tokenUrl: supplied('token_url', validated.tokenUrl),
+					userInfoUrl: supplied('userinfo_url', validated.userInfoUrl),
+					jwksUrl: supplied('jwks_url', validated.jwksUrl),
+					clientId: supplied('client_id', validated.clientId),
 					clientSecret: readOptionalField(sso, 'client_secret'),
-					scope: next.scope,
-					allowedEmailDomains: validated.allowedEmailDomains,
-					autoProvision: next.autoProvision,
-					redirectUri: null,
+					scope: supplied('scope', next.scope),
+					allowedEmailDomains: supplied('allowed_domains', validated.allowedEmailDomains),
+					autoProvision: supplied('auto_provision', next.autoProvision),
 				});
 			}
 			if (data.registration) {
@@ -625,7 +690,6 @@ export function InstanceConfigAdminController(app: HonoApp) {
 		async (ctx) => {
 			const userId = ctx.req.valid('param').user_id.toString();
 			const decision = ctx.req.valid('json').status === 'approved' ? 'approve' : 'reject';
-			await instanceConfigRepository.getPendingRegistrations();
 			await updatePendingRegistrationUser(ctx, userId, decision);
 			await instanceConfigRepository.removePendingRegistration(userId);
 			return ctx.json(await buildInstanceConfigResponse());
@@ -638,27 +702,47 @@ async function applyInstancePolicyUpdate(
 	policy: NonNullable<InstanceConfigUpdateRequest['policy']>,
 ): Promise<void> {
 	const instanceConfigRepository = getInstanceConfigRepository();
-	const [current, appPublic] = await Promise.all([
-		instanceConfigRepository.getInstancePolicyConfig(),
-		instanceConfigRepository.getAppPublicConfig(),
-	]);
+	const appPublic = await instanceConfigRepository.getAppPublicConfig();
+	const adminUser =
+		policy.single_community_enabled === true
+			? await ctx.get('userRepository').findUnique(ctx.get('adminUserId'))
+			: null;
+	let enablesSingleCommunity = false;
+	await instanceConfigRepository.updateInstancePolicyConfig((current) => {
+		const planned = planInstancePolicyPatch(policy, current, {
+			setupConfigured: appPublic.setup.configured,
+			adminUserFound: adminUser !== null,
+		});
+		enablesSingleCommunity = planned.enablesSingleCommunity;
+		return planned.patch;
+	});
+	if (enablesSingleCommunity && adminUser) {
+		await ctx.get('singleCommunityService').ensureStockCommunity({
+			owner: adminUser,
+			name: policy.single_community_name?.trim() || appPublic.branding.product_name,
+		});
+	}
+	if (policy.premium_mode !== undefined) {
+		await ctx.get('limitConfigService').updatePolicyConfig({premium_mode: policy.premium_mode});
+	}
+}
+
+function planInstancePolicyPatch(
+	policy: NonNullable<InstanceConfigUpdateRequest['policy']>,
+	current: InstancePolicyConfig,
+	context: {setupConfigured: boolean; adminUserFound: boolean},
+): {patch: Partial<InstancePolicyConfig>; enablesSingleCommunity: boolean} {
 	const patch: Partial<InstancePolicyConfig> = {};
+	let enablesSingleCommunity = false;
 	if (
 		policy.single_community_enabled !== undefined &&
 		policy.single_community_enabled !== current.single_community_enabled
 	) {
 		if (policy.single_community_enabled) {
-			if (appPublic.setup.configured && current.single_community_guild_id == null) {
+			if ((context.setupConfigured && current.single_community_guild_id == null) || !context.adminUserFound) {
 				throw new InstancePolicyTransitionNotAllowedError();
 			}
-			const adminUser = await ctx.get('userRepository').findUnique(ctx.get('adminUserId'));
-			if (!adminUser) {
-				throw new InstancePolicyTransitionNotAllowedError();
-			}
-			await ctx.get('singleCommunityService').ensureStockCommunity({
-				owner: adminUser,
-				name: policy.single_community_name?.trim() || appPublic.branding.product_name,
-			});
+			enablesSingleCommunity = true;
 		} else {
 			patch.single_community_enabled = false;
 		}
@@ -679,9 +763,6 @@ async function applyInstancePolicyUpdate(
 			patch.direct_messages_locked = true;
 		}
 	}
-	if (policy.premium_mode !== undefined) {
-		patch.premium_mode = policy.premium_mode;
-	}
 	if (policy.services) {
 		if (policy.services.gif_enabled !== undefined) {
 			patch.gif_enabled = policy.services.gif_enabled ?? null;
@@ -704,11 +785,7 @@ async function applyInstancePolicyUpdate(
 			patch.deferred_phone_gate_member_threshold = policy.deferred_phone_gate.member_threshold;
 		}
 	}
-	if (patch.premium_mode !== undefined) {
-		await ctx.get('limitConfigService').updatePolicyConfig(patch);
-	} else if (Object.keys(patch).length > 0) {
-		await instanceConfigRepository.setInstancePolicyConfig(patch);
-	}
+	return {patch, enablesSingleCommunity};
 }

 async function updatePendingRegistrationUser(
@@ -11,6 +11,7 @@ import {Logger} from '@app/api/Logger';
 import {getGuildSearchService, getUserSearchService} from '@app/api/SearchFactory';
 import {FeatureTemporarilyDisabledError} from '@fluxer/errors/src/domains/core/FeatureTemporarilyDisabledError';
 import {InputValidationError} from '@fluxer/errors/src/domains/core/InputValidationError';
+import type {UserSearchFilters} from '@fluxer/schema/src/contracts/search/SearchDocumentTypes';
 import type {WorkerJobPayload} from '@pkgs/worker/src/contracts/WorkerTypes';

 interface RefreshSearchIndexJobPayload extends WorkerJobPayload {
@@ -130,16 +131,28 @@ export class AdminSearchService {
 			throw new FeatureTemporarilyDisabledError();
 		}
 		const query = data.query?.trim() || '';
+		const isBrowseAll = query === '' || query === '*';
+		const searchFilters: UserSearchFilters = isBrowseAll
+			? {sortBy: 'createdAt', sortOrder: 'asc'}
+			: {sortBy: 'relevance'};
 		const directUserId = /^\d+$/.test(query) ? createUserID(BigInt(query)) : null;
 		const canResolveDirectUser = directUserId !== null && !isSyntheticUserId(directUserId) && data.offset === 0;
 		const [searchResult, directUser] = await Promise.all([
-			userSearchService.search(query, {}, {limit: data.limit, offset: data.offset}),
+			userSearchService.search(query, searchFilters, {limit: data.limit, offset: data.offset}),
 			canResolveDirectUser ? userRepository.findUnique(directUserId).catch(() => null) : Promise.resolve(null),
 		]);
 		const {hits, total} = searchResult;
 		const userIds = hits.map((hit) => createUserID(BigInt(hit.id)));
 		const users = await userRepository.listUsers(userIds);
-		const response = await Promise.all(users.map((user) => mapUserToAdminResponse(user, cacheService, acls)));
+		const usersById = new Map(users.map((user) => [user.id.toString(), user]));
+		const orderedUsers = [];
+		for (const userId of userIds) {
+			const user = usersById.get(userId.toString());
+			if (user) {
+				orderedUsers.push(user);
+			}
+		}
+		const response = await Promise.all(orderedUsers.map((user) => mapUserToAdminResponse(user, cacheService, acls)));
 		if (directUser && data.offset === 0) {
 			const directId = directUser.id.toString();
 			if (!response.some((u) => u.id === directId)) {
@@ -8,12 +8,14 @@ import * as AuthEmail from '@app/api/auth/AuthEmail';
 import * as AuthMfa from '@app/api/auth/AuthMfa';
 import * as AuthSession from '@app/api/auth/AuthSession';
 import * as AuthUtility from '@app/api/auth/AuthUtility';
+import {visibleWebAuthnCredentials} from '@app/api/auth/services/PasskeyRelyingParty';
 import {createPasswordResetToken, createUserID, type UserID} from '@app/api/BrandedTypes';
 import type {UserRow} from '@app/api/database/types/UserTypes';
 import {Logger} from '@app/api/Logger';
 import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
 import type {IRiskHistoryRepository} from '@app/api/risk/HistoricalOutcomeRepository';
 import type {HistoricalOutcomeCode} from '@app/api/risk/RiskHistoryTypes';
+import {mapWebAuthnCredentialToResponse} from '@app/api/user/UserMappers';
 import {resolveAssignedTraits} from '@app/api/user/UserTraits';
 import {getIpAddressReverse, getLocationLabelFromIp} from '@app/api/utils/IpUtils';
 import {resolveSessionClientInfo} from '@app/api/utils/SessionClientIdentity';
@@ -545,7 +547,7 @@ export class AdminUserSecurityService {
 		if (!user) {
 			throw new UnknownUserError();
 		}
-		const credentials = await userRepository.listWebAuthnCredentials(userId);
+		const credentials = visibleWebAuthnCredentials(await userRepository.listWebAuthnCredentials(userId));
 		await auditService.createAuditLog({
 			adminUserId,
 			targetType: 'user',
@@ -554,12 +556,9 @@ export class AdminUserSecurityService {
 			auditLogReason,
 			metadata: new Map([['credential_count', credentials.length.toString()]]),
 		});
-		return credentials.map((cred) => ({
-			id: cred.credentialId,
-			name: cred.name,
-			created_at: cred.createdAt.toISOString(),
-			last_used_at: cred.lastUsedAt?.toISOString() ?? null,
-		}));
+		return credentials.map((cred) =>
+			mapWebAuthnCredentialToResponse(cred, this.deps.apiContext.services.config.auth.passkeys.rpId),
+		);
 	}

 	async deleteWebAuthnCredential(
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {AdminAuditLog} from '@app/api/admin/IAdminRepository';
+import type {TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {createTestAccount, setUserACLs} from '@app/api/auth/tests/AuthTestUtils';
+import {setCassandraQueryExecutorForTesting} from '@app/api/database/CassandraQueryExecution';
+import {PushRelayConfigPublisher} from '@app/api/instance/PushRelayConfigPublisher';
+import {InstanceConfigWriteRaceExecutor} from '@app/api/instance/tests/InstanceConfigWriteRaceExecutor';
+import {getAdminRepository} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {createApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {InMemoryCassandraQueryExecutor} from '@app/api/test/InMemoryCassandraQueryExecutor';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder} from '@app/api/test/TestRequestBuilder';
+import {AdminACLs} from '@fluxer/constants/src/AdminACLs';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import type {InstanceConfigResponse} from '@fluxer/schema/src/domains/admin/AdminSchemas';
+import {
+	type LegacyPushServiceDeliveryWire,
+	toLegacyPushServiceDeliveryWire,
+} from '@fluxer/schema/src/domains/admin/PushRelaySchemas';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi} from 'vitest';
+
+const PUSH_RELAY_CONFIG_KEY = 'push_service_delivery_config';
+
+describe('instance config admin PATCH under concurrent writes', () => {
+	let harness: ApiTestHarness;
+	let executor: InstanceConfigWriteRaceExecutor;
+
+	beforeAll(async () => {
+		harness = await createApiTestHarness();
+		executor = new InstanceConfigWriteRaceExecutor(new InMemoryCassandraQueryExecutor());
+		setCassandraQueryExecutorForTesting(executor);
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	afterAll(async () => {
+		await harness.shutdown();
+	});
+
+	const createAdmin = async (): Promise<TestAccount> =>
+		await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+
+	const patchConfig = (admin: TestAccount, body: Record<string, unknown>) =>
+		createBuilder<InstanceConfigResponse>(harness, admin.token).patch('/admin/instance/config').body(body);
+
+	const spyOnPushRelayPublishes = () =>
+		vi.spyOn(PushRelayConfigPublisher.prototype, 'publish').mockResolvedValue(undefined);
+
+	async function readStoredPushRelay(): Promise<LegacyPushServiceDeliveryWire> {
+		const raw = await executor.readDirectly(PUSH_RELAY_CONFIG_KEY);
+		if (raw === null) throw new Error('push relay config was never stored');
+		return JSON.parse(raw) as LegacyPushServiceDeliveryWire;
+	}
+
+	async function listConfigUpdateAudits(): Promise<Array<AdminAuditLog>> {
+		const logs = await getAdminRepository().listAllAuditLogsPaginated(100000);
+		return logs.filter((log) => log.action === 'update_instance_config');
+	}
+
+	it('merges a standalone forwarding patch into the stored domain migration config', async () => {
+		const admin = await createAdmin();
+		await patchConfig(admin, {domain_migration: {enabled: true, rollout_basis_points: 250}}).execute();
+
+		const updated = await patchConfig(admin, {domain_migration: {standalone_forwarding: true}}).execute();
+
+		expect(updated.domain_migration).toMatchObject({
+			enabled: true,
+			rollout_basis_points: 250,
+			standalone_forwarding: true,
+			config_version: 2,
+		});
+	});
+
+	it('answers with a conflict and neither writes, publishes nor audits once every attempt has lost the race', async () => {
+		const publish = spyOnPushRelayPublishes();
+		const admin = await createAdmin();
+		await patchConfig(admin, {push_relay: {relay_consent_accepted: false}}).execute();
+		publish.mockClear();
+		const auditsBefore = await listConfigUpdateAudits();
+		executor.watch(PUSH_RELAY_CONFIG_KEY);
+		const unaccepted = {
+			relay_consent_accepted: false,
+			relay_consent_accepted_at: null,
+			relay_consent_accepted_by: null,
+		};
+		let competingWrites = 0;
+		executor.competeBeforeEachWrite(async () => {
+			competingWrites++;
+			await executor.writeDirectly(
+				PUSH_RELAY_CONFIG_KEY,
+				JSON.stringify(toLegacyPushServiceDeliveryWire(unaccepted, 100 + competingWrites)),
+			);
+		});
+
+		await patchConfig(admin, {push_relay: {relay_consent_accepted: true}})
+			.expect(HTTP_STATUS.CONFLICT, APIErrorCodes.CONFLICT)
+			.execute();
+
+		expect(executor.events).not.toContain('write');
+		expect(await readStoredPushRelay()).toEqual(toLegacyPushServiceDeliveryWire(unaccepted, 100 + competingWrites));
+		expect(publish).not.toHaveBeenCalled();
+		expect(await listConfigUpdateAudits()).toHaveLength(auditsBefore.length);
+	});
+});
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {createTestAccount, setUserACLs} from '@app/api/auth/tests/AuthTestUtils';
+import {setCassandraQueryExecutorForTesting} from '@app/api/database/CassandraQueryExecution';
+import {InstanceConfigWriteRaceExecutor} from '@app/api/instance/tests/InstanceConfigWriteRaceExecutor';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {createApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {InMemoryCassandraQueryExecutor} from '@app/api/test/InMemoryCassandraQueryExecutor';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder} from '@app/api/test/TestRequestBuilder';
+import {AdminACLs} from '@fluxer/constants/src/AdminACLs';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import type {InstanceConfigResponse} from '@fluxer/schema/src/domains/admin/AdminSchemas';
+import {afterAll, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+const INSTANCE_POLICY_CONFIG_KEY = 'instance_policy_config';
+
+describe('instance config admin PATCH against state another node changed', () => {
+	let harness: ApiTestHarness;
+	let executor: InstanceConfigWriteRaceExecutor;
+
+	beforeAll(async () => {
+		harness = await createApiTestHarness();
+		executor = new InstanceConfigWriteRaceExecutor(new InMemoryCassandraQueryExecutor());
+		setCassandraQueryExecutorForTesting(executor);
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterAll(async () => {
+		await harness.shutdown();
+	});
+
+	const createAdmin = async (): Promise<TestAccount> =>
+		await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+
+	const patchConfig = (admin: TestAccount, body: Record<string, unknown>) =>
+		createBuilder<InstanceConfigResponse>(harness, admin.token).patch('/admin/instance/config').body(body);
+
+	it('keeps an SSO field another node changed when a patch changes a different one', async () => {
+		const admin = await createAdmin();
+		await patchConfig(admin, {sso: {display_name: 'Before', client_id: 'client-before'}}).execute();
+		await executor.writeDirectly('sso_display_name', 'Changed on another node');
+
+		await patchConfig(admin, {sso: {client_id: 'client-after'}}).execute();
+
+		expect(await executor.readDirectly('sso_display_name')).toBe('Changed on another node');
+		expect(await executor.readDirectly('sso_client_id')).toBe('client-after');
+	});
+
+	it('refuses to disable direct messages when their lock lands between the read and the write', async () => {
+		const admin = await createAdmin();
+		await patchConfig(admin, {policy: {services: {gif_enabled: true}}}).execute();
+		executor.watch(INSTANCE_POLICY_CONFIG_KEY);
+		let competed = false;
+		executor.competeBeforeEachWrite(async () => {
+			if (competed) return;
+			competed = true;
+			await executor.writeDirectly(
+				INSTANCE_POLICY_CONFIG_KEY,
+				JSON.stringify({direct_messages_disabled: false, direct_messages_locked: true, gif_enabled: true}),
+			);
+		});
+
+		await patchConfig(admin, {policy: {direct_messages_disabled: true}})
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.INSTANCE_POLICY_TRANSITION_NOT_ALLOWED)
+			.execute();
+
+		const stored = JSON.parse((await executor.readDirectly(INSTANCE_POLICY_CONFIG_KEY)) ?? 'null');
+		expect(stored).toMatchObject({direct_messages_disabled: false, direct_messages_locked: true, gif_enabled: true});
+	});
+
+	it('applies the DM rule and a premium mode change from one request', async () => {
+		const admin = await createAdmin();
+		await patchConfig(admin, {policy: {direct_messages_disabled: true}}).execute();
+
+		const updated = await patchConfig(admin, {
+			policy: {direct_messages_disabled: false, premium_mode: 'mirror'},
+		}).execute();
+
+		expect(updated.policy).toMatchObject({
+			direct_messages_disabled: false,
+			direct_messages_locked: true,
+			premium_mode: 'mirror',
+		});
+	});
+});
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {createTestAccount, setUserACLs} from '@app/api/auth/tests/AuthTestUtils';
+import {setCassandraQueryExecutorForTesting} from '@app/api/database/CassandraQueryExecution';
+import {PushRelayConfigPublisher} from '@app/api/instance/PushRelayConfigPublisher';
+import {InstanceConfigWriteRaceExecutor} from '@app/api/instance/tests/InstanceConfigWriteRaceExecutor';
+import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {createApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {InMemoryCassandraQueryExecutor} from '@app/api/test/InMemoryCassandraQueryExecutor';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder} from '@app/api/test/TestRequestBuilder';
+import {AdminACLs} from '@fluxer/constants/src/AdminACLs';
+import type {InstanceConfigResponse} from '@fluxer/schema/src/domains/admin/AdminSchemas';
+import type {LegacyPushServiceDeliveryWire} from '@fluxer/schema/src/domains/admin/PushRelaySchemas';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi} from 'vitest';
+
+const PUSH_RELAY_CONFIG_KEY = 'push_service_delivery_config';
+const ACCEPTED_AT = '2026-09-20T08:00:00.000Z';
+const ACCEPTED_BY = '1500000000000000007';
+
+const PROD_ROW = {
+	enabled: true,
+	config_version: 41,
+	rollout_basis_points: 10000,
+	rollout_salt: 'push-service-delivery-v1',
+	included_user_ids: [],
+	excluded_user_ids: [],
+	relay_consent_accepted: true,
+	relay_consent_accepted_at: ACCEPTED_AT,
+	relay_consent_accepted_by: ACCEPTED_BY,
+};
+
+interface PushServiceDeliveryRpcResponse {
+	type: 'get_push_service_delivery_config';
+	data: {config: LegacyPushServiceDeliveryWire};
+}
+
+describe('push relay supplemental notice consent', () => {
+	let harness: ApiTestHarness;
+	let executor: InstanceConfigWriteRaceExecutor;
+
+	beforeAll(async () => {
+		harness = await createApiTestHarness();
+		executor = new InstanceConfigWriteRaceExecutor(new InMemoryCassandraQueryExecutor());
+		setCassandraQueryExecutorForTesting(executor);
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+		vi.spyOn(PushRelayConfigPublisher.prototype, 'publish').mockResolvedValue(undefined);
+	});
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	afterAll(async () => {
+		await harness.shutdown();
+	});
+
+	const createAdmin = async (): Promise<TestAccount> =>
+		await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+
+	const patchConfig = (admin: TestAccount, body: Record<string, unknown>) =>
+		createBuilder<InstanceConfigResponse>(harness, admin.token).patch('/admin/instance/config').body(body);
+
+	const readConfig = (admin: TestAccount) =>
+		createBuilder<InstanceConfigResponse>(harness, admin.token).get('/admin/instance/config');
+
+	const readRpcConfig = async (): Promise<LegacyPushServiceDeliveryWire> => {
+		const response = await createBuilder<PushServiceDeliveryRpcResponse>(harness, '')
+			.post('/test/rpc-session-init')
+			.body({type: 'get_push_service_delivery_config'})
+			.expect(HTTP_STATUS.OK)
+			.execute();
+		expect(response.type).toBe('get_push_service_delivery_config');
+		return response.data.config;
+	};
+
+	async function storeRow(row: Record<string, unknown>): Promise<void> {
+		await executor.writeDirectly(PUSH_RELAY_CONFIG_KEY, JSON.stringify(row));
+		getInstanceConfigRepository().clearCacheForTesting();
+	}
+
+	async function readStoredRow(): Promise<unknown> {
+		const raw = await executor.readDirectly(PUSH_RELAY_CONFIG_KEY);
+		if (raw === null) throw new Error('push relay config was never stored');
+		return JSON.parse(raw);
+	}
+
+	it('reads back as unaccepted before an operator agrees', async () => {
+		const admin = await createAdmin();
+
+		const config = await readConfig(admin).execute();
+
+		expect(config.push_relay).toEqual({
+			relay_consent_accepted: false,
+			relay_consent_accepted_at: null,
+			relay_consent_accepted_by: null,
+		});
+	});
+
+	it('keeps the consent of a stored push service delivery row', async () => {
+		const admin = await createAdmin();
+		await storeRow(PROD_ROW);
+
+		const config = await readConfig(admin).execute();
+
+		expect(config.push_relay).toEqual({
+			relay_consent_accepted: true,
+			relay_consent_accepted_at: ACCEPTED_AT,
+			relay_consent_accepted_by: ACCEPTED_BY,
+		});
+	});
+
+	it('reads a stored row without consent fields as unaccepted', async () => {
+		const admin = await createAdmin();
+		await storeRow({enabled: true, config_version: 3, rollout_basis_points: 10000});
+
+		const config = await readConfig(admin).execute();
+
+		expect(config.push_relay.relay_consent_accepted).toBe(false);
+		expect(await readRpcConfig()).toMatchObject({config_version: 3, relay_consent_accepted: false});
+	});
+
+	it('stamps the acting admin and the acceptance time when consent is given', async () => {
+		const admin = await createAdmin();
+
+		const updated = await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		expect(updated.push_relay.relay_consent_accepted).toBe(true);
+		expect(updated.push_relay.relay_consent_accepted_by).toBe(admin.userId);
+		expect(Date.parse(updated.push_relay.relay_consent_accepted_at ?? '')).not.toBeNaN();
+	});
+
+	it('keeps the stamp untouched when consent is re-sent unchanged', async () => {
+		const admin = await createAdmin();
+		const accepted = await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		const resent = await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		expect(resent.push_relay).toEqual(accepted.push_relay);
+	});
+
+	it('clears the stamp when an operator withdraws consent', async () => {
+		const admin = await createAdmin();
+		await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		const withdrawn = await patchConfig(admin, {push_relay: {relay_consent_accepted: false}}).execute();
+
+		expect(withdrawn.push_relay).toEqual({
+			relay_consent_accepted: false,
+			relay_consent_accepted_at: null,
+			relay_consent_accepted_by: null,
+		});
+	});
+
+	it('ignores an acceptance stamp supplied by the caller', async () => {
+		const admin = await createAdmin();
+
+		const updated = await patchConfig(admin, {
+			push_relay: {
+				relay_consent_accepted: true,
+				relay_consent_accepted_at: '2020-01-01T00:00:00.000Z',
+				relay_consent_accepted_by: '1500000000000000009',
+			},
+		}).execute();
+
+		expect(updated.push_relay.relay_consent_accepted_at).not.toBe('2020-01-01T00:00:00.000Z');
+		expect(updated.push_relay.relay_consent_accepted_by).toBe(admin.userId);
+	});
+
+	it('writes the full legacy document and bumps the stored config version', async () => {
+		const admin = await createAdmin();
+		await storeRow({
+			...PROD_ROW,
+			relay_consent_accepted: false,
+			relay_consent_accepted_at: null,
+			relay_consent_accepted_by: null,
+		});
+
+		const updated = await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		expect(await readStoredRow()).toEqual({
+			enabled: true,
+			config_version: 42,
+			rollout_basis_points: 10000,
+			rollout_salt: 'push-service-delivery-v1',
+			included_user_ids: [],
+			excluded_user_ids: [],
+			relay_consent_accepted: true,
+			relay_consent_accepted_at: updated.push_relay.relay_consent_accepted_at,
+			relay_consent_accepted_by: admin.userId,
+		});
+
+		await patchConfig(admin, {push_relay: {relay_consent_accepted: false}}).execute();
+
+		expect(await readStoredRow()).toMatchObject({
+			enabled: true,
+			config_version: 43,
+			rollout_basis_points: 10000,
+			relay_consent_accepted: false,
+			relay_consent_accepted_at: null,
+			relay_consent_accepted_by: null,
+		});
+	});
+
+	it('rewrites a partially enrolled stored row as full enrolment', async () => {
+		const admin = await createAdmin();
+		await storeRow({
+			...PROD_ROW,
+			enabled: false,
+			rollout_basis_points: 250,
+			rollout_salt: 'custom-salt',
+			included_user_ids: ['1500000000000000003'],
+			excluded_user_ids: ['1500000000000000004'],
+		});
+
+		await patchConfig(admin, {push_relay: {relay_consent_accepted: false}}).execute();
+
+		expect(await readStoredRow()).toMatchObject({
+			enabled: true,
+			config_version: 42,
+			rollout_basis_points: 10000,
+			rollout_salt: 'push-service-delivery-v1',
+			included_user_ids: [],
+			excluded_user_ids: [],
+		});
+	});
+
+	it('publishes the legacy delivery document with the consent', async () => {
+		const admin = await createAdmin();
+		const publish = vi.mocked(PushRelayConfigPublisher.prototype.publish);
+
+		const updated = await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		expect(publish).toHaveBeenCalledTimes(1);
+		expect(publish).toHaveBeenCalledWith({
+			enabled: true,
+			config_version: 1,
+			rollout_basis_points: 10000,
+			rollout_salt: 'push-service-delivery-v1',
+			included_user_ids: [],
+			excluded_user_ids: [],
+			relay_consent_accepted: true,
+			relay_consent_accepted_at: updated.push_relay.relay_consent_accepted_at,
+			relay_consent_accepted_by: admin.userId,
+		});
+	});
+
+	it('does not write or publish for an empty push relay patch', async () => {
+		const admin = await createAdmin();
+		const publish = vi.mocked(PushRelayConfigPublisher.prototype.publish);
+
+		await patchConfig(admin, {push_relay: {}}).execute();
+
+		expect(publish).not.toHaveBeenCalled();
+		expect(await executor.readDirectly(PUSH_RELAY_CONFIG_KEY)).toBeNull();
+	});
+
+	it('ignores the retired push_service_delivery section', async () => {
+		const admin = await createAdmin();
+		const publish = vi.mocked(PushRelayConfigPublisher.prototype.publish);
+
+		const updated = await patchConfig(admin, {push_service_delivery: {relay_consent_accepted: true}}).execute();
+
+		expect(updated.push_relay.relay_consent_accepted).toBe(false);
+		expect(publish).not.toHaveBeenCalled();
+	});
+
+	it('answers the legacy delivery RPC with full enrolment and the stored consent', async () => {
+		await storeRow(PROD_ROW);
+
+		expect(await readRpcConfig()).toEqual(PROD_ROW);
+	});
+
+	it('answers the legacy delivery RPC with defaults before anything is stored', async () => {
+		expect(await readRpcConfig()).toEqual({
+			enabled: true,
+			config_version: 0,
+			rollout_basis_points: 10000,
+			rollout_salt: 'push-service-delivery-v1',
+			included_user_ids: [],
+			excluded_user_ids: [],
+			relay_consent_accepted: false,
+			relay_consent_accepted_at: null,
+			relay_consent_accepted_by: null,
+		});
+	});
+
+	it('answers the legacy delivery RPC with consent given through the admin API', async () => {
+		const admin = await createAdmin();
+		const updated = await patchConfig(admin, {push_relay: {relay_consent_accepted: true}}).execute();
+
+		expect(await readRpcConfig()).toMatchObject({
+			enabled: true,
+			config_version: 1,
+			rollout_basis_points: 10000,
+			relay_consent_accepted: true,
+			relay_consent_accepted_at: updated.push_relay.relay_consent_accepted_at,
+			relay_consent_accepted_by: admin.userId,
+		});
+	});
+});
@@ -3,6 +3,8 @@
 import {registerAdminControllers} from '@app/api/admin/controllers/index';
 import {AttachmentController} from '@app/api/attachment/AttachmentController';
 import {AuthController} from '@app/api/auth/AuthController';
+import {OriginHandoffController} from '@app/api/auth/OriginHandoffController';
+import {PasskeyBridgeController} from '@app/api/auth/PasskeyBridgeController';
 import {BlueskyOAuthController} from '@app/api/bluesky/BlueskyOAuthController';
 import {Config} from '@app/api/Config';
 import {ChannelController} from '@app/api/channel/ChannelController';
@@ -46,6 +48,8 @@ export function registerControllers(routes: HonoApp, config: APIConfig): void {
 	GeolocationController(routes);
 	registerAdminControllers(routes);
 	AuthController(routes);
+	OriginHandoffController(routes);
+	PasskeyBridgeController(routes);
 	AttachmentController(routes);
 	ChannelController(routes);
 	ConnectionController(routes);
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {configureMiddleware} from '@app/api/app/MiddlewarePipeline';
+import {Config} from '@app/api/Config';
+import {setInjectedWorkerService} from '@app/api/middleware/ServiceRegistry';
+import {NoopLogger} from '@app/api/test/mocks/NoopLogger';
+import {NoopWorkerService} from '@app/api/test/NoopWorkerService';
+import type {HonoEnv} from '@app/api/types/HonoEnv';
+import {AppErrorHandler, AppNotFoundHandler} from '@fluxer/errors/src/domains/core/ErrorHandlers';
+import {Hono} from 'hono';
+import {afterEach, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+const CLIENT_IP_HEADER_NAME = 'x-real-ip';
+
+function createProductionApp(): Hono<HonoEnv> {
+	const routes = new Hono<HonoEnv>({strict: true});
+	configureMiddleware(routes, {
+		logger: new NoopLogger(),
+		nodeEnv: 'production',
+		corsOrigins: ['https://web.fluxer.app'],
+		trustClientIpHeader: true,
+		clientIpHeaderName: CLIENT_IP_HEADER_NAME,
+		maxInflightRequests: 100,
+		torExitBlockingEnabled: false,
+	});
+	routes.onError(AppErrorHandler);
+	routes.notFound(AppNotFoundHandler);
+	routes.post('/internal/rpc', (ctx) => ctx.json({ok: true}));
+	routes.get('/connections/bluesky/jwks.json', (ctx) => ctx.json({keys: []}));
+	routes.get('/users/@me', (ctx) => ctx.json({ok: true}));
+	const app = new Hono<HonoEnv>({strict: true});
+	app.route('/v1', routes);
+	app.route('/', routes);
+	app.onError(AppErrorHandler);
+	app.notFound(AppNotFoundHandler);
+	return app;
+}
+
+describe('client ip requirements across the production middleware pipeline', () => {
+	let previousTestModeEnabled: boolean;
+	let previousTrustClientIpHeader: boolean;
+	let previousClientIpHeader: string;
+
+	beforeAll(() => {
+		setInjectedWorkerService(new NoopWorkerService());
+	});
+
+	beforeEach(() => {
+		previousTestModeEnabled = Config.dev.testModeEnabled;
+		previousTrustClientIpHeader = Config.proxy.trust_client_ip_header;
+		previousClientIpHeader = Config.proxy.client_ip_header;
+		Config.dev.testModeEnabled = false;
+		Config.proxy.trust_client_ip_header = true;
+		Config.proxy.client_ip_header = CLIENT_IP_HEADER_NAME;
+	});
+
+	afterEach(() => {
+		Config.dev.testModeEnabled = previousTestModeEnabled;
+		Config.proxy.trust_client_ip_header = previousTrustClientIpHeader;
+		Config.proxy.client_ip_header = previousClientIpHeader;
+	});
+
+	it('serves the internal rpc route without a client ip header', async () => {
+		const app = createProductionApp();
+		const response = await app.request('http://api:8080/internal/rpc', {
+			method: 'POST',
+			headers: {'content-type': 'application/json'},
+			body: '{}',
+		});
+		expect(response.status).toBe(200);
+	});
+
+	it('serves the internal rpc route with a client ip header', async () => {
+		const app = createProductionApp();
+		const response = await app.request('http://api:8080/internal/rpc', {
+			method: 'POST',
+			headers: {'content-type': 'application/json', [CLIENT_IP_HEADER_NAME]: '203.0.113.10'},
+			body: '{}',
+		});
+		expect(response.status).toBe(200);
+	});
+
+	it('serves an exempt public route without a client ip header', async () => {
+		const app = createProductionApp();
+		const response = await app.request('http://api:8080/connections/bluesky/jwks.json');
+		expect(response.status).toBe(200);
+	});
+
+	it('still rejects a non exempt route without a client ip header', async () => {
+		const app = createProductionApp();
+		const response = await app.request('http://api:8080/users/@me');
+		expect(response.status).toBe(403);
+		expect(await response.json()).toMatchObject({code: 'FORBIDDEN'});
+	});
+});
@@ -447,7 +447,7 @@ export function AuthController(app: HonoApp) {
 				'Retrieve WebAuthn authentication challenge and options for passwordless login with biometrics or security keys.',
 		}),
 		async (ctx) => {
-			return ctx.json(await ctx.get('authRequestService').getWebAuthnAuthenticationOptions());
+			return ctx.json(await ctx.get('authRequestService').getWebAuthnAuthenticationOptions(ctx.req.header('origin')));
 		},
 	);
 	app.post(
@@ -490,7 +490,9 @@ export function AuthController(app: HonoApp) {
 				'Retrieve WebAuthn challenge and options for multi-factor authentication. Requires the MFA ticket from initial login.',
 		}),
 		async (ctx) => {
-			return ctx.json(await ctx.get('authRequestService').getWebAuthnMfaOptions(ctx.req.valid('json')));
+			return ctx.json(
+				await ctx.get('authRequestService').getWebAuthnMfaOptions(ctx.req.valid('json'), ctx.req.header('origin')),
+			);
 		},
 	);
 	app.post(
@@ -602,6 +604,7 @@ export function AuthController(app: HonoApp) {
 				data: ctx.req.valid('json'),
 				clientIp,
 				authToken: ctx.get('authToken') ?? undefined,
+				approverOrigin: ctx.req.header('origin'),
 			});
 			return ctx.body(null, 204);
 		},
@@ -23,6 +23,7 @@ import type {InviteService} from '@app/api/invite/InviteService';
 import {Logger} from '@app/api/Logger';
 import {createRequestCache} from '@app/api/middleware/RequestCacheMiddleware';
 import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import type {AuthSession as AuthSessionModel} from '@app/api/models/AuthSession';
 import type {User} from '@app/api/models/User';
 import {lookupGeoip} from '@app/api/utils/IpUtils';
 import {createRateLimitError} from '@app/api/utils/RateLimitUtils';
@@ -353,7 +354,7 @@ export async function login(
 const MFA_TICKET_MAX_ATTEMPTS = 5;
 const MFA_USER_MAX_ATTEMPTS = 10;

-async function consumeMfaAttempt(
+export async function consumeMfaAttempt(
 	ctx: ApiContext,
 	{userId, ticket, field}: {userId: string; ticket: string; field: string},
 ): Promise<void> {
@@ -381,7 +382,7 @@ export async function loginMfaTotp(
 	ctx: ApiContext,
 	{code, ticket, request}: LoginMfaTotpParams,
 ): Promise<LoginTokenResult> {
-	const {users, cache, rateLimit} = ctx.services;
+	const {users, cache} = ctx.services;
 	const userId = await cache.get<string>(`mfa-ticket:${ticket}`);
 	if (!userId) {
 		throw InputValidationError.fromCode('ticket', ValidationErrorCodes.SESSION_TIMEOUT);
@@ -405,21 +406,36 @@ export async function loginMfaTotp(
 	if (!isValid) {
 		throw InputValidationError.fromCode('code', ValidationErrorCodes.INVALID_CODE);
 	}
+	const [token] = await completeMfaLogin(ctx, user, ticket, request);
+	return {user_id: user.id.toString(), token};
+}
+
+export async function createLoginSession(
+	ctx: ApiContext,
+	user: User,
+	request: Request,
+): Promise<[token: string, AuthSessionModel]> {
+	return AuthSession.createAuthSession(ctx, {user, origin: AuthSession.resolveSessionOrigin(ctx, request)});
+}
+
+export async function completeMfaLogin(
+	ctx: ApiContext,
+	user: User,
+	ticket: string,
+	request: Request,
+): Promise<[token: string, AuthSessionModel]> {
+	const {cache, rateLimit} = ctx.services;
 	await cache.delete(`mfa-ticket:${ticket}`);
 	await rateLimit.resetLimit(`mfa:ticket:${ticket}`);
 	await rateLimit.resetLimit(`mfa:user:${user.id}`);
-	const [token] = await AuthSession.createAuthSession(ctx, {
-		user,
-		origin: AuthSession.resolveSessionOrigin(ctx, request),
-	});
-	return {user_id: user.id.toString(), token};
+	return createLoginSession(ctx, user, request);
 }

 export async function loginMfaWebAuthn(
 	ctx: ApiContext,
 	{response, challenge, ticket, request}: LoginMfaWebAuthnParams,
 ): Promise<LoginTokenResult> {
-	const {users, cache, rateLimit} = ctx.services;
+	const {users, cache} = ctx.services;
 	const userId = await cache.get<string>(`mfa-ticket:${ticket}`);
 	if (!userId) {
 		throw InputValidationError.fromCode('ticket', ValidationErrorCodes.SESSION_TIMEOUT);
@@ -434,13 +450,7 @@ export async function loginMfaWebAuthn(
 	}
 	await consumeMfaAttempt(ctx, {userId: user.id.toString(), ticket, field: 'ticket'});
 	await AuthMfa.verifyWebAuthnAuthentication(ctx, user.id, response, challenge, 'mfa', ticket);
-	await cache.delete(`mfa-ticket:${ticket}`);
-	await rateLimit.resetLimit(`mfa:ticket:${ticket}`);
-	await rateLimit.resetLimit(`mfa:user:${user.id}`);
-	const [token] = await AuthSession.createAuthSession(ctx, {
-		user,
-		origin: AuthSession.resolveSessionOrigin(ctx, request),
-	});
+	const [token] = await completeMfaLogin(ctx, user, ticket, request);
 	return {user_id: user.id.toString(), token};
 }

@@ -3,13 +3,20 @@
 import {timingSafeEqual} from 'node:crypto';
 import type {ApiContext} from '@app/api/ApiContext';
 import * as AuthUtility from '@app/api/auth/AuthUtility';
+import {
+	type CredentialRpSelection,
+	effectiveRpId,
+	originRpId,
+	selectCredentialRp,
+	visibleWebAuthnCredentials,
+} from '@app/api/auth/services/PasskeyRelyingParty';
 import {deriveSudoMethods, userHasMfa, userHasSudoCapability} from '@app/api/auth/services/SudoMethods';
 import {createUserID, type UserID} from '@app/api/BrandedTypes';
 import {Logger} from '@app/api/Logger';
 import type {MfaBackupCode} from '@app/api/models/MfaBackupCode';
 import type {User} from '@app/api/models/User';
 import type {WebAuthnCredential} from '@app/api/models/WebAuthnCredential';
-import {mapUserToPrivateResponse} from '@app/api/user/UserMappers';
+import {mapUserToPrivateResponse, mapWebAuthnCredentialToResponse} from '@app/api/user/UserMappers';
 import {TotpGenerator} from '@app/api/utils/TotpGenerator';
 import {UserAuthenticatorTypes} from '@fluxer/constants/src/UserConstants';
 import {ValidationErrorCodes} from '@fluxer/constants/src/ValidationErrorCodes';
@@ -22,7 +29,12 @@ import {PasskeyAuthenticationFailedError} from '@fluxer/errors/src/domains/auth/
 import {UnknownWebAuthnCredentialError} from '@fluxer/errors/src/domains/auth/UnknownWebAuthnCredentialError';
 import {WebAuthnCredentialLimitReachedError} from '@fluxer/errors/src/domains/auth/WebAuthnCredentialLimitReachedError';
 import {InputValidationError} from '@fluxer/errors/src/domains/core/InputValidationError';
-import type {AuthenticationResponseJSON, RegistrationResponseJSON} from '@simplewebauthn/server';
+import type {
+	AuthenticationResponseJSON,
+	PublicKeyCredentialCreationOptionsJSON,
+	PublicKeyCredentialRequestOptionsJSON,
+	RegistrationResponseJSON,
+} from '@simplewebauthn/server';
 import {
 	generateAuthenticationOptions,
 	generateRegistrationOptions,
@@ -33,7 +45,41 @@ import {
 } from '@simplewebauthn/server';
 import {ms, seconds} from 'itty-time';

-type WebAuthnChallengeContext = 'registration' | 'discoverable' | 'mfa' | 'sudo';
+type WebAuthnChallengeContext = 'registration' | 'discoverable' | 'mfa' | 'sudo' | 'bridge' | 'migration_registration';
+
+interface WebAuthnChallengeEntry {
+	context: WebAuthnChallengeContext;
+	userId?: string;
+	ticket?: string;
+	rpId?: string;
+	credentialIds?: Array<string> | null;
+}
+
+interface WebAuthnChallengeScope {
+	rpId: string;
+	credentialIds: Array<string> | null;
+}
+
+interface WebAuthnAuthenticationOptionsParams {
+	selection: CredentialRpSelection | {rpId: string; credentials: null};
+	context: WebAuthnChallengeContext;
+	userId?: UserID;
+	ticket?: string;
+}
+
+interface WebAuthnRegistrationOptionsParams {
+	rpId: string;
+	context: WebAuthnChallengeContext;
+	excludeCredentials: Array<WebAuthnCredential>;
+}
+
+interface VerifiedWebAuthnRegistration {
+	credentialId: string;
+	publicKey: Buffer;
+	counter: bigint;
+	transports: Set<string> | null;
+	rpId: string;
+}

 interface SudoMfaVerificationParams {
 	userId: UserID;
@@ -122,37 +168,117 @@ export async function verifyMfaCode(ctx: ApiContext, params: VerifyMfaCodeParams
 	return false;
 }

-export async function generateWebAuthnRegistrationOptions(ctx: ApiContext, userId: UserID) {
+function toCredentialDescriptor(credential: WebAuthnCredential) {
+	return {
+		id: credential.credentialId,
+		transports: credential.transports
+			? (Array.from(credential.transports) as Array<'usb' | 'nfc' | 'ble' | 'internal' | 'cable' | 'hybrid'>)
+			: undefined,
+	};
+}
+
+export function storedRpId(ctx: ApiContext, rpId: string): string | null {
+	return rpId === ctx.services.config.auth.passkeys.rpId ? null : rpId;
+}
+
+export async function createWebAuthnRegistrationOptions(
+	ctx: ApiContext,
+	userId: UserID,
+	{rpId, context, excludeCredentials}: WebAuthnRegistrationOptionsParams,
+): Promise<PublicKeyCredentialCreationOptionsJSON> {
 	const {users, config} = ctx.services;
 	const user = await users.findUniqueAssert(userId);
-	const existingCredentials = await users.listWebAuthnCredentials(userId);
-	if (existingCredentials.length >= 10) {
-		throw new WebAuthnCredentialLimitReachedError();
-	}
 	const options = await generateRegistrationOptions({
 		rpName: config.auth.passkeys.rpName,
-		rpID: config.auth.passkeys.rpId,
+		rpID: rpId,
 		userID: new TextEncoder().encode(user.id.toString()),
 		userName: user.username!,
 		userDisplayName: user.username!,
 		attestationType: 'none',
 		supportedAlgorithmIDs: [-8, -7, -257],
-		excludeCredentials: existingCredentials.map((cred) => ({
-			id: cred.credentialId,
-			transports: cred.transports
-				? (Array.from(cred.transports) as Array<'usb' | 'nfc' | 'ble' | 'internal' | 'cable' | 'hybrid'>)
-				: undefined,
-		})),
+		excludeCredentials: excludeCredentials.map(toCredentialDescriptor),
 		authenticatorSelection: {
 			residentKey: 'preferred',
 			requireResidentKey: false,
 			userVerification: 'preferred',
 		},
 	});
-	await saveWebAuthnChallenge(ctx, options.challenge, {context: 'registration', userId});
+	await saveWebAuthnChallenge(ctx, options.challenge, {context, userId, rpId, credentialIds: null});
 	return options;
 }

+export async function generateWebAuthnRegistrationOptions(
+	ctx: ApiContext,
+	userId: UserID,
+	origin: string | null | undefined,
+): Promise<PublicKeyCredentialCreationOptionsJSON> {
+	const existingCredentials = await ctx.services.users.listWebAuthnCredentials(userId);
+	if (visibleWebAuthnCredentials(existingCredentials).length >= 10) {
+		throw new WebAuthnCredentialLimitReachedError();
+	}
+	return createWebAuthnRegistrationOptions(ctx, userId, {
+		rpId: originRpId(ctx, origin),
+		context: 'registration',
+		excludeCredentials: existingCredentials,
+	});
+}
+
+export async function verifyWebAuthnRegistrationResponse(
+	ctx: ApiContext,
+	userId: UserID,
+	response: RegistrationResponseJSON,
+	expectedChallenge: string,
+	context: WebAuthnChallengeContext,
+	expectedOrigin: Array<string> = ctx.services.config.auth.passkeys.allowedOrigins,
+): Promise<VerifiedWebAuthnRegistration> {
+	const {config} = ctx.services;
+	const {rpId} = await consumeWebAuthnChallenge(ctx, expectedChallenge, context, {userId});
+	const responseObj = response as {id?: string; response?: {transports?: Array<string>}};
+	const transports = responseObj.response?.transports ? new Set(responseObj.response.transports) : null;
+	if (config.dev.testModeEnabled) {
+		const credentialId = responseObj.id ?? `test-credential:${userId.toString()}:${Date.now()}`;
+		return {credentialId, publicKey: Buffer.from(`test-public-key:${credentialId}`), counter: 0n, transports, rpId};
+	}
+	let verification: VerifiedRegistrationResponse;
+	try {
+		verification = await verifyRegistrationResponse({
+			response,
+			expectedChallenge,
+			expectedOrigin,
+			expectedRPID: rpId,
+			requireUserVerification: false,
+			supportedAlgorithmIDs: [-8, -7, -257],
+		});
+	} catch (error) {
+		Logger.error({error, userId, expectedChallenge, rpId, expectedOrigin}, 'WebAuthn verification failed');
+		throw new InvalidWebAuthnCredentialError();
+	}
+	if (!verification.verified || !verification.registrationInfo) {
+		Logger.error(
+			{userId, verified: verification.verified, hasRegistrationInfo: !!verification.registrationInfo},
+			'WebAuthn verification result invalid',
+		);
+		throw new InvalidWebAuthnCredentialError();
+	}
+	const {credential} = verification.registrationInfo;
+	let publicKeyBuffer: Buffer;
+	let counterBigInt: bigint;
+	try {
+		publicKeyBuffer = Buffer.from(credential.publicKey);
+	} catch (_error) {
+		throw new InvalidWebAuthnPublicKeyFormatError();
+	}
+	try {
+		if (credential.counter === undefined || credential.counter === null) {
+			throw new Error('Counter value is undefined or null');
+		}
+		counterBigInt = BigInt(credential.counter);
+	} catch (_error) {
+		throw new InvalidWebAuthnCredentialCounterError();
+	}
+	return {credentialId: credential.id, publicKey: publicKeyBuffer, counter: counterBigInt, transports, rpId};
+}
+
 export async function verifyWebAuthnRegistration(
 	ctx: ApiContext,
 	userId: UserID,
@@ -160,85 +286,39 @@ export async function verifyWebAuthnRegistration(
 	expectedChallenge: string,
 	name: string,
 ): Promise<void> {
-	const {users, config} = ctx.services;
+	const {users} = ctx.services;
 	const existingCredentials = await users.listWebAuthnCredentials(userId);
-	await consumeWebAuthnChallenge(ctx, expectedChallenge, 'registration', {userId});
-	if (existingCredentials.length >= 10) {
+	if (visibleWebAuthnCredentials(existingCredentials).length >= 10) {
 		throw new WebAuthnCredentialLimitReachedError();
 	}
-	if (config.dev.testModeEnabled) {
-		const responseObj = response as {id?: string; response?: {transports?: Array<string>}};
-		const credentialId = responseObj.id ?? `test-credential:${userId.toString()}:${Date.now()}`;
-		const publicKeyBuffer = Buffer.from(`test-public-key:${credentialId}`);
-		await users.createWebAuthnCredential(
-			userId,
-			credentialId,
-			publicKeyBuffer,
-			0n,
-			responseObj.response?.transports ? new Set(responseObj.response.transports) : null,
-			name,
-		);
-	} else {
-		const expectedOrigin = config.auth.passkeys.allowedOrigins;
-		const rpID = config.auth.passkeys.rpId;
-		let verification: VerifiedRegistrationResponse;
-		try {
-			verification = await verifyRegistrationResponse({
-				response,
-				expectedChallenge,
-				expectedOrigin,
-				expectedRPID: rpID,
-				requireUserVerification: false,
-				supportedAlgorithmIDs: [-8, -7, -257],
-			});
-		} catch (error) {
-			Logger.error({error, userId, expectedChallenge, rpID, expectedOrigin}, 'WebAuthn verification failed');
-			throw new InvalidWebAuthnCredentialError();
-		}
-		if (!verification.verified || !verification.registrationInfo) {
-			Logger.error(
-				{userId, verified: verification.verified, hasRegistrationInfo: !!verification.registrationInfo},
-				'WebAuthn verification result invalid',
-			);
-			throw new InvalidWebAuthnCredentialError();
-		}
-		const {credential} = verification.registrationInfo;
-		let publicKeyBuffer: Buffer;
-		let counterBigInt: bigint;
-		try {
-			publicKeyBuffer = Buffer.from(credential.publicKey);
-		} catch (_error) {
-			throw new InvalidWebAuthnPublicKeyFormatError();
-		}
-		try {
-			if (credential.counter === undefined || credential.counter === null) {
-				throw new Error('Counter value is undefined or null');
-			}
-			counterBigInt = BigInt(credential.counter);
-		} catch (_error) {
-			throw new InvalidWebAuthnCredentialCounterError();
-		}
-		const responseObj = response as {response?: {transports?: Array<string>}};
-		await users.createWebAuthnCredential(
-			userId,
-			credential.id,
-			publicKeyBuffer,
-			counterBigInt,
-			responseObj.response?.transports ? new Set(responseObj.response.transports) : null,
-			name,
-		);
-	}
+	const verified = await verifyWebAuthnRegistrationResponse(ctx, userId, response, expectedChallenge, 'registration');
+	await users.createWebAuthnCredential(
+		userId,
+		verified.credentialId,
+		verified.publicKey,
+		verified.counter,
+		verified.transports,
+		name,
+		storedRpId(ctx, verified.rpId),
+	);
 	await dispatchWebAuthnCredentialsUpdate(ctx, userId);
 }

 export async function deleteWebAuthnCredential(ctx: ApiContext, userId: UserID, credentialId: string): Promise<void> {
 	const {users, gateway, botMfaMirror} = ctx.services;
 	const credential = await users.getWebAuthnCredential(userId, credentialId);
-	if (!credential) {
+	if (!credential || credential.supersededBy !== null) {
 		throw new UnknownWebAuthnCredentialError();
 	}
 	await users.deleteWebAuthnCredential(userId, credentialId);
-	const remainingCredentials = await users.listWebAuthnCredentials(userId);
+	const remaining = await users.listWebAuthnCredentials(userId);
+	const remainingCredentials = visibleWebAuthnCredentials(remaining);
+	const orphanedTwins = remaining.filter(
+		(cred) => cred.supersededBy === credentialId || (cred.supersededBy !== null && remainingCredentials.length === 0),
+	);
+	for (const twin of orphanedTwins) {
+		await users.deleteWebAuthnCredential(userId, twin.credentialId);
+	}
 	if (remainingCredentials.length === 0) {
 		const user = await users.findUniqueAssert(userId);
 		if (user.authenticatorTypes.has(UserAuthenticatorTypes.WEBAUTHN)) {
@@ -298,37 +378,66 @@ export async function renameWebAuthnCredential(
 ): Promise<void> {
 	const {users} = ctx.services;
 	const credential = await users.getWebAuthnCredential(userId, credentialId);
-	if (!credential) {
+	if (!credential || credential.supersededBy !== null) {
 		throw new UnknownWebAuthnCredentialError();
 	}
 	await users.updateWebAuthnCredentialName(userId, credentialId, name);
 	await dispatchWebAuthnCredentialsUpdate(ctx, userId);
 }

-async function dispatchWebAuthnCredentialsUpdate(ctx: ApiContext, userId: UserID): Promise<void> {
-	const {users, gateway} = ctx.services;
+export async function dispatchWebAuthnCredentialsUpdate(ctx: ApiContext, userId: UserID): Promise<void> {
+	const {users, gateway, config} = ctx.services;
 	const credentials = await users.listWebAuthnCredentials(userId);
 	await gateway.dispatchPresence({
 		userId,
 		event: 'WEBAUTHN_CREDENTIALS_UPDATE',
-		data: credentials.map((cred: WebAuthnCredential) => ({
-			id: cred.credentialId,
-			name: cred.name,
-			created_at: cred.createdAt.toISOString(),
-			last_used_at: cred.lastUsedAt?.toISOString() ?? null,
-		})),
+		data: visibleWebAuthnCredentials(credentials).map((cred) =>
+			mapWebAuthnCredentialToResponse(cred, config.auth.passkeys.rpId),
+		),
 	});
 }

-export async function generateWebAuthnAuthenticationOptionsDiscoverable(ctx: ApiContext) {
+export async function generateWebAuthnAuthenticationOptions(
+	ctx: ApiContext,
+	{selection, context, userId, ticket}: WebAuthnAuthenticationOptionsParams,
+): Promise<PublicKeyCredentialRequestOptionsJSON> {
 	const options = await generateAuthenticationOptions({
-		rpID: ctx.services.config.auth.passkeys.rpId,
-		userVerification: 'required',
+		rpID: selection.rpId,
+		allowCredentials: selection.credentials?.map(toCredentialDescriptor),
+		userVerification: selection.credentials === null ? 'required' : 'discouraged',
+	});
+	await saveWebAuthnChallenge(ctx, options.challenge, {
+		context,
+		userId,
+		ticket,
+		rpId: selection.rpId,
+		credentialIds: selection.credentials?.map((cred) => cred.credentialId) ?? null,
 	});
-	await saveWebAuthnChallenge(ctx, options.challenge, {context: 'discoverable'});
 	return options;
 }

+function selectCredentialRpOrThrow(
+	ctx: ApiContext,
+	origin: string | null | undefined,
+	credentials: Array<WebAuthnCredential>,
+): CredentialRpSelection {
+	const selection = selectCredentialRp(ctx, origin, credentials);
+	if (selection.credentials.length === 0) {
+		throw new NoPasskeysRegisteredError();
+	}
+	return selection;
+}
+
+export async function generateWebAuthnAuthenticationOptionsDiscoverable(
+	ctx: ApiContext,
+	origin: string | null | undefined,
+): Promise<PublicKeyCredentialRequestOptionsJSON> {
+	return generateWebAuthnAuthenticationOptions(ctx, {
+		selection: {rpId: originRpId(ctx, origin), credentials: null},
+		context: 'discoverable',
+	});
+}
+
 export async function verifyWebAuthnAuthenticationDiscoverable(
 	ctx: ApiContext,
 	response: AuthenticationResponseJSON,
@@ -344,29 +453,24 @@ export async function verifyWebAuthnAuthenticationDiscoverable(
 	return users.findUniqueAssert(userId);
 }

-export async function generateWebAuthnAuthenticationOptionsForMfa(ctx: ApiContext, ticket: string) {
-	const {users, cache, config} = ctx.services;
+export async function generateWebAuthnAuthenticationOptionsForMfa(
+	ctx: ApiContext,
+	ticket: string,
+	origin: string | null | undefined,
+): Promise<PublicKeyCredentialRequestOptionsJSON> {
+	const {users, cache} = ctx.services;
 	const userIdStr = await cache.get<string>(`mfa-ticket:${ticket}`);
 	if (!userIdStr) {
 		throw InputValidationError.fromCode('ticket', ValidationErrorCodes.SESSION_TIMEOUT);
 	}
 	const userId = createUserID(BigInt(userIdStr));
 	const credentials = await users.listWebAuthnCredentials(userId);
-	if (credentials.length === 0) {
-		throw new NoPasskeysRegisteredError();
-	}
-	const options = await generateAuthenticationOptions({
-		rpID: config.auth.passkeys.rpId,
-		allowCredentials: credentials.map((cred) => ({
-			id: cred.credentialId,
-			transports: cred.transports
-				? (Array.from(cred.transports) as Array<'usb' | 'nfc' | 'ble' | 'internal' | 'cable' | 'hybrid'>)
-				: undefined,
-		})),
-		userVerification: 'discouraged',
+	return generateWebAuthnAuthenticationOptions(ctx, {
+		selection: selectCredentialRpOrThrow(ctx, origin, credentials),
+		context: 'mfa',
+		userId,
+		ticket,
 	});
-	await saveWebAuthnChallenge(ctx, options.challenge, {context: 'mfa', userId, ticket});
-	return options;
 }

 export async function verifyWebAuthnAuthentication(
@@ -376,21 +480,26 @@ export async function verifyWebAuthnAuthentication(
 	expectedChallenge: string,
 	context: WebAuthnChallengeContext = 'mfa',
 	ticket?: string,
-): Promise<void> {
+	expectedOrigin: Array<string> = ctx.services.config.auth.passkeys.allowedOrigins,
+): Promise<WebAuthnCredential> {
 	const {users, config} = ctx.services;
-	await consumeWebAuthnChallenge(ctx, expectedChallenge, context, {userId, ticket});
+	const scope = await consumeWebAuthnChallenge(ctx, expectedChallenge, context, {userId, ticket});
 	const credentialId = (response as {id: string}).id;
 	const credential = await users.getWebAuthnCredential(userId, credentialId);
 	if (!credential) {
 		throw new PasskeyAuthenticationFailedError();
 	}
+	if (
+		effectiveRpId(ctx, credential) !== scope.rpId ||
+		(scope.credentialIds !== null && !scope.credentialIds.includes(credentialId))
+	) {
+		throw new PasskeyAuthenticationFailedError();
+	}
 	if (config.dev.testModeEnabled) {
 		await users.updateWebAuthnCredentialCounter(userId, credentialId, credential.counter + 1n);
 		await users.updateWebAuthnCredentialLastUsed(userId, credentialId);
-		return;
+		return credential;
 	}
-	const expectedOrigin = config.auth.passkeys.allowedOrigins;
-	const rpID = config.auth.passkeys.rpId;
 	let verification: VerifiedAuthenticationResponse;
 	try {
 		let publicKeyUint8Array: Uint8Array<ArrayBuffer>;
@@ -405,15 +514,12 @@ export async function verifyWebAuthnAuthentication(
 			response,
 			expectedChallenge,
 			expectedOrigin,
-			expectedRPID: rpID,
-			requireUserVerification: requiresWebAuthnUserVerification(context),
+			expectedRPID: scope.rpId,
+			requireUserVerification: requiresWebAuthnUserVerification(context, scope),
 			credential: {
-				id: credential.credentialId,
+				...toCredentialDescriptor(credential),
 				publicKey: publicKeyUint8Array,
 				counter: Number(credential.counter),
-				transports: credential.transports
-					? (Array.from(credential.transports) as Array<'usb' | 'nfc' | 'ble' | 'internal' | 'cable' | 'hybrid'>)
-					: undefined,
 			},
 		});
 	} catch (_error) {
@@ -434,31 +540,25 @@ export async function verifyWebAuthnAuthentication(
 	}
 	await users.updateWebAuthnCredentialCounter(userId, credentialId, newCounter);
 	await users.updateWebAuthnCredentialLastUsed(userId, credentialId);
+	return credential;
 }

-export async function generateWebAuthnOptionsForSudo(ctx: ApiContext, userId: UserID) {
-	const {users, config} = ctx.services;
-	const credentials = await users.listWebAuthnCredentials(userId);
-	if (credentials.length === 0) {
-		throw new NoPasskeysRegisteredError();
-	}
-	const options = await generateAuthenticationOptions({
-		rpID: config.auth.passkeys.rpId,
-		allowCredentials: credentials.map((cred) => ({
-			id: cred.credentialId,
-			transports: cred.transports
-				? (Array.from(cred.transports) as Array<'usb' | 'nfc' | 'ble' | 'internal' | 'cable' | 'hybrid'>)
-				: undefined,
-		})),
-		userVerification: 'discouraged',
+export async function generateWebAuthnOptionsForSudo(
+	ctx: ApiContext,
+	userId: UserID,
+	origin: string | null | undefined,
+): Promise<PublicKeyCredentialRequestOptionsJSON> {
+	const credentials = await ctx.services.users.listWebAuthnCredentials(userId);
+	return generateWebAuthnAuthenticationOptions(ctx, {
+		selection: selectCredentialRpOrThrow(ctx, origin, credentials),
+		context: 'sudo',
+		userId,
 	});
-	await saveWebAuthnChallenge(ctx, options.challenge, {context: 'sudo', userId});
-	return options;
 }

 const SUDO_MFA_USER_MAX_ATTEMPTS = 10;

-async function consumeSudoMfaAttempt(ctx: ApiContext, userId: UserID): Promise<void> {
+export async function consumeSudoMfaAttempt(ctx: ApiContext, userId: UserID): Promise<void> {
 	const {rateLimit} = ctx.services;
 	const userLimit = await rateLimit.checkLimit({
 		identifier: `sudo-mfa:user:${userId}`,
@@ -535,20 +635,33 @@ function webAuthnChallengeCacheKey(challenge: string): string {
 	return `webauthn:challenge:${challenge}`;
 }

-function requiresWebAuthnUserVerification(context: WebAuthnChallengeContext): boolean {
-	return context === 'discoverable';
+function requiresWebAuthnUserVerification(context: WebAuthnChallengeContext, scope: WebAuthnChallengeScope): boolean {
+	return context === 'discoverable' || (context === 'bridge' && scope.credentialIds === null);
 }

 async function saveWebAuthnChallenge(
 	ctx: ApiContext,
 	challenge: string,
-	entry: {context: WebAuthnChallengeContext; userId?: UserID; ticket?: string},
+	entry: {
+		context: WebAuthnChallengeContext;
+		userId?: UserID;
+		ticket?: string;
+		rpId: string;
+		credentialIds: Array<string> | null;
+	},
 ): Promise<void> {
-	await ctx.services.cache.set(
-		webAuthnChallengeCacheKey(challenge),
-		{context: entry.context, userId: entry.userId?.toString(), ticket: entry.ticket},
-		seconds('5 minutes'),
-	);
+	const value: WebAuthnChallengeEntry = {
+		context: entry.context,
+		userId: entry.userId?.toString(),
+		ticket: entry.ticket,
+		rpId: entry.rpId,
+		credentialIds: entry.credentialIds,
+	};
+	await ctx.services.cache.set(webAuthnChallengeCacheKey(challenge), value, seconds('5 minutes'));
+}
+
+export async function deleteWebAuthnChallenge(ctx: ApiContext, challenge: string): Promise<void> {
+	await ctx.services.cache.delete(webAuthnChallengeCacheKey(challenge));
 }

 async function consumeWebAuthnChallenge(
@@ -556,10 +669,8 @@ async function consumeWebAuthnChallenge(
 	challenge: string,
 	expectedContext: WebAuthnChallengeContext,
 	{userId, ticket}: {userId?: UserID; ticket?: string} = {},
-): Promise<void> {
-	const {cache} = ctx.services;
-	const key = webAuthnChallengeCacheKey(challenge);
-	const cached = await cache.get<{context: WebAuthnChallengeContext; userId?: string; ticket?: string}>(key);
+): Promise<WebAuthnChallengeScope> {
+	const cached = await ctx.services.cache.getAndDelete<WebAuthnChallengeEntry>(webAuthnChallengeCacheKey(challenge));
 	const challengeMatches =
 		cached &&
 		cached.context === expectedContext &&
@@ -581,11 +692,14 @@ async function consumeWebAuthnChallenge(
 		);
 		throw createChallengeError(expectedContext);
 	}
-	await cache.delete(key);
+	return {
+		rpId: cached.rpId ?? ctx.services.config.auth.passkeys.rpId,
+		credentialIds: cached.credentialIds ?? null,
+	};
 }

 function createChallengeError(context: WebAuthnChallengeContext) {
-	if (context === 'registration') {
+	if (context === 'registration' || context === 'migration_registration') {
 		return new InvalidWebAuthnCredentialError();
 	}
 	return new PasskeyAuthenticationFailedError();
@@ -7,12 +7,14 @@ import * as AuthUtility from '@app/api/auth/AuthUtility';
 import type {IRegistrationRiskEvaluator} from '@app/api/auth/services/IRegistrationRiskEvaluator';
 import {createEmailVerificationToken, createInviteCode, createUserID, type UserID} from '@app/api/BrandedTypes';
 import type {APIConfig} from '@app/api/config/APIConfig';
+import type {UserRow} from '@app/api/database/types/UserTypes';
 import type {IDiscriminatorService} from '@app/api/infrastructure/DiscriminatorService';
 import type {KVActivityTracker} from '@app/api/infrastructure/KVActivityTracker';
 import {
 	type InstanceConfigRepository,
 	type InstanceRegistrationUrl,
 	REGISTRATION_PENDING_APPROVAL_TRAIT,
+	type RegistrationUrlClaim,
 } from '@app/api/instance/InstanceConfigRepository';
 import type {SingleCommunityService} from '@app/api/instance/SingleCommunityService';
 import type {InviteService} from '@app/api/invite/InviteService';
@@ -21,7 +23,7 @@ import {profileSubstringBlocklistCache} from '@app/api/middleware/ProfileSubstri
 import type {RequestCache} from '@app/api/middleware/RequestCacheMiddleware';
 import type {User} from '@app/api/models/User';
 import {UserSettings} from '@app/api/models/UserSettings';
-import {countryRequiresInboundPhoneVerification} from '@app/api/risk/AbusePolicy';
+import {countryRequiresInboundPhoneVerification, stripDisallowedPhoneFlags} from '@app/api/risk/AbusePolicy';
 import {
 	type IAccountPolicyEvaluator,
 	isAssessmentThresholdAuditEvent,
@@ -135,9 +137,6 @@ export async function register(
 	}
 	const now = new Date();
 	const registrationAccess = await resolveRegistrationAccess(instanceConfigRepository, data.registration_url_code);
-	if (registrationAccess.pendingApproval) {
-		await instanceConfigRepository.getPendingRegistrations();
-	}
 	const clientIp = requireClientIp(request, {
 		trustClientIpHeader: config.proxy.trust_client_ip_header,
 		clientIpHeaderName: config.proxy.client_ip_header,
@@ -228,7 +227,7 @@ export async function register(
 	const userLocale = parseAcceptLanguage(acceptLanguage);
 	const passwordHash = data.password ? await AuthPassword.hashPassword(ctx, data.password) : null;
 	const flags = config.nodeEnv === 'development' ? UserFlags.STAFF : 0n;
-	let user = await users.create({
+	const userRow: UserRow = {
 		user_id: userId,
 		username,
 		discriminator,
@@ -287,7 +286,39 @@ export async function register(
 		mention_flags: null,
 		last_voice_activity_sharing_change_at: null,
 		version: 1,
-	});
+	};
+	const registrationUrlUse = await claimRegistrationUrlUse(
+		instanceConfigRepository,
+		registrationAccess.registrationUrl,
+		userId,
+	);
+	let user: User;
+	let createAttempted = false;
+	try {
+		if (registrationAccess.pendingApproval) {
+			await instanceConfigRepository.addPendingRegistration({
+				user_id: userId.toString(),
+				username: userRow.username,
+				discriminator: userRow.discriminator,
+				global_name: userRow.global_name,
+				email: rawEmail,
+				requested_at: now.toISOString(),
+				registration_url_id: registrationAccess.registrationUrl?.id ?? null,
+				client_ip: clientIp,
+			});
+		}
+		createAttempted = true;
+		user = await users.create(userRow);
+	} catch (error) {
+		if (!createAttempted) {
+			await withdrawSignupOfUncreatedAccount(instanceConfigRepository, {
+				userId,
+				registrationUrlUse,
+				pendingApproval: registrationAccess.pendingApproval,
+			});
+		}
+		throw error;
+	}
 	await users.upsertSettings(
 		UserSettings.getDefaultUserSettings({
 			userId,
@@ -331,7 +362,9 @@ export async function register(
 			action: riskResult.recommendedAction,
 		},
 	});
-	const combinedFlags = await deferPhoneFlagsUntilCommunityJoin(policyDecision.flagBits);
+	const combinedFlags = await deferPhoneFlagsUntilCommunityJoin(
+		await stripDisallowedPhoneFlags(policyDecision.flagBits, async () => countryCode),
+	);
 	const createdAt = new Date();
 	const riskContext = deriveLatestRiskContext({
 		userId: userId.toString(),
@@ -401,20 +434,7 @@ export async function register(
 	}
 	if (rawEmail && emailEnabled) await maybeSendVerificationEmail(ctx, {user, email: rawEmail});
 	await users.createAuthorizedIp(userId, clientIp);
-	if (registrationAccess.registrationUrl) {
-		await instanceConfigRepository.recordRegistrationUrlUse(registrationAccess.registrationUrl.id, user.id.toString());
-	}
 	if (registrationAccess.pendingApproval) {
-		await instanceConfigRepository.addPendingRegistration({
-			user_id: user.id.toString(),
-			username: user.username,
-			discriminator: user.discriminator,
-			global_name: user.globalName,
-			email: rawEmail,
-			requested_at: now.toISOString(),
-			registration_url_id: registrationAccess.registrationUrl?.id ?? null,
-			client_ip: clientIp,
-		});
 		return {
 			registration_pending_approval: true,
 			user_id: user.id.toString(),
@@ -469,6 +489,38 @@ function shouldAttemptBootstrapAdminGrant(
 	);
 }

+async function claimRegistrationUrlUse(
+	instanceConfigRepository: InstanceConfigRepository,
+	registrationUrl: InstanceRegistrationUrl | null,
+	userId: UserID,
+): Promise<RegistrationUrlClaim | null> {
+	if (registrationUrl === null) return null;
+	const use = await instanceConfigRepository.claimRegistrationUrlUse(registrationUrl.id, userId.toString());
+	if (use === null) {
+		throw new RegistrationUrlInvalidError();
+	}
+	return use;
+}
+
+async function withdrawSignupOfUncreatedAccount(
+	instanceConfigRepository: InstanceConfigRepository,
+	signup: {userId: UserID; registrationUrlUse: RegistrationUrlClaim | null; pendingApproval: boolean},
+): Promise<void> {
+	try {
+		if (signup.registrationUrlUse !== null) {
+			await instanceConfigRepository.releaseRegistrationUrlUse(signup.registrationUrlUse);
+		}
+		if (signup.pendingApproval) {
+			await instanceConfigRepository.removePendingRegistration(signup.userId.toString());
+		}
+	} catch (error) {
+		Logger.warn(
+			{userId: signup.userId.toString(), registrationUrlId: signup.registrationUrlUse?.registration_url_id, error},
+			'[AuthRegistration] Failed to withdraw the registration URL use or pending approval of an account that was never created',
+		);
+	}
+}
+
 async function resolveRegistrationAccess(
 	instanceConfigRepository: InstanceConfigRepository,
 	registrationUrlCode: string | null | undefined,
@@ -8,12 +8,19 @@ import * as AuthMfa from '@app/api/auth/AuthMfa';
 import * as AuthPassword from '@app/api/auth/AuthPassword';
 import * as AuthRegistration from '@app/api/auth/AuthRegistration';
 import * as AuthSession from '@app/api/auth/AuthSession';
+import {getTokenIdHash} from '@app/api/auth/AuthUtility';
 import type {DesktopHandoffService} from '@app/api/auth/services/DesktopHandoffService';
 import type {SsoService} from '@app/api/auth/services/SsoService';
 import {createUserID, type UserID} from '@app/api/BrandedTypes';
+import {Logger} from '@app/api/Logger';
 import type {RequestCache} from '@app/api/middleware/RequestCacheMiddleware';
 import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
 import type {User} from '@app/api/models/User';
+import {
+	classifyWebPushOrigin,
+	encodePushSessionIdHash,
+	recordPushSessionPredecessor,
+} from '@app/api/user/services/WebPushOriginReplacement';
 import {mapUserToPartialResponse} from '@app/api/user/UserMappers';
 import {lookupGeoip} from '@app/api/utils/IpUtils';
 import {parseJsonRecord} from '@app/api/utils/JsonBoundaryUtils';
@@ -91,6 +98,7 @@ interface AuthHandoffCompleteRequest {
 	data: HandoffCompleteRequest;
 	clientIp: string;
 	authToken?: string;
+	approverOrigin?: string | null;
 }

 interface AuthAuthorizeIpRequest {
@@ -272,21 +280,18 @@ export class AuthRequestService {
 		return {completed: false};
 	}

-	async getWebAuthnAuthenticationOptions() {
-		return AuthMfa.generateWebAuthnAuthenticationOptionsDiscoverable(this.apiContext);
+	async getWebAuthnAuthenticationOptions(origin: string | undefined) {
+		return AuthMfa.generateWebAuthnAuthenticationOptionsDiscoverable(this.apiContext, origin);
 	}

 	async authenticateWebAuthnDiscoverable({data, request}: AuthWebAuthnAuthenticateRequest) {
 		const user = await AuthMfa.verifyWebAuthnAuthenticationDiscoverable(this.apiContext, data.response, data.challenge);
-		const [token] = await AuthSession.createAuthSession(this.apiContext, {
-			user,
-			origin: AuthSession.resolveSessionOrigin(this.apiContext, request),
-		});
+		const [token] = await AuthLogin.createLoginSession(this.apiContext, user, request);
 		return {token, user_id: user.id.toString(), user: mapUserToPartialResponse(user)};
 	}

-	async getWebAuthnMfaOptions({ticket}: MfaTicketRequest) {
-		return AuthMfa.generateWebAuthnAuthenticationOptionsForMfa(this.apiContext, ticket);
+	async getWebAuthnMfaOptions({ticket}: MfaTicketRequest, origin: string | undefined) {
+		return AuthMfa.generateWebAuthnAuthenticationOptionsForMfa(this.apiContext, ticket, origin);
 	}

 	async loginMfaWebAuthn({data, request}: AuthWebAuthnMfaRequest): Promise<AuthTokenWithUserIdResponse> {
@@ -305,7 +310,10 @@ export class AuthRequestService {

 	async initiateHandoff({request}: AuthHandoffInitiateRequest): Promise<HandoffInitiateResponse> {
 		const origin = AuthSession.resolveSessionOrigin(this.apiContext, request);
-		const result = await this.desktopHandoffService.initiateHandoff({origin});
+		const result = await this.desktopHandoffService.initiateHandoff({
+			origin,
+			initiatorOrigin: request.headers.get('origin'),
+		});
 		return {
 			code: result.code,
 			expires_at: result.expiresAt.toISOString(),
@@ -340,21 +348,53 @@ export class AuthRequestService {
 		};
 	}

-	async completeHandoff({data, clientIp, authToken}: AuthHandoffCompleteRequest): Promise<void> {
+	async completeHandoff({data, clientIp, authToken, approverOrigin}: AuthHandoffCompleteRequest): Promise<void> {
 		const sessionToken = data.token ?? authToken;
 		if (!sessionToken) {
 			throw new UnauthorizedError();
 		}
-		await this.desktopHandoffService.completeHandoff(
+		let createdToken: string | null = null;
+		const {initiatorOrigin} = await this.desktopHandoffService.completeHandoff(
 			data.code,
-			(origin) =>
-				AuthSession.createAdditionalAuthSessionFromToken(this.apiContext, {
+			async (origin) => {
+				const created = await AuthSession.createAdditionalAuthSessionFromToken(this.apiContext, {
 					token: sessionToken,
 					expectedUserId: data.user_id,
 					origin,
-				}),
+				});
+				createdToken = created.token;
+				return created;
+			},
 			clientIp,
 		);
+		if (createdToken !== null) {
+			await this.recordPushSessionPredecessor(createdToken, sessionToken, initiatorOrigin, approverOrigin);
+		}
+	}
+
+	private async recordPushSessionPredecessor(
+		createdToken: string,
+		approverToken: string,
+		initiatorOrigin: string | null,
+		approverOrigin: string | null | undefined,
+	): Promise<void> {
+		const {config, kv} = this.apiContext.services;
+		const {selfHosted} = config.instance;
+		if (
+			classifyWebPushOrigin(initiatorOrigin, selfHosted) !== 'target' ||
+			classifyWebPushOrigin(approverOrigin, selfHosted) !== 'legacy'
+		) {
+			return;
+		}
+		try {
+			await recordPushSessionPredecessor(
+				kv,
+				encodePushSessionIdHash(getTokenIdHash(this.apiContext, createdToken)),
+				encodePushSessionIdHash(getTokenIdHash(this.apiContext, approverToken)),
+			);
+		} catch (error) {
+			Logger.warn({error}, 'Failed to record the push session predecessor');
+		}
 	}

 	async getHandoffStatus({code, clientIp, pollSecret}: AuthHandoffStatusRequest): Promise<HandoffStatusResponse> {
@@ -43,7 +43,6 @@ async function revokeSessionTargets(
 			scope === 'all'
 				? users.deleteAllPushSubscriptions(userId)
 				: users.deletePushSubscriptionsForAuthSessions(userId, sessionIdHashes, {deleteUnboundSubscriptions: true}),
-		() => gateway.invalidatePushSubscriptions({userId}),
 	];
 	if (scope === 'selected' || targets.length > 0) {
 		steps.push(
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createOriginHandoff, redeemOriginHandoff} from '@app/api/auth/services/OriginHandoffService';
+import {Config} from '@app/api/Config';
+import {DefaultUserOnly, LoginRequired} from '@app/api/middleware/AuthMiddleware';
+import {RateLimitMiddleware} from '@app/api/middleware/RateLimitMiddleware';
+import {OpenAPI} from '@app/api/middleware/ResponseTypeMiddleware';
+import {RateLimitConfigs} from '@app/api/RateLimitConfig';
+import type {HonoApp} from '@app/api/types/HonoEnv';
+import {Validator} from '@app/api/Validator';
+import {FileSizeTooLargeError} from '@fluxer/errors/src/domains/core/FileSizeTooLargeError';
+import {InvalidApiOriginError} from '@fluxer/errors/src/domains/core/InvalidApiOriginError';
+import {
+	ORIGIN_HANDOFF_MAX_PAYLOAD_LENGTH,
+	OriginHandoffCreateRequest,
+	OriginHandoffCreateResponse,
+	OriginHandoffRedeemRequest,
+	OriginHandoffRedeemResponse,
+} from '@fluxer/schema/src/domains/auth/OriginHandoffSchemas';
+import {bodyLimit} from 'hono/body-limit';
+
+const ORIGIN_HANDOFF_CREATE_MAX_BODY_BYTES = ORIGIN_HANDOFF_MAX_PAYLOAD_LENGTH + 1024;
+
+export function OriginHandoffController(app: HonoApp) {
+	app.post(
+		'/auth/origin-handoff',
+		RateLimitMiddleware(RateLimitConfigs.AUTH_ORIGIN_HANDOFF_CREATE),
+		LoginRequired,
+		DefaultUserOnly,
+		bodyLimit({
+			maxSize: ORIGIN_HANDOFF_CREATE_MAX_BODY_BYTES,
+			onError: () => {
+				throw new FileSizeTooLargeError(ORIGIN_HANDOFF_CREATE_MAX_BODY_BYTES);
+			},
+		}),
+		Validator('json', OriginHandoffCreateRequest),
+		OpenAPI({
+			operationId: 'create_origin_handoff',
+			summary: 'Create origin handoff',
+			responseSchema: OriginHandoffCreateResponse,
+			statusCode: 200,
+			security: ['sessionToken'],
+			tags: ['Auth'],
+			description:
+				'Store encrypted client state for up to two minutes so another first-party web origin can redeem it once. The receiving origin must present the nonce whose SHA-256 digest is sent here.',
+		}),
+		async (ctx) => {
+			const body = ctx.req.valid('json');
+			const handoffId = await createOriginHandoff(ctx.get('cacheService'), {
+				userId: ctx.get('user').id,
+				nonceHash: body.nonce_hash,
+				payload: body.payload,
+			});
+			const response: OriginHandoffCreateResponse = {handoff_id: handoffId};
+			return ctx.json(response);
+		},
+	);
+	app.post(
+		'/auth/origin-handoff/redeem',
+		RateLimitMiddleware(RateLimitConfigs.AUTH_ORIGIN_HANDOFF_REDEEM),
+		Validator('json', OriginHandoffRedeemRequest),
+		OpenAPI({
+			operationId: 'redeem_origin_handoff',
+			summary: 'Redeem origin handoff',
+			responseSchema: OriginHandoffRedeemResponse,
+			statusCode: 200,
+			security: [],
+			tags: ['Auth'],
+			description:
+				'Return the encrypted client state stored by create origin handoff and delete it in the same step. A wrong nonce also consumes the handoff. On the official instance the request must come from a first-party web origin.',
+		}),
+		async (ctx) => {
+			if (!Config.instance.selfHosted) {
+				const origin = ctx.req.header('origin');
+				if (origin === undefined || !Config.endpoints.webAppOrigins.includes(origin)) {
+					throw new InvalidApiOriginError();
+				}
+			}
+			const body = ctx.req.valid('json');
+			const payload = await redeemOriginHandoff(ctx.get('cacheService'), {
+				handoffId: body.handoff_id,
+				nonce: body.nonce,
+			});
+			const response: OriginHandoffRedeemResponse = {payload};
+			return ctx.json(response);
+		},
+	);
+}
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {
+	cancelPasskeyBridge,
+	completePasskeyBridge,
+	getPasskeyBridgeOptions,
+	redeemPasskeyBridgeLogin,
+	redeemPasskeyBridgeSudo,
+	startPasskeyBridgeLogin,
+	startPasskeyBridgeSudo,
+} from '@app/api/auth/services/PasskeyBridgeService';
+import {DefaultUserOnly, LoginRequired} from '@app/api/middleware/AuthMiddleware';
+import {LocalAuthMiddleware} from '@app/api/middleware/LocalAuthMiddleware';
+import {RateLimitMiddleware} from '@app/api/middleware/RateLimitMiddleware';
+import {OpenAPI} from '@app/api/middleware/ResponseTypeMiddleware';
+import {RateLimitConfigs} from '@app/api/RateLimitConfig';
+import type {HonoApp} from '@app/api/types/HonoEnv';
+import {Validator} from '@app/api/Validator';
+import {
+	PasskeyBridgeCeremonyIdParam,
+	PasskeyBridgeCompleteRequest,
+	PasskeyBridgeFinishResponse,
+	PasskeyBridgeLoginRedeemResponse,
+	PasskeyBridgeLoginStartRequest,
+	PasskeyBridgeOptionsResponse,
+	PasskeyBridgeRedeemRequest,
+	PasskeyBridgeStartResponse,
+	PasskeyBridgeSudoRedeemResponse,
+	PasskeyBridgeSudoStartRequest,
+} from '@fluxer/schema/src/domains/auth/PasskeyBridgeSchemas';
+
+export function PasskeyBridgeController(app: HonoApp) {
+	app.post(
+		'/auth/passkey-bridge',
+		LocalAuthMiddleware,
+		RateLimitMiddleware(RateLimitConfigs.AUTH_PASSKEY_BRIDGE_START),
+		Validator('json', PasskeyBridgeLoginStartRequest),
+		OpenAPI({
+			operationId: 'start_passkey_bridge_login',
+			summary: 'Start passkey bridge sign in',
+			responseSchema: PasskeyBridgeStartResponse,
+			statusCode: 200,
+			security: [],
+			tags: ['Auth'],
+			description:
+				'Start a sign in or two-factor ceremony for a passkey that belongs to the paired first-party origin. Only available on the official instance from the new origin.',
+		}),
+		async (ctx) => {
+			return ctx.json(
+				await startPasskeyBridgeLogin(ctx.get('apiContext'), ctx.req.header('origin'), ctx.req.valid('json')),
+			);
+		},
+	);
+	app.post(
+		'/users/@me/passkey-bridge',
+		RateLimitMiddleware(RateLimitConfigs.USER_PASSKEY_BRIDGE_START),
+		LoginRequired,
+		DefaultUserOnly,
+		Validator('json', PasskeyBridgeSudoStartRequest),
+		OpenAPI({
+			operationId: 'start_passkey_bridge_sudo',
+			summary: 'Start passkey bridge sudo verification',
+			responseSchema: PasskeyBridgeStartResponse,
+			statusCode: 200,
+			security: ['bearerToken', 'sessionToken'],
+			tags: ['Users'],
+			description:
+				'Start a sudo verification ceremony for a passkey that belongs to the paired first-party origin. Only available on the official instance from the new origin.',
+		}),
+		async (ctx) => {
+			return ctx.json(
+				await startPasskeyBridgeSudo(
+					ctx.get('apiContext'),
+					ctx.req.header('origin'),
+					ctx.get('user').id,
+					ctx.req.valid('json'),
+				),
+			);
+		},
+	);
+	app.post(
+		'/auth/passkey-bridge/:ceremony_id/options',
+		RateLimitMiddleware(RateLimitConfigs.AUTH_PASSKEY_BRIDGE_CEREMONY),
+		Validator('param', PasskeyBridgeCeremonyIdParam),
+		OpenAPI({
+			operationId: 'get_passkey_bridge_options',
+			summary: 'Get passkey bridge options',
+			responseSchema: PasskeyBridgeOptionsResponse,
+			statusCode: 200,
+			security: [],
+			tags: ['Auth'],
+			description:
+				'Issue WebAuthn authentication options for a pending passkey bridge ceremony. The request must come from the origin that runs the ceremony.',
+		}),
+		async (ctx) => {
+			const {ceremony_id} = ctx.req.valid('param');
+			return ctx.json(await getPasskeyBridgeOptions(ctx.get('apiContext'), ceremony_id, ctx.req.header('origin')));
+		},
+	);
+	app.post(
+		'/auth/passkey-bridge/:ceremony_id/complete',
+		RateLimitMiddleware(RateLimitConfigs.AUTH_PASSKEY_BRIDGE_CEREMONY),
+		Validator('param', PasskeyBridgeCeremonyIdParam),
+		Validator('json', PasskeyBridgeCompleteRequest),
+		OpenAPI({
+			operationId: 'complete_passkey_bridge',
+			summary: 'Complete passkey bridge',
+			responseSchema: PasskeyBridgeFinishResponse,
+			statusCode: 200,
+			security: [],
+			tags: ['Auth'],
+			description:
+				'Verify the WebAuthn response for a pending passkey bridge ceremony. A failed verification leaves the ceremony pending so it can be retried.',
+		}),
+		async (ctx) => {
+			const {ceremony_id} = ctx.req.valid('param');
+			return ctx.json(
+				await completePasskeyBridge(
+					ctx.get('apiContext'),
+					ceremony_id,
+					ctx.req.header('origin'),
+					ctx.req.valid('json'),
+				),
+			);
+		},
+	);
+	app.post(
+		'/auth/passkey-bridge/:ceremony_id/cancel',
+		RateLimitMiddleware(RateLimitConfigs.AUTH_PASSKEY_BRIDGE_CEREMONY),
+		Validator('param', PasskeyBridgeCeremonyIdParam),
+		OpenAPI({
+			operationId: 'cancel_passkey_bridge',
+			summary: 'Cancel passkey bridge',
+			responseSchema: PasskeyBridgeFinishResponse,
+			statusCode: 200,
+			security: [],
+			tags: ['Auth'],
+			description: 'Cancel a passkey bridge ceremony that has not completed.',
+		}),
+		async (ctx) => {
+			const {ceremony_id} = ctx.req.valid('param');
+			return ctx.json(await cancelPasskeyBridge(ctx.get('apiContext'), ceremony_id, ctx.req.header('origin')));
+		},
+	);
+	app.post(
+		'/auth/passkey-bridge/:ceremony_id/redeem',
+		LocalAuthMiddleware,
+		RateLimitMiddleware(RateLimitConfigs.AUTH_PASSKEY_BRIDGE_REDEEM),
+		Validator('param', PasskeyBridgeCeremonyIdParam),
+		Validator('json', PasskeyBridgeRedeemRequest),
+		OpenAPI({
+			operationId: 'redeem_passkey_bridge_login',
+			summary: 'Redeem passkey bridge sign in',
+			responseSchema: PasskeyBridgeLoginRedeemResponse,
+			statusCode: 200,
+			security: [],
+			tags: ['Auth'],
+			description:
+				'Redeem a finished sign in or two-factor passkey bridge ceremony once. Requires the nonce kept by the starting page and the completion code handed back when the ceremony finished.',
+		}),
+		async (ctx) => {
+			const {ceremony_id} = ctx.req.valid('param');
+			return ctx.json(
+				await redeemPasskeyBridgeLogin(
+					ctx.get('apiContext'),
+					ceremony_id,
+					ctx.req.header('origin'),
+					ctx.req.valid('json'),
+					ctx.req.raw,
+				),
+			);
+		},
+	);
+	app.post(
+		'/users/@me/passkey-bridge/:ceremony_id/redeem',
+		RateLimitMiddleware(RateLimitConfigs.USER_PASSKEY_BRIDGE_REDEEM),
+		LoginRequired,
+		DefaultUserOnly,
+		Validator('param', PasskeyBridgeCeremonyIdParam),
+		Validator('json', PasskeyBridgeRedeemRequest),
+		OpenAPI({
+			operationId: 'redeem_passkey_bridge_sudo',
+			summary: 'Redeem passkey bridge sudo verification',
+			responseSchema: PasskeyBridgeSudoRedeemResponse,
+			statusCode: 200,
+			security: ['bearerToken', 'sessionToken'],
+			tags: ['Users'],
+			description:
+				'Redeem a finished sudo passkey bridge ceremony once for a sudo mode token. Requires the nonce kept by the starting page and the completion code handed back when the ceremony finished.',
+		}),
+		async (ctx) => {
+			const {ceremony_id} = ctx.req.valid('param');
+			return ctx.json(
+				await redeemPasskeyBridgeSudo(
+					ctx.get('apiContext'),
+					ceremony_id,
+					ctx.req.header('origin'),
+					ctx.req.valid('json'),
+					ctx.get('user').id,
+					ctx.get('authSession'),
+				),
+			);
+		},
+	);
+}
@@ -25,6 +25,7 @@ const POLL_SECRET_BYTES = 32;
 interface HandoffData {
 	createdAt: number;
 	origin: SessionOrigin;
+	initiatorOrigin?: string | null;
 	infoLookupCount: number;
 	pollSecretHash: string;
 }
@@ -84,7 +85,7 @@ function pollSecretMatches(presented: string | undefined, storedHash: string | u
 export class DesktopHandoffService {
 	constructor(private readonly apiContext: ApiContext) {}

-	async initiateHandoff(args: {origin: SessionOrigin}): Promise<{
+	async initiateHandoff(args: {origin: SessionOrigin; initiatorOrigin?: string | null}): Promise<{
 		code: string;
 		expiresAt: Date;
 		pollSecret: string;
@@ -95,6 +96,7 @@ export class DesktopHandoffService {
 		const handoffData: HandoffData = {
 			createdAt: Date.now(),
 			origin: args.origin,
+			initiatorOrigin: args.initiatorOrigin ?? null,
 			infoLookupCount: 0,
 			pollSecretHash: hashPollSecret(pollSecret),
 		};
@@ -108,7 +110,7 @@ export class DesktopHandoffService {
 		code: string,
 		createTokenData: (origin: SessionOrigin) => Promise<{token: string; userId: string}>,
 		approverIp: string,
-	): Promise<void> {
+	): Promise<{initiatorOrigin: string | null}> {
 		const {cache} = this.apiContext.services;
 		const normalizedCode = requireNormalizedHandoffCode(code);
 		await this.checkAttemptLimit(approverIp);
@@ -138,6 +140,7 @@ export class DesktopHandoffService {
 		await cache.set(`${HANDOFF_TOKEN_PREFIX}${normalizedCode}`, tokenData, remainingSeconds);
 		await cache.delete(`${HANDOFF_CODE_PREFIX}${normalizedCode}`);
 		await cache.delete(`${HANDOFF_APPROVER_PREFIX}${normalizedCode}`);
+		return {initiatorOrigin: handoffData.initiatorOrigin ?? null};
 	}

 	async getHandoffInfo(
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createHash, randomBytes, timingSafeEqual} from 'node:crypto';
+import type {UserID} from '@app/api/BrandedTypes';
+import {InvalidOriginHandoffNonceError} from '@fluxer/errors/src/domains/auth/InvalidOriginHandoffNonceError';
+import {UnknownOriginHandoffError} from '@fluxer/errors/src/domains/auth/UnknownOriginHandoffError';
+import type {ICacheService} from '@pkgs/cache/src/ICacheService';
+import {seconds} from 'itty-time';
+
+const ORIGIN_HANDOFF_KEY_PREFIX = 'origin_handoff:';
+const ORIGIN_HANDOFF_ID_BYTES = 32;
+
+interface OriginHandoffRecord {
+	nonce_hash: string;
+	payload: string;
+	user_id: string;
+	created_at: number;
+}
+
+function sha256Hex(value: string): string {
+	return createHash('sha256').update(value).digest('hex');
+}
+
+function originHandoffKey(handoffId: string): string {
+	return `${ORIGIN_HANDOFF_KEY_PREFIX}${sha256Hex(handoffId)}`;
+}
+
+export async function createOriginHandoff(
+	cache: ICacheService,
+	args: {userId: UserID; nonceHash: string; payload: string},
+): Promise<string> {
+	const handoffId = randomBytes(ORIGIN_HANDOFF_ID_BYTES).toString('base64url');
+	const record: OriginHandoffRecord = {
+		nonce_hash: args.nonceHash,
+		payload: args.payload,
+		user_id: args.userId.toString(),
+		created_at: Date.now(),
+	};
+	await cache.set(originHandoffKey(handoffId), record, seconds('2 minutes'));
+	return handoffId;
+}
+
+export async function redeemOriginHandoff(
+	cache: ICacheService,
+	args: {handoffId: string; nonce: string},
+): Promise<string> {
+	const record = await cache.getAndDelete<OriginHandoffRecord>(originHandoffKey(args.handoffId));
+	if (!record) {
+		throw new UnknownOriginHandoffError();
+	}
+	const presented = Buffer.from(sha256Hex(args.nonce), 'hex');
+	const stored = Buffer.from(record.nonce_hash, 'hex');
+	if (presented.length !== stored.length || !timingSafeEqual(presented, stored)) {
+		throw new InvalidOriginHandoffNonceError();
+	}
+	return record.payload;
+}
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createHash, randomBytes, timingSafeEqual} from 'node:crypto';
+import type {ApiContext} from '@app/api/ApiContext';
+import * as AuthLogin from '@app/api/auth/AuthLogin';
+import * as AuthMfa from '@app/api/auth/AuthMfa';
+import * as AuthUtility from '@app/api/auth/AuthUtility';
+import {recordPendingPasskeyMigration} from '@app/api/auth/services/PasskeyMigrationService';
+import {
+	effectiveRpId,
+	isPasskeyMigrationActive,
+	isPasskeyTargetOrigin,
+	passkeyLegacyOriginFor,
+	visibleWebAuthnCredentials,
+} from '@app/api/auth/services/PasskeyRelyingParty';
+import {getSudoModeService} from '@app/api/auth/services/SudoModeService';
+import {resolveWebAuthnSecondFactor} from '@app/api/auth/services/WebAuthnSecondFactor';
+import {createUserID, type UserID} from '@app/api/BrandedTypes';
+import type {AuthSession} from '@app/api/models/AuthSession';
+import type {User} from '@app/api/models/User';
+import type {WebAuthnCredential} from '@app/api/models/WebAuthnCredential';
+import {mapUserToPartialResponse} from '@app/api/user/UserMappers';
+import {PASSKEY_BRIDGE_PATH, PASSKEY_BRIDGE_RETURN_FRAGMENT_KEY} from '@fluxer/constants/src/PasskeyConstants';
+import {ValidationErrorCodes} from '@fluxer/constants/src/ValidationErrorCodes';
+import {InvalidPasskeyBridgeNonceError} from '@fluxer/errors/src/domains/auth/InvalidPasskeyBridgeNonceError';
+import {MfaNotEnabledError} from '@fluxer/errors/src/domains/auth/MfaNotEnabledError';
+import {NoPasskeysRegisteredError} from '@fluxer/errors/src/domains/auth/NoPasskeysRegisteredError';
+import {PasskeyAuthenticationFailedError} from '@fluxer/errors/src/domains/auth/PasskeyAuthenticationFailedError';
+import {UnknownPasskeyBridgeError} from '@fluxer/errors/src/domains/auth/UnknownPasskeyBridgeError';
+import {InputValidationError} from '@fluxer/errors/src/domains/core/InputValidationError';
+import {InvalidApiOriginError} from '@fluxer/errors/src/domains/core/InvalidApiOriginError';
+import type {
+	PasskeyBridgeCompleteRequest,
+	PasskeyBridgeFinishResponse,
+	PasskeyBridgeLoginRedeemResponse,
+	PasskeyBridgeLoginStartRequest,
+	PasskeyBridgeRedeemRequest,
+	PasskeyBridgeRunner,
+	PasskeyBridgeStartResponse,
+	PasskeyBridgeSudoRedeemResponse,
+	PasskeyBridgeSudoStartRequest,
+} from '@fluxer/schema/src/domains/auth/PasskeyBridgeSchemas';
+import type {PublicKeyCredentialRequestOptionsJSON} from '@simplewebauthn/server';
+import {ms, seconds} from 'itty-time';
+
+type PasskeyBridgePurpose = 'login' | 'login_mfa' | 'sudo';
+
+interface PasskeyBridgeRecord {
+	purpose: PasskeyBridgePurpose;
+	runner: PasskeyBridgeRunner;
+	target_origin: string;
+	ceremony_origin: string;
+	nonce_hash: string;
+	user_id: string | null;
+	ticket: string | null;
+	challenge: string | null;
+	credential_id: string | null;
+	cross_device: boolean;
+	completion_code_hash: string | null;
+	status: 'pending' | 'completed' | 'cancelled';
+	created_at: number;
+	expires_at: number;
+}
+
+interface CompletedPasskeyBridge {
+	record: PasskeyBridgeRecord;
+	userId: UserID;
+}
+
+const PASSKEY_BRIDGE_KEY_PREFIX = 'passkey_bridge:';
+const PASSKEY_BRIDGE_LOCK_PREFIX = 'passkey_bridge_lock:';
+const PASSKEY_BRIDGE_SECRET_BYTES = 32;
+
+function sha256Hex(value: string): string {
+	return createHash('sha256').update(value).digest('hex');
+}
+
+function hashMatches(value: string, storedHash: string | null): boolean {
+	if (storedHash === null) return false;
+	const presented = Buffer.from(sha256Hex(value), 'hex');
+	const stored = Buffer.from(storedHash, 'hex');
+	return presented.length === stored.length && timingSafeEqual(presented, stored);
+}
+
+function createSecret(): string {
+	return randomBytes(PASSKEY_BRIDGE_SECRET_BYTES).toString('base64url');
+}
+
+function passkeyBridgeKey(ceremonyId: string): string {
+	return `${PASSKEY_BRIDGE_KEY_PREFIX}${sha256Hex(ceremonyId)}`;
+}
+
+async function writeRecord(ctx: ApiContext, ceremonyId: string, record: PasskeyBridgeRecord): Promise<void> {
+	const ttlSeconds = Math.floor((record.expires_at - Date.now()) / 1000);
+	if (ttlSeconds <= 0) {
+		throw new UnknownPasskeyBridgeError();
+	}
+	await ctx.services.cache.set(passkeyBridgeKey(ceremonyId), record, ttlSeconds);
+}
+
+function assertCeremonyOrigin(
+	ctx: ApiContext,
+	record: PasskeyBridgeRecord,
+	origin: string | undefined,
+	expectedOrigin: string,
+): void {
+	if (origin !== expectedOrigin || !isPasskeyTargetOrigin(ctx, record.target_origin)) {
+		throw new InvalidApiOriginError();
+	}
+}
+
+async function mutateRecord<T>(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+	mutate: (record: PasskeyBridgeRecord) => Promise<T>,
+): Promise<T> {
+	const {cache} = ctx.services;
+	const lockKey = `${PASSKEY_BRIDGE_LOCK_PREFIX}${sha256Hex(ceremonyId)}`;
+	const lockToken = await cache.acquireLock(lockKey, seconds('10 seconds'));
+	if (!lockToken) {
+		throw new UnknownPasskeyBridgeError();
+	}
+	try {
+		const record = await cache.get<PasskeyBridgeRecord>(passkeyBridgeKey(ceremonyId));
+		if (!record) {
+			throw new UnknownPasskeyBridgeError();
+		}
+		assertCeremonyOrigin(ctx, record, origin, record.ceremony_origin);
+		return await mutate(record);
+	} finally {
+		await cache.releaseLock(lockKey, lockToken);
+	}
+}
+
+async function requireMfaTicketUser(ctx: ApiContext, ticket: string, expectedUserId?: string): Promise<User> {
+	const userId = await ctx.services.cache.get<string>(`mfa-ticket:${ticket}`);
+	if (!userId || (expectedUserId !== undefined && userId !== expectedUserId)) {
+		throw InputValidationError.fromCode('ticket', ValidationErrorCodes.SESSION_TIMEOUT);
+	}
+	const user = await ctx.services.users.findUniqueAssert(createUserID(BigInt(userId)));
+	AuthUtility.assertNonBotUser(ctx, user);
+	return user;
+}
+
+async function requireLegacyCredentials(ctx: ApiContext, userId: UserID): Promise<Array<WebAuthnCredential>> {
+	const legacyRpId = ctx.services.config.auth.passkeys.rpId;
+	const credentials = visibleWebAuthnCredentials(await ctx.services.users.listWebAuthnCredentials(userId)).filter(
+		(credential) => effectiveRpId(ctx, credential) === legacyRpId,
+	);
+	if (credentials.length === 0) {
+		throw new NoPasskeysRegisteredError();
+	}
+	return credentials;
+}
+
+function assertBridgeStartOrigin(ctx: ApiContext, origin: string | undefined): string {
+	if (!origin || !isPasskeyTargetOrigin(ctx, origin)) {
+		throw new InvalidApiOriginError();
+	}
+	return origin;
+}
+
+async function startPasskeyBridge(
+	ctx: ApiContext,
+	origin: string,
+	fields: Pick<PasskeyBridgeRecord, 'purpose' | 'runner' | 'nonce_hash' | 'user_id' | 'ticket'>,
+): Promise<PasskeyBridgeStartResponse> {
+	const ceremonyId = createSecret();
+	const createdAt = Date.now();
+	const ceremonyOrigin = fields.runner === 'page' ? passkeyLegacyOriginFor(origin) : origin;
+	await writeRecord(ctx, ceremonyId, {
+		...fields,
+		target_origin: origin,
+		ceremony_origin: ceremonyOrigin,
+		challenge: null,
+		credential_id: null,
+		cross_device: false,
+		completion_code_hash: null,
+		status: 'pending',
+		created_at: createdAt,
+		expires_at: createdAt + (fields.purpose === 'login_mfa' ? ms('5 minutes') : ms('10 minutes')),
+	});
+	return {
+		ceremony_id: ceremonyId,
+		bridge_url: fields.runner === 'page' ? `${ceremonyOrigin}${PASSKEY_BRIDGE_PATH}#${ceremonyId}` : null,
+	};
+}
+
+export async function startPasskeyBridgeLogin(
+	ctx: ApiContext,
+	origin: string | undefined,
+	data: PasskeyBridgeLoginStartRequest,
+): Promise<PasskeyBridgeStartResponse> {
+	const targetOrigin = assertBridgeStartOrigin(ctx, origin);
+	let userId: string | null = null;
+	if (data.purpose === 'login_mfa') {
+		const user = await requireMfaTicketUser(ctx, data.ticket!);
+		if (!(await resolveWebAuthnSecondFactor(ctx, user))) {
+			throw new MfaNotEnabledError();
+		}
+		await requireLegacyCredentials(ctx, user.id);
+		userId = user.id.toString();
+	}
+	return startPasskeyBridge(ctx, targetOrigin, {
+		purpose: data.purpose,
+		runner: data.runner,
+		nonce_hash: data.nonce_hash,
+		user_id: userId,
+		ticket: data.ticket ?? null,
+	});
+}
+
+export async function startPasskeyBridgeSudo(
+	ctx: ApiContext,
+	origin: string | undefined,
+	userId: UserID,
+	data: PasskeyBridgeSudoStartRequest,
+): Promise<PasskeyBridgeStartResponse> {
+	const targetOrigin = assertBridgeStartOrigin(ctx, origin);
+	await requireLegacyCredentials(ctx, userId);
+	return startPasskeyBridge(ctx, targetOrigin, {
+		purpose: 'sudo',
+		runner: data.runner,
+		nonce_hash: data.nonce_hash,
+		user_id: userId.toString(),
+		ticket: null,
+	});
+}
+
+export async function getPasskeyBridgeOptions(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+): Promise<{options: PublicKeyCredentialRequestOptionsJSON}> {
+	return mutateRecord(ctx, ceremonyId, origin, async (record) => {
+		if (record.status !== 'pending') {
+			throw new UnknownPasskeyBridgeError();
+		}
+		const legacyRpId = ctx.services.config.auth.passkeys.rpId;
+		const userId = record.user_id === null ? undefined : createUserID(BigInt(record.user_id));
+		const options = await AuthMfa.generateWebAuthnAuthenticationOptions(ctx, {
+			selection: {
+				rpId: legacyRpId,
+				credentials: userId === undefined ? null : await requireLegacyCredentials(ctx, userId),
+			},
+			context: 'bridge',
+			userId,
+		});
+		if (record.challenge !== null) {
+			await AuthMfa.deleteWebAuthnChallenge(ctx, record.challenge);
+		}
+		await writeRecord(ctx, ceremonyId, {...record, challenge: options.challenge});
+		return {options};
+	});
+}
+
+function buildReturnUrl(record: PasskeyBridgeRecord, ceremonyId: string, completionCode: string): string {
+	return `${record.target_origin}${PASSKEY_BRIDGE_PATH}#${PASSKEY_BRIDGE_RETURN_FRAGMENT_KEY}=${ceremonyId}.${completionCode}`;
+}
+
+async function finishRecord(
+	ctx: ApiContext,
+	ceremonyId: string,
+	record: PasskeyBridgeRecord,
+): Promise<PasskeyBridgeFinishResponse> {
+	const completionCode = createSecret();
+	await writeRecord(ctx, ceremonyId, {...record, completion_code_hash: sha256Hex(completionCode)});
+	if (record.runner === 'native') {
+		return {return_url: null, completion_code: completionCode};
+	}
+	return {return_url: buildReturnUrl(record, ceremonyId, completionCode), completion_code: null};
+}
+
+export async function completePasskeyBridge(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+	data: PasskeyBridgeCompleteRequest,
+): Promise<PasskeyBridgeFinishResponse> {
+	return mutateRecord(ctx, ceremonyId, origin, async (record) => {
+		if (record.status !== 'pending') {
+			throw new UnknownPasskeyBridgeError();
+		}
+		const {users} = ctx.services;
+		const credentialId = data.response.id;
+		const userId =
+			record.user_id === null
+				? await users.getUserIdByCredentialId(credentialId)
+				: createUserID(BigInt(record.user_id));
+		const credential = userId === null ? null : await users.getWebAuthnCredential(userId, credentialId);
+		if (
+			userId === null ||
+			record.challenge === null ||
+			credential === null ||
+			credential.supersededBy !== null ||
+			effectiveRpId(ctx, credential) !== ctx.services.config.auth.passkeys.rpId
+		) {
+			throw new PasskeyAuthenticationFailedError();
+		}
+		if (record.purpose === 'login_mfa') {
+			await requireMfaTicketUser(ctx, record.ticket!, record.user_id!);
+			await AuthLogin.consumeMfaAttempt(ctx, {userId: record.user_id!, ticket: record.ticket!, field: 'ticket'});
+		} else if (record.purpose === 'sudo') {
+			await AuthMfa.consumeSudoMfaAttempt(ctx, userId);
+		}
+		await AuthMfa.verifyWebAuthnAuthentication(ctx, userId, data.response, record.challenge, 'bridge', undefined, [
+			record.ceremony_origin,
+		]);
+		return finishRecord(ctx, ceremonyId, {
+			...record,
+			status: 'completed',
+			user_id: userId.toString(),
+			credential_id: credentialId,
+			cross_device: data.response.authenticatorAttachment === 'cross-platform',
+		});
+	});
+}
+
+export async function cancelPasskeyBridge(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+): Promise<PasskeyBridgeFinishResponse> {
+	return mutateRecord(ctx, ceremonyId, origin, async (record) => {
+		if (record.status === 'completed') {
+			throw new UnknownPasskeyBridgeError();
+		}
+		return finishRecord(ctx, ceremonyId, {...record, status: 'cancelled'});
+	});
+}
+
+function assertRedeemable(
+	record: PasskeyBridgeRecord | null,
+	purposes: ReadonlyArray<PasskeyBridgePurpose>,
+	expectedUserId: UserID | null,
+): asserts record is PasskeyBridgeRecord {
+	if (
+		!record ||
+		!purposes.includes(record.purpose) ||
+		(expectedUserId !== null && record.user_id !== expectedUserId.toString()) ||
+		record.status === 'pending'
+	) {
+		throw new UnknownPasskeyBridgeError();
+	}
+}
+
+async function redeemPasskeyBridge(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+	data: PasskeyBridgeRedeemRequest,
+	purposes: ReadonlyArray<PasskeyBridgePurpose>,
+	expectedUserId: UserID | null,
+): Promise<CompletedPasskeyBridge | null> {
+	const {cache} = ctx.services;
+	const key = passkeyBridgeKey(ceremonyId);
+	const record = await cache.get<PasskeyBridgeRecord>(key);
+	if (!record) {
+		throw new UnknownPasskeyBridgeError();
+	}
+	assertCeremonyOrigin(ctx, record, origin, record.target_origin);
+	assertRedeemable(record, purposes, expectedUserId);
+	if (!hashMatches(data.nonce, record.nonce_hash) || !hashMatches(data.completion_code, record.completion_code_hash)) {
+		await cache.delete(key);
+		throw new InvalidPasskeyBridgeNonceError();
+	}
+	const taken = await cache.getAndDelete<PasskeyBridgeRecord>(key);
+	assertRedeemable(taken, purposes, expectedUserId);
+	if (!hashMatches(data.nonce, taken.nonce_hash) || !hashMatches(data.completion_code, taken.completion_code_hash)) {
+		throw new InvalidPasskeyBridgeNonceError();
+	}
+	if (taken.status === 'cancelled') {
+		return null;
+	}
+	return {record: taken, userId: createUserID(BigInt(taken.user_id!))};
+}
+
+async function recordMigrationIfActive(
+	ctx: ApiContext,
+	origin: string | undefined,
+	completed: CompletedPasskeyBridge,
+	authSession: AuthSession | undefined,
+): Promise<void> {
+	if (!authSession || !(await isPasskeyMigrationActive(ctx, origin))) return;
+	await recordPendingPasskeyMigration(ctx, authSession, {
+		user_id: completed.userId.toString(),
+		credential_id: completed.record.credential_id!,
+		cross_device: completed.record.cross_device,
+	});
+}
+
+export async function redeemPasskeyBridgeLogin(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+	data: PasskeyBridgeRedeemRequest,
+	request: Request,
+): Promise<PasskeyBridgeLoginRedeemResponse> {
+	const completed = await redeemPasskeyBridge(ctx, ceremonyId, origin, data, ['login', 'login_mfa'], null);
+	if (!completed) {
+		return {status: 'cancelled'};
+	}
+	let token: string;
+	let authSession: AuthSession;
+	let user: User;
+	if (completed.record.purpose === 'login_mfa') {
+		user = await requireMfaTicketUser(ctx, completed.record.ticket!, completed.record.user_id!);
+		if (!(await resolveWebAuthnSecondFactor(ctx, user))) {
+			throw new MfaNotEnabledError();
+		}
+		[token, authSession] = await AuthLogin.completeMfaLogin(ctx, user, completed.record.ticket!, request);
+	} else {
+		user = await ctx.services.users.findUniqueAssert(completed.userId);
+		[token, authSession] = await AuthLogin.createLoginSession(ctx, user, request);
+	}
+	await recordMigrationIfActive(ctx, origin, completed, authSession);
+	return {status: 'completed', token, user_id: user.id.toString(), user: mapUserToPartialResponse(user)};
+}
+
+export async function redeemPasskeyBridgeSudo(
+	ctx: ApiContext,
+	ceremonyId: string,
+	origin: string | undefined,
+	data: PasskeyBridgeRedeemRequest,
+	userId: UserID,
+	authSession: AuthSession | undefined,
+): Promise<PasskeyBridgeSudoRedeemResponse> {
+	const completed = await redeemPasskeyBridge(ctx, ceremonyId, origin, data, ['sudo'], userId);
+	if (!completed) {
+		return {status: 'cancelled'};
+	}
+	const sudoToken = await getSudoModeService().generateSudoToken(userId);
+	await recordMigrationIfActive(ctx, origin, completed, authSession);
+	return {status: 'completed', sudo_token: sudoToken};
+}
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {ApiContext} from '@app/api/ApiContext';
+import * as AuthMfa from '@app/api/auth/AuthMfa';
+import {
+	effectiveRpId,
+	isPasskeyTargetOrigin,
+	visibleWebAuthnCredentials,
+} from '@app/api/auth/services/PasskeyRelyingParty';
+import type {UserID} from '@app/api/BrandedTypes';
+import type {AuthSession} from '@app/api/models/AuthSession';
+import type {WebAuthnCredential} from '@app/api/models/WebAuthnCredential';
+import {PASSKEY_MIGRATION_RP_ID} from '@fluxer/constants/src/PasskeyConstants';
+import {UnknownPasskeyMigrationError} from '@fluxer/errors/src/domains/auth/UnknownPasskeyMigrationError';
+import type {
+	PasskeyMigrationCompleteRequest,
+	PasskeyMigrationResponse,
+} from '@fluxer/schema/src/domains/auth/PasskeyMigrationSchemas';
+import type {PublicKeyCredentialCreationOptionsJSON} from '@simplewebauthn/server';
+import {seconds} from 'itty-time';
+
+const PASSKEY_MIGRATION_KEY_PREFIX = 'passkey_migration:';
+
+interface PendingPasskeyMigration {
+	user_id: string;
+	credential_id: string;
+	cross_device: boolean;
+}
+
+interface LivePasskeyMigration {
+	key: string;
+	pending: PendingPasskeyMigration;
+	credential: WebAuthnCredential;
+}
+
+function passkeyMigrationKey(authSession: AuthSession): string {
+	return `${PASSKEY_MIGRATION_KEY_PREFIX}${authSession.sessionIdHash.toString('base64url')}`;
+}
+
+function isLegacyVisibleCredential(ctx: ApiContext, credential: WebAuthnCredential): boolean {
+	return credential.supersededBy === null && effectiveRpId(ctx, credential) === ctx.services.config.auth.passkeys.rpId;
+}
+
+export async function recordPendingPasskeyMigration(
+	ctx: ApiContext,
+	authSession: AuthSession,
+	pending: PendingPasskeyMigration,
+): Promise<void> {
+	await ctx.services.cache.set(passkeyMigrationKey(authSession), pending, seconds('5 minutes'));
+}
+
+async function loadLivePasskeyMigration(
+	ctx: ApiContext,
+	userId: UserID,
+	authSession: AuthSession | undefined,
+): Promise<LivePasskeyMigration | null> {
+	if (!authSession) return null;
+	const {cache, users} = ctx.services;
+	const key = passkeyMigrationKey(authSession);
+	const pending = await cache.get<PendingPasskeyMigration>(key);
+	if (!pending) return null;
+	const credential =
+		pending.user_id === userId.toString() ? await users.getWebAuthnCredential(userId, pending.credential_id) : null;
+	if (credential === null || !isLegacyVisibleCredential(ctx, credential)) {
+		await cache.delete(key);
+		return null;
+	}
+	return {key, pending, credential};
+}
+
+async function requireLivePasskeyMigration(
+	ctx: ApiContext,
+	userId: UserID,
+	authSession: AuthSession | undefined,
+	origin: string | undefined,
+): Promise<LivePasskeyMigration> {
+	const live = isPasskeyTargetOrigin(ctx, origin) ? await loadLivePasskeyMigration(ctx, userId, authSession) : null;
+	if (!live) {
+		throw new UnknownPasskeyMigrationError();
+	}
+	return live;
+}
+
+async function takeLivePasskeyMigration(ctx: ApiContext, userId: UserID, key: string): Promise<WebAuthnCredential> {
+	const pending = await ctx.services.cache.getAndDelete<PendingPasskeyMigration>(key);
+	if (!pending || pending.user_id !== userId.toString()) {
+		throw new UnknownPasskeyMigrationError();
+	}
+	const credential = await ctx.services.users.getWebAuthnCredential(userId, pending.credential_id);
+	if (credential === null || !isLegacyVisibleCredential(ctx, credential)) {
+		throw new UnknownPasskeyMigrationError();
+	}
+	return credential;
+}
+
+function visibleTargetCredentials(ctx: ApiContext, credentials: Array<WebAuthnCredential>): Array<WebAuthnCredential> {
+	return visibleWebAuthnCredentials(credentials).filter(
+		(credential) => effectiveRpId(ctx, credential) === PASSKEY_MIGRATION_RP_ID,
+	);
+}
+
+export async function getPasskeyMigration(
+	ctx: ApiContext,
+	userId: UserID,
+	authSession: AuthSession | undefined,
+): Promise<PasskeyMigrationResponse> {
+	const live = await loadLivePasskeyMigration(ctx, userId, authSession);
+	if (!live) return {pending: null};
+	return {
+		pending: {
+			credential_id: live.credential.credentialId,
+			name: live.credential.name,
+			cross_device: live.pending.cross_device,
+		},
+	};
+}
+
+export async function getPasskeyMigrationRegistrationOptions(
+	ctx: ApiContext,
+	userId: UserID,
+	authSession: AuthSession | undefined,
+	origin: string | undefined,
+): Promise<PublicKeyCredentialCreationOptionsJSON> {
+	const live = await requireLivePasskeyMigration(ctx, userId, authSession, origin);
+	const credentials = await ctx.services.users.listWebAuthnCredentials(userId);
+	const options = await AuthMfa.createWebAuthnRegistrationOptions(ctx, userId, {
+		rpId: PASSKEY_MIGRATION_RP_ID,
+		context: 'migration_registration',
+		excludeCredentials: visibleTargetCredentials(ctx, credentials),
+	});
+	if (live.pending.cross_device) {
+		options.hints = ['hybrid', 'security-key'];
+	}
+	return options;
+}
+
+export async function completePasskeyMigration(
+	ctx: ApiContext,
+	userId: UserID,
+	authSession: AuthSession | undefined,
+	origin: string | undefined,
+	data: PasskeyMigrationCompleteRequest,
+): Promise<void> {
+	const {users} = ctx.services;
+	const live = await requireLivePasskeyMigration(ctx, userId, authSession, origin);
+	const verified = await AuthMfa.verifyWebAuthnRegistrationResponse(
+		ctx,
+		userId,
+		data.response,
+		data.challenge,
+		'migration_registration',
+		[origin!],
+	);
+	const legacy = await takeLivePasskeyMigration(ctx, userId, live.key);
+	await users.createWebAuthnCredential(
+		userId,
+		verified.credentialId,
+		verified.publicKey,
+		verified.counter,
+		verified.transports,
+		legacy.name,
+		AuthMfa.storedRpId(ctx, verified.rpId),
+	);
+	await users.setWebAuthnCredentialSupersededBy(userId, legacy.credentialId, verified.credentialId);
+	await AuthMfa.dispatchWebAuthnCredentialsUpdate(ctx, userId);
+}
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {ApiContext} from '@app/api/ApiContext';
+import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import type {WebAuthnCredential} from '@app/api/models/WebAuthnCredential';
+import {PASSKEY_MIGRATION_RP_ID} from '@fluxer/constants/src/PasskeyConstants';
+
+const PASSKEY_TARGET_TO_LEGACY_ORIGIN: ReadonlyMap<string, string> = new Map([
+	['https://fluxer.com', 'https://web.fluxer.app'],
+	['https://canary.fluxer.com', 'https://web.canary.fluxer.app'],
+]);
+
+export interface CredentialRpSelection {
+	rpId: string;
+	credentials: Array<WebAuthnCredential>;
+}
+
+export function isPasskeyTargetOrigin(ctx: ApiContext, origin: string | null | undefined): boolean {
+	if (ctx.services.config.instance.selfHosted || !origin) return false;
+	return PASSKEY_TARGET_TO_LEGACY_ORIGIN.has(origin);
+}
+
+export function passkeyLegacyOriginFor(targetOrigin: string): string {
+	return PASSKEY_TARGET_TO_LEGACY_ORIGIN.get(targetOrigin)!;
+}
+
+export function effectiveRpId(ctx: ApiContext, credential: WebAuthnCredential): string {
+	return credential.rpId ?? ctx.services.config.auth.passkeys.rpId;
+}
+
+export function visibleWebAuthnCredentials(credentials: Array<WebAuthnCredential>): Array<WebAuthnCredential> {
+	return credentials.filter((credential) => credential.supersededBy === null);
+}
+
+export function originRpId(ctx: ApiContext, origin: string | null | undefined): string {
+	return isPasskeyTargetOrigin(ctx, origin) ? PASSKEY_MIGRATION_RP_ID : ctx.services.config.auth.passkeys.rpId;
+}
+
+export async function isPasskeyMigrationActive(ctx: ApiContext, origin: string | null | undefined): Promise<boolean> {
+	if (!isPasskeyTargetOrigin(ctx, origin)) return false;
+	const config = await getInstanceConfigRepository().getDomainMigrationConfig();
+	return config.enabled;
+}
+
+function credentialGroup(ctx: ApiContext, credentials: Array<WebAuthnCredential>, rpId: string): CredentialRpSelection {
+	return {rpId, credentials: credentials.filter((credential) => effectiveRpId(ctx, credential) === rpId)};
+}
+
+export function selectCredentialRp(
+	ctx: ApiContext,
+	origin: string | null | undefined,
+	credentials: Array<WebAuthnCredential>,
+): CredentialRpSelection {
+	const legacyRpId = ctx.services.config.auth.passkeys.rpId;
+	const visible = visibleWebAuthnCredentials(credentials);
+	if (isPasskeyTargetOrigin(ctx, origin)) {
+		const target = credentialGroup(ctx, visible, PASSKEY_MIGRATION_RP_ID);
+		return target.credentials.length > 0 ? target : credentialGroup(ctx, visible, legacyRpId);
+	}
+	const legacy = credentialGroup(ctx, credentials, legacyRpId);
+	return legacy.credentials.length > 0 ? legacy : credentialGroup(ctx, visible, PASSKEY_MIGRATION_RP_ID);
+}
@@ -382,21 +382,8 @@ export class SsoService {
 			throw new RegistrationClosedError();
 		}
 		const pendingApproval = registrationConfig.mode === 'approval';
-		if (pendingApproval) {
-			await this.instanceConfigRepository.getPendingRegistrations();
-		}
 		const user = await this.provisionUserFromClaims(claims, config, {pendingApproval});
 		if (pendingApproval) {
-			await this.instanceConfigRepository.addPendingRegistration({
-				user_id: user.id.toString(),
-				username: user.username,
-				discriminator: user.discriminator,
-				global_name: user.globalName,
-				email: user.email,
-				requested_at: new Date().toISOString(),
-				registration_url_id: null,
-				client_ip: null,
-			});
 			throw new RegistrationPendingApprovalError();
 		}
 		return user;
@@ -537,8 +524,22 @@ export class SsoService {
 			version: 1,
 		} as const;
 		await this.claimSsoIdentity(userId, claims.sub, config);
+		let createAttempted = false;
 		let userCreated = false;
 		try {
+			if (options?.pendingApproval) {
+				await this.instanceConfigRepository.addPendingRegistration({
+					user_id: userId.toString(),
+					username,
+					discriminator: discriminatorResult.discriminator,
+					global_name: globalName,
+					email: userRow.email,
+					requested_at: now.toISOString(),
+					registration_url_id: null,
+					client_ip: null,
+				});
+			}
+			createAttempted = true;
 			const user = await users.create(userRow);
 			userCreated = true;
 			await users.upsertSettings(
@@ -557,6 +558,16 @@ export class SsoService {
 				await this.ssoIdentityRepository.releaseIdentity(config.providerId, claims.sub).catch((releaseError) => {
 					getLogger().error({releaseError}, 'Failed to release SSO identity after user provisioning failed');
 				});
+				if (options?.pendingApproval && !createAttempted) {
+					await this.instanceConfigRepository
+						.removePendingRegistration(userId.toString())
+						.catch((removeError: unknown) => {
+							getLogger().error(
+								{userId: userId.toString(), removeError},
+								'Failed to withdraw the pending approval of an SSO user that was never created',
+							);
+						});
+				}
 			}
 			throw error;
 		}
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createTestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {Config} from '@app/api/Config';
+import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import {type ApiTestHarness, createApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder, createBuilderWithoutAuth, type TestRequestBuilder} from '@app/api/test/TestRequestBuilder';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import {
+	type AltchaCaptchaConfig,
+	DEFAULT_ALTCHA_CAPTCHA_CONFIG,
+} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
+import {solveChallenge} from 'altcha-lib';
+import {deriveKey} from 'altcha-lib/algorithms/pbkdf2';
+import type {Challenge} from 'altcha-lib/types';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+interface CaptchaErrorBody {
+	code: string;
+	captcha_provider?: string;
+	altcha_challenge?: Challenge;
+}
+
+const FORGOT_PATH = '/auth/forgot';
+const FORGOT_BODY = {email: '[email protected]'};
+
+async function setAltchaConfig(overrides: Partial<AltchaCaptchaConfig>): Promise<void> {
+	await getInstanceConfigRepository().setAltchaCaptchaConfig({
+		...DEFAULT_ALTCHA_CAPTCHA_CONFIG,
+		enabled: true,
+		cost: 1000,
+		max_counter: 100,
+		...overrides,
+	});
+}
+
+async function solve(challenge: Challenge): Promise<string> {
+	const solution = await solveChallenge({challenge, deriveKey, timeout: 0});
+	if (!solution) throw new Error('ALTCHA challenge was not solved');
+	return Buffer.from(JSON.stringify({challenge, solution}), 'utf8').toString('base64');
+}
+
+async function rejectWith(builder: TestRequestBuilder<CaptchaErrorBody>, code: string): Promise<CaptchaErrorBody> {
+	const {json} = await builder.expect(HTTP_STATUS.BAD_REQUEST, code).executeWithResponse();
+	expect(json.code).toBe(code);
+	return json;
+}
+
+function forgot(harness: ApiTestHarness): TestRequestBuilder<CaptchaErrorBody> {
+	return createBuilderWithoutAuth<CaptchaErrorBody>(harness).post(FORGOT_PATH).body(FORGOT_BODY);
+}
+
+describe('ALTCHA captcha experiment', () => {
+	let harness: ApiTestHarness;
+	let previousCaptchaEnabled: boolean;
+	let previousTestModeEnabled: boolean;
+
+	beforeAll(async () => {
+		harness = await createApiTestHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+		previousCaptchaEnabled = Config.captcha.enabled;
+		previousTestModeEnabled = Config.dev.testModeEnabled;
+		Config.captcha.enabled = true;
+		Config.dev.testModeEnabled = true;
+	});
+
+	afterEach(() => {
+		Config.captcha.enabled = previousCaptchaEnabled;
+		Config.dev.testModeEnabled = previousTestModeEnabled;
+	});
+
+	afterAll(async () => {
+		await harness.shutdown();
+	});
+
+	it('keeps the configured provider while the experiment is off', async () => {
+		const body = await rejectWith(forgot(harness), APIErrorCodes.CAPTCHA_REQUIRED);
+		expect(body).not.toHaveProperty('captcha_provider');
+		expect(body).not.toHaveProperty('altcha_challenge');
+	});
+
+	it('leaves anonymous requests on the configured provider unless anonymous_enabled is set', async () => {
+		await setAltchaConfig({rollout_basis_points: 10000});
+		const body = await rejectWith(forgot(harness), APIErrorCodes.CAPTCHA_REQUIRED);
+		expect(body).not.toHaveProperty('altcha_challenge');
+	});
+
+	it('serves anonymous requests a challenge and accepts the solved payload once', async () => {
+		await setAltchaConfig({anonymous_enabled: true});
+		const required = await rejectWith(forgot(harness), APIErrorCodes.CAPTCHA_REQUIRED);
+		expect(required.captcha_provider).toBe('altcha');
+		expect(required.altcha_challenge?.parameters).toMatchObject({algorithm: 'PBKDF2/SHA-256', cost: 1000});
+		const token = await solve(required.altcha_challenge as Challenge);
+
+		await forgot(harness)
+			.header('X-Captcha-Token', token)
+			.header('X-Captcha-Type', 'altcha')
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+
+		const replayed = await rejectWith(
+			forgot(harness).header('X-Captcha-Token', token).header('X-Captcha-Type', 'altcha'),
+			APIErrorCodes.INVALID_CAPTCHA,
+		);
+		expect(replayed.captcha_provider).toBe('altcha');
+		expect(replayed.altcha_challenge?.signature).not.toBe(required.altcha_challenge?.signature);
+	});
+
+	it('rejects a payload whose derived key does not match the challenge', async () => {
+		await setAltchaConfig({anonymous_enabled: true});
+		const required = await rejectWith(forgot(harness), APIErrorCodes.CAPTCHA_REQUIRED);
+		const challenge = required.altcha_challenge as Challenge;
+		const forged = Buffer.from(
+			JSON.stringify({challenge, solution: {counter: 1, derivedKey: '00'.repeat(32)}}),
+			'utf8',
+		).toString('base64');
+
+		await rejectWith(
+			forgot(harness).header('X-Captcha-Token', forged).header('X-Captcha-Type', 'altcha'),
+			APIErrorCodes.INVALID_CAPTCHA,
+		);
+	});
+
+	it('rejects an ALTCHA payload from a requester outside the experiment', async () => {
+		await setAltchaConfig({anonymous_enabled: true});
+		const required = await rejectWith(forgot(harness), APIErrorCodes.CAPTCHA_REQUIRED);
+		const token = await solve(required.altcha_challenge as Challenge);
+		await setAltchaConfig({anonymous_enabled: false});
+
+		const rejected = await rejectWith(
+			forgot(harness).header('X-Captcha-Token', token).header('X-Captcha-Type', 'altcha'),
+			APIErrorCodes.INVALID_CAPTCHA,
+		);
+		expect(rejected).not.toHaveProperty('altcha_challenge');
+	});
+
+	it('buckets signed-in users by their own rollout and still accepts the configured provider', async () => {
+		Config.captcha.enabled = false;
+		const included = await createTestAccount(harness);
+		const excluded = await createTestAccount(harness);
+		Config.captcha.enabled = true;
+		await setAltchaConfig({
+			anonymous_enabled: true,
+			included_user_ids: [included.userId],
+			excluded_user_ids: [excluded.userId],
+		});
+		const redeemPath = '/gifts/altcha-gift-code/redeem';
+
+		const excludedBody = await rejectWith(
+			createBuilder<CaptchaErrorBody>(harness, excluded.token).post(redeemPath),
+			APIErrorCodes.CAPTCHA_REQUIRED,
+		);
+		expect(excludedBody).not.toHaveProperty('altcha_challenge');
+
+		const includedBody = await rejectWith(
+			createBuilder<CaptchaErrorBody>(harness, included.token).post(redeemPath),
+			APIErrorCodes.CAPTCHA_REQUIRED,
+		);
+		const token = await solve(includedBody.altcha_challenge as Challenge);
+		const solved = await createBuilder<CaptchaErrorBody>(harness, included.token)
+			.post(redeemPath)
+			.header('X-Captcha-Token', token)
+			.header('X-Captcha-Type', 'altcha')
+			.executeRaw();
+		expect([APIErrorCodes.CAPTCHA_REQUIRED, APIErrorCodes.INVALID_CAPTCHA]).not.toContain(solved.json?.code);
+
+		const classic = await createBuilder<CaptchaErrorBody>(harness, included.token)
+			.post(redeemPath)
+			.header('X-Captcha-Token', 'hcaptcha-token')
+			.header('X-Captcha-Type', 'hcaptcha')
+			.executeRaw();
+		expect([APIErrorCodes.CAPTCHA_REQUIRED, APIErrorCodes.INVALID_CAPTCHA]).not.toContain(classic.json?.code);
+	});
+});
@@ -9,6 +9,7 @@ import {
 	loginAccount,
 	registerUser,
 } from '@app/api/auth/tests/AuthTestUtils';
+import {Config} from '@app/api/Config';
 import {setInjectedRegistrationRiskEvaluator} from '@app/api/middleware/ServiceMiddleware';
 import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
 import {
@@ -33,7 +34,7 @@ import {
 	SuspiciousActivityFlags,
 } from '@fluxer/constants/src/UserConstants';
 import type {GuildResponse} from '@fluxer/schema/src/domains/guild/GuildResponseSchemas';
-import {afterAll, beforeAll, beforeEach, describe, expect, it, vi} from 'vitest';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi} from 'vitest';

 function phoneRiskEvaluator(level: RiskLevelType, riskScore: number): IRegistrationRiskEvaluator {
 	return {
@@ -241,6 +242,59 @@ describe('Deferred phone verification gate', () => {
 		expect(flags & SuspiciousActivityFlags.REQUIRE_VERIFIED_PHONE).not.toBe(0);
 	});

+	describe('with phone flagging disabled', () => {
+		const originalPhoneFlagging = {...Config.abusePolicy.phoneFlagging};
+		afterEach(() => {
+			Config.abusePolicy.phoneFlagging = originalPhoneFlagging;
+		});
+
+		it('sets no phone requirement and no deferral at registration', async () => {
+			await getInstanceConfigRepository().setInstancePolicyConfig({deferred_phone_gate_enabled: true});
+			Config.abusePolicy.phoneFlagging = {enabled: false, exemptCountryCodes: []};
+			setInjectedRegistrationRiskEvaluator(phoneRiskEvaluator(RiskLevel.High, 70));
+			const registration = await registerUser(harness, {
+				email: createUniqueEmail('flagging-off'),
+				username: createUniqueUsername('flagging_off'),
+				global_name: 'Flagging Off',
+				password: 'StrongPassword!123',
+				date_of_birth: '2000-01-01',
+				consent: true,
+			});
+			const flags = await readFlags(registration.user_id);
+			expect(flags & SuspiciousActivityFlags.REQUIRE_VERIFIED_PHONE).toBe(0);
+			expect(flags & DEFERRED_PHONE_ON_COMMUNITY_JOIN).toBe(0);
+		});
+
+		it('keeps an existing deferral dormant on a qualifying join', async () => {
+			await getInstanceConfigRepository().setInstancePolicyConfig({
+				deferred_phone_gate_enabled: true,
+				deferred_phone_gate_member_threshold: 1,
+				deferred_phone_gate_window_hours: 24,
+			});
+			const {inviteCode} = await createGuildWithInvite(harness);
+			const filler = await createTestAccount(harness);
+			await createBuilder(harness, filler.token).post(`/invites/${inviteCode}`).expect(200).execute();
+			setInjectedRegistrationRiskEvaluator(phoneRiskEvaluator(RiskLevel.High, 70));
+			const registration = await registerUser(harness, {
+				email: createUniqueEmail('flagging-off-join'),
+				username: createUniqueUsername('flagging_off_join'),
+				global_name: 'Flagging Off Join',
+				password: 'StrongPassword!123',
+				date_of_birth: '2000-01-01',
+				consent: true,
+			});
+			setInjectedRegistrationRiskEvaluator(undefined);
+			expect((await readFlags(registration.user_id)) & DEFERRED_PHONE_ON_COMMUNITY_JOIN).not.toBe(0);
+
+			Config.abusePolicy.phoneFlagging = {enabled: false, exemptCountryCodes: []};
+			await createBuilder(harness, registration.token).post(`/invites/${inviteCode}`).expect(200).execute();
+
+			const flags = await readFlags(registration.user_id);
+			expect(flags & DEFERRED_PHONE_ON_COMMUNITY_JOIN).not.toBe(0);
+			expect(flags & PHONE_GATE_PROMOTED_FROM_DEFERRAL).toBe(0);
+		});
+	});
+
 	describe('phone gate escape', () => {
 		async function configurePhoneGate(
 			overrides: {
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createHash, randomBytes} from 'node:crypto';
+import {createAuthHarness, createTestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {createTestBotAccount} from '@app/api/bot/tests/BotTestUtils';
+import {getConfig} from '@app/api/Config';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import {SuspiciousActivityFlags} from '@fluxer/constants/src/UserConstants';
+import {
+	ORIGIN_HANDOFF_MAX_PAYLOAD_LENGTH,
+	type OriginHandoffCreateResponse,
+	type OriginHandoffRedeemResponse,
+} from '@fluxer/schema/src/domains/auth/OriginHandoffSchemas';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+const CREATE_PATH = '/auth/origin-handoff';
+const REDEEM_PATH = '/auth/origin-handoff/redeem';
+const PAYLOAD = randomBytes(96).toString('base64url');
+
+function createNonce(): {nonce: string; nonceHash: string} {
+	const nonce = randomBytes(32).toString('base64url');
+	return {nonce, nonceHash: createHash('sha256').update(nonce).digest('hex')};
+}
+
+describe('Origin handoff', () => {
+	let harness: ApiTestHarness;
+	let webAppOrigin: string;
+
+	beforeAll(async () => {
+		harness = await createAuthHarness();
+		webAppOrigin = getConfig().endpoints.webAppOrigins[0];
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterEach(() => {
+		getConfig().instance.selfHosted = false;
+		getConfig().endpoints.webAppOrigins = [webAppOrigin];
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	async function createHandoff(token: string, nonceHash: string): Promise<string> {
+		const response = await createBuilder<OriginHandoffCreateResponse>(harness, token)
+			.post(CREATE_PATH)
+			.body({nonce_hash: nonceHash, payload: PAYLOAD})
+			.execute();
+		expect(response.handoff_id).toMatch(/^[A-Za-z0-9_-]{43}$/);
+		return response.handoff_id;
+	}
+
+	it('hands the payload over once to the origin that holds the nonce', async () => {
+		const account = await createTestAccount(harness);
+		const {nonce, nonceHash} = createNonce();
+		const handoffId = await createHandoff(account.token, nonceHash);
+
+		const redeemed = await createBuilderWithoutAuth<OriginHandoffRedeemResponse>(harness)
+			.post(REDEEM_PATH)
+			.header('origin', webAppOrigin)
+			.body({handoff_id: handoffId, nonce})
+			.execute();
+		expect(redeemed).toEqual({payload: PAYLOAD});
+
+		await createBuilderWithoutAuth(harness)
+			.post(REDEEM_PATH)
+			.header('origin', webAppOrigin)
+			.body({handoff_id: handoffId, nonce})
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_ORIGIN_HANDOFF)
+			.execute();
+	});
+
+	it('consumes the handoff when the nonce does not match', async () => {
+		const account = await createTestAccount(harness);
+		const {nonce, nonceHash} = createNonce();
+		const handoffId = await createHandoff(account.token, nonceHash);
+
+		await createBuilderWithoutAuth(harness)
+			.post(REDEEM_PATH)
+			.header('origin', webAppOrigin)
+			.body({handoff_id: handoffId, nonce: createNonce().nonce})
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.INVALID_ORIGIN_HANDOFF_NONCE)
+			.execute();
+
+		await createBuilderWithoutAuth(harness)
+			.post(REDEEM_PATH)
+			.header('origin', webAppOrigin)
+			.body({handoff_id: handoffId, nonce})
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_ORIGIN_HANDOFF)
+			.execute();
+	});
+
+	it('answers an unknown handoff id with its own error code', async () => {
+		await createBuilderWithoutAuth(harness)
+			.post(REDEEM_PATH)
+			.header('origin', webAppOrigin)
+			.body({handoff_id: randomBytes(32).toString('base64url'), nonce: createNonce().nonce})
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_ORIGIN_HANDOFF)
+			.execute();
+	});
+
+	it('requires a logged-in user to create a handoff', async () => {
+		await createBuilderWithoutAuth(harness)
+			.post(CREATE_PATH)
+			.body({nonce_hash: createNonce().nonceHash, payload: PAYLOAD})
+			.expect(HTTP_STATUS.UNAUTHORIZED)
+			.execute();
+	});
+
+	it('refuses to create a handoff for an account flagged as suspicious', async () => {
+		const account = await createTestAccount(harness);
+		await createBuilderWithoutAuth(harness)
+			.post(`/test/users/${account.userId}/security-flags`)
+			.body({suspicious_activity_flags: SuspiciousActivityFlags.REQUIRE_VERIFIED_PHONE})
+			.execute();
+		await createBuilder(harness, account.token)
+			.post(CREATE_PATH)
+			.body({nonce_hash: createNonce().nonceHash, payload: PAYLOAD})
+			.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.ACCOUNT_SUSPICIOUS_ACTIVITY)
+			.execute();
+	});
+
+	it('refuses a create body larger than the payload ceiling before parsing it', async () => {
+		const account = await createTestAccount(harness);
+		await createBuilder(harness, account.token)
+			.post(CREATE_PATH)
+			.body({nonce_hash: createNonce().nonceHash, payload: 'a'.repeat(ORIGIN_HANDOFF_MAX_PAYLOAD_LENGTH + 2048)})
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.FILE_SIZE_TOO_LARGE)
+			.execute();
+	});
+
+	it('refuses to create a handoff for a bot', async () => {
+		const bot = await createTestBotAccount(harness);
+		await createBuilder(harness, `Bot ${bot.botToken}`)
+			.post(CREATE_PATH)
+			.body({nonce_hash: createNonce().nonceHash, payload: PAYLOAD})
+			.expect(HTTP_STATUS.FORBIDDEN)
+			.execute();
+	});
+
+	it.each([
+		{name: 'an uppercase nonce hash', body: {nonce_hash: 'A'.repeat(64), payload: PAYLOAD}},
+		{name: 'a short nonce hash', body: {nonce_hash: 'a'.repeat(63), payload: PAYLOAD}},
+		{name: 'a payload outside base64url', body: {nonce_hash: 'a'.repeat(64), payload: 'not+base64/url='}},
+		{name: 'an empty payload', body: {nonce_hash: 'a'.repeat(64), payload: ''}},
+	])('rejects $name', async ({body}) => {
+		const account = await createTestAccount(harness);
+		await createBuilder(harness, account.token)
+			.post(CREATE_PATH)
+			.body(body)
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.INVALID_FORM_BODY)
+			.execute();
+	});
+
+	it('refuses a redeem from an origin outside the first-party web origins', async () => {
+		const account = await createTestAccount(harness);
+		const {nonce, nonceHash} = createNonce();
+		const handoffId = await createHandoff(account.token, nonceHash);
+
+		await createBuilderWithoutAuth(harness)
+			.post(REDEEM_PATH)
+			.header('origin', 'https://evil.example')
+			.body({handoff_id: handoffId, nonce})
+			.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.INVALID_API_ORIGIN)
+			.execute();
+
+		await createBuilderWithoutAuth(harness)
+			.post(REDEEM_PATH)
+			.body({handoff_id: handoffId, nonce})
+			.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.INVALID_API_ORIGIN)
+			.execute();
+
+		const redeemed = await createBuilderWithoutAuth<OriginHandoffRedeemResponse>(harness)
+			.post(REDEEM_PATH)
+			.header('origin', webAppOrigin)
+			.body({handoff_id: handoffId, nonce})
+			.execute();
+		expect(redeemed.payload).toBe(PAYLOAD);
+	});
+
+	it('accepts a redeem from a configured web app origin alias', async () => {
+		getConfig().endpoints.webAppOrigins = [webAppOrigin, 'https://fluxer.com'];
+		const account = await createTestAccount(harness);
+		const {nonce, nonceHash} = createNonce();
+		const handoffId = await createHandoff(account.token, nonceHash);
+
+		const redeemed = await createBuilderWithoutAuth<OriginHandoffRedeemResponse>(harness)
+			.post(REDEEM_PATH)
+			.header('origin', 'https://fluxer.com')
+			.body({handoff_id: handoffId, nonce})
+			.execute();
+		expect(redeemed.payload).toBe(PAYLOAD);
+	});
+
+	it('skips the origin check on a self-hosted instance', async () => {
+		getConfig().instance.selfHosted = true;
+		const account = await createTestAccount(harness);
+		const {nonce, nonceHash} = createNonce();
+		const handoffId = await createHandoff(account.token, nonceHash);
+
+		const redeemed = await createBuilderWithoutAuth<OriginHandoffRedeemResponse>(harness)
+			.post(REDEEM_PATH)
+			.body({handoff_id: handoffId, nonce})
+			.execute();
+		expect(redeemed.payload).toBe(PAYLOAD);
+	});
+});
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createHash} from 'node:crypto';
+import {
+	createAuthHarness,
+	createTestAccount,
+	type LoginMfaResponse,
+	loginUser,
+	type TestAccount,
+} from '@app/api/auth/tests/AuthTestUtils';
+import {
+	type BridgeNonce,
+	createBridgeNonce,
+	LEGACY_ORIGIN,
+	LEGACY_RP_ID,
+	registerPasskey,
+	runNativeSudoBridge,
+	setDomainMigration,
+	TARGET_ORIGIN,
+} from '@app/api/auth/tests/PasskeyTestUtils';
+import {
+	createAuthenticationResponse,
+	createTotpSecret,
+	createWebAuthnDevice,
+	generateTotpCode,
+	setWebAuthnTwoFactor,
+	type WebAuthnAuthenticationOptions,
+	type WebAuthnDevice,
+} from '@app/api/auth/tests/WebAuthnTestUtils';
+import {getConfig} from '@app/api/Config';
+import {getCacheService} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import type {
+	PasskeyBridgeFinishResponse,
+	PasskeyBridgeLoginRedeemResponse,
+	PasskeyBridgeStartResponse,
+	PasskeyBridgeSudoRedeemResponse,
+} from '@fluxer/schema/src/domains/auth/PasskeyBridgeSchemas';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+const SUDO_MODE_HEADER = 'X-Fluxer-Sudo-Mode-JWT';
+
+interface StartedBridge {
+	ceremonyId: string;
+	bridgeUrl: string | null;
+	nonce: BridgeNonce;
+}
+
+describe('Passkey bridge', () => {
+	let harness: ApiTestHarness;
+
+	beforeAll(async () => {
+		harness = await createAuthHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+		await setDomainMigration(true);
+	});
+
+	afterEach(() => {
+		getConfig().instance.selfHosted = false;
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	async function createLegacyAccount(): Promise<{account: TestAccount; device: WebAuthnDevice}> {
+		const account = await createTestAccount(harness);
+		const device = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, device, {password: account.password}, 'Old');
+		return {account, device};
+	}
+
+	async function startLogin(body: Record<string, unknown> = {}, origin = TARGET_ORIGIN): Promise<StartedBridge> {
+		const nonce = createBridgeNonce();
+		const start = await createBuilderWithoutAuth<PasskeyBridgeStartResponse>(harness)
+			.post('/auth/passkey-bridge')
+			.header('origin', origin)
+			.body({purpose: 'login', runner: 'page', nonce_hash: nonce.nonceHash, ...body})
+			.execute();
+		return {ceremonyId: start.ceremony_id, bridgeUrl: start.bridge_url, nonce};
+	}
+
+	async function startSudo(token: string, runner: 'page' | 'native' = 'page'): Promise<StartedBridge> {
+		const nonce = createBridgeNonce();
+		const start = await createBuilder<PasskeyBridgeStartResponse>(harness, token)
+			.post('/users/@me/passkey-bridge')
+			.header('origin', TARGET_ORIGIN)
+			.body({runner, nonce_hash: nonce.nonceHash})
+			.execute();
+		return {ceremonyId: start.ceremony_id, bridgeUrl: start.bridge_url, nonce};
+	}
+
+	async function fetchOptions(ceremonyId: string, origin = LEGACY_ORIGIN): Promise<WebAuthnAuthenticationOptions> {
+		const {options} = await createBuilderWithoutAuth<{options: WebAuthnAuthenticationOptions}>(harness)
+			.post(`/auth/passkey-bridge/${ceremonyId}/options`)
+			.header('origin', origin)
+			.execute();
+		return options;
+	}
+
+	async function complete(
+		ceremonyId: string,
+		device: WebAuthnDevice,
+		origin = LEGACY_ORIGIN,
+	): Promise<PasskeyBridgeFinishResponse> {
+		const options = await fetchOptions(ceremonyId, origin);
+		return createBuilderWithoutAuth<PasskeyBridgeFinishResponse>(harness)
+			.post(`/auth/passkey-bridge/${ceremonyId}/complete`)
+			.header('origin', origin)
+			.body({response: createAuthenticationResponse(device, options)})
+			.execute();
+	}
+
+	function completionCodeFrom(finish: PasskeyBridgeFinishResponse, ceremonyId: string): string {
+		const url = new URL(finish.return_url!);
+		const [id, code] = url.hash.slice('#passkey-bridge='.length).split('.');
+		expect(id).toBe(ceremonyId);
+		return code;
+	}
+
+	function redeemLogin(ceremonyId: string, nonce: string, completionCode: string) {
+		return createBuilderWithoutAuth<PasskeyBridgeLoginRedeemResponse>(harness)
+			.post(`/auth/passkey-bridge/${ceremonyId}/redeem`)
+			.header('origin', TARGET_ORIGIN)
+			.body({nonce, completion_code: completionCode});
+	}
+
+	it('refuses to start outside the new origin and on a self-hosted instance, whatever the switch', async () => {
+		const nonce = createBridgeNonce();
+		const body = {purpose: 'login', runner: 'native', nonce_hash: nonce.nonceHash};
+		for (const origin of [LEGACY_ORIGIN, 'https://evil.example']) {
+			await createBuilderWithoutAuth(harness)
+				.post('/auth/passkey-bridge')
+				.header('origin', origin)
+				.body(body)
+				.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.INVALID_API_ORIGIN)
+				.execute();
+		}
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/passkey-bridge')
+			.body(body)
+			.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.INVALID_API_ORIGIN)
+			.execute();
+		getConfig().instance.selfHosted = true;
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/passkey-bridge')
+			.header('origin', TARGET_ORIGIN)
+			.body(body)
+			.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.INVALID_API_ORIGIN)
+			.execute();
+		getConfig().instance.selfHosted = false;
+		await setDomainMigration(false);
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/passkey-bridge')
+			.header('origin', TARGET_ORIGIN)
+			.body(body)
+			.expect(HTTP_STATUS.OK)
+			.execute();
+	});
+
+	it('runs the ceremony only on the paired origin and keeps going when the switch goes off', async () => {
+		const {device} = await createLegacyAccount();
+		const started = await startLogin();
+		expect(started.bridgeUrl).toBe(`${LEGACY_ORIGIN}/passkey-bridge#${started.ceremonyId}`);
+		await createBuilderWithoutAuth(harness)
+			.post(`/auth/passkey-bridge/${started.ceremonyId}/options`)
+			.header('origin', TARGET_ORIGIN)
+			.expect(HTTP_STATUS.FORBIDDEN, APIErrorCodes.INVALID_API_ORIGIN)
+			.execute();
+		const options = await fetchOptions(started.ceremonyId);
+		expect(options.rpId).toBe(LEGACY_RP_ID);
+		expect(options.allowCredentials).toBeUndefined();
+		expect(options.userVerification).toBe('required');
+		await setDomainMigration(false);
+		await createBuilderWithoutAuth(harness)
+			.post(`/auth/passkey-bridge/${started.ceremonyId}/complete`)
+			.header('origin', LEGACY_ORIGIN)
+			.body({response: createAuthenticationResponse(device, options)})
+			.expect(HTTP_STATUS.OK)
+			.execute();
+	});
+
+	it('signs in through a page ceremony and always returns to the bridge page', async () => {
+		const {account, device} = await createLegacyAccount();
+		const started = await startLogin({
+			return_path: '/api/v1/oauth2/authorize?prompt=none&redirect_uri=https://evil.example/cb',
+		});
+		const finish = await complete(started.ceremonyId, device);
+		expect(finish.completion_code).toBeNull();
+		const returnUrl = new URL(finish.return_url!);
+		expect(`${returnUrl.origin}${returnUrl.pathname}${returnUrl.search}`).toBe(`${TARGET_ORIGIN}/passkey-bridge`);
+		const code = completionCodeFrom(finish, started.ceremonyId);
+		const redeemed = await redeemLogin(started.ceremonyId, started.nonce.nonce, code).execute();
+		expect(redeemed.status).toBe('completed');
+		if (redeemed.status !== 'completed') return;
+		expect(redeemed.user_id).toBe(account.userId);
+		const me = await createBuilder<{id: string}>(harness, redeemed.token).get('/users/@me').execute();
+		expect(me.id).toBe(account.userId);
+		await redeemLogin(started.ceremonyId, started.nonce.nonce, code)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+	});
+
+	it('needs both the nonce and the completion code', async () => {
+		const {device} = await createLegacyAccount();
+		const started = await startLogin();
+		const code = completionCodeFrom(await complete(started.ceremonyId, device), started.ceremonyId);
+		const attacker = createBridgeNonce();
+		await redeemLogin(started.ceremonyId, attacker.nonce, code)
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.INVALID_PASSKEY_BRIDGE_NONCE)
+			.execute();
+		await redeemLogin(started.ceremonyId, started.nonce.nonce, code)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+
+		const second = await startLogin();
+		completionCodeFrom(await complete(second.ceremonyId, device), second.ceremonyId);
+		await redeemLogin(second.ceremonyId, second.nonce.nonce, 'A'.repeat(43))
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.INVALID_PASSKEY_BRIDGE_NONCE)
+			.execute();
+		await redeemLogin(second.ceremonyId, second.nonce.nonce, 'A'.repeat(43))
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+	});
+
+	it('keeps a pending ceremony when redeemed early or verification fails', async () => {
+		const {account, device} = await createLegacyAccount();
+		const target = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, target, {password: account.password}, 'New', TARGET_ORIGIN);
+		const started = await startLogin();
+		await redeemLogin(started.ceremonyId, started.nonce.nonce, 'A'.repeat(43))
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+		const options = await fetchOptions(started.ceremonyId);
+		await createBuilderWithoutAuth(harness)
+			.post(`/auth/passkey-bridge/${started.ceremonyId}/complete`)
+			.header('origin', LEGACY_ORIGIN)
+			.body({response: createAuthenticationResponse(target, options)})
+			.expect(HTTP_STATUS.UNAUTHORIZED, APIErrorCodes.PASSKEY_AUTHENTICATION_FAILED)
+			.execute();
+		const code = completionCodeFrom(await complete(started.ceremonyId, device), started.ceremonyId);
+		const redeemed = await redeemLogin(started.ceremonyId, started.nonce.nonce, code).execute();
+		expect(redeemed.status).toBe('completed');
+	});
+
+	it('never lets a bridge challenge through the normal endpoints', async () => {
+		const {device} = await createLegacyAccount();
+		const started = await startLogin();
+		const options = await fetchOptions(started.ceremonyId);
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/webauthn/authenticate')
+			.header('origin', LEGACY_ORIGIN)
+			.body({response: createAuthenticationResponse(device, options), challenge: options.challenge})
+			.expect(HTTP_STATUS.UNAUTHORIZED, APIErrorCodes.PASSKEY_AUTHENTICATION_FAILED)
+			.execute();
+	});
+
+	it('reports a cancelled ceremony and refuses to cancel a completed one', async () => {
+		const {device} = await createLegacyAccount();
+		const started = await startLogin();
+		const cancelled = await createBuilderWithoutAuth<PasskeyBridgeFinishResponse>(harness)
+			.post(`/auth/passkey-bridge/${started.ceremonyId}/cancel`)
+			.header('origin', LEGACY_ORIGIN)
+			.execute();
+		const code = completionCodeFrom(cancelled, started.ceremonyId);
+		expect(await redeemLogin(started.ceremonyId, started.nonce.nonce, code).execute()).toEqual({status: 'cancelled'});
+
+		const second = await startLogin();
+		await complete(second.ceremonyId, device);
+		await createBuilderWithoutAuth(harness)
+			.post(`/auth/passkey-bridge/${second.ceremonyId}/cancel`)
+			.header('origin', LEGACY_ORIGIN)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+	});
+
+	it('completes two-factor sign in for the ticket holder', async () => {
+		const account = await createTestAccount(harness);
+		const device = createWebAuthnDevice();
+		const secret = createTotpSecret();
+		await createBuilder(harness, account.token)
+			.post('/users/@me/mfa/totp/enable')
+			.body({secret, code: generateTotpCode(secret), password: account.password})
+			.execute();
+		await registerPasskey(
+			harness,
+			account.token,
+			device,
+			{mfa_method: 'totp', mfa_code: generateTotpCode(secret)},
+			'Old',
+		);
+		await setWebAuthnTwoFactor(harness, account.token, true, {mfa_method: 'totp', mfa_code: generateTotpCode(secret)});
+		const login = (await loginUser(harness, {email: account.email, password: account.password})) as LoginMfaResponse;
+		const started = await startLogin({purpose: 'login_mfa', ticket: login.ticket});
+		const options = await fetchOptions(started.ceremonyId);
+		expect(options.allowCredentials?.map((cred) => cred.id)).toEqual([device.credentialId.toString('base64url')]);
+		expect(options.userVerification).toBe('discouraged');
+		const code = completionCodeFrom(await complete(started.ceremonyId, device), started.ceremonyId);
+		const redeemed = await redeemLogin(started.ceremonyId, started.nonce.nonce, code).execute();
+		expect(redeemed.status).toBe('completed');
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/login/mfa/totp')
+			.body({code: generateTotpCode(secret), ticket: login.ticket})
+			.expect(HTTP_STATUS.BAD_REQUEST)
+			.execute();
+	});
+
+	it('issues a sudo token that passes a sudo-protected route', async () => {
+		const {account, device} = await createLegacyAccount();
+		const credentialId = device.credentialId.toString('base64url');
+		await createBuilder(harness, account.token)
+			.patch(`/users/@me/mfa/webauthn/credentials/${credentialId}`)
+			.body({name: 'Renamed'})
+			.expect(HTTP_STATUS.FORBIDDEN)
+			.execute();
+		const redeemed = await runNativeSudoBridge(harness, account.token, device);
+		expect(redeemed.status).toBe('completed');
+		if (redeemed.status !== 'completed') return;
+		await createBuilder(harness, account.token)
+			.patch(`/users/@me/mfa/webauthn/credentials/${credentialId}`)
+			.header(SUDO_MODE_HEADER, redeemed.sudo_token)
+			.body({name: 'Renamed'})
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+	});
+
+	it('returns sudo page ceremonies to the bridge page on the new origin', async () => {
+		const {account, device} = await createLegacyAccount();
+		const started = await startSudo(account.token);
+		const finish = await complete(started.ceremonyId, device);
+		const returnUrl = new URL(finish.return_url!);
+		expect(`${returnUrl.origin}${returnUrl.pathname}`).toBe(`${TARGET_ORIGIN}/passkey-bridge`);
+		const code = completionCodeFrom(finish, started.ceremonyId);
+		const redeemed = await createBuilder<PasskeyBridgeSudoRedeemResponse>(harness, account.token)
+			.post(`/users/@me/passkey-bridge/${started.ceremonyId}/redeem`)
+			.header('origin', TARGET_ORIGIN)
+			.body({nonce: started.nonce.nonce, completion_code: code})
+			.execute();
+		expect(redeemed.status).toBe('completed');
+	});
+
+	it('does not consume a ceremony redeemed on the wrong route or by another user', async () => {
+		const {account, device} = await createLegacyAccount();
+		const other = await createTestAccount(harness);
+		const started = await startSudo(account.token, 'native');
+		const options = await fetchOptions(started.ceremonyId, TARGET_ORIGIN);
+		const finish = await createBuilderWithoutAuth<PasskeyBridgeFinishResponse>(harness)
+			.post(`/auth/passkey-bridge/${started.ceremonyId}/complete`)
+			.header('origin', TARGET_ORIGIN)
+			.body({response: createAuthenticationResponse(device, options)})
+			.execute();
+		const body = {nonce: started.nonce.nonce, completion_code: finish.completion_code};
+		await redeemLogin(started.ceremonyId, body.nonce, body.completion_code!)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+		await createBuilder(harness, other.token)
+			.post(`/users/@me/passkey-bridge/${started.ceremonyId}/redeem`)
+			.header('origin', TARGET_ORIGIN)
+			.body(body)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_BRIDGE)
+			.execute();
+		const redeemed = await createBuilder<PasskeyBridgeSudoRedeemResponse>(harness, account.token)
+			.post(`/users/@me/passkey-bridge/${started.ceremonyId}/redeem`)
+			.header('origin', TARGET_ORIGIN)
+			.body(body)
+			.execute();
+		expect(redeemed.status).toBe('completed');
+	});
+
+	it('always stores the ceremony with an expiry', async () => {
+		const {device} = await createLegacyAccount();
+		const started = await startLogin();
+		const key = `passkey_bridge:${createHash('sha256').update(started.ceremonyId).digest('hex')}`;
+		const cache = getCacheService();
+		const ttls = [await cache.ttl(key)];
+		await fetchOptions(started.ceremonyId);
+		ttls.push(await cache.ttl(key));
+		await complete(started.ceremonyId, device);
+		ttls.push(await cache.ttl(key));
+		for (const ttl of ttls) {
+			expect(ttl).toBeGreaterThan(0);
+			expect(ttl).toBeLessThanOrEqual(600);
+		}
+	});
+});
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createAuthHarness, createTestAccount, type TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {
+	LEGACY_RP_ID,
+	listPasskeys,
+	registerPasskey,
+	runNativeSudoBridge,
+	setDomainMigration,
+	TARGET_ORIGIN,
+	TARGET_RP_ID,
+} from '@app/api/auth/tests/PasskeyTestUtils';
+import {
+	createAuthenticationResponse,
+	createRegistrationResponse,
+	createWebAuthnDevice,
+	type WebAuthnAuthenticationOptions,
+	type WebAuthnDevice,
+	type WebAuthnRegistrationOptions,
+} from '@app/api/auth/tests/WebAuthnTestUtils';
+import {createUserID} from '@app/api/BrandedTypes';
+import {getUserRepository} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import type {PasskeyMigrationResponse} from '@fluxer/schema/src/domains/auth/PasskeyMigrationSchemas';
+import {afterAll, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+const MIGRATION_PATH = '/users/@me/mfa/webauthn/migration';
+const MIGRATION_OPTIONS_PATH = '/users/@me/mfa/webauthn/migration/registration-options';
+
+function credentialIdOf(device: WebAuthnDevice): string {
+	return device.credentialId.toString('base64url');
+}
+
+interface RpcSessionResponse {
+	data: {webauthn_credentials: Array<{id: string; rp_id: string}>};
+}
+
+describe('Passkey migration', () => {
+	let harness: ApiTestHarness;
+
+	beforeAll(async () => {
+		harness = await createAuthHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	async function createAssignedAccount(): Promise<{account: TestAccount; legacy: WebAuthnDevice}> {
+		const account = await createTestAccount(harness);
+		const legacy = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, legacy, {password: account.password}, 'Laptop');
+		await setDomainMigration(true, [account.userId]);
+		return {account, legacy};
+	}
+
+	async function getPending(token: string): Promise<PasskeyMigrationResponse['pending']> {
+		const response = await createBuilder<PasskeyMigrationResponse>(harness, token).get(MIGRATION_PATH).execute();
+		return response.pending;
+	}
+
+	async function migrationOptions(token: string): Promise<WebAuthnRegistrationOptions> {
+		return createBuilder<WebAuthnRegistrationOptions>(harness, token)
+			.post(MIGRATION_OPTIONS_PATH)
+			.header('origin', TARGET_ORIGIN)
+			.execute();
+	}
+
+	function completeMigration(token: string, device: WebAuthnDevice, options: WebAuthnRegistrationOptions) {
+		return createBuilder(harness, token)
+			.post(MIGRATION_PATH)
+			.header('origin', TARGET_ORIGIN)
+			.body({response: createRegistrationResponse(device, options, 'Laptop'), challenge: options.challenge});
+	}
+
+	async function migrate(account: TestAccount, legacy: WebAuthnDevice): Promise<WebAuthnDevice> {
+		await runNativeSudoBridge(harness, account.token, legacy);
+		const target = createWebAuthnDevice();
+		await completeMigration(account.token, target, await migrationOptions(account.token))
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+		return target;
+	}
+
+	async function discoverableLogin(device: WebAuthnDevice, origin?: string, status: number = HTTP_STATUS.OK) {
+		const optionsBuilder = createBuilderWithoutAuth<WebAuthnAuthenticationOptions>(harness)
+			.post('/auth/webauthn/authentication-options')
+			.body(null);
+		if (origin) optionsBuilder.header('origin', origin);
+		const options = await optionsBuilder.execute();
+		const builder = createBuilderWithoutAuth(harness)
+			.post('/auth/webauthn/authenticate')
+			.body({response: createAuthenticationResponse(device, options), challenge: options.challenge})
+			.expect(status);
+		if (origin) builder.header('origin', origin);
+		await builder.execute();
+	}
+
+	it('records a pending update for any account on the new origin while the switch is on', async () => {
+		const unassigned = await createTestAccount(harness);
+		const unassignedDevice = createWebAuthnDevice();
+		await registerPasskey(harness, unassigned.token, unassignedDevice, {password: unassigned.password}, 'Laptop');
+		await setDomainMigration(false);
+		expect((await runNativeSudoBridge(harness, unassigned.token, unassignedDevice)).status).toBe('completed');
+		expect(await getPending(unassigned.token)).toBeNull();
+
+		await setDomainMigration(true);
+		expect((await runNativeSudoBridge(harness, unassigned.token, unassignedDevice)).status).toBe('completed');
+		expect(await getPending(unassigned.token)).toEqual({
+			credential_id: credentialIdOf(unassignedDevice),
+			name: 'Laptop',
+			cross_device: false,
+		});
+	});
+
+	it('needs a pending update and the new origin for registration options', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		await createBuilder(harness, account.token)
+			.post(MIGRATION_OPTIONS_PATH)
+			.header('origin', TARGET_ORIGIN)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_MIGRATION)
+			.execute();
+		await runNativeSudoBridge(harness, account.token, legacy);
+		await createBuilder(harness, account.token)
+			.post(MIGRATION_OPTIONS_PATH)
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_PASSKEY_MIGRATION)
+			.execute();
+		const options = await migrationOptions(account.token);
+		expect(options.rp.id).toBe(TARGET_RP_ID);
+	});
+
+	it('replaces the passkey under the same name and hides the old one', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		const target = await migrate(account, legacy);
+		const credentials = await listPasskeys(harness, account.token);
+		expect(credentials).toEqual([
+			expect.objectContaining({id: credentialIdOf(target), name: 'Laptop', rp_id: TARGET_RP_ID}),
+		]);
+		const old = await getUserRepository().getWebAuthnCredential(
+			createUserID(BigInt(account.userId)),
+			credentialIdOf(legacy),
+		);
+		expect(old?.supersededBy).toBe(credentialIdOf(target));
+		expect(await getPending(account.token)).toBeNull();
+		const ready = await createBuilder<RpcSessionResponse>(harness, '')
+			.post('/test/rpc-session-init')
+			.body({type: 'session', token: account.token, version: 1, ip: '127.0.0.1'})
+			.execute();
+		expect(ready.data.webauthn_credentials.map(({id, rp_id}) => ({id, rp_id}))).toEqual([
+			{id: credentialIdOf(target), rp_id: TARGET_RP_ID},
+		]);
+	});
+
+	it('keeps the old passkey working off the new origin', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		const target = await migrate(account, legacy);
+		await discoverableLogin(legacy);
+		await discoverableLogin(legacy, TARGET_ORIGIN, HTTP_STATUS.UNAUTHORIZED);
+		await discoverableLogin(target, TARGET_ORIGIN);
+		await createBuilder(harness, account.token)
+			.patch(`/users/@me/mfa/webauthn/credentials/${credentialIdOf(legacy)}`)
+			.body({name: 'Renamed', password: account.password})
+			.expect(HTTP_STATUS.NOT_FOUND, APIErrorCodes.UNKNOWN_WEBAUTHN_CREDENTIAL)
+			.execute();
+		const sudoOptions = await createBuilder<WebAuthnAuthenticationOptions>(harness, account.token)
+			.post('/users/@me/sudo/webauthn/authentication-options')
+			.body(null)
+			.execute();
+		expect(sudoOptions.rpId).toBe(LEGACY_RP_ID);
+		expect(sudoOptions.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(legacy)]);
+	});
+
+	it('removes the old passkey together with its replacement', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		const target = await migrate(account, legacy);
+		await createBuilder(harness, account.token)
+			.delete(`/users/@me/mfa/webauthn/credentials/${credentialIdOf(target)}`)
+			.body({password: account.password})
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+		expect(await getUserRepository().listWebAuthnCredentials(createUserID(BigInt(account.userId)))).toEqual([]);
+		await discoverableLogin(legacy, undefined, HTTP_STATUS.UNAUTHORIZED);
+	});
+
+	it('removes every remaining superseded passkey with the last visible one', async () => {
+		const account = await createTestAccount(harness);
+		const orphan = createWebAuthnDevice();
+		const visible = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, orphan, {password: account.password}, 'Orphan');
+		await registerPasskey(harness, account.token, visible, {password: account.password}, 'Visible');
+		const userId = createUserID(BigInt(account.userId));
+		await getUserRepository().setWebAuthnCredentialSupersededBy(userId, credentialIdOf(orphan), 'gone');
+		await createBuilder(harness, account.token)
+			.delete(`/users/@me/mfa/webauthn/credentials/${credentialIdOf(visible)}`)
+			.body({password: account.password})
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+		expect(await getUserRepository().listWebAuthnCredentials(userId)).toEqual([]);
+	});
+
+	it('has no way to attach the old passkey to another one', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		await runNativeSudoBridge(harness, account.token, legacy);
+		const target = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, target, {password: account.password}, 'Phone', TARGET_ORIGIN);
+		await createBuilder(harness, account.token)
+			.delete(MIGRATION_PATH)
+			.header('origin', TARGET_ORIGIN)
+			.expect(HTTP_STATUS.NOT_FOUND)
+			.execute();
+		expect((await listPasskeys(harness, account.token)).map((cred) => cred.id).sort()).toEqual(
+			[credentialIdOf(legacy), credentialIdOf(target)].sort(),
+		);
+	});
+
+	it('never lets a migration challenge through the normal registration route', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		await runNativeSudoBridge(harness, account.token, legacy);
+		const options = await migrationOptions(account.token);
+		await createBuilder(harness, account.token)
+			.post('/users/@me/mfa/webauthn/credentials')
+			.header('origin', TARGET_ORIGIN)
+			.body({
+				response: createRegistrationResponse(createWebAuthnDevice(), options, 'Sneaky'),
+				challenge: options.challenge,
+				name: 'Sneaky',
+			})
+			.expect(HTTP_STATUS.BAD_REQUEST, APIErrorCodes.INVALID_WEBAUTHN_CREDENTIAL)
+			.execute();
+	});
+
+	it('creates one credential when two updates race', async () => {
+		const {account, legacy} = await createAssignedAccount();
+		await runNativeSudoBridge(harness, account.token, legacy);
+		const first = await migrationOptions(account.token);
+		const second = await migrationOptions(account.token);
+		const results = await Promise.all(
+			[first, second].map((options) =>
+				completeMigration(account.token, createWebAuthnDevice(), options)
+					.expect(HTTP_STATUS.NO_CONTENT)
+					.executeWithResponse()
+					.then(
+						() => 'ok',
+						() => 'failed',
+					),
+			),
+		);
+		expect(results.sort()).toEqual(['failed', 'ok']);
+		const credentials = await listPasskeys(harness, account.token);
+		expect(credentials).toHaveLength(1);
+		expect(credentials[0].rp_id).toBe(TARGET_RP_ID);
+	});
+});
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createAuthHarness, createTestAccount, type TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {
+	LEGACY_ORIGIN,
+	LEGACY_RP_ID,
+	listPasskeys,
+	registerPasskey,
+	TARGET_ORIGIN,
+	TARGET_RP_ID,
+} from '@app/api/auth/tests/PasskeyTestUtils';
+import {
+	createAuthenticationResponse,
+	createWebAuthnDevice,
+	type WebAuthnAuthenticationOptions,
+	type WebAuthnDevice,
+	type WebAuthnRegistrationOptions,
+} from '@app/api/auth/tests/WebAuthnTestUtils';
+import {createUserID} from '@app/api/BrandedTypes';
+import {getConfig} from '@app/api/Config';
+import {getUserRepository} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it} from 'vitest';
+
+function credentialIdOf(device: WebAuthnDevice): string {
+	return device.credentialId.toString('base64url');
+}
+
+describe('Passkey relying party selection', () => {
+	let harness: ApiTestHarness;
+
+	beforeAll(async () => {
+		harness = await createAuthHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterEach(() => {
+		getConfig().instance.selfHosted = false;
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	async function registrationRpId(account: TestAccount, origin?: string): Promise<string> {
+		const builder = createBuilder<WebAuthnRegistrationOptions>(harness, account.token)
+			.post('/users/@me/mfa/webauthn/credentials/registration-options')
+			.body({password: account.password});
+		if (origin) builder.header('origin', origin);
+		return (await builder.execute()).rp.id;
+	}
+
+	async function discoverableOptions(origin?: string): Promise<WebAuthnAuthenticationOptions> {
+		const builder = createBuilderWithoutAuth<WebAuthnAuthenticationOptions>(harness)
+			.post('/auth/webauthn/authentication-options')
+			.body(null);
+		if (origin) builder.header('origin', origin);
+		return builder.execute();
+	}
+
+	async function sudoOptions(token: string, origin?: string): Promise<WebAuthnAuthenticationOptions> {
+		const builder = createBuilder<WebAuthnAuthenticationOptions>(harness, token)
+			.post('/users/@me/sudo/webauthn/authentication-options')
+			.body(null);
+		if (origin) builder.header('origin', origin);
+		return builder.execute();
+	}
+
+	async function createMixedAccount(): Promise<{account: TestAccount; legacy: WebAuthnDevice; target: WebAuthnDevice}> {
+		const account = await createTestAccount(harness);
+		const legacy = createWebAuthnDevice();
+		const target = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, legacy, {password: account.password}, 'Old');
+		await registerPasskey(harness, account.token, target, {password: account.password}, 'New', TARGET_ORIGIN);
+		return {account, legacy, target};
+	}
+
+	it('uses the new relying party only for requests from the new origin', async () => {
+		const account = await createTestAccount(harness);
+		expect(await registrationRpId(account)).toBe(LEGACY_RP_ID);
+		expect(await registrationRpId(account, LEGACY_ORIGIN)).toBe(LEGACY_RP_ID);
+		expect(await registrationRpId(account, TARGET_ORIGIN)).toBe(TARGET_RP_ID);
+		expect((await discoverableOptions()).rpId).toBe(LEGACY_RP_ID);
+		expect((await discoverableOptions(LEGACY_ORIGIN)).rpId).toBe(LEGACY_RP_ID);
+		expect((await discoverableOptions(TARGET_ORIGIN)).rpId).toBe(TARGET_RP_ID);
+	});
+
+	it('keeps the legacy relying party everywhere on a self-hosted instance', async () => {
+		getConfig().instance.selfHosted = true;
+		const account = await createTestAccount(harness);
+		expect(await registrationRpId(account, TARGET_ORIGIN)).toBe(LEGACY_RP_ID);
+		expect((await discoverableOptions(TARGET_ORIGIN)).rpId).toBe(LEGACY_RP_ID);
+	});
+
+	it('stores and exposes the relying party of each passkey', async () => {
+		const {account, legacy, target} = await createMixedAccount();
+		const credentials = await listPasskeys(harness, account.token);
+		expect(credentials.map(({id, rp_id}) => ({id, rp_id}))).toEqual(
+			expect.arrayContaining([
+				{id: credentialIdOf(legacy), rp_id: LEGACY_RP_ID},
+				{id: credentialIdOf(target), rp_id: TARGET_RP_ID},
+			]),
+		);
+		const legacyRow = await getUserRepository().getWebAuthnCredential(
+			createUserID(BigInt(account.userId)),
+			credentialIdOf(legacy),
+		);
+		expect(legacyRow?.rpId).toBeNull();
+	});
+
+	it('keeps the legacy options unchanged for a legacy-only account off the new origin', async () => {
+		const account = await createTestAccount(harness);
+		const device = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, device, {password: account.password}, 'Old');
+		for (const origin of [undefined, LEGACY_ORIGIN]) {
+			const options = await sudoOptions(account.token, origin);
+			expect(options.rpId).toBe(LEGACY_RP_ID);
+			expect(options.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(device)]);
+			expect(options.userVerification).toBe('discouraged');
+		}
+	});
+
+	it('offers one relying party group per request', async () => {
+		const {account, legacy, target} = await createMixedAccount();
+		const onTarget = await sudoOptions(account.token, TARGET_ORIGIN);
+		expect(onTarget.rpId).toBe(TARGET_RP_ID);
+		expect(onTarget.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(target)]);
+		const offTarget = await sudoOptions(account.token);
+		expect(offTarget.rpId).toBe(LEGACY_RP_ID);
+		expect(offTarget.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(legacy)]);
+	});
+
+	it('falls back to the other group when the preferred one is empty', async () => {
+		const legacyOnly = await createTestAccount(harness);
+		const legacy = createWebAuthnDevice();
+		await registerPasskey(harness, legacyOnly.token, legacy, {password: legacyOnly.password}, 'Old');
+		expect((await sudoOptions(legacyOnly.token, TARGET_ORIGIN)).rpId).toBe(LEGACY_RP_ID);
+		const targetOnly = await createTestAccount(harness);
+		const target = createWebAuthnDevice();
+		await registerPasskey(harness, targetOnly.token, target, {password: targetOnly.password}, 'New', TARGET_ORIGIN);
+		expect((await sudoOptions(targetOnly.token)).rpId).toBe(TARGET_RP_ID);
+	});
+
+	it('rejects a passkey from another relying party before the test mode shortcut', async () => {
+		const {legacy} = await createMixedAccount();
+		const options = await discoverableOptions(TARGET_ORIGIN);
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/webauthn/authenticate')
+			.header('origin', TARGET_ORIGIN)
+			.body({response: createAuthenticationResponse(legacy, options), challenge: options.challenge})
+			.expect(HTTP_STATUS.UNAUTHORIZED, APIErrorCodes.PASSKEY_AUTHENTICATION_FAILED)
+			.execute();
+	});
+
+	it('rejects a passkey outside the offered list before the test mode shortcut', async () => {
+		const account = await createTestAccount(harness);
+		const visible = createWebAuthnDevice();
+		const superseded = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, visible, {password: account.password}, 'Visible');
+		await registerPasskey(harness, account.token, superseded, {password: account.password}, 'Superseded');
+		await getUserRepository().setWebAuthnCredentialSupersededBy(
+			createUserID(BigInt(account.userId)),
+			credentialIdOf(superseded),
+			credentialIdOf(visible),
+		);
+		const options = await sudoOptions(account.token, TARGET_ORIGIN);
+		expect(options.rpId).toBe(LEGACY_RP_ID);
+		expect(options.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(visible)]);
+		await createBuilder(harness, account.token)
+			.patch(`/users/@me/mfa/webauthn/credentials/${credentialIdOf(visible)}`)
+			.header('origin', TARGET_ORIGIN)
+			.body({
+				name: 'Renamed',
+				mfa_method: 'webauthn',
+				webauthn_response: createAuthenticationResponse(superseded, options),
+				webauthn_challenge: options.challenge,
+			})
+			.expect(HTTP_STATUS.BAD_REQUEST)
+			.execute();
+		const retry = await sudoOptions(account.token, TARGET_ORIGIN);
+		await createBuilder(harness, account.token)
+			.patch(`/users/@me/mfa/webauthn/credentials/${credentialIdOf(visible)}`)
+			.header('origin', TARGET_ORIGIN)
+			.body({
+				name: 'Renamed',
+				mfa_method: 'webauthn',
+				webauthn_response: createAuthenticationResponse(visible, retry),
+				webauthn_challenge: retry.challenge,
+			})
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+	});
+
+	it('accepts a superseded passkey only off the new origin', async () => {
+		const account = await createTestAccount(harness);
+		const legacy = createWebAuthnDevice();
+		const target = createWebAuthnDevice();
+		await registerPasskey(harness, account.token, legacy, {password: account.password}, 'Old');
+		await registerPasskey(harness, account.token, target, {password: account.password}, 'New', TARGET_ORIGIN);
+		await getUserRepository().setWebAuthnCredentialSupersededBy(
+			createUserID(BigInt(account.userId)),
+			credentialIdOf(legacy),
+			credentialIdOf(target),
+		);
+		expect((await listPasskeys(harness, account.token)).map((cred) => cred.id)).toEqual([credentialIdOf(target)]);
+
+		const offTarget = await discoverableOptions();
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/webauthn/authenticate')
+			.body({response: createAuthenticationResponse(legacy, offTarget), challenge: offTarget.challenge})
+			.expect(HTTP_STATUS.OK)
+			.execute();
+		const sudoOffTarget = await sudoOptions(account.token);
+		expect(sudoOffTarget.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(legacy)]);
+
+		const onTarget = await discoverableOptions(TARGET_ORIGIN);
+		await createBuilderWithoutAuth(harness)
+			.post('/auth/webauthn/authenticate')
+			.header('origin', TARGET_ORIGIN)
+			.body({response: createAuthenticationResponse(legacy, onTarget), challenge: onTarget.challenge})
+			.expect(HTTP_STATUS.UNAUTHORIZED, APIErrorCodes.PASSKEY_AUTHENTICATION_FAILED)
+			.execute();
+		const sudoOnTarget = await sudoOptions(account.token, TARGET_ORIGIN);
+		expect(sudoOnTarget.allowCredentials?.map((cred) => cred.id)).toEqual([credentialIdOf(target)]);
+	});
+});
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createHash, randomBytes} from 'node:crypto';
+import {
+	createAuthenticationResponse,
+	createRegistrationResponse,
+	type WebAuthnAuthenticationOptions,
+	type WebAuthnDevice,
+	type WebAuthnRegistrationOptions,
+} from '@app/api/auth/tests/WebAuthnTestUtils';
+import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {DEFAULT_DOMAIN_MIGRATION_CONFIG} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
+import type {
+	PasskeyBridgeFinishResponse,
+	PasskeyBridgeStartResponse,
+	PasskeyBridgeSudoRedeemResponse,
+} from '@fluxer/schema/src/domains/auth/PasskeyBridgeSchemas';
+
+export const TARGET_ORIGIN = 'https://fluxer.com';
+export const LEGACY_ORIGIN = 'https://web.fluxer.app';
+export const LEGACY_RP_ID = 'localhost';
+export const TARGET_RP_ID = 'fluxer.com';
+
+export interface PasskeyCredentialListItem {
+	id: string;
+	name: string;
+	rp_id: string;
+}
+
+export interface BridgeNonce {
+	nonce: string;
+	nonceHash: string;
+}
+
+export function createBridgeNonce(): BridgeNonce {
+	const nonce = randomBytes(32).toString('base64url');
+	return {nonce, nonceHash: createHash('sha256').update(nonce).digest('hex')};
+}
+
+export async function setDomainMigration(enabled: boolean, includedUserIds: Array<string> = []): Promise<void> {
+	await getInstanceConfigRepository().setDomainMigrationConfig({
+		...DEFAULT_DOMAIN_MIGRATION_CONFIG,
+		enabled,
+		included_user_ids: includedUserIds,
+	});
+}
+
+export async function registerPasskey(
+	harness: ApiTestHarness,
+	token: string,
+	device: WebAuthnDevice,
+	sudo: Record<string, unknown>,
+	name: string,
+	origin?: string,
+): Promise<void> {
+	const optionsBuilder = createBuilder<WebAuthnRegistrationOptions>(harness, token)
+		.post('/users/@me/mfa/webauthn/credentials/registration-options')
+		.body(sudo);
+	if (origin) optionsBuilder.header('origin', origin);
+	const options = await optionsBuilder.execute();
+	const registerBuilder = createBuilder(harness, token)
+		.post('/users/@me/mfa/webauthn/credentials')
+		.body({response: createRegistrationResponse(device, options, name), challenge: options.challenge, name})
+		.expect(204);
+	if (origin) registerBuilder.header('origin', origin);
+	await registerBuilder.execute();
+}
+
+export async function listPasskeys(harness: ApiTestHarness, token: string): Promise<Array<PasskeyCredentialListItem>> {
+	return createBuilder<Array<PasskeyCredentialListItem>>(harness, token)
+		.get('/users/@me/mfa/webauthn/credentials')
+		.execute();
+}
+
+export async function runNativeSudoBridge(
+	harness: ApiTestHarness,
+	token: string,
+	device: WebAuthnDevice,
+	nonce: BridgeNonce = createBridgeNonce(),
+): Promise<PasskeyBridgeSudoRedeemResponse> {
+	const start = await createBuilder<PasskeyBridgeStartResponse>(harness, token)
+		.post('/users/@me/passkey-bridge')
+		.header('origin', TARGET_ORIGIN)
+		.body({runner: 'native', nonce_hash: nonce.nonceHash})
+		.execute();
+	const {options} = await createBuilderWithoutAuth<{options: WebAuthnAuthenticationOptions}>(harness)
+		.post(`/auth/passkey-bridge/${start.ceremony_id}/options`)
+		.header('origin', TARGET_ORIGIN)
+		.execute();
+	const finish = await createBuilderWithoutAuth<PasskeyBridgeFinishResponse>(harness)
+		.post(`/auth/passkey-bridge/${start.ceremony_id}/complete`)
+		.header('origin', TARGET_ORIGIN)
+		.body({response: createAuthenticationResponse(device, options)})
+		.execute();
+	return createBuilder<PasskeyBridgeSudoRedeemResponse>(harness, token)
+		.post(`/users/@me/passkey-bridge/${start.ceremony_id}/redeem`)
+		.header('origin', TARGET_ORIGIN)
+		.body({nonce: nonce.nonce, completion_code: finish.completion_code})
+		.execute();
+}
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createHash} from 'node:crypto';
+import {
+	createAuthHarness,
+	createTestAccount,
+	createUniqueEmail,
+	createUniqueUsername,
+	enableSso,
+	setUserACLs,
+	type TestAccount,
+} from '@app/api/auth/tests/AuthTestUtils';
+import {createUserID} from '@app/api/BrandedTypes';
+import type {UserRow} from '@app/api/database/types/UserTypes';
+import {
+	InstanceConfigRepository,
+	REGISTRATION_PENDING_APPROVAL_TRAIT,
+} from '@app/api/instance/InstanceConfigRepository';
+import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
+import type {ApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {UserRepository} from '@app/api/user/repositories/UserRepository';
+import {AdminACLs} from '@fluxer/constants/src/AdminACLs';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import type {InstanceConfigResponse} from '@fluxer/schema/src/domains/admin/AdminSchemas';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi} from 'vitest';
+
+const REGISTRATION_URLS_KEY = 'registration_urls';
+const REGISTRATION_PENDING_APPROVALS_KEY = 'registration_pending_approvals';
+
+interface RegistrationResponse {
+	user_id?: string;
+	token?: string;
+	registration_pending_approval?: true;
+	code?: string;
+}
+
+function registrationBody(prefix: string, registrationUrlCode?: string): Record<string, unknown> {
+	return {
+		email: createUniqueEmail(prefix),
+		username: createUniqueUsername(prefix),
+		global_name: 'Signup Race',
+		password: 'a-strong-password',
+		date_of_birth: '2000-01-01',
+		consent: true,
+		...(registrationUrlCode === undefined ? {} : {registration_url_code: registrationUrlCode}),
+	};
+}
+
+describe('signups racing on registration URLs and pending approvals', () => {
+	let harness: ApiTestHarness;
+	let admin: TestAccount;
+
+	beforeAll(async () => {
+		harness = await createAuthHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+		admin = await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+	});
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	const register = (prefix: string, registrationUrlCode?: string) =>
+		createBuilderWithoutAuth<RegistrationResponse>(harness)
+			.post('/auth/register')
+			.body(registrationBody(prefix, registrationUrlCode))
+			.executeRaw();
+
+	const readAdminConfig = (): Promise<InstanceConfigResponse> =>
+		createBuilder<InstanceConfigResponse>(harness, admin.token).get('/admin/instance/config').execute();
+
+	const completeSso = async (prefix: string) => {
+		const start = await createBuilderWithoutAuth<{state: string}>(harness)
+			.post('/auth/sso/start')
+			.body({redirect_to: '/me'})
+			.execute();
+		return createBuilderWithoutAuth(harness)
+			.post('/auth/sso/complete')
+			.body({code: createUniqueEmail(prefix), state: start.state})
+			.executeRaw();
+	};
+
+	const failCreateAfterTheUserRowIsWritten = () => {
+		const create = UserRepository.prototype.create;
+		vi.spyOn(UserRepository.prototype, 'create').mockImplementationOnce(async function (
+			this: UserRepository,
+			row: UserRow,
+		) {
+			await create.call(this, row);
+			throw new Error('the user indexes could not be written after the user row');
+		});
+	};
+
+	const failAfterThePendingApprovalIsStored = () => {
+		const addPendingRegistration = InstanceConfigRepository.prototype.addPendingRegistration;
+		vi.spyOn(InstanceConfigRepository.prototype, 'addPendingRegistration').mockImplementationOnce(async function (
+			this: InstanceConfigRepository,
+			entry: Parameters<InstanceConfigRepository['addPendingRegistration']>[0],
+		) {
+			await addPendingRegistration.call(this, entry);
+			throw new Error('the pending approval could not be published');
+		});
+	};
+
+	const expectOnePendingAccount = async () => {
+		const pending = (await readAdminConfig()).registration.pending_registrations;
+		expect(pending).toHaveLength(1);
+		const account = await new UserRepository().findUnique(createUserID(BigInt(pending[0]!.user_id)));
+		expect(account?.traits.has(REGISTRATION_PENDING_APPROVAL_TRAIT)).toBe(true);
+	};
+
+	it('never lets concurrent signups through a capped registration URL exceed max_uses', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const {code, registrationUrl} = await repository.createRegistrationUrl({
+			label: 'Capped',
+			createdByUserId: '1',
+			expiresAt: null,
+			maxUses: 2,
+			approvalRequired: false,
+		});
+
+		const attempts = await Promise.all(Array.from({length: 6}, (_, index) => register(`capped${index}`, code)));
+
+		const admitted = attempts.filter((attempt) => attempt.response.status === HTTP_STATUS.OK);
+		const refused = attempts.filter((attempt) => attempt.response.status !== HTTP_STATUS.OK);
+		expect(admitted).toHaveLength(2);
+		for (const attempt of refused) {
+			expect(attempt.response.status).toBe(HTTP_STATUS.BAD_REQUEST);
+			expect(attempt.json.code).toBe(APIErrorCodes.REGISTRATION_URL_INVALID);
+		}
+		const stored = (await readAdminConfig()).registration.urls.find((url) => url.id === registrationUrl.id);
+		expect(stored?.use_count).toBe(2);
+		expect(admitted.map((attempt) => attempt.json.user_id)).toContain(stored?.last_used_by_user_id);
+	});
+
+	it('admits exactly max_uses when 120 signups race through a registration URL capped at 40', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const {code, registrationUrl} = await repository.createRegistrationUrl({
+			label: 'Capped at 40',
+			createdByUserId: '1',
+			expiresAt: null,
+			maxUses: 40,
+			approvalRequired: false,
+		});
+		const registerUntilDecided = async (prefix: string) => {
+			for (let attempt = 0; attempt < 20; attempt += 1) {
+				const result = await register(`${prefix}r${attempt}`, code);
+				if (result.response.status !== HTTP_STATUS.SERVICE_UNAVAILABLE) return result;
+			}
+			throw new Error('a signup never reached a decision');
+		};
+
+		const attempts = await Promise.all(Array.from({length: 120}, (_, index) => registerUntilDecided(`surge${index}`)));
+
+		const admitted = attempts.filter((attempt) => attempt.response.status === HTTP_STATUS.OK);
+		expect(admitted).toHaveLength(40);
+		for (const attempt of attempts.filter((entry) => entry.response.status !== HTTP_STATUS.OK)) {
+			expect(attempt.response.status).toBe(HTTP_STATUS.BAD_REQUEST);
+			expect(attempt.json.code).toBe(APIErrorCodes.REGISTRATION_URL_INVALID);
+		}
+		const stored = (await readAdminConfig()).registration.urls.find((url) => url.id === registrationUrl.id);
+		expect(stored?.use_count).toBe(40);
+	});
+
+	it('counts every concurrent signup through an uncapped registration URL', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const {code, registrationUrl} = await repository.createRegistrationUrl({
+			label: 'Uncapped',
+			createdByUserId: '1',
+			expiresAt: null,
+			maxUses: null,
+			approvalRequired: false,
+		});
+
+		const attempts = await Promise.all(Array.from({length: 5}, (_, index) => register(`uncapped${index}`, code)));
+
+		expect(attempts.map((attempt) => attempt.response.status)).toEqual(Array(5).fill(HTTP_STATUS.OK));
+		const stored = (await readAdminConfig()).registration.urls.find((url) => url.id === registrationUrl.id);
+		expect(stored?.use_count).toBe(5);
+	});
+
+	it('gives the seat and the pending entry back when the signup failed before the account was created', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const {code, registrationUrl} = await repository.createRegistrationUrl({
+			label: 'Single use',
+			createdByUserId: '1',
+			expiresAt: null,
+			maxUses: 1,
+			approvalRequired: true,
+		});
+		failAfterThePendingApprovalIsStored();
+
+		const failed = await register('seatreleased', code);
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		const withdrawn = await readAdminConfig();
+		expect(withdrawn.registration.pending_registrations).toEqual([]);
+		expect(withdrawn.registration.urls.find((url) => url.id === registrationUrl.id)?.use_count).toBe(0);
+
+		const retried = await register('seatreleasedretry', code);
+
+		expect(retried.response.status).toBe(HTTP_STATUS.OK);
+		const stored = (await readAdminConfig()).registration.urls.find((url) => url.id === registrationUrl.id);
+		expect(stored).toMatchObject({use_count: 1, last_used_by_user_id: retried.json.user_id});
+	});
+
+	it('keeps the seat when the account create itself failed, because the row may still have landed', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const {code, registrationUrl} = await repository.createRegistrationUrl({
+			label: 'Single use',
+			createdByUserId: '1',
+			expiresAt: null,
+			maxUses: 1,
+			approvalRequired: false,
+		});
+		vi.spyOn(UserRepository.prototype, 'create').mockRejectedValueOnce(new Error('the user row write failed'));
+
+		const failed = await register('seatkeptoncreate', code);
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		const second = await register('seatkeptcreate2', code);
+
+		expect(second.response.status).toBe(HTTP_STATUS.BAD_REQUEST);
+		expect(second.json.code).toBe(APIErrorCodes.REGISTRATION_URL_INVALID);
+		const stored = (await readAdminConfig()).registration.urls.find((url) => url.id === registrationUrl.id);
+		expect(stored?.use_count).toBe(1);
+	});
+
+	it('keeps the seat of an account whose row was written before its creation failed', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const {code, registrationUrl} = await repository.createRegistrationUrl({
+			label: 'Single use',
+			createdByUserId: '1',
+			expiresAt: null,
+			maxUses: 1,
+			approvalRequired: false,
+		});
+		failCreateAfterTheUserRowIsWritten();
+
+		const failed = await register('seatkept', code);
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		const second = await register('seatkeptsecond', code);
+
+		expect(second.response.status).toBe(HTTP_STATUS.BAD_REQUEST);
+		expect(second.json.code).toBe(APIErrorCodes.REGISTRATION_URL_INVALID);
+		const stored = (await readAdminConfig()).registration.urls.find((url) => url.id === registrationUrl.id);
+		expect(stored?.use_count).toBe(1);
+	});
+
+	it('honours the use count and cap already stored on a registration URL', async () => {
+		const repository = getInstanceConfigRepository();
+		await repository.setRegistrationConfig({mode: 'closed', admin_registration_urls_enabled: true});
+		const id = 'b3c4f0b2-8a6e-4c41-9f55-3f0c2a7d1e90';
+		await repository.setConfig(
+			REGISTRATION_URLS_KEY,
+			JSON.stringify([
+				{
+					id,
+					label: 'Issued earlier',
+					code_hash: createHash('sha256').update(id).digest('hex'),
+					created_by_user_id: '1400000000000000001',
+					created_at: '2026-09-01T00:00:00.000Z',
+					expires_at: null,
+					max_uses: 2,
+					use_count: 1,
+					revoked_at: null,
+					approval_required: false,
+					last_used_at: '2026-09-02T00:00:00.000Z',
+					last_used_by_user_id: '1400000000000000002',
+				},
+			]),
+		);
+
+		const before = (await readAdminConfig()).registration.urls.find((url) => url.id === id);
+		expect(before).toMatchObject({use_count: 1, max_uses: 2, last_used_by_user_id: '1400000000000000002'});
+
+		const first = await register('storedinvite', id);
+		expect(first.response.status).toBe(HTTP_STATUS.OK);
+		const second = await register('storedinviteagain', id);
+		expect(second.response.status).toBe(HTTP_STATUS.BAD_REQUEST);
+		expect(second.json.code).toBe(APIErrorCodes.REGISTRATION_URL_INVALID);
+
+		const after = (await readAdminConfig()).registration.urls.find((url) => url.id === id);
+		expect(after).toMatchObject({use_count: 2, max_uses: 2, last_used_by_user_id: first.json.user_id});
+	});
+
+	it('keeps every pending approval when approval-mode signups race', async () => {
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+
+		const attempts = await Promise.all(Array.from({length: 5}, (_, index) => register(`pending${index}`)));
+
+		expect(attempts.map((attempt) => attempt.json.registration_pending_approval)).toEqual(Array(5).fill(true));
+		const pending = (await readAdminConfig()).registration.pending_registrations.map((entry) => entry.user_id);
+		expect(pending.toSorted()).toEqual(attempts.map((attempt) => attempt.json.user_id).toSorted());
+	});
+
+	it('lists an approval-mode account whose signup failed after the account was created', async () => {
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		vi.spyOn(UserRepository.prototype, 'createAuthorizedIp').mockRejectedValueOnce(
+			new Error('the authorized IP write failed'),
+		);
+
+		const failed = await register('pendingstranded');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		await expectOnePendingAccount();
+	});
+
+	it('lists an approval-mode account whose row was written before its creation failed', async () => {
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		failCreateAfterTheUserRowIsWritten();
+
+		const failed = await register('pendingrowwritten');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		await expectOnePendingAccount();
+	});
+
+	it('keeps the pending approval of an approval-mode signup whose account create failed', async () => {
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		vi.spyOn(UserRepository.prototype, 'create').mockRejectedValueOnce(new Error('the user row write failed'));
+
+		const failed = await register('pendingkept');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		expect((await readAdminConfig()).registration.pending_registrations).toHaveLength(1);
+	});
+
+	it('lists no pending approval for an approval-mode signup that failed before the account was created', async () => {
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		failAfterThePendingApprovalIsStored();
+
+		const failed = await register('pendingnever');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		expect((await readAdminConfig()).registration.pending_registrations).toEqual([]);
+	});
+
+	it('lists an SSO account provisioned in approval mode whose provisioning failed after the account was created', async () => {
+		await enableSso(harness, admin.token, {enforced: false});
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		vi.spyOn(UserRepository.prototype, 'upsertSettings').mockRejectedValueOnce(new Error('the settings write failed'));
+
+		const failed = await completeSso('ssopendingstranded');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		await expectOnePendingAccount();
+	});
+
+	it('lists an SSO account provisioned in approval mode whose row was written before its creation failed', async () => {
+		await enableSso(harness, admin.token, {enforced: false});
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		failCreateAfterTheUserRowIsWritten();
+
+		const failed = await completeSso('ssopendingrowwritten');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		await expectOnePendingAccount();
+	});
+
+	it('keeps the pending approval of an SSO signup in approval mode whose account create failed', async () => {
+		await enableSso(harness, admin.token, {enforced: false});
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		vi.spyOn(UserRepository.prototype, 'create').mockRejectedValueOnce(new Error('the user row write failed'));
+
+		const failed = await completeSso('ssopendingkept');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		expect((await readAdminConfig()).registration.pending_registrations).toHaveLength(1);
+	});
+
+	it('lists no pending approval for an SSO signup in approval mode that failed before the account was created', async () => {
+		await enableSso(harness, admin.token, {enforced: false});
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		failAfterThePendingApprovalIsStored();
+
+		const failed = await completeSso('ssopendingnever');
+
+		expect(failed.response.status).toBe(HTTP_STATUS.INTERNAL_SERVER_ERROR);
+		expect((await readAdminConfig()).registration.pending_registrations).toEqual([]);
+	});
+
+	it('keeps a stored pending approval listed until an admin decides it', async () => {
+		const account = await createTestAccount(harness);
+		await getInstanceConfigRepository().setConfig(
+			REGISTRATION_PENDING_APPROVALS_KEY,
+			JSON.stringify([
+				{
+					user_id: account.userId,
+					username: 'stored_pending',
+					discriminator: 1,
+					global_name: null,
+					email: account.email,
+					requested_at: '2026-09-01T00:00:00.000Z',
+					registration_url_id: null,
+					client_ip: '127.0.0.1',
+				},
+			]),
+		);
+		await getInstanceConfigRepository().setRegistrationConfig({mode: 'approval'});
+		const fresh = await register('pendingafter');
+
+		const listed = (await readAdminConfig()).registration.pending_registrations.map((entry) => entry.user_id);
+		expect(listed.toSorted()).toEqual([account.userId, fresh.json.user_id].toSorted());
+
+		const decided = await createBuilder<InstanceConfigResponse>(harness, admin.token)
+			.patch(`/admin/instance/pending-registrations/${account.userId}`)
+			.body({status: 'approved'})
+			.expect(HTTP_STATUS.OK)
+			.execute();
+
+		expect(decided.registration.pending_registrations.map((entry) => entry.user_id)).toEqual([fresh.json.user_id]);
+		expect(
+			JSON.parse(
+				(await getInstanceConfigRepository().getConfig(REGISTRATION_PENDING_APPROVALS_KEY)) ?? 'null',
+			) as Array<{user_id: string}>,
+		).toEqual([expect.objectContaining({user_id: fresh.json.user_id})]);
+	});
+});
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createChannelID, createUserID, type UserID} from '@app/api/BrandedTypes';
+import type {IChannelRepository} from '@app/api/channel/IChannelRepository';
+import {CallService} from '@app/api/channel/services/CallService';
+import type {IGuildRepositoryAggregate} from '@app/api/guild/repositories/IGuildRepositoryAggregate';
+import type {CallCaller, CallData, IGatewayService} from '@app/api/infrastructure/IGatewayService';
+import type {ISnowflakeService} from '@app/api/infrastructure/ISnowflakeService';
+import type {IVoiceRoomStore} from '@app/api/infrastructure/IVoiceRoomStore';
+import type {UserCacheService} from '@app/api/infrastructure/UserCacheService';
+import type {RequestCache} from '@app/api/middleware/RequestCacheMiddleware';
+import type {Channel} from '@app/api/models/Channel';
+import type {User} from '@app/api/models/User';
+import type {ReadStateService} from '@app/api/read_state/ReadStateService';
+import type {IUserRepository} from '@app/api/user/IUserRepository';
+import {ChannelTypes} from '@fluxer/constants/src/ChannelConstants';
+import type {UserPartialResponse} from '@fluxer/schema/src/domains/user/UserResponseSchemas';
+import {beforeEach, describe, expect, it} from 'vitest';
+
+const CALLER_ID = createUserID(1n);
+const RECIPIENT_ID = createUserID(2n);
+const CHANNEL_ID = createChannelID(12n);
+
+interface CallerOverrides {
+	username?: string;
+	globalName?: string | null;
+	avatar?: string | null;
+	nickname?: string;
+	userRowMissing?: boolean;
+}
+
+interface Harness {
+	service: CallService;
+	created: Array<CallCaller | undefined>;
+	rung: Array<CallCaller | undefined>;
+}
+
+const EXISTING_CALL: CallData = {
+	channel_id: CHANNEL_ID.toString(),
+	message_id: '99',
+	region: 'automatic',
+	ringing: [],
+	recipients: [CALLER_ID.toString(), RECIPIENT_ID.toString()],
+	voice_states: [],
+};
+
+function harness(overrides: CallerOverrides, existingCall: CallData | null): Harness {
+	const username = overrides.username ?? 'elias';
+	const globalName = overrides.globalName === undefined ? 'Elias' : overrides.globalName;
+	const avatar = overrides.avatar === undefined ? 'a1b2c3d4' : overrides.avatar;
+	const nicknames = new Map<string, string>();
+	if (overrides.nickname !== undefined) {
+		nicknames.set(CALLER_ID.toString(), overrides.nickname);
+	}
+	const channel = {
+		id: CHANNEL_ID,
+		type: ChannelTypes.GROUP_DM,
+		recipientIds: new Set<UserID>([CALLER_ID, RECIPIENT_ID]),
+		nicknames,
+	} as unknown as Channel;
+	const created: Array<CallCaller | undefined> = [];
+	const rung: Array<CallCaller | undefined> = [];
+	const channelRepository = {
+		findUnique: async () => channel,
+		upsertMessage: async () => {},
+		getMessage: async () => null,
+	} as unknown as IChannelRepository;
+	const userRepository = {
+		findUnique: async () => (overrides.userRowMissing ? null : ({...callerUser(username, globalName, avatar)} as User)),
+		listUsers: async () => [],
+		findSettings: async () => null,
+		isDmChannelOpen: async () => true,
+	} as unknown as IUserRepository;
+	const gatewayService = {
+		getCall: async () => existingCall,
+		createCall: async (
+			_channelId: unknown,
+			_messageId: string,
+			_region: string,
+			_ringing: Array<string>,
+			_recipients: Array<string>,
+			caller?: CallCaller,
+		) => {
+			created.push(caller);
+			return EXISTING_CALL;
+		},
+		ringCallRecipients: async (_channelId: unknown, _recipients: Array<string>, caller?: CallCaller) => {
+			rung.push(caller);
+			return true;
+		},
+	} as unknown as IGatewayService;
+	const userCacheService = {
+		getUserPartialResponse: async (): Promise<UserPartialResponse> =>
+			({
+				id: CALLER_ID.toString(),
+				username,
+				discriminator: '0001',
+				global_name: globalName,
+				avatar,
+				avatar_color: null,
+				flags: 0,
+			}) as unknown as UserPartialResponse,
+	} as unknown as UserCacheService;
+	const snowflakeService = {
+		generateForChannel: async () => 7777n,
+	} as unknown as ISnowflakeService;
+	const readStateService = {
+		ackMessage: async () => {},
+		bulkIncrementMentionCounts: async () => {},
+	} as unknown as ReadStateService;
+	const service = new CallService(
+		channelRepository,
+		userRepository,
+		{} as unknown as IGuildRepositoryAggregate,
+		gatewayService,
+		userCacheService,
+		snowflakeService,
+		readStateService,
+		null,
+		{} as unknown as IVoiceRoomStore,
+	);
+	return {service, created, rung};
+}
+
+function callerUser(username: string, globalName: string | null, avatar: string | null): Partial<User> {
+	return {
+		id: CALLER_ID,
+		username,
+		globalName,
+		avatarHash: avatar,
+		isBot: false,
+	};
+}
+
+const requestCache = {
+	userPartials: new Map(),
+} as unknown as RequestCache;
+
+describe('CallService caller identity', () => {
+	let harnessState: Harness;
+
+	const createCall = (overrides: CallerOverrides = {}) => {
+		harnessState = harness(overrides, null);
+		return harnessState.service.createOrGetCall({
+			userId: CALLER_ID,
+			channelId: CHANNEL_ID,
+			ringing: [RECIPIENT_ID],
+			requestCache,
+		});
+	};
+
+	const ringExistingCall = (overrides: CallerOverrides = {}) => {
+		harnessState = harness(overrides, EXISTING_CALL);
+		return harnessState.service.ringCallRecipients({
+			userId: CALLER_ID,
+			channelId: CHANNEL_ID,
+			requestCache,
+		});
+	};
+
+	beforeEach(() => {
+		requestCache.userPartials.clear();
+	});
+
+	it('sends the caller id, display name and avatar hash to createCall', async () => {
+		await createCall();
+		expect(harnessState.created).toEqual([{id: '1', name: 'Elias', avatar: 'a1b2c3d4'}]);
+	});
+
+	it('prefers the group dm nickname over the global name on createCall', async () => {
+		await createCall({nickname: 'Eli'});
+		expect(harnessState.created[0]?.name).toBe('Eli');
+	});
+
+	it('falls back to the username when the caller has no nickname and no global name', async () => {
+		await createCall({globalName: null});
+		expect(harnessState.created[0]?.name).toBe('elias');
+	});
+
+	it('sends a null avatar when the caller has no custom avatar', async () => {
+		await createCall({avatar: null});
+		expect(harnessState.created[0]).toEqual({id: '1', name: 'Elias', avatar: null});
+	});
+
+	it('sends no caller at all when the caller user row is gone', async () => {
+		await createCall({userRowMissing: true});
+		expect(harnessState.created).toEqual([undefined]);
+	});
+
+	it('sends the caller id, display name and avatar hash to ringCallRecipients', async () => {
+		await ringExistingCall();
+		expect(harnessState.rung).toEqual([{id: '1', name: 'Elias', avatar: 'a1b2c3d4'}]);
+	});
+
+	it('prefers the group dm nickname over the global name on ringCallRecipients', async () => {
+		await ringExistingCall({nickname: 'Eli'});
+		expect(harnessState.rung[0]?.name).toBe('Eli');
+	});
+
+	it('falls back to the username on ringCallRecipients', async () => {
+		await ringExistingCall({globalName: null});
+		expect(harnessState.rung[0]?.name).toBe('elias');
+	});
+
+	it('resolves the caller on the ring branch and not on the create branch', async () => {
+		await ringExistingCall();
+		expect(harnessState.created).toEqual([]);
+		expect(harnessState.rung).toHaveLength(1);
+	});
+});
@@ -12,6 +12,7 @@ import type {ISnowflakeService} from '@app/api/infrastructure/ISnowflakeService'
 import type {IVoiceRoomStore} from '@app/api/infrastructure/IVoiceRoomStore';
 import type {UserCacheService} from '@app/api/infrastructure/UserCacheService';
 import type {RequestCache} from '@app/api/middleware/RequestCacheMiddleware';
+import type {Channel} from '@app/api/models/Channel';
 import type {ReadStateService} from '@app/api/read_state/ReadStateService';
 import type {IUserRepository} from '@app/api/user/IUserRepository';
 import type {VoiceAccessContext, VoiceAvailabilityService} from '@app/api/voice/VoiceAvailabilityService';
@@ -208,14 +209,26 @@ export class CallService {
 			has_reaction: false,
 			version: 1,
 		});
+		const author = await this.userRepository.findUnique(userId);
 		const call = await this.gatewayService.createCall(
 			channelId,
 			messageId.toString(),
 			selectedRegion,
 			ringing.map((id) => id.toString()),
 			allRecipients.map((id) => id.toString()),
+			author
+				? {
+						id: userId.toString(),
+						name: this.resolveCallerName({
+							channel,
+							userId,
+							globalName: author.globalName,
+							username: author.username,
+						}),
+						avatar: author.avatarHash,
+					}
+				: undefined,
 		);
-		const author = await this.userRepository.findUnique(userId);
 		await incrementDmMentionCounts({
 			readStateService: this.readStateService,
 			userRepository: this.userRepository,
@@ -390,13 +403,45 @@ export class CallService {
 				longitude,
 			});
 		} else {
+			const caller = await this.userCacheService.getUserPartialResponse(userId, requestCache);
 			await this.gatewayService.ringCallRecipients(
 				channelId,
 				recipientsToRing.map((id) => id.toString()),
+				{
+					id: userId.toString(),
+					name: this.resolveCallerName({
+						channel,
+						userId,
+						globalName: caller.global_name,
+						username: caller.username,
+					}),
+					avatar: caller.avatar,
+				},
 			);
 		}
 	}

+	private resolveCallerName({
+		channel,
+		userId,
+		globalName,
+		username,
+	}: {
+		channel: Channel;
+		userId: UserID;
+		globalName: string | null;
+		username: string;
+	}): string {
+		const nickname = channel.nicknames.get(userId.toString());
+		if (nickname) {
+			return nickname;
+		}
+		if (globalName) {
+			return globalName;
+		}
+		return username;
+	}
+
 	async stopRingingCallRecipients({
 		userId,
 		channelId,
@@ -3,7 +3,7 @@
 import type {AttachmentID, ChannelID} from '@app/api/BrandedTypes';
 import type {AttachmentRequestData} from '@app/api/channel/AttachmentDTOs';
 import type {RichEmbedMediaWithMetadata} from '@app/api/channel/EmbedTypes';
-import {makeAttachmentCdnUrl} from '@app/api/channel/services/message/MessageHelpers';
+import {getContentType, makeAttachmentCdnUrl} from '@app/api/channel/services/message/MessageHelpers';
 import {ValidationErrorCodes} from '@fluxer/constants/src/ValidationErrorCodes';
 import {InputValidationError} from '@fluxer/errors/src/domains/core/InputValidationError';
 import type {RichEmbedRequest} from '@fluxer/schema/src/domains/message/MessageRequestSchemas';
@@ -26,7 +26,10 @@ interface RichEmbedRequestWithMetadata extends Omit<RichEmbedRequest, 'image' |
 	thumbnail?: RichEmbedMediaWithMetadata | null;
 }

-const SUPPORTED_IMAGE_EXTENSIONS = new Set(['png', 'jpg', 'jpeg', 'webp', 'gif']);
+function isEmbeddableMediaType(contentType: string): boolean {
+	const normalized = contentType.toLowerCase();
+	return normalized.startsWith('image/') || normalized.startsWith('video/');
+}

 export class MessageEmbedAttachmentResolver {
 	validateAttachmentReferences(params: {
@@ -69,8 +72,7 @@ export class MessageEmbedAttachmentResolver {
 					{filename},
 				);
 			}
-			const extension = filename.split('.').pop()?.toLowerCase();
-			if (!extension || !SUPPORTED_IMAGE_EXTENSIONS.has(extension)) {
+			if (!isEmbeddableMediaType(getContentType(filename))) {
 				throw InputValidationError.fromCode(
 					`embeds[${embedIndex}].${field}`,
 					ValidationErrorCodes.ATTACHMENT_MUST_BE_IMAGE,
@@ -137,8 +139,7 @@ export class MessageEmbedAttachmentResolver {
 			if (!attachmentData) {
 				throw InputValidationError.fromCode(field, ValidationErrorCodes.REFERENCED_ATTACHMENT_NOT_FOUND, {filename});
 			}
-			const extension = filename.split('.').pop()?.toLowerCase();
-			if (!extension || !SUPPORTED_IMAGE_EXTENSIONS.has(extension)) {
+			if (!isEmbeddableMediaType(attachmentData.metadata.content_type)) {
 				throw InputValidationError.fromCode(field, ValidationErrorCodes.ATTACHMENT_MUST_BE_IMAGE, {filename});
 			}
 			return attachmentData;
@@ -252,9 +252,7 @@ export class MessageValidationService {
 		const isAuthor = message.authorId === userId;
 		if (!guild) return isAuthor;
 		if (isAuthor) return true;
-		const canManageMessages =
-			(await hasPermission(Permissions.SEND_MESSAGES)) && (await hasPermission(Permissions.MANAGE_MESSAGES));
-		return canManageMessages;
+		return hasPermission(Permissions.MANAGE_MESSAGES);
 	}

 	private validateVoiceMessageConstraints(
@@ -512,6 +512,34 @@ describe('Embed Attachment URL Resolution', () => {
 			expect(json.embeds).toHaveLength(1);
 			expect(json.embeds![0].image?.url).not.toContain('attachment://');
 		});
+		it('should accept image and video attachments beyond the legacy image extensions', async () => {
+			const account = await createTestAccount(harness);
+			const guild = await createGuild(harness, account.token, 'Media Type Guild');
+			const channel = await createChannel(harness, account.token, guild.id, 'test-channel');
+			const channelId = guild.system_channel_id ?? channel.id;
+			const payload = {
+				content: 'Test with jxl and mp4 embed media',
+				attachments: [
+					{id: 0, filename: 'photo.jxl'},
+					{id: 1, filename: 'clip.mp4'},
+				],
+				embeds: [
+					{
+						title: 'Media Embed',
+						image: {url: 'attachment://clip.mp4'},
+						thumbnail: {url: 'attachment://photo.jxl'},
+					},
+				],
+			};
+			const {response, json} = await sendMessageWithAttachments(harness, account.token, channelId, payload, [
+				{index: 0, filename: 'photo.jxl', data: Buffer.from('jxl bytes')},
+				{index: 1, filename: 'clip.mp4', data: Buffer.from('mp4 bytes')},
+			]);
+			expect(response.status).toBe(200);
+			expect(json.embeds).toHaveLength(1);
+			expect(json.embeds![0].image?.url).not.toContain('attachment://');
+			expect(json.embeds![0].thumbnail?.url).not.toContain('attachment://');
+		});
 	});
 	describe('Multiple Embeds and Files', () => {
 		it('should handle multiple embeds with different URL types', async () => {
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {TestAccount} from '@app/api/auth/tests/AuthTestUtils';
+import {
+	createPermissionOverwrite,
+	sendChannelMessage,
+	setupTestGuildWithMembers,
+} from '@app/api/channel/tests/ChannelTestUtils';
+import {type ApiTestHarness, createApiTestHarness} from '@app/api/test/ApiTestHarness';
+import {HTTP_STATUS} from '@app/api/test/TestConstants';
+import {createBuilder} from '@app/api/test/TestRequestBuilder';
+import {Permissions} from '@fluxer/constants/src/ChannelConstants';
+import {afterAll, beforeAll, beforeEach, describe, it} from 'vitest';
+
+describe('Message delete permissions', () => {
+	let harness: ApiTestHarness;
+
+	beforeAll(async () => {
+		harness = await createApiTestHarness();
+	});
+
+	beforeEach(async () => {
+		await harness.reset();
+	});
+
+	afterAll(async () => {
+		await harness?.shutdown();
+	});
+
+	it('lets a member with MANAGE_MESSAGES but without SEND_MESSAGES delete another member message', async () => {
+		const {owner, members, systemChannel} = await setupTestGuildWithMembers(harness, 2);
+		const [author, moderator] = members as [TestAccount, TestAccount];
+		const message = await sendChannelMessage(harness, author.token, systemChannel.id, 'delete me');
+		await createPermissionOverwrite(harness, owner.token, systemChannel.id, moderator.userId, {
+			type: 1,
+			allow: Permissions.MANAGE_MESSAGES.toString(),
+			deny: Permissions.SEND_MESSAGES.toString(),
+		});
+
+		await createBuilder(harness, moderator.token)
+			.delete(`/channels/${systemChannel.id}/messages/${message.id}`)
+			.expect(HTTP_STATUS.NO_CONTENT)
+			.execute();
+
+		await createBuilder(harness, author.token)
+			.get(`/channels/${systemChannel.id}/messages/${message.id}`)
+			.expect(HTTP_STATUS.NOT_FOUND)
+			.execute();
+	});
+
+	it('refuses a member without MANAGE_MESSAGES deleting another member message', async () => {
+		const {members, systemChannel} = await setupTestGuildWithMembers(harness, 2);
+		const [author, other] = members as [TestAccount, TestAccount];
+		const message = await sendChannelMessage(harness, author.token, systemChannel.id, 'keep me');
+
+		await createBuilder(harness, other.token)
+			.delete(`/channels/${systemChannel.id}/messages/${message.id}`)
+			.expect(HTTP_STATUS.FORBIDDEN, 'MISSING_PERMISSIONS')
+			.execute();
+	});
+});
@@ -129,6 +129,7 @@ export interface APIConfig {
 		apiPublic: string;
 		apiClient: string;
 		webApp: string;
+		webAppOrigins: Array<string>;
 		gateway: string;
 		media: string;
 		staticCdn: string;
@@ -143,8 +144,6 @@ export interface APIConfig {
 		donationProxyKey: string;
 	};
 	hosts: {
-		invite: string;
-		gift: string;
 		marketing: string;
 		unfurlIgnored: Array<string>;
 	};
@@ -338,6 +337,10 @@ export interface APIConfig {
 	};
 	abusePolicy: {
 		inboundPhoneCountryCodes: Array<string>;
+		phoneFlagging: {
+			enabled: boolean;
+			exemptCountryCodes: Array<string>;
+		};
 		phoneVerification: {
 			inboundRequiredPrefixes: Array<string>;
 		};
@@ -100,6 +100,8 @@ export interface WebAuthnCredentialRow {
 	created_at: Date;
 	last_used_at: Nullish<Date>;
 	version: number;
+	rp_id: Nullish<string>;
+	superseded_by: Nullish<string>;
 }

 export interface EmailChangeTicketRow {
@@ -193,6 +195,8 @@ export const WEBAUTHN_CREDENTIAL_COLUMNS = [
 	'created_at',
 	'last_used_at',
 	'version',
+	'rp_id',
+	'superseded_by',
 ] as const satisfies ReadonlyArray<keyof WebAuthnCredentialRow>;

 export interface PhoneTokenRow {
@@ -15,7 +15,12 @@ import type {GuildFolderIcon, MentionReplyPreference} from '@fluxer/constants/sr
 import type {types} from 'cassandra-driver';

 type Nullish<T> = T | null;
-export type PushSubscriptionPlatform = 'web_push' | 'android_fcm' | 'ios_apns' | 'android_unified_push';
+export type PushSubscriptionPlatform =
+	| 'web_push'
+	| 'android_fcm'
+	| 'ios_apns'
+	| 'ios_apns_voip'
+	| 'android_unified_push';

 export interface UserRow {
 	user_id: UserID;
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

 import {createHash} from 'node:crypto';
+import {resolveExperimentTargeting} from '@app/api/experiment/ExperimentTargeting';
 import {LoginRequired} from '@app/api/middleware/AuthMiddleware';
 import {RateLimitMiddleware} from '@app/api/middleware/RateLimitMiddleware';
 import {OpenAPI} from '@app/api/middleware/ResponseTypeMiddleware';
@@ -8,7 +9,9 @@ import {RateLimitConfigs} from '@app/api/RateLimitConfig';
 import type {HonoApp} from '@app/api/types/HonoEnv';
 import {entityTagMatches} from '@app/api/utils/EntityTag';
 import {Headers as HttpHeaders} from '@fluxer/constants/src/Headers';
-import {resolveScreenShareDeliveryAssignment} from '@fluxer/schema/src/domains/admin/ScreenShareDeliverySchemas';
+import {resolveAltchaCaptchaAssignment} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
+import {resolveDomainMigrationAssignment} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
+import {resolveProfileTimezoneAssignment} from '@fluxer/schema/src/domains/admin/ProfileTimezoneSchemas';
 import {resolveVoiceNoiseSuppressionAssignment} from '@fluxer/schema/src/domains/admin/VoiceNoiseSuppressionSchemas';
 import {ExperimentAssignmentsResponse} from '@fluxer/schema/src/domains/experiment/ExperimentSchemas';

@@ -29,18 +32,30 @@ export function ExperimentController(app: HonoApp) {
 		}),
 		async (ctx) => {
 			const instanceConfigRepository = ctx.get('instanceConfigRepository');
-			const [delivery, voiceConfig, screenShareConfig] = await Promise.all([
-				instanceConfigRepository.getExperimentDeliveryConfig(),
-				instanceConfigRepository.getVoiceNoiseSuppressionConfig(),
-				instanceConfigRepository.getScreenShareDeliveryConfig(),
+			const [delivery, voiceConfig, domainMigrationConfig, altchaCaptchaConfig, profileTimezoneConfig] =
+				await Promise.all([
+					instanceConfigRepository.getExperimentDeliveryConfig(),
+					instanceConfigRepository.getVoiceNoiseSuppressionConfig(),
+					instanceConfigRepository.getDomainMigrationConfig(),
+					instanceConfigRepository.getAltchaCaptchaConfig(),
+					instanceConfigRepository.getProfileTimezoneConfig(),
+				]);
+			const user = ctx.get('user');
+			const userId = user.id.toString();
+			const targeting = await resolveExperimentTargeting(user, [
+				voiceConfig,
+				domainMigrationConfig,
+				altchaCaptchaConfig,
+				profileTimezoneConfig,
 			]);
-			const userId = ctx.get('user').id.toString();
 			const body: ExperimentAssignmentsResponse = {
 				poll_interval_seconds: delivery.poll_interval_seconds,
 				poll_jitter_percent: delivery.poll_jitter_percent,
 				assignments: {
-					voice_noise_suppression: resolveVoiceNoiseSuppressionAssignment(voiceConfig, userId),
-					screen_share_delivery: resolveScreenShareDeliveryAssignment(screenShareConfig, userId),
+					voice_noise_suppression: resolveVoiceNoiseSuppressionAssignment(voiceConfig, userId, targeting),
+					domain_migration: resolveDomainMigrationAssignment(domainMigrationConfig, userId, targeting),
+					altcha_captcha: resolveAltchaCaptchaAssignment(altchaCaptchaConfig, userId, targeting),
+					profile_timezone: resolveProfileTimezoneAssignment(profileTimezoneConfig, userId, targeting),
 				},
 			};
 			const etag = `"${createHash('sha256').update(JSON.stringify(body)).digest('hex')}"`;
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {getUserRepository} from '@app/api/middleware/ServiceSingletons';
+import type {User} from '@app/api/models/User';
+import type {ExperimentTargeting} from '@fluxer/schema/src/domains/experiment/ExperimentBucket';
+
+interface TargetableExperimentConfig {
+	readonly enabled: boolean;
+	readonly included_guild_ids: ReadonlyArray<string>;
+}
+
+const NO_GUILDS: ReadonlySet<string> = new Set();
+
+export const ANONYMOUS_EXPERIMENT_TARGETING: ExperimentTargeting = {
+	memberGuildIds: NO_GUILDS,
+	premium: false,
+};
+
+export async function resolveExperimentTargeting(
+	user: User,
+	configs: ReadonlyArray<TargetableExperimentConfig>,
+): Promise<ExperimentTargeting> {
+	const needsGuilds = configs.some((config) => config.enabled && config.included_guild_ids.length > 0);
+	const memberGuildIds = needsGuilds
+		? new Set((await getUserRepository().getUserGuildIds(user.id)).map((guildId) => guildId.toString()))
+		: NO_GUILDS;
+	return {memberGuildIds, premium: !user.isBot && user.isPremium()};
+}
@@ -1,15 +1,26 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

 import {createTestAccount, setUserACLs} from '@app/api/auth/tests/AuthTestUtils';
+import {acceptInvite, createChannelInvite, createGuild, getChannel} from '@app/api/guild/tests/GuildTestUtils';
 import {getInstanceConfigRepository} from '@app/api/middleware/ServiceSingletons';
 import {type ApiTestHarness, createApiTestHarness} from '@app/api/test/ApiTestHarness';
 import {HTTP_STATUS} from '@app/api/test/TestConstants';
 import {createBuilder, createBuilderWithoutAuth} from '@app/api/test/TestRequestBuilder';
+import {grantPremium} from '@app/api/user/tests/UserTestUtils';
 import {AdminACLs} from '@fluxer/constants/src/AdminACLs';
+import {UserPremiumTypes} from '@fluxer/constants/src/UserConstants';
 import {
-	DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
-	INERT_SCREEN_SHARE_DELIVERY_ASSIGNMENT,
-} from '@fluxer/schema/src/domains/admin/ScreenShareDeliverySchemas';
+	DEFAULT_ALTCHA_CAPTCHA_CONFIG,
+	INERT_ALTCHA_CAPTCHA_ASSIGNMENT,
+} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
+import {
+	DEFAULT_DOMAIN_MIGRATION_CONFIG,
+	INERT_DOMAIN_MIGRATION_ASSIGNMENT,
+} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
+import {
+	DEFAULT_PROFILE_TIMEZONE_CONFIG,
+	INERT_PROFILE_TIMEZONE_ASSIGNMENT,
+} from '@fluxer/schema/src/domains/admin/ProfileTimezoneSchemas';
 import {
 	DEFAULT_VOICE_NOISE_SUPPRESSION_CONFIG,
 	INERT_VOICE_NOISE_SUPPRESSION_ASSIGNMENT,
@@ -19,7 +30,7 @@ import {
 	DEFAULT_EXPERIMENT_POLL_JITTER_PERCENT,
 	type ExperimentAssignmentsResponse,
 	type ExperimentDeliveryConfigResponse,
-	readScreenShareDeliveryAssignment,
+	readDomainMigrationAssignment,
 	readVoiceNoiseSuppressionAssignment,
 } from '@fluxer/schema/src/domains/experiment/ExperimentSchemas';
 import {afterAll, beforeAll, beforeEach, describe, expect, it} from 'vitest';
@@ -56,7 +67,9 @@ describe('GET /experiments', () => {
 			poll_jitter_percent: DEFAULT_EXPERIMENT_POLL_JITTER_PERCENT,
 			assignments: {
 				voice_noise_suppression: INERT_VOICE_NOISE_SUPPRESSION_ASSIGNMENT,
-				screen_share_delivery: INERT_SCREEN_SHARE_DELIVERY_ASSIGNMENT,
+				domain_migration: INERT_DOMAIN_MIGRATION_ASSIGNMENT,
+				altcha_captcha: INERT_ALTCHA_CAPTCHA_ASSIGNMENT,
+				profile_timezone: INERT_PROFILE_TIMEZONE_ASSIGNMENT,
 			},
 		});
 	});
@@ -88,20 +101,20 @@ describe('GET /experiments', () => {
 		expect(readVoiceNoiseSuppressionAssignment(body).enabled).toBe(false);
 	});

-	it('populates the screen share assignment key even when the rollout is disabled', async () => {
+	it('populates the domain migration assignment key even when the rollout is disabled', async () => {
 		const account = await createTestAccount(harness);

 		const body = await createBuilder<ExperimentAssignmentsResponse>(harness, account.token).get(ENDPOINT).execute();

-		expect(Object.hasOwn(body.assignments, 'screen_share_delivery')).toBe(true);
-		expect(readScreenShareDeliveryAssignment(body).enabled).toBe(false);
+		expect(Object.hasOwn(body.assignments, 'domain_migration')).toBe(true);
+		expect(readDomainMigrationAssignment(body).enabled).toBe(false);
 	});

-	it('resolves the screen share caller through the allowlist', async () => {
+	it('resolves the domain migration caller through the allowlist', async () => {
 		const targeted = await createTestAccount(harness);
 		const untargeted = await createTestAccount(harness);
-		await getInstanceConfigRepository().setScreenShareDeliveryConfig({
-			...DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
+		await getInstanceConfigRepository().setDomainMigrationConfig({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
 			enabled: true,
 			config_version: 4,
 			rollout_basis_points: 0,
@@ -111,18 +124,18 @@ describe('GET /experiments', () => {
 		const targetedBody = await createBuilder<ExperimentAssignmentsResponse>(harness, targeted.token)
 			.get(ENDPOINT)
 			.execute();
-		expect(targetedBody.assignments.screen_share_delivery).toEqual({enabled: true});
+		expect(targetedBody.assignments.domain_migration).toEqual({enabled: true});

 		const untargetedBody = await createBuilder<ExperimentAssignmentsResponse>(harness, untargeted.token)
 			.get(ENDPOINT)
 			.execute();
-		expect(untargetedBody.assignments.screen_share_delivery).toEqual({enabled: false});
+		expect(untargetedBody.assignments.domain_migration).toEqual({enabled: false});
 	});

-	it('keeps the screen share exclusion ahead of a full rollout', async () => {
+	it('keeps the domain migration exclusion ahead of a full rollout', async () => {
 		const excluded = await createTestAccount(harness);
-		await getInstanceConfigRepository().setScreenShareDeliveryConfig({
-			...DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
+		await getInstanceConfigRepository().setDomainMigrationConfig({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
 			enabled: true,
 			rollout_basis_points: 10000,
 			included_user_ids: [excluded.userId],
@@ -131,7 +144,216 @@ describe('GET /experiments', () => {

 		const body = await createBuilder<ExperimentAssignmentsResponse>(harness, excluded.token).get(ENDPOINT).execute();

-		expect(body.assignments.screen_share_delivery).toEqual({enabled: false});
+		expect(body.assignments.domain_migration).toEqual({enabled: false});
+	});
+
+	it('resolves the altcha captcha caller through the allowlist and the exclusion list', async () => {
+		const targeted = await createTestAccount(harness);
+		const excluded = await createTestAccount(harness);
+		await getInstanceConfigRepository().setAltchaCaptchaConfig({
+			...DEFAULT_ALTCHA_CAPTCHA_CONFIG,
+			enabled: true,
+			rollout_basis_points: 10000,
+			anonymous_enabled: true,
+			included_user_ids: [targeted.userId],
+			excluded_user_ids: [excluded.userId],
+		});
+
+		const targetedBody = await createBuilder<ExperimentAssignmentsResponse>(harness, targeted.token)
+			.get(ENDPOINT)
+			.execute();
+		expect(targetedBody.assignments.altcha_captcha).toEqual({enabled: true});
+
+		const excludedBody = await createBuilder<ExperimentAssignmentsResponse>(harness, excluded.token)
+			.get(ENDPOINT)
+			.execute();
+		expect(excludedBody.assignments.altcha_captcha).toEqual({enabled: false});
+	});
+
+	it('bumps the altcha captcha config version on every admin update without the client sending one', async () => {
+		const admin = await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+
+		const afterFirst = await createBuilder<{altcha_captcha: {config_version: number; enabled: boolean}}>(
+			harness,
+			admin.token,
+		)
+			.patch('/admin/instance/config')
+			.body({altcha_captcha: {enabled: true, included_user_ids: [admin.userId]}})
+			.execute();
+		expect(afterFirst.altcha_captcha).toMatchObject({config_version: 1, enabled: true});
+
+		const afterSecond = await createBuilder<{
+			altcha_captcha: {config_version: number; anonymous_enabled: boolean; cost: number; max_counter: number};
+		}>(harness, admin.token)
+			.patch('/admin/instance/config')
+			.body({altcha_captcha: {anonymous_enabled: true, cost: 2000, max_counter: 400}})
+			.execute();
+		expect(afterSecond.altcha_captcha).toMatchObject({
+			config_version: 2,
+			anonymous_enabled: true,
+			cost: 2000,
+			max_counter: 400,
+		});
+
+		const body = await createBuilder<ExperimentAssignmentsResponse>(harness, admin.token).get(ENDPOINT).execute();
+		expect(body.assignments.altcha_captcha).toEqual({enabled: true});
+	});
+
+	it('resolves the profile timezone caller through the allowlist and the exclusion list', async () => {
+		const targeted = await createTestAccount(harness);
+		const excluded = await createTestAccount(harness);
+		await getInstanceConfigRepository().setProfileTimezoneConfig({
+			...DEFAULT_PROFILE_TIMEZONE_CONFIG,
+			enabled: true,
+			rollout_basis_points: 10000,
+			included_user_ids: [targeted.userId],
+			excluded_user_ids: [excluded.userId],
+		});
+
+		const targetedBody = await createBuilder<ExperimentAssignmentsResponse>(harness, targeted.token)
+			.get(ENDPOINT)
+			.execute();
+		expect(targetedBody.assignments.profile_timezone).toEqual({enabled: true});
+
+		const excludedBody = await createBuilder<ExperimentAssignmentsResponse>(harness, excluded.token)
+			.get(ENDPOINT)
+			.execute();
+		expect(excludedBody.assignments.profile_timezone).toEqual({enabled: false});
+	});
+
+	it('bumps the profile timezone config version on every admin update without the client sending one', async () => {
+		const admin = await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+
+		const afterFirst = await createBuilder<{profile_timezone: {config_version: number; enabled: boolean}}>(
+			harness,
+			admin.token,
+		)
+			.patch('/admin/instance/config')
+			.body({profile_timezone: {enabled: true, included_user_ids: [admin.userId]}})
+			.execute();
+		expect(afterFirst.profile_timezone).toMatchObject({config_version: 1, enabled: true});
+
+		const afterSecond = await createBuilder<{
+			profile_timezone: {config_version: number; rollout_basis_points: number};
+		}>(harness, admin.token)
+			.patch('/admin/instance/config')
+			.body({profile_timezone: {rollout_basis_points: 2500}})
+			.execute();
+		expect(afterSecond.profile_timezone).toMatchObject({config_version: 2, rollout_basis_points: 2500});
+
+		const body = await createBuilder<ExperimentAssignmentsResponse>(harness, admin.token).get(ENDPOINT).execute();
+		expect(body.assignments.profile_timezone).toEqual({enabled: true});
+	});
+
+	it('enrols members of an included guild in every experiment and leaves everyone else out', async () => {
+		const owner = await createTestAccount(harness);
+		const member = await createTestAccount(harness);
+		const outsider = await createTestAccount(harness);
+		const guild = await createGuild(harness, owner.token, 'Experiment Guild');
+		const systemChannel = await getChannel(harness, owner.token, guild.system_channel_id!);
+		const invite = await createChannelInvite(harness, owner.token, systemChannel.id);
+		await acceptInvite(harness, member.token, invite.code);
+		const repository = getInstanceConfigRepository();
+		await repository.setVoiceNoiseSuppressionConfig({
+			...DEFAULT_VOICE_NOISE_SUPPRESSION_CONFIG,
+			enabled: true,
+			included_guild_ids: [guild.id],
+		});
+		await repository.setDomainMigrationConfig({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
+			enabled: true,
+			included_guild_ids: [guild.id],
+		});
+		await repository.setAltchaCaptchaConfig({
+			...DEFAULT_ALTCHA_CAPTCHA_CONFIG,
+			enabled: true,
+			included_guild_ids: [guild.id],
+		});
+		await repository.setProfileTimezoneConfig({
+			...DEFAULT_PROFILE_TIMEZONE_CONFIG,
+			enabled: true,
+			included_guild_ids: [guild.id],
+		});
+
+		const memberBody = await createBuilder<ExperimentAssignmentsResponse>(harness, member.token)
+			.get(ENDPOINT)
+			.execute();
+		expect(memberBody.assignments.voice_noise_suppression).toMatchObject({user_targeted: true, source: 'user_rule'});
+		expect(memberBody.assignments.domain_migration).toEqual({enabled: true});
+		expect(memberBody.assignments.altcha_captcha).toEqual({enabled: true});
+		expect(memberBody.assignments.profile_timezone).toEqual({enabled: true});
+
+		const outsiderBody = await createBuilder<ExperimentAssignmentsResponse>(harness, outsider.token)
+			.get(ENDPOINT)
+			.execute();
+		expect(outsiderBody.assignments.voice_noise_suppression).toMatchObject({user_targeted: false, source: null});
+		expect(outsiderBody.assignments.domain_migration).toEqual({enabled: false});
+		expect(outsiderBody.assignments.altcha_captcha).toEqual({enabled: false});
+		expect(outsiderBody.assignments.profile_timezone).toEqual({enabled: false});
+	});
+
+	it('enrols premium users, subscription and lifetime alike, when the switch is on', async () => {
+		const subscriber = await createTestAccount(harness);
+		const visionary = await createTestAccount(harness);
+		const free = await createTestAccount(harness);
+		await grantPremium(harness, subscriber.userId, UserPremiumTypes.SUBSCRIPTION);
+		await grantPremium(harness, visionary.userId, UserPremiumTypes.LIFETIME);
+		await getInstanceConfigRepository().setProfileTimezoneConfig({
+			...DEFAULT_PROFILE_TIMEZONE_CONFIG,
+			enabled: true,
+			include_premium_users: true,
+		});
+		for (const [account, expected] of [
+			[subscriber, true],
+			[visionary, true],
+			[free, false],
+		] as const) {
+			const body = await createBuilder<ExperimentAssignmentsResponse>(harness, account.token).get(ENDPOINT).execute();
+			expect(body.assignments.profile_timezone).toEqual({enabled: expected});
+		}
+	});
+
+	it('stores the guild ids and premium switch an admin sets for each experiment', async () => {
+		const admin = await setUserACLs(harness, await createTestAccount(harness), [
+			AdminACLs.AUTHENTICATE,
+			AdminACLs.INSTANCE_CONFIG_VIEW,
+			AdminACLs.INSTANCE_CONFIG_UPDATE,
+		]);
+		const guildIds = ['1500000000000000001', '1500000000000000002'];
+		const body = await createBuilder<
+			Record<
+				'voice_noise_suppression' | 'domain_migration' | 'altcha_captcha' | 'profile_timezone',
+				{included_guild_ids: Array<string>; include_premium_users: boolean}
+			>
+		>(harness, admin.token)
+			.patch('/admin/instance/config')
+			.body({
+				voice_noise_suppression: {included_guild_ids: guildIds, include_premium_users: true},
+				domain_migration: {included_guild_ids: guildIds, include_premium_users: true},
+				altcha_captcha: {included_guild_ids: guildIds, include_premium_users: true},
+				profile_timezone: {included_guild_ids: guildIds, include_premium_users: true},
+			})
+			.execute();
+		expect(body.voice_noise_suppression.included_guild_ids).toEqual(guildIds);
+		expect(body.domain_migration.included_guild_ids).toEqual(guildIds);
+		expect(body.altcha_captcha.included_guild_ids).toEqual(guildIds);
+		expect(body.profile_timezone.included_guild_ids).toEqual(guildIds);
+		for (const section of [
+			body.voice_noise_suppression,
+			body.domain_migration,
+			body.altcha_captcha,
+			body.profile_timezone,
+		]) {
+			expect(section.include_premium_users).toBe(true);
+		}
 	});

 	it('serves the delivery cadence from the delivery config and not from the voice config', async () => {
@@ -248,7 +470,7 @@ describe('GET /experiments', () => {
 		});
 	});

-	it('serves a fresh body once the screen share config changes', async () => {
+	it('serves a fresh body once the domain migration config changes', async () => {
 		const account = await createTestAccount(harness);

 		const first = await createBuilder<ExperimentAssignmentsResponse>(harness, account.token)
@@ -256,8 +478,8 @@ describe('GET /experiments', () => {
 			.executeWithResponse();
 		const staleEtag = first.response.headers.get('etag') as string;

-		await getInstanceConfigRepository().setScreenShareDeliveryConfig({
-			...DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
+		await getInstanceConfigRepository().setDomainMigrationConfig({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
 			enabled: true,
 			config_version: 1,
 			rollout_basis_points: 10000,
@@ -269,7 +491,7 @@ describe('GET /experiments', () => {
 			.executeWithResponse();
 		expect(refreshed.response.status).toBe(HTTP_STATUS.OK);
 		expect(refreshed.response.headers.get('etag')).not.toBe(staleEtag);
-		expect(refreshed.json?.assignments.screen_share_delivery).toEqual({enabled: true});
+		expect(refreshed.json?.assignments.domain_migration).toEqual({enabled: true});
 	});

 	it('serves a fresh body once the delivery config changes', async () => {
@@ -328,42 +550,45 @@ describe('GET /experiments', () => {
 		});
 	});

-	it('bumps the screen share config version on every admin update without the client sending one', async () => {
+	it('bumps the domain migration config version on every admin update without the client sending one', async () => {
 		const admin = await setUserACLs(harness, await createTestAccount(harness), [
 			AdminACLs.AUTHENTICATE,
 			AdminACLs.INSTANCE_CONFIG_VIEW,
 			AdminACLs.INSTANCE_CONFIG_UPDATE,
 		]);

-		const afterFirst = await createBuilder<{screen_share_delivery: {config_version: number; enabled: boolean}}>(
+		const afterFirst = await createBuilder<{domain_migration: {config_version: number; enabled: boolean}}>(
 			harness,
 			admin.token,
 		)
 			.patch('/admin/instance/config')
-			.body({screen_share_delivery: {enabled: true, rollout_basis_points: 10000}})
+			.body({domain_migration: {enabled: true, rollout_basis_points: 10000}})
 			.execute();
-		expect(afterFirst.screen_share_delivery).toMatchObject({config_version: 1, enabled: true});
+		expect(afterFirst.domain_migration).toMatchObject({config_version: 1, enabled: true});

-		const afterSecond = await createBuilder<{screen_share_delivery: {config_version: number; enabled: boolean}}>(
-			harness,
-			admin.token,
-		)
+		const afterSecond = await createBuilder<{
+			domain_migration: {config_version: number; enabled: boolean; anonymous_rollout_basis_points: number};
+		}>(harness, admin.token)
 			.patch('/admin/instance/config')
-			.body({screen_share_delivery: {rollout_salt: 'screen-share-delivery-v2'}})
+			.body({domain_migration: {anonymous_rollout_basis_points: 2500}})
 			.execute();
-		expect(afterSecond.screen_share_delivery).toMatchObject({config_version: 2, enabled: true});
+		expect(afterSecond.domain_migration).toMatchObject({
+			config_version: 2,
+			enabled: true,
+			anonymous_rollout_basis_points: 2500,
+		});

-		const afterEmpty = await createBuilder<{screen_share_delivery: {config_version: number; enabled: boolean}}>(
+		const afterEmpty = await createBuilder<{domain_migration: {config_version: number; enabled: boolean}}>(
 			harness,
 			admin.token,
 		)
 			.patch('/admin/instance/config')
-			.body({screen_share_delivery: {}})
+			.body({domain_migration: {}})
 			.execute();
-		expect(afterEmpty.screen_share_delivery).toMatchObject({config_version: 2, enabled: true});
+		expect(afterEmpty.domain_migration).toMatchObject({config_version: 2, enabled: true});

 		const body = await createBuilder<ExperimentAssignmentsResponse>(harness, admin.token).get(ENDPOINT).execute();
-		expect(body.assignments.screen_share_delivery).toEqual({enabled: true});
+		expect(body.assignments.domain_migration).toEqual({enabled: true});
 	});

 	it('leaves the config version alone for an admin update that sets no field', async () => {
@@ -3,6 +3,7 @@
 import {requireEmailVerified} from '@app/api/auth/EmailVerificationUtils';
 import type {GuildID, InviteCode, RoleID, UserID} from '@app/api/BrandedTypes';
 import {createChannelID, createRoleID} from '@app/api/BrandedTypes';
+import {Config} from '@app/api/Config';
 import type {ChannelService} from '@app/api/channel/services/ChannelService';
 import {assertMutableUserId} from '@app/api/constants/Core';
 import type {GuildMemberRow} from '@app/api/database/types/GuildTypes';
@@ -421,6 +422,13 @@ export class GuildMemberOperationsService {
 			memberCount: guild.memberCount,
 			accountAgeMs: Date.now() - snowflakeToDate(BigInt(user.id)).getTime(),
 		};
+		if (
+			!Config.abusePolicy.phoneFlagging.enabled &&
+			(getEffectiveSuspiciousFlags(user) & PHONE_REQUIREMENT_FLAGS) === 0
+		) {
+			Logger.info(logContext, 'deferred_phone_gate.skipped_phone_flagging_disabled');
+			return;
+		}
 		if (status !== 'ok') {
 			const undeferredFlags = getEffectiveSuspiciousFlags({
 				...user,
@@ -3,7 +3,7 @@
 import {Config} from '@app/api/Config';
 import {GatewayRpcMethodError, GatewayRpcMethodErrorCodes} from '@app/api/infrastructure/GatewayRpcError';
 import type {IGatewayRpcTransport} from '@app/api/infrastructure/IGatewayRpcTransport';
-import type {CallData} from '@app/api/infrastructure/IGatewayService';
+import {type CallCaller, type CallData, callCallerRpcParams} from '@app/api/infrastructure/IGatewayService';
 import {NatsGatewayRpcTransport} from '@app/api/infrastructure/NatsGatewayRpcTransport';
 import {Logger} from '@app/api/Logger';
 import {NatsConnectionManager} from '@pkgs/nats/src/NatsConnectionManager';
@@ -128,6 +128,7 @@ export class GatewayRpcClient {
 		region: string,
 		ringing: Array<string>,
 		recipients: Array<string>,
+		caller?: CallCaller,
 	): Promise<CallData> {
 		return this.call<CallData>('call.create', {
 			channel_id: channelId,
@@ -135,6 +136,7 @@ export class GatewayRpcClient {
 			region,
 			ringing,
 			recipients,
+			...callCallerRpcParams(caller),
 		});
 	}

@@ -142,8 +144,8 @@ export class GatewayRpcClient {
 		return this.call('call.update_region', {channel_id: channelId, region});
 	}

-	async ringCallRecipients(channelId: string, recipients: Array<string>): Promise<boolean> {
-		return this.call('call.ring', {channel_id: channelId, recipients});
+	async ringCallRecipients(channelId: string, recipients: Array<string>, caller?: CallCaller): Promise<boolean> {
+		return this.call('call.ring', {channel_id: channelId, recipients, ...callCallerRpcParams(caller)});
 	}

 	async stopRingingCallRecipients(channelId: string, recipients: Array<string>): Promise<boolean> {
@@ -6,16 +6,18 @@ import {SYSTEM_USER_ID} from '@app/api/constants/Core';
 import type {GatewayDispatchEvent} from '@app/api/constants/Gateway';
 import {GatewayRpcClient} from '@app/api/infrastructure/GatewayRpcClient';
 import {GatewayRpcMethodError, GatewayRpcMethodErrorCodes} from '@app/api/infrastructure/GatewayRpcError';
-import type {
-	CallData,
-	GatewayChannelMention,
-	GatewayGuildMemoryStats,
-	GatewayMentionSources,
-	GatewayMentionSourcesPage,
-	GatewayNodeStats,
-	GatewayVoiceStateCounts,
-	GatewayVoiceStateEntry,
-	GuildChannelAuthContext,
+import {
+	type CallCaller,
+	type CallData,
+	callCallerRpcParams,
+	type GatewayChannelMention,
+	type GatewayGuildMemoryStats,
+	type GatewayMentionSources,
+	type GatewayMentionSourcesPage,
+	type GatewayNodeStats,
+	type GatewayVoiceStateCounts,
+	type GatewayVoiceStateEntry,
+	type GuildChannelAuthContext,
 } from '@app/api/infrastructure/IGatewayService';
 import {Logger} from '@app/api/Logger';
 import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
@@ -35,7 +37,6 @@ import type {GuildMemberResponse} from '@fluxer/schema/src/domains/guild/GuildMe
 import type {GuildResponse} from '@fluxer/schema/src/domains/guild/GuildResponseSchemas';
 import {ms} from 'itty-time';

-const PUSH_BADGE_COUNT_BATCH_SIZE = 100;
 const USER_PERMISSIONS_BATCH_SIZE = 100;

 const GATEWAY_ERROR_TO_DOMAIN_ERROR: Record<string, () => Error> = {
@@ -65,18 +66,6 @@ interface DispatchPresenceParams {
 	data: unknown;
 }

-interface InvalidatePushBadgeCountParams {
-	userId: UserID;
-}
-
-interface InvalidatePushBadgeCountsParams {
-	userIds: Array<UserID>;
-}
-
-interface InvalidatePushSubscriptionsParams {
-	userId: UserID;
-}
-
 interface ClearPushChannelNotificationsParams {
 	userId: UserID;
 	channelId: ChannelID;
@@ -285,8 +274,6 @@ export class GatewayService {
 	private readonly MAX_BATCH_CONCURRENCY = 50;
 	private readonly PENDING_REQUEST_TIMEOUT_MS = ms('30 seconds');
 	private readonly AUTH_CONTEXT_FALLBACK_MS = ms('5 minutes');
-	private readonly BADGE_COUNTS_FALLBACK_MS = ms('5 minutes');
-	private badgeCountsUnsupportedUntil = 0;

 	constructor() {
 		this.rpcClient = GatewayRpcClient.getInstance();
@@ -702,48 +689,6 @@ export class GatewayService {
 		});
 	}

-	async invalidatePushBadgeCount({userId}: InvalidatePushBadgeCountParams): Promise<void> {
-		await this.call('push.invalidate_badge_count', {
-			user_id: userId.toString(),
-		});
-	}
-
-	async invalidatePushBadgeCounts({userIds}: InvalidatePushBadgeCountsParams): Promise<void> {
-		if (Date.now() < this.badgeCountsUnsupportedUntil) {
-			await this.invalidatePushBadgeCountsIndividually(userIds);
-			return;
-		}
-		const batches: Array<Array<UserID>> = [];
-		for (let index = 0; index < userIds.length; index += PUSH_BADGE_COUNT_BATCH_SIZE) {
-			batches.push(userIds.slice(index, index + PUSH_BADGE_COUNT_BATCH_SIZE));
-		}
-		try {
-			await Promise.all(
-				batches.map((batch) =>
-					this.call('push.invalidate_badge_counts', {user_ids: batch.map((userId) => userId.toString())}),
-				),
-			);
-		} catch (error) {
-			const transformedError = this.transformGatewayError(error);
-			if (!this.isAuthContextUnsupportedError(transformedError)) {
-				throw transformedError;
-			}
-			this.badgeCountsUnsupportedUntil = Date.now() + this.BADGE_COUNTS_FALLBACK_MS;
-			Logger.warn({error}, '[gateway-rpc] push.invalidate_badge_counts unavailable, falling back to per-user calls');
-			await this.invalidatePushBadgeCountsIndividually(userIds);
-		}
-	}
-
-	private async invalidatePushBadgeCountsIndividually(userIds: ReadonlyArray<UserID>): Promise<void> {
-		await Promise.all(userIds.map((userId) => this.invalidatePushBadgeCount({userId})));
-	}
-
-	async invalidatePushSubscriptions({userId}: InvalidatePushSubscriptionsParams): Promise<void> {
-		await this.call('push.invalidate_subscriptions', {
-			user_id: userId.toString(),
-		});
-	}
-
 	async clearPushChannelNotifications({
 		userId,
 		channelId,
@@ -1695,6 +1640,7 @@ export class GatewayService {
 		region: string,
 		ringing: Array<string>,
 		recipients: Array<string>,
+		caller?: CallCaller,
 	): Promise<CallData> {
 		return this.call<CallData>('call.create', {
 			channel_id: channelId.toString(),
@@ -1702,6 +1648,7 @@ export class GatewayService {
 			region,
 			ringing,
 			recipients,
+			...callCallerRpcParams(caller),
 		});
 	}

@@ -1709,8 +1656,12 @@ export class GatewayService {
 		return this.call<boolean>('call.update_region', {channel_id: channelId.toString(), region});
 	}

-	async ringCallRecipients(channelId: ChannelID, recipients: Array<string>): Promise<boolean> {
-		return this.call<boolean>('call.ring', {channel_id: channelId.toString(), recipients});
+	async ringCallRecipients(channelId: ChannelID, recipients: Array<string>, caller?: CallCaller): Promise<boolean> {
+		return this.call<boolean>('call.ring', {
+			channel_id: channelId.toString(),
+			recipients,
+			...callCallerRpcParams(caller),
+		});
 	}

 	async stopRingingCallRecipients(channelId: ChannelID, recipients: Array<string>): Promise<boolean> {
@@ -24,6 +24,19 @@ export interface CallData {
 	voice_states: Array<VoiceState>;
 }

+export interface CallCaller {
+	id: string;
+	name: string;
+	avatar: string | null;
+}
+
+export function callCallerRpcParams(caller: CallCaller | undefined): Record<string, unknown> {
+	if (!caller) {
+		return {};
+	}
+	return {caller_id: caller.id, caller_name: caller.name, caller_avatar: caller.avatar};
+}
+
 export interface GatewayGuildMemoryStatsEntry {
 	node_id: string;
 	guild_id: string | null;
@@ -279,12 +292,6 @@ export abstract class IGatewayService {

 	abstract dispatchPresence(params: {userId: UserID; event: GatewayDispatchEvent; data: unknown}): Promise<void>;

-	abstract invalidatePushBadgeCount(params: {userId: UserID}): Promise<void>;
-
-	abstract invalidatePushBadgeCounts(params: {userIds: Array<UserID>}): Promise<void>;
-
-	abstract invalidatePushSubscriptions(params: {userId: UserID}): Promise<void>;
-
 	abstract clearPushChannelNotifications(params: {
 		userId: UserID;
 		channelId: ChannelID;
@@ -381,11 +388,12 @@ export abstract class IGatewayService {
 		region: string,
 		ringing: Array<string>,
 		recipients: Array<string>,
+		caller?: CallCaller,
 	): Promise<CallData>;

 	abstract updateCallRegion(channelId: ChannelID, region: string | null): Promise<boolean>;

-	abstract ringCallRecipients(channelId: ChannelID, recipients: Array<string>): Promise<boolean>;
+	abstract ringCallRecipients(channelId: ChannelID, recipients: Array<string>, caller?: CallCaller): Promise<boolean>;

 	abstract stopRingingCallRecipients(channelId: ChannelID, recipients: Array<string>): Promise<boolean>;

@@ -84,6 +84,41 @@ describe('stripNonJpegImageMetadataForUpload', () => {
 	});
 });

+function riffChunk(type: string, data: Uint8Array): Uint8Array {
+	const out = new Uint8Array(8 + data.length + (data.length & 1));
+	out.set(textBytes(type), 0);
+	new DataView(out.buffer).setUint32(4, data.length, true);
+	out.set(data, 8);
+	return out;
+}
+
+function webp(chunks: ReadonlyArray<Uint8Array>): Uint8Array {
+	const body = concatBytes(chunks);
+	const header = concatBytes([textBytes('RIFF'), new Uint8Array(4), textBytes('WEBP')]);
+	new DataView(header.buffer).setUint32(4, 4 + body.length, true);
+	return concatBytes([header, body]);
+}
+
+describe('stripNonJpegImageMetadataForUpload for WebP', () => {
+	it('drops EXIF and XMP chunks without re-encoding frames', async () => {
+		const vp8x = new Uint8Array(10);
+		vp8x[0] = 0x02 | 0x08 | 0x04;
+		const anmf = riffChunk('ANMF', new Uint8Array([9, 8, 7]));
+		const input = webp([
+			riffChunk('VP8X', vp8x),
+			riffChunk('ANIM', new Uint8Array(6)),
+			anmf,
+			riffChunk('EXIF', textBytes('GPS=1,2')),
+			riffChunk('XMP ', textBytes('private metadata')),
+		]);
+		const stripped = await stripNonJpegImageMetadataForUpload(input, 'image/webp');
+		const expectedVp8x = new Uint8Array(10);
+		expectedVp8x[0] = 0x02;
+		expect(stripped.contentType).toBe('image/webp');
+		expect(stripped.body).toEqual(webp([riffChunk('VP8X', expectedVp8x), riffChunk('ANIM', new Uint8Array(6)), anmf]));
+	});
+});
+
 describe('buildProcessedMediaObject', () => {
 	it('leaves non-media objects for plain copy', async () => {
 		await expect(buildProcessedMediaObject(textBytes('plain text'), 'text/plain')).resolves.toBeNull();
@@ -162,6 +162,8 @@ export async function stripNonJpegImageMetadataForUpload(
 			contentType: normalizedContentType === 'image/apng' ? 'image/apng' : 'image/png',
 		};
 	}
+	const strippedWebp = isWebp(data) ? stripWebpMetadataChunks(data) : null;
+	if (strippedWebp) return {body: strippedWebp, contentType: 'image/webp'};
 	const image = sharp(data, {animated: true});
 	const metadata = await image.metadata();
 	switch (metadata.format) {
@@ -242,6 +244,50 @@ function stripPngMetadataChunks(data: Uint8Array): Uint8Array {
 	return output;
 }

+const WEBP_CHUNKS_TO_KEEP = new Set(['VP8 ', 'VP8L', 'VP8X', 'ALPH', 'ANIM', 'ANMF', 'ICCP']);
+const WEBP_VP8X_EXIF_FLAG = 0x08;
+const WEBP_VP8X_XMP_FLAG = 0x04;
+
+function readFourCc(data: Uint8Array, offset: number): string {
+	return String.fromCharCode(data[offset]!, data[offset + 1]!, data[offset + 2]!, data[offset + 3]!);
+}
+
+function readU32LE(data: Uint8Array, offset: number): number {
+	return (data[offset]! | (data[offset + 1]! << 8) | (data[offset + 2]! << 16) | (data[offset + 3]! << 24)) >>> 0;
+}
+
+function isWebp(data: Uint8Array): boolean {
+	return data.length >= 12 && readFourCc(data, 0) === 'RIFF' && readFourCc(data, 8) === 'WEBP';
+}
+
+function stripWebpMetadataChunks(data: Uint8Array): Uint8Array | null {
+	const riffEnd = Math.min(data.length, 8 + readU32LE(data, 4));
+	const chunks: Array<Uint8Array> = [];
+	let offset = 12;
+	while (offset + 8 <= riffEnd) {
+		const length = readU32LE(data, offset + 4);
+		const chunkEnd = offset + 8 + length + (length & 1);
+		if (offset + 8 + length > riffEnd) return null;
+		const type = readFourCc(data, offset);
+		if (WEBP_CHUNKS_TO_KEEP.has(type)) {
+			const chunk = data.slice(offset, Math.min(chunkEnd, riffEnd));
+			if (type === 'VP8X' && length > 0) chunk[8] = (chunk[8] ?? 0) & ~(WEBP_VP8X_EXIF_FLAG | WEBP_VP8X_XMP_FLAG);
+			chunks.push(chunk);
+		}
+		offset = chunkEnd;
+	}
+	const bodyLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
+	const output = new Uint8Array(12 + bodyLength);
+	output.set(data.subarray(0, 12));
+	new DataView(output.buffer).setUint32(4, 4 + bodyLength, true);
+	let cursor = 12;
+	for (const chunk of chunks) {
+		output.set(chunk, cursor);
+		cursor += chunk.length;
+	}
+	return output;
+}
+
 function imageExtensionForContentType(contentType: string): string {
 	if (contentType.includes('svg')) return 'svg';
 	if (contentType.includes('tiff')) return 'tiff';
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {createChannelID} from '@app/api/BrandedTypes';
+import {GatewayRpcClient} from '@app/api/infrastructure/GatewayRpcClient';
+import {GatewayService} from '@app/api/infrastructure/GatewayService';
+import type {IGatewayRpcTransport} from '@app/api/infrastructure/IGatewayRpcTransport';
+import {afterEach, describe, expect, it} from 'vitest';
+
+const CHANNEL_ID = createChannelID(12n);
+
+interface RecordedCall {
+	method: string;
+	params: Record<string, unknown>;
+}
+
+function recordingService(recorded: Array<RecordedCall>): GatewayService {
+	const transport: IGatewayRpcTransport = {
+		async call(method: string, params: Record<string, unknown>): Promise<unknown> {
+			recorded.push({method, params});
+			return null;
+		},
+		async destroy(): Promise<void> {},
+	};
+	GatewayRpcClient.createForTests(transport);
+	return new GatewayService();
+}
+
+describe('call rpc caller params', () => {
+	afterEach(async () => {
+		await GatewayRpcClient.resetForTests();
+	});
+
+	it('sends the caller to call.create as caller_id, caller_name and caller_avatar', async () => {
+		const recorded: Array<RecordedCall> = [];
+		const service = recordingService(recorded);
+		await service.createCall(CHANNEL_ID, '99', 'automatic', ['2'], ['1', '2'], {
+			id: '1',
+			name: 'Elias',
+			avatar: 'a1b2c3d4',
+		});
+		expect(recorded).toHaveLength(1);
+		expect(recorded[0].method).toBe('call.create');
+		expect(recorded[0].params.caller_id).toBe('1');
+		expect(recorded[0].params.caller_name).toBe('Elias');
+		expect(recorded[0].params.caller_avatar).toBe('a1b2c3d4');
+	});
+
+	it('sends the caller to call.ring as caller_id, caller_name and caller_avatar', async () => {
+		const recorded: Array<RecordedCall> = [];
+		const service = recordingService(recorded);
+		await service.ringCallRecipients(CHANNEL_ID, ['2'], {id: '1', name: 'Elias', avatar: 'a1b2c3d4'});
+		expect(recorded).toHaveLength(1);
+		expect(recorded[0].method).toBe('call.ring');
+		expect(recorded[0].params.caller_id).toBe('1');
+		expect(recorded[0].params.caller_name).toBe('Elias');
+		expect(recorded[0].params.caller_avatar).toBe('a1b2c3d4');
+	});
+
+	it('sends caller_avatar as null when the caller has no avatar', async () => {
+		const recorded: Array<RecordedCall> = [];
+		const service = recordingService(recorded);
+		await service.ringCallRecipients(CHANNEL_ID, ['2'], {id: '1', name: 'Elias', avatar: null});
+		expect(recorded[0].params.caller_avatar).toBeNull();
+		expect(Object.hasOwn(recorded[0].params, 'caller_avatar')).toBe(true);
+	});
+
+	it('omits every caller key from call.create when no caller was resolved', async () => {
+		const recorded: Array<RecordedCall> = [];
+		const service = recordingService(recorded);
+		await service.createCall(CHANNEL_ID, '99', 'automatic', ['2'], ['1', '2']);
+		expect(recorded[0].params).toEqual({
+			channel_id: '12',
+			message_id: '99',
+			region: 'automatic',
+			ringing: ['2'],
+			recipients: ['1', '2'],
+		});
+	});
+
+	it('omits every caller key from call.ring when no caller was resolved', async () => {
+		const recorded: Array<RecordedCall> = [];
+		const service = recordingService(recorded);
+		await service.ringCallRecipients(CHANNEL_ID, ['2']);
+		expect(recorded[0].params).toEqual({channel_id: '12', recipients: ['2']});
+	});
+});
@@ -1,18 +1,27 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

+import {spawnSync} from 'node:child_process';
+import {createHash} from 'node:crypto';
+import {createServer} from 'node:net';
+import type {CassandraQueryExecutorForTesting} from '@app/api/database/CassandraQueryExecution';
 import {setCassandraQueryExecutorForTesting} from '@app/api/database/CassandraQueryExecution';
 import type {PreparedQuery} from '@app/api/database/CassandraTypes';
+import {ensurePostgresKvSchema, PostgresKvQueryExecutor} from '@app/api/database/PostgresKvQueryExecutor';
 import {
 	INSTANCE_CONFIG_REFRESH_CHANNEL,
+	INSTANCE_CONFIG_WRITE_ATTEMPTS,
 	InstanceConfigRepository,
+	InstanceConfigWriteConflictError,
 	type InstanceRegistrationConfig,
 } from '@app/api/instance/InstanceConfigRepository';
+import {InstanceConfigWriteRaceExecutor} from '@app/api/instance/tests/InstanceConfigWriteRaceExecutor';
+import {startDockerContainer} from '@app/api/test/DockerTestContainer';
 import {InMemoryCassandraQueryExecutor} from '@app/api/test/InMemoryCassandraQueryExecutor';
 import {MockKVProvider} from '@app/api/test/mocks/MockKVProvider';
 import {
-	DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
-	type ScreenShareDeliveryConfig,
-} from '@fluxer/schema/src/domains/admin/ScreenShareDeliverySchemas';
+	DEFAULT_DOMAIN_MIGRATION_CONFIG,
+	type DomainMigrationConfig,
+} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
 import {
 	DEFAULT_VOICE_NOISE_SUPPRESSION_CONFIG,
 	type VoiceNoiseSuppressionConfig,
@@ -21,14 +30,26 @@ import {
 	DEFAULT_EXPERIMENT_DELIVERY_CONFIG,
 	type ExperimentDeliveryConfig,
 } from '@fluxer/schema/src/domains/experiment/ExperimentSchemas';
-import {afterEach, describe, expect, it, vi} from 'vitest';
+import {
+	getDefaultPostgresClient,
+	type IPostgresClient,
+	initPostgres,
+	shutdownPostgres,
+} from '@pkgs/postgres/src/Client';
+import {afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi} from 'vitest';

 const VOICE_NOISE_SUPPRESSION_CONFIG_KEY = 'voice_noise_suppression_config';
-const SCREEN_SHARE_DELIVERY_CONFIG_KEY = 'screen_share_delivery_config';
+const DOMAIN_MIGRATION_CONFIG_KEY = 'domain_migration_config';
 const EXPERIMENT_DELIVERY_CONFIG_KEY = 'experiment_delivery_config';
 const APP_PUBLIC_CONFIG_KEY = 'app_public_config';
 const INSTANCE_POLICY_CONFIG_KEY = 'instance_policy_config';
 const INSTANCE_INTEGRATIONS_CONFIG_KEY = 'instance_integrations_config';
+const REGISTRATION_CONFIG_KEY = 'registration_config';
+const REGISTRATION_URLS_KEY = 'registration_urls';
+const REGISTRATION_PENDING_APPROVALS_KEY = 'registration_pending_approvals';
+const POSTGRES_KV_TABLE = 'kv_instance_config_races';
+const POSTGRES_CONTAINER = `fluxer-instance-config-races-${process.pid.toString(36)}-${Date.now().toString(36)}`;
+const dockerAvailable = spawnSync('docker', ['version'], {stdio: 'ignore'}).status === 0;

 class CountingInMemoryCassandraQueryExecutor extends InMemoryCassandraQueryExecutor {
 	instanceConfigSelects = 0;
@@ -335,13 +356,13 @@ describe('InstanceConfigRepository', () => {
 		});
 	});

-	it('returns the default screen share delivery config when the key is absent', async () => {
+	it('returns the default domain migration config when the key is absent', async () => {
 		const executor = new CountingInMemoryCassandraQueryExecutor();
 		setCassandraQueryExecutorForTesting(executor);
 		const kvProvider = new MockKVProvider();
 		const repository = createRepository(kvProvider);

-		await expect(repository.getScreenShareDeliveryConfig()).resolves.toEqual(DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG);
+		await expect(repository.getDomainMigrationConfig()).resolves.toEqual(DEFAULT_DOMAIN_MIGRATION_CONFIG);
 	});

 	it.each([
@@ -349,56 +370,78 @@ describe('InstanceConfigRepository', () => {
 		{name: 'a json array', stored: '[]'},
 		{name: 'out-of-range values', stored: '{"rollout_basis_points":99999}'},
 		{name: 'a non-boolean enabled flag', stored: '{"enabled":"yes"}'},
-	])('falls back to the default screen share delivery config for $name', async ({stored}) => {
+	])('falls back to the default domain migration config for $name', async ({stored}) => {
 		const executor = new CountingInMemoryCassandraQueryExecutor();
 		setCassandraQueryExecutorForTesting(executor);
 		const kvProvider = new MockKVProvider();
 		const repository = createRepository(kvProvider);

-		await repository.setConfig(SCREEN_SHARE_DELIVERY_CONFIG_KEY, stored);
+		await repository.setConfig(DOMAIN_MIGRATION_CONFIG_KEY, stored);

-		await expect(repository.getScreenShareDeliveryConfig()).resolves.toEqual(DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG);
+		await expect(repository.getDomainMigrationConfig()).resolves.toEqual(DEFAULT_DOMAIN_MIGRATION_CONFIG);
 	});

-	it('round-trips a stored screen share delivery config', async () => {
+	it('round-trips a stored domain migration config', async () => {
 		const executor = new CountingInMemoryCassandraQueryExecutor();
 		setCassandraQueryExecutorForTesting(executor);
 		const kvProvider = new MockKVProvider();
 		const repository = createRepository(kvProvider);

-		const config: ScreenShareDeliveryConfig = {
-			...DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
+		const config: DomainMigrationConfig = {
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
 			enabled: true,
 			config_version: 5,
 			rollout_basis_points: 2500,
-			rollout_salt: 'screen-share-delivery-v2',
+			rollout_salt: 'domain-migration-v2',
 			included_user_ids: ['1400000000000000001'],
 			excluded_user_ids: ['1400000000000000002'],
+			anonymous_rollout_basis_points: 300,
+			standalone_forwarding: true,
 		};
-		await repository.setScreenShareDeliveryConfig(config);
+		await repository.setDomainMigrationConfig(config);

-		await expect(repository.getScreenShareDeliveryConfig()).resolves.toEqual(config);
+		await expect(repository.getDomainMigrationConfig()).resolves.toEqual(config);
 	});

-	it('fills newly added screen share delivery fields from the schema defaults', async () => {
+	it('fills newly added domain migration fields from the schema defaults', async () => {
 		const executor = new CountingInMemoryCassandraQueryExecutor();
 		setCassandraQueryExecutorForTesting(executor);
 		const kvProvider = new MockKVProvider();
 		const repository = createRepository(kvProvider);

 		await repository.setConfig(
-			SCREEN_SHARE_DELIVERY_CONFIG_KEY,
+			DOMAIN_MIGRATION_CONFIG_KEY,
 			JSON.stringify({enabled: true, config_version: 2, rollout_basis_points: 1000}),
 		);

-		await expect(repository.getScreenShareDeliveryConfig()).resolves.toEqual({
-			...DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
+		await expect(repository.getDomainMigrationConfig()).resolves.toEqual({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
 			enabled: true,
 			config_version: 2,
 			rollout_basis_points: 1000,
 		});
 	});

+	it('publishes a refresh so another repository observes the domain migration config', async () => {
+		const executor = new CountingInMemoryCassandraQueryExecutor();
+		setCassandraQueryExecutorForTesting(executor);
+		const kvProvider = new MockKVProvider();
+		const reader = createRepository(kvProvider);
+		const writer = createRepository(kvProvider);
+
+		await expect(reader.getDomainMigrationConfig()).resolves.toEqual(DEFAULT_DOMAIN_MIGRATION_CONFIG);
+
+		await writer.setDomainMigrationConfig({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
+			enabled: true,
+			config_version: 1,
+		});
+
+		await vi.waitFor(async () => {
+			expect(await reader.getDomainMigrationConfig()).toMatchObject({enabled: true, config_version: 1});
+		});
+	});
+
 	it('returns the default experiment delivery config when the key is absent', async () => {
 		const executor = new CountingInMemoryCassandraQueryExecutor();
 		setCassandraQueryExecutorForTesting(executor);
@@ -471,26 +514,6 @@ describe('InstanceConfigRepository', () => {
 		});
 	});

-	it('publishes a refresh so another repository observes the screen share delivery config', async () => {
-		const executor = new CountingInMemoryCassandraQueryExecutor();
-		setCassandraQueryExecutorForTesting(executor);
-		const kvProvider = new MockKVProvider();
-		const reader = createRepository(kvProvider);
-		const writer = createRepository(kvProvider);
-
-		await expect(reader.getScreenShareDeliveryConfig()).resolves.toEqual(DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG);
-
-		await writer.setScreenShareDeliveryConfig({
-			...DEFAULT_SCREEN_SHARE_DELIVERY_CONFIG,
-			enabled: true,
-			config_version: 1,
-		});
-
-		await vi.waitFor(async () => {
-			expect(await reader.getScreenShareDeliveryConfig()).toMatchObject({enabled: true, config_version: 1});
-		});
-	});
-
 	it('uses the registration URL id as the admin-visible registration code', async () => {
 		const executor = new CountingInMemoryCassandraQueryExecutor();
 		setCassandraQueryExecutorForTesting(executor);
@@ -512,3 +535,466 @@ describe('InstanceConfigRepository', () => {
 		});
 	});
 });
+
+async function sleep(ms: number): Promise<void> {
+	await new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function freePort(): Promise<number> {
+	return new Promise((resolve, reject) => {
+		const server = createServer();
+		server.on('error', reject);
+		server.listen(0, '127.0.0.1', () => {
+			const address = server.address();
+			if (typeof address === 'string' || address === null) {
+				reject(new Error('no port'));
+				return;
+			}
+			server.close(() => resolve(address.port));
+		});
+	});
+}
+
+function describeConcurrentInstanceConfigWrites(prepareBase: () => Promise<CassandraQueryExecutorForTesting>): void {
+	const pods: Array<InstanceConfigRepository> = [];
+	let executor: InstanceConfigWriteRaceExecutor;
+
+	beforeEach(async () => {
+		executor = new InstanceConfigWriteRaceExecutor(await prepareBase());
+		setCassandraQueryExecutorForTesting(executor);
+	});
+
+	afterEach(async () => {
+		await Promise.all(pods.map((pod) => pod.shutdown()));
+		pods.length = 0;
+	});
+
+	function createPod(): InstanceConfigRepository {
+		const pod = new InstanceConfigRepository(new MockKVProvider());
+		pods.push(pod);
+		return pod;
+	}
+
+	async function readStoredRegistrationConfig(): Promise<unknown> {
+		const raw = await executor.readDirectly(REGISTRATION_CONFIG_KEY);
+		return raw === null ? null : JSON.parse(raw);
+	}
+
+	it('applies two concurrent patches on top of each other instead of dropping one', async () => {
+		const first = createPod();
+		const second = createPod();
+		await first.setRegistrationConfig({mode: 'open', admin_registration_urls_enabled: true});
+		await second.getRegistrationConfig();
+		executor.watch(REGISTRATION_CONFIG_KEY);
+		executor.pauseWritesUntil(2);
+
+		await Promise.all([
+			first.setRegistrationConfig({mode: 'closed'}),
+			second.setRegistrationConfig({admin_registration_urls_enabled: false}),
+		]);
+
+		expect(executor.events.filter((event) => event === 'write rejected')).toHaveLength(1);
+		expect(executor.events.filter((event) => event === 'write')).toHaveLength(2);
+		expect(await readStoredRegistrationConfig()).toEqual({mode: 'closed', admin_registration_urls_enabled: false});
+	});
+
+	it('lets one of two concurrent first writes create the config and applies the other on top', async () => {
+		const first = createPod();
+		const second = createPod();
+		await first.getRegistrationConfig();
+		await second.getRegistrationConfig();
+		executor.watch(REGISTRATION_CONFIG_KEY);
+		executor.pauseWritesUntil(2);
+
+		await Promise.all([
+			first.setRegistrationConfig({mode: 'closed'}),
+			second.setRegistrationConfig({admin_registration_urls_enabled: false}),
+		]);
+
+		expect(executor.events.filter((event) => event === 'write rejected')).toHaveLength(1);
+		expect(executor.events.filter((event) => event === 'write')).toHaveLength(2);
+		expect(await readStoredRegistrationConfig()).toEqual({mode: 'closed', admin_registration_urls_enabled: false});
+	});
+
+	it('re-reads the database, not its stale cache, when a concurrent write lands between its read and its write', async () => {
+		const stale = createPod();
+		const other = createPod();
+		await stale.setRegistrationConfig({mode: 'open', admin_registration_urls_enabled: true});
+		await stale.getRegistrationConfig();
+		await other.setRegistrationConfig({mode: 'approval'});
+		expect(await stale.getRegistrationConfig()).toEqual({mode: 'open', admin_registration_urls_enabled: true});
+		executor.watch(REGISTRATION_CONFIG_KEY);
+		let competed = false;
+		executor.competeBeforeEachWrite(async () => {
+			if (competed) return;
+			competed = true;
+			await executor.writeDirectly(
+				REGISTRATION_CONFIG_KEY,
+				JSON.stringify({mode: 'approval', admin_registration_urls_enabled: false}),
+			);
+		});
+
+		await stale.setRegistrationConfig({mode: 'closed'});
+
+		expect(executor.events).toEqual(['read', 'write rejected', 'read', 'write']);
+		expect(await readStoredRegistrationConfig()).toEqual({mode: 'closed', admin_registration_urls_enabled: false});
+	});
+
+	it('fails loudly and writes nothing once every attempt has lost the race', async () => {
+		const pod = createPod();
+		await pod.setRegistrationConfig({mode: 'open', admin_registration_urls_enabled: true});
+		executor.watch(REGISTRATION_CONFIG_KEY);
+		let competingWrites = 0;
+		executor.competeBeforeEachWrite(async () => {
+			competingWrites++;
+			await executor.writeDirectly(
+				REGISTRATION_CONFIG_KEY,
+				JSON.stringify({mode: 'approval', admin_registration_urls_enabled: competingWrites % 2 === 0}),
+			);
+		});
+
+		const write = pod.setRegistrationConfig({mode: 'closed'});
+
+		await expect(write).rejects.toBeInstanceOf(InstanceConfigWriteConflictError);
+		await expect(write).rejects.toMatchObject({
+			status: 409,
+			code: 'CONFLICT',
+			message: expect.stringContaining(REGISTRATION_CONFIG_KEY),
+		});
+		expect(executor.events.filter((event) => event === 'write rejected')).toHaveLength(INSTANCE_CONFIG_WRITE_ATTEMPTS);
+		expect(executor.events).not.toContain('write');
+		expect(await readStoredRegistrationConfig()).toEqual({
+			mode: 'approval',
+			admin_registration_urls_enabled: INSTANCE_CONFIG_WRITE_ATTEMPTS % 2 === 0,
+		});
+	});
+
+	it('keeps a pending registration another pod added while this pod held a stale list', async () => {
+		const first = createPod();
+		const second = createPod();
+		await first.getPendingRegistrations();
+		await second.getPendingRegistrations();
+
+		await first.addPendingRegistration(pendingRegistration('1400000000000000011'));
+		await second.addPendingRegistration(pendingRegistration('1400000000000000012'));
+
+		const listed = await createPod().getPendingRegistrations();
+		expect(listed.map((entry) => entry.user_id)).toEqual(['1400000000000000011', '1400000000000000012']);
+	});
+
+	it('keeps a pending registration another pod stored and removes it once decided', async () => {
+		const pod = createPod();
+		await executor.writeDirectly(
+			REGISTRATION_PENDING_APPROVALS_KEY,
+			JSON.stringify([pendingRegistration('1400000000000000021')]),
+		);
+		await pod.addPendingRegistration(pendingRegistration('1400000000000000022'));
+
+		expect((await createPod().getPendingRegistrations()).map((entry) => entry.user_id)).toEqual([
+			'1400000000000000021',
+			'1400000000000000022',
+		]);
+
+		await pod.removePendingRegistration('1400000000000000021');
+		await pod.removePendingRegistration('1400000000000000022');
+
+		expect(await createPod().getPendingRegistrations()).toEqual([]);
+		expect(await executor.readDirectly(REGISTRATION_PENDING_APPROVALS_KEY)).toBe('[]');
+	});
+
+	it('keeps a registration URL another pod created while this pod held a stale list', async () => {
+		const first = createPod();
+		const second = createPod();
+		await first.getRegistrationUrls();
+		await second.getRegistrationUrls();
+
+		const created = [
+			await first.createRegistrationUrl(registrationUrlParams(null)),
+			await second.createRegistrationUrl(registrationUrlParams(null)),
+		];
+
+		const listed = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed.map((url) => url.id).toSorted()).toEqual(created.map((entry) => entry.registrationUrl.id).toSorted());
+	});
+
+	it('refuses a registration URL another pod revoked while this pod held a stale list', async () => {
+		const admin = createPod();
+		const signup = createPod();
+		const {code, registrationUrl} = await admin.createRegistrationUrl(registrationUrlParams(null));
+		expect(await signup.resolveRegistrationUrlCode(code)).not.toBeNull();
+
+		await admin.revokeRegistrationUrl(registrationUrl.id);
+
+		await expect(signup.resolveRegistrationUrlCode(code)).resolves.toBeNull();
+		await expect(signup.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000501')).resolves.toBeNull();
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed?.use_count).toBe(0);
+	});
+
+	it('admits a registration URL another pod created while this pod held a stale list', async () => {
+		const admin = createPod();
+		const signup = createPod();
+		await signup.getRegistrationUrls();
+
+		const {code, registrationUrl} = await admin.createRegistrationUrl(registrationUrlParams(1));
+
+		await expect(signup.resolveRegistrationUrlCode(code)).resolves.toMatchObject({
+			id: registrationUrl.id,
+			approval_required: false,
+		});
+		await expect(signup.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000601')).resolves.not.toBeNull();
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed?.use_count).toBe(1);
+	});
+
+	it('never seats more signups than max_uses when pods claim the same registration URL at once', async () => {
+		const pods = [createPod(), createPod(), createPod()];
+		const {code} = await pods[0]!.createRegistrationUrl(registrationUrlParams(2));
+		const registrationUrl = await pods[0]!.resolveRegistrationUrlCode(code);
+		if (registrationUrl === null) throw new Error('registration URL did not resolve');
+
+		const claims = await Promise.all(
+			Array.from({length: 6}, (_, index) =>
+				pods[index % pods.length]!.claimRegistrationUrlUse(registrationUrl.id, `14000000000000001${index}0`),
+			),
+		);
+
+		expect(claims.filter((claim) => claim !== null)).toHaveLength(2);
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed?.use_count).toBe(2);
+		await expect(createPod().resolveRegistrationUrlCode(code)).resolves.toBeNull();
+	});
+
+	it('refuses a claim whose retry finds the registration URL exhausted, rather than reporting the lost attempt', async () => {
+		const pod = createPod();
+		const {code, registrationUrl} = await pod.createRegistrationUrl(registrationUrlParams(1));
+		expect(await pod.resolveRegistrationUrlCode(code)).not.toBeNull();
+		executor.watch(REGISTRATION_URLS_KEY);
+		let competed = false;
+		executor.competeBeforeEachWrite(async () => {
+			if (competed) return;
+			competed = true;
+			const stored = JSON.parse((await executor.readDirectly(REGISTRATION_URLS_KEY)) ?? 'null') as Array<
+				Record<string, unknown>
+			>;
+			await executor.writeDirectly(
+				REGISTRATION_URLS_KEY,
+				JSON.stringify(
+					stored.map((entry) => ({
+						...entry,
+						use_count: 1,
+						last_used_at: '2026-09-20T00:00:00.000Z',
+						last_used_by_user_id: '1400000000000000901',
+					})),
+				),
+			);
+		});
+
+		await expect(pod.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000902')).resolves.toBeNull();
+
+		expect(executor.events).toEqual(['read', 'write rejected', 'read']);
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed).toMatchObject({use_count: 1, last_used_by_user_id: '1400000000000000901'});
+	});
+
+	it('counts concurrent uses of an uncapped registration URL without ever refusing one', async () => {
+		const pods = [createPod(), createPod()];
+		const {code} = await pods[0]!.createRegistrationUrl(registrationUrlParams(null));
+		const registrationUrl = await pods[0]!.resolveRegistrationUrlCode(code);
+		if (registrationUrl === null) throw new Error('registration URL did not resolve');
+
+		const claims = await Promise.all(
+			Array.from({length: 5}, (_, index) =>
+				pods[index % pods.length]!.claimRegistrationUrlUse(registrationUrl.id, `14000000000000002${index}0`),
+			),
+		);
+
+		expect(claims.every((claim) => claim !== null)).toBe(true);
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed?.use_count).toBe(5);
+	});
+
+	it('frees a released seat for the next signup', async () => {
+		const pod = createPod();
+		const {code} = await pod.createRegistrationUrl(registrationUrlParams(1));
+		const registrationUrl = await pod.resolveRegistrationUrlCode(code);
+		if (registrationUrl === null) throw new Error('registration URL did not resolve');
+
+		const failedSignup = await pod.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000301');
+		if (failedSignup === null) throw new Error('the first claim was refused');
+		await expect(pod.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000302')).resolves.toBeNull();
+		await pod.releaseRegistrationUrlUse(failedSignup);
+
+		await expect(pod.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000303')).resolves.not.toBeNull();
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed).toMatchObject({use_count: 1, last_used_by_user_id: '1400000000000000303'});
+	});
+
+	it('enforces max_uses against the use count already stored in the blob', async () => {
+		const pod = createPod();
+		const id = 'b3c4f0b2-8a6e-4c41-9f55-3f0c2a7d1e91';
+		await executor.writeDirectly(
+			REGISTRATION_URLS_KEY,
+			JSON.stringify([
+				{
+					id,
+					label: 'Issued earlier',
+					code_hash: createHash('sha256').update(id).digest('hex'),
+					created_by_user_id: '1400000000000000001',
+					created_at: '2026-09-01T00:00:00.000Z',
+					expires_at: null,
+					max_uses: 3,
+					use_count: 2,
+					revoked_at: null,
+					approval_required: true,
+					last_used_at: '2026-09-02T00:00:00.000Z',
+					last_used_by_user_id: '1400000000000000002',
+				},
+			]),
+		);
+
+		expect(await pod.getRegistrationUrlsForAdmin()).toEqual([
+			expect.objectContaining({
+				id,
+				use_count: 2,
+				max_uses: 3,
+				approval_required: true,
+				last_used_at: '2026-09-02T00:00:00.000Z',
+				last_used_by_user_id: '1400000000000000002',
+			}),
+		]);
+		const registrationUrl = await pod.resolveRegistrationUrlCode(id);
+		if (registrationUrl === null) throw new Error('stored registration URL did not resolve');
+		expect(registrationUrl).toMatchObject({id, approval_required: true});
+
+		await expect(pod.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000401')).resolves.not.toBeNull();
+		await expect(pod.claimRegistrationUrlUse(registrationUrl.id, '1400000000000000402')).resolves.toBeNull();
+
+		const [listed] = await createPod().getRegistrationUrlsForAdmin();
+		expect(listed).toMatchObject({use_count: 3, max_uses: 3, last_used_by_user_id: '1400000000000000401'});
+		await expect(pod.resolveRegistrationUrlCode(id)).resolves.toBeNull();
+		expect(JSON.parse((await executor.readDirectly(REGISTRATION_URLS_KEY)) ?? 'null')[0]).toMatchObject({
+			use_count: 3,
+			max_uses: 3,
+		});
+	});
+
+	it('keeps an SSO field another pod changed while this pod held a stale snapshot', async () => {
+		const first = createPod();
+		const second = createPod();
+		await first.getSsoConfig();
+		await second.getSsoConfig();
+
+		await first.setSsoConfig({displayName: 'Set by the first pod'});
+		await second.setSsoConfig({clientId: 'set-by-the-second-pod'});
+
+		expect(await createPod().getSsoConfig()).toMatchObject({
+			displayName: 'Set by the first pod',
+			clientId: 'set-by-the-second-pod',
+		});
+	});
+
+	it('leaves an SSO row alone when another pod wrote it between this pod reading and writing it', async () => {
+		const pod = createPod();
+		await pod.getSsoConfig();
+		executor.watch('sso_enforced');
+		let competed = false;
+		executor.competeBeforeEachWrite(async () => {
+			if (competed) return;
+			competed = true;
+			await executor.writeDirectly('sso_enforced', 'true');
+		});
+
+		await pod.setSsoConfig({displayName: 'Only the display name'});
+
+		expect(await executor.readDirectly('sso_enforced')).toBe('true');
+		expect(await executor.readDirectly('sso_display_name')).toBe('Only the display name');
+	});
+}
+
+function pendingRegistration(userId: string) {
+	return {
+		user_id: userId,
+		username: `pending_${userId.slice(-3)}`,
+		discriminator: 1,
+		global_name: null,
+		email: `${userId}@example.com`,
+		requested_at: `2026-09-01T00:00:${userId.slice(-2)}.000Z`,
+		registration_url_id: null,
+		client_ip: '127.0.0.1',
+	};
+}
+
+function registrationUrlParams(maxUses: number | null) {
+	return {
+		label: maxUses === null ? 'Uncapped' : `Capped at ${maxUses}`,
+		createdByUserId: '1400000000000000001',
+		expiresAt: null,
+		maxUses,
+		approvalRequired: false,
+	};
+}
+
+describe('InstanceConfigRepository concurrent writes', () => {
+	describe('in memory', () => {
+		describeConcurrentInstanceConfigWrites(async () => new InMemoryCassandraQueryExecutor());
+	});
+
+	describe.skipIf(!dockerAvailable)('on postgres', () => {
+		let client: IPostgresClient;
+
+		beforeAll(async () => {
+			const port = await freePort();
+			startDockerContainer([
+				'run',
+				'-d',
+				'--name',
+				POSTGRES_CONTAINER,
+				'-e',
+				'POSTGRES_USER=fluxer',
+				'-e',
+				'POSTGRES_PASSWORD=fluxer',
+				'-e',
+				'POSTGRES_DB=fluxer',
+				'-p',
+				`127.0.0.1:${port}:5432`,
+				'postgres:16-alpine',
+				'-c',
+				'fsync=off',
+			]);
+			let ready = false;
+			for (let attempt = 0; attempt < 180 && !ready; attempt += 1) {
+				await sleep(500);
+				const probe = spawnSync('docker', ['exec', POSTGRES_CONTAINER, 'pg_isready', '-U', 'fluxer', '-d', 'fluxer'], {
+					stdio: 'ignore',
+				});
+				if (probe.status !== 0) continue;
+				try {
+					await initPostgres({
+						url: `postgres://fluxer:[email protected]:${port}/fluxer`,
+						maxConnections: 4,
+						kvTable: POSTGRES_KV_TABLE,
+					});
+					await getDefaultPostgresClient().query('SELECT 1');
+					ready = true;
+				} catch {
+					await shutdownPostgres().catch(() => {});
+				}
+			}
+			if (!ready) throw new Error('postgres never came up');
+			client = getDefaultPostgresClient();
+			await ensurePostgresKvSchema(client);
+		}, 900_000);
+
+		afterAll(async () => {
+			setCassandraQueryExecutorForTesting(new InMemoryCassandraQueryExecutor());
+			await shutdownPostgres().catch(() => {});
+			spawnSync('docker', ['rm', '-f', POSTGRES_CONTAINER], {stdio: 'ignore'});
+		});
+
+		describeConcurrentInstanceConfigWrites(async () => {
+			await client.query(`DELETE FROM ${POSTGRES_KV_TABLE}`);
+			return new PostgresKvQueryExecutor(client);
+		});
+	});
+});
@@ -3,7 +3,8 @@
 import crypto from 'node:crypto';
 import {Config} from '@app/api/Config';
 import type {APIConfig, BlueskyOAuthConfig, BlueskyOAuthKeyConfig} from '@app/api/config/APIConfig';
-import {fetchMany, fetchOne, upsertOne} from '@app/api/database/CassandraQueryExecution';
+import {executeConditional, fetchMany, fetchOne, upsertOne} from '@app/api/database/CassandraQueryExecution';
+import {Db, type PreparedQuery} from '@app/api/database/CassandraTypes';
 import type {InstanceConfigurationRow} from '@app/api/database/types/InstanceConfigTypes';
 import {
 	getDefaultDateOfBirthCollection,
@@ -17,6 +18,9 @@ import {resolveDeferredPhoneGateEnabled, setCachedDeferredPhoneGateEnabled} from
 import {InstanceConfiguration} from '@app/api/Tables';
 import {DEFAULT_DECAY_CONSTANTS, DEFAULT_RENEWAL_CONSTANTS} from '@app/api/utils/AttachmentDecay';
 import {isJsonRecord} from '@app/api/utils/JsonBoundaryUtils';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import {ConflictError} from '@fluxer/errors/src/domains/core/ConflictError';
+import {ServiceUnavailableError} from '@fluxer/errors/src/domains/core/ServiceUnavailableError';
 import type {LimitConfigSnapshot} from '@fluxer/limits/src/LimitTypes';
 import {
 	InstanceConfigResponse,
@@ -24,14 +28,28 @@ import {
 	type PendingRegistrationResponse,
 	type RegistrationUrlResponse,
 } from '@fluxer/schema/src/domains/admin/AdminSchemas';
+import {
+	type AltchaCaptchaConfig,
+	AltchaCaptchaConfigSchema,
+} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
+import {
+	type DomainMigrationConfig,
+	DomainMigrationConfigSchema,
+} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
 import {
 	type GatewayRolloutConfig,
 	GatewayRolloutConfigSchema,
 } from '@fluxer/schema/src/domains/admin/GatewayRolloutSchemas';
 import {
-	type ScreenShareDeliveryConfig,
-	ScreenShareDeliveryConfigSchema,
-} from '@fluxer/schema/src/domains/admin/ScreenShareDeliverySchemas';
+	type ProfileTimezoneConfig,
+	ProfileTimezoneConfigSchema,
+} from '@fluxer/schema/src/domains/admin/ProfileTimezoneSchemas';
+import {
+	type LegacyPushServiceDeliveryWire,
+	type PushRelayConfig,
+	PushRelayConfigSchema,
+	toLegacyPushServiceDeliveryWire,
+} from '@fluxer/schema/src/domains/admin/PushRelaySchemas';
 import {
 	type VoiceNoiseSuppressionConfig,
 	VoiceNoiseSuppressionConfigSchema,
@@ -58,7 +76,10 @@ import {z} from 'zod';

 const GATEWAY_ROLLOUT_CONFIG_KEY = 'gateway_rollout_config';
 const VOICE_NOISE_SUPPRESSION_CONFIG_KEY = 'voice_noise_suppression_config';
-const SCREEN_SHARE_DELIVERY_CONFIG_KEY = 'screen_share_delivery_config';
+const PUSH_RELAY_CONFIG_KEY = 'push_service_delivery_config';
+const DOMAIN_MIGRATION_CONFIG_KEY = 'domain_migration_config';
+const ALTCHA_CAPTCHA_CONFIG_KEY = 'altcha_captcha_config';
+const PROFILE_TIMEZONE_CONFIG_KEY = 'profile_timezone_config';
 const EXPERIMENT_DELIVERY_CONFIG_KEY = 'experiment_delivery_config';
 const REGISTRATION_CONFIG_KEY = 'registration_config';
 const REGISTRATION_URLS_KEY = 'registration_urls';
@@ -72,6 +93,22 @@ const INSTANCE_MEDIA_CONFIG_KEY = 'instance_media_config';
 export const INSTANCE_CONFIG_REFRESH_CHANNEL = 'instance-config-refresh';
 export const REGISTRATION_PENDING_APPROVAL_TRAIT = 'registration_pending_approval';
 export const REGISTRATION_REJECTED_TRAIT = 'registration_rejected';
+export const INSTANCE_CONFIG_WRITE_ATTEMPTS = 5;
+
+export class InstanceConfigWriteConflictError extends ConflictError {
+	constructor(key: string) {
+		super({
+			code: APIErrorCodes.CONFLICT,
+			message: `Instance config "${key}" changed concurrently on all ${INSTANCE_CONFIG_WRITE_ATTEMPTS} write attempts. Nothing was written. Retry the change.`,
+		});
+		this.name = 'InstanceConfigWriteConflictError';
+	}
+}
+
+interface StoredValueUpdate<T> {
+	value: string | null;
+	result: T;
+}

 export type InstanceRegistrationConfig = InstanceRegistration;

@@ -277,6 +314,11 @@ export interface InstanceRegistrationUrl extends RegistrationUrlResponse {
 type InstanceRegistrationUrlPublic = RegistrationUrlResponse;
 type InstancePendingRegistration = PendingRegistrationResponse;

+export interface RegistrationUrlClaim {
+	registration_url_id: string;
+	user_id: string;
+}
+
 const DEFAULT_REGISTRATION_CONFIG: InstanceRegistrationConfig = {
 	mode: 'open',
 	admin_registration_urls_enabled: true,
@@ -344,7 +386,10 @@ type StoredConfigSection =
 	| 'app public'
 	| 'gateway rollout'
 	| 'voice noise suppression'
-	| 'screen share delivery'
+	| 'push relay'
+	| 'domain migration'
+	| 'altcha captcha'
+	| 'profile timezone'
 	| 'experiment delivery'
 	| 'instance policy'
 	| 'integrations'
@@ -483,8 +528,37 @@ function parseStoredVoiceNoiseSuppressionConfig(raw: string | null): VoiceNoiseS
 	return parseStoredConfigOrDefault(VoiceNoiseSuppressionConfigSchema, raw, 'voice noise suppression');
 }

-function parseStoredScreenShareDeliveryConfig(raw: string | null): ScreenShareDeliveryConfig {
-	return parseStoredConfigOrDefault(ScreenShareDeliveryConfigSchema, raw, 'screen share delivery');
+const StoredPushRelayConfigSchema = PushRelayConfigSchema.extend({
+	config_version: z.number().int().min(0).default(0),
+});
+
+function parseStoredPushRelayConfig(raw: string | null): LegacyPushServiceDeliveryWire {
+	const {config_version, ...config} = salvageStoredConfig(
+		StoredPushRelayConfigSchema,
+		readStoredConfigValue(raw, 'push relay'),
+		'push relay',
+	);
+	return toLegacyPushServiceDeliveryWire(config, config_version);
+}
+
+function toPushRelayConfig(wire: LegacyPushServiceDeliveryWire): PushRelayConfig {
+	return {
+		relay_consent_accepted: wire.relay_consent_accepted,
+		relay_consent_accepted_at: wire.relay_consent_accepted_at,
+		relay_consent_accepted_by: wire.relay_consent_accepted_by,
+	};
+}
+
+function parseStoredDomainMigrationConfig(raw: string | null): DomainMigrationConfig {
+	return parseStoredConfigOrDefault(DomainMigrationConfigSchema, raw, 'domain migration');
+}
+
+function parseStoredAltchaCaptchaConfig(raw: string | null): AltchaCaptchaConfig {
+	return parseStoredConfigOrDefault(AltchaCaptchaConfigSchema, raw, 'altcha captcha');
+}
+
+function parseStoredProfileTimezoneConfig(raw: string | null): ProfileTimezoneConfig {
+	return parseStoredConfigOrDefault(ProfileTimezoneConfigSchema, raw, 'profile timezone');
 }

 function parseStoredExperimentDeliveryConfig(raw: string | null): ExperimentDeliveryConfig {
@@ -910,6 +984,75 @@ function parseStoredSsoAllowedEmailDomains(raw: string | undefined, log = false)
 	return Array.from(domains).slice(0, MAX_SSO_ALLOWED_DOMAINS);
 }

+function readStoredSsoConfig(
+	configs: ReadonlyMap<string, string>,
+	options?: {includeSecret?: boolean},
+): InstanceSsoConfig {
+	const flags = readStoredSsoFlags(configs);
+	const read = (key: string): string | null => {
+		const v = configs.get(key);
+		if (!v) return null;
+		const trimmed = v.trim();
+		return trimmed.length === 0 ? null : trimmed;
+	};
+	const allowedDomains = parseStoredSsoAllowedEmailDomains(configs.get('sso_allowed_domains'));
+	const clientSecret = read('sso_client_secret');
+	return {
+		...flags,
+		displayName: read('sso_display_name'),
+		issuer: read('sso_issuer'),
+		authorizationUrl: read('sso_authorization_url'),
+		tokenUrl: read('sso_token_url'),
+		userInfoUrl: read('sso_userinfo_url'),
+		jwksUrl: read('sso_jwks_url'),
+		clientId: read('sso_client_id'),
+		clientSecret: options?.includeSecret ? clientSecret : undefined,
+		clientSecretSet: Boolean(clientSecret),
+		scope: read('sso_scope'),
+		allowedEmailDomains: allowedDomains,
+		redirectUri: null,
+	};
+}
+
+interface SsoRowWrite {
+	key: string;
+	value: string | undefined;
+	unset: string;
+}
+
+function ssoRow<T>(key: string, value: T | undefined, current: T, format: (value: T) => string): SsoRowWrite {
+	return {key, value: value === undefined ? undefined : format(value), unset: format(current)};
+}
+
+function nextSsoRowValue(row: SsoRowWrite, raw: string | null): string | null {
+	const value = row.value ?? raw ?? row.unset;
+	return value === raw ? null : value;
+}
+
+function formatSsoBoolean(value: boolean): string {
+	return value ? 'true' : 'false';
+}
+
+function formatSsoString(value: string | null): string {
+	return value ?? '';
+}
+
+function formatSsoDomains(value: Array<string>): string {
+	return JSON.stringify(value);
+}
+
+function normalizeSsoAllowedEmailDomainsForWrite(domains: Array<string>, enabled: boolean): Array<string> {
+	try {
+		return normalizeSsoAllowedEmailDomains(domains);
+	} catch (error) {
+		if (enabled) {
+			throw error;
+		}
+		Logger.warn({error}, 'Clearing invalid SSO allowed domain config while SSO is disabled');
+		return [];
+	}
+}
+
 export class InstanceConfigRepository {
 	private readonly kvClient: IKVProvider | null;
 	private configCache: InstanceConfigCache;
@@ -993,6 +1136,57 @@ export class InstanceConfigRepository {
 		);
 	}

+	private async updateStoredConfig<T>(key: string, next: (raw: string | null) => T): Promise<T> {
+		const cache = this.configCache;
+		const {result} = await this.compareAndSetStoredValue(cache, key, (raw) => {
+			const config = next(raw);
+			return {value: JSON.stringify(config), result: config};
+		});
+		await this.publishRefresh(cache.sourceId);
+		return result;
+	}
+
+	private async compareAndSetStoredValue<T>(
+		cache: InstanceConfigCache,
+		key: string,
+		next: (raw: string | null) => StoredValueUpdate<T>,
+	): Promise<{result: T; written: boolean}> {
+		await cache.getSnapshot();
+		for (let attempt = 0; attempt < INSTANCE_CONFIG_WRITE_ATTEMPTS; attempt++) {
+			cache.assertActive();
+			const current = await this.fetchConfigForWrite(key);
+			cache.assertActive();
+			const {value, result} = next(current);
+			if (value === null) return {result, written: false};
+			if (await executeConditional(this.compareAndSetConfig(key, current, value))) {
+				cache.update(key, value);
+				return {result, written: true};
+			}
+		}
+		Logger.error(
+			{key, attempts: INSTANCE_CONFIG_WRITE_ATTEMPTS},
+			'Instance config write lost to a concurrent write on every attempt',
+		);
+		throw new InstanceConfigWriteConflictError(key);
+	}
+
+	private compareAndSetConfig(key: string, current: string | null, value: string): PreparedQuery {
+		const updatedAt = new Date();
+		if (current === null) {
+			return InstanceConfiguration.insertIfNotExists({key, value, updated_at: updatedAt});
+		}
+		return InstanceConfiguration.conditionalPatchByPk(
+			{key},
+			{value: Db.set(value), updated_at: Db.set(updatedAt)},
+			{value: current},
+		);
+	}
+
+	private async fetchConfigForWrite(key: string): Promise<string | null> {
+		const [row] = await fetchMany<InstanceConfigurationRow>(FETCH_CONFIG_QUERY, {key}, {consistency: 'serial'});
+		return row?.value ?? null;
+	}
+
 	private async fetchConfigFromDatabase(key: string): Promise<string | null> {
 		const row = await fetchOne<InstanceConfigurationRow>(FETCH_CONFIG_QUERY, {key});
 		return row?.value ?? null;
@@ -1014,7 +1208,10 @@ export class InstanceConfigRepository {
 			parseStoredGatewayRolloutConfig(snapshot.get(GATEWAY_ROLLOUT_CONFIG_KEY) ?? null),
 		);
 		parseStoredVoiceNoiseSuppressionConfig(snapshot.get(VOICE_NOISE_SUPPRESSION_CONFIG_KEY) ?? null);
-		parseStoredScreenShareDeliveryConfig(snapshot.get(SCREEN_SHARE_DELIVERY_CONFIG_KEY) ?? null);
+		parseStoredPushRelayConfig(snapshot.get(PUSH_RELAY_CONFIG_KEY) ?? null);
+		parseStoredDomainMigrationConfig(snapshot.get(DOMAIN_MIGRATION_CONFIG_KEY) ?? null);
+		parseStoredAltchaCaptchaConfig(snapshot.get(ALTCHA_CAPTCHA_CONFIG_KEY) ?? null);
+		parseStoredProfileTimezoneConfig(snapshot.get(PROFILE_TIMEZONE_CONFIG_KEY) ?? null);
 		parseStoredExperimentDeliveryConfig(snapshot.get(EXPERIMENT_DELIVERY_CONFIG_KEY) ?? null);
 		const policy = parseStoredInstancePolicyConfig(snapshot.get(INSTANCE_POLICY_CONFIG_KEY) ?? null);
 		checkStoredConfig('registration', () =>
@@ -1082,8 +1279,12 @@ export class InstanceConfigRepository {
 		return parseStoredGatewayRolloutConfig(raw);
 	}

-	async setGatewayRolloutConfig(config: GatewayRolloutConfig): Promise<void> {
-		await this.setConfig(GATEWAY_ROLLOUT_CONFIG_KEY, JSON.stringify(decodeGatewayRolloutConfig(config)));
+	updateGatewayRolloutConfig(
+		update: (current: GatewayRolloutConfig) => GatewayRolloutConfig,
+	): Promise<GatewayRolloutConfig> {
+		return this.updateStoredConfig(GATEWAY_ROLLOUT_CONFIG_KEY, (raw) =>
+			decodeGatewayRolloutConfig(update(parseStoredGatewayRolloutConfig(raw))),
+		);
 	}

 	async getVoiceNoiseSuppressionConfig(): Promise<VoiceNoiseSuppressionConfig> {
@@ -1092,18 +1293,95 @@ export class InstanceConfigRepository {
 	}

 	async setVoiceNoiseSuppressionConfig(config: VoiceNoiseSuppressionConfig): Promise<void> {
-		const validated = validateStoredConfig(VoiceNoiseSuppressionConfigSchema, config, 'voice noise suppression');
-		await this.setConfig(VOICE_NOISE_SUPPRESSION_CONFIG_KEY, JSON.stringify(validated));
+		await this.updateVoiceNoiseSuppressionConfig(() => config);
 	}

-	async getScreenShareDeliveryConfig(): Promise<ScreenShareDeliveryConfig> {
-		const raw = await this.getConfig(SCREEN_SHARE_DELIVERY_CONFIG_KEY);
-		return parseStoredScreenShareDeliveryConfig(raw);
+	updateVoiceNoiseSuppressionConfig(
+		update: (current: VoiceNoiseSuppressionConfig) => VoiceNoiseSuppressionConfig,
+	): Promise<VoiceNoiseSuppressionConfig> {
+		return this.updateStoredConfig(VOICE_NOISE_SUPPRESSION_CONFIG_KEY, (raw) =>
+			validateStoredConfig(
+				VoiceNoiseSuppressionConfigSchema,
+				update(parseStoredVoiceNoiseSuppressionConfig(raw)),
+				'voice noise suppression',
+			),
+		);
 	}

-	async setScreenShareDeliveryConfig(config: ScreenShareDeliveryConfig): Promise<void> {
-		const validated = validateStoredConfig(ScreenShareDeliveryConfigSchema, config, 'screen share delivery');
-		await this.setConfig(SCREEN_SHARE_DELIVERY_CONFIG_KEY, JSON.stringify(validated));
+	async getLegacyPushServiceDeliveryWire(): Promise<LegacyPushServiceDeliveryWire> {
+		const raw = await this.getConfig(PUSH_RELAY_CONFIG_KEY);
+		return parseStoredPushRelayConfig(raw);
+	}
+
+	async getPushRelayConfig(): Promise<PushRelayConfig> {
+		return toPushRelayConfig(await this.getLegacyPushServiceDeliveryWire());
+	}
+
+	updatePushRelayConfig(update: (current: PushRelayConfig) => PushRelayConfig): Promise<LegacyPushServiceDeliveryWire> {
+		return this.updateStoredConfig(PUSH_RELAY_CONFIG_KEY, (raw) => {
+			const current = parseStoredPushRelayConfig(raw);
+			const next = validateStoredConfig(PushRelayConfigSchema, update(toPushRelayConfig(current)), 'push relay');
+			return toLegacyPushServiceDeliveryWire(next, current.config_version + 1);
+		});
+	}
+
+	async getDomainMigrationConfig(): Promise<DomainMigrationConfig> {
+		const raw = await this.getConfig(DOMAIN_MIGRATION_CONFIG_KEY);
+		return parseStoredDomainMigrationConfig(raw);
+	}
+
+	async setDomainMigrationConfig(config: DomainMigrationConfig): Promise<void> {
+		await this.updateDomainMigrationConfig(() => config);
+	}
+
+	updateDomainMigrationConfig(
+		update: (current: DomainMigrationConfig) => DomainMigrationConfig,
+	): Promise<DomainMigrationConfig> {
+		return this.updateStoredConfig(DOMAIN_MIGRATION_CONFIG_KEY, (raw) =>
+			validateStoredConfig(
+				DomainMigrationConfigSchema,
+				update(parseStoredDomainMigrationConfig(raw)),
+				'domain migration',
+			),
+		);
+	}
+
+	async getAltchaCaptchaConfig(): Promise<AltchaCaptchaConfig> {
+		const raw = await this.getConfig(ALTCHA_CAPTCHA_CONFIG_KEY);
+		return parseStoredAltchaCaptchaConfig(raw);
+	}
+
+	async setAltchaCaptchaConfig(config: AltchaCaptchaConfig): Promise<void> {
+		await this.updateAltchaCaptchaConfig(() => config);
+	}
+
+	updateAltchaCaptchaConfig(
+		update: (current: AltchaCaptchaConfig) => AltchaCaptchaConfig,
+	): Promise<AltchaCaptchaConfig> {
+		return this.updateStoredConfig(ALTCHA_CAPTCHA_CONFIG_KEY, (raw) =>
+			validateStoredConfig(AltchaCaptchaConfigSchema, update(parseStoredAltchaCaptchaConfig(raw)), 'altcha captcha'),
+		);
+	}
+
+	async getProfileTimezoneConfig(): Promise<ProfileTimezoneConfig> {
+		const raw = await this.getConfig(PROFILE_TIMEZONE_CONFIG_KEY);
+		return parseStoredProfileTimezoneConfig(raw);
+	}
+
+	async setProfileTimezoneConfig(config: ProfileTimezoneConfig): Promise<void> {
+		await this.updateProfileTimezoneConfig(() => config);
+	}
+
+	updateProfileTimezoneConfig(
+		update: (current: ProfileTimezoneConfig) => ProfileTimezoneConfig,
+	): Promise<ProfileTimezoneConfig> {
+		return this.updateStoredConfig(PROFILE_TIMEZONE_CONFIG_KEY, (raw) =>
+			validateStoredConfig(
+				ProfileTimezoneConfigSchema,
+				update(parseStoredProfileTimezoneConfig(raw)),
+				'profile timezone',
+			),
+		);
 	}

 	async getExperimentDeliveryConfig(): Promise<ExperimentDeliveryConfig> {
@@ -1112,8 +1390,19 @@ export class InstanceConfigRepository {
 	}

 	async setExperimentDeliveryConfig(config: ExperimentDeliveryConfig): Promise<void> {
-		const validated = validateStoredConfig(ExperimentDeliveryConfigSchema, config, 'experiment delivery');
-		await this.setConfig(EXPERIMENT_DELIVERY_CONFIG_KEY, JSON.stringify(validated));
+		await this.updateExperimentDeliveryConfig(() => config);
+	}
+
+	updateExperimentDeliveryConfig(
+		update: (current: ExperimentDeliveryConfig) => ExperimentDeliveryConfig,
+	): Promise<ExperimentDeliveryConfig> {
+		return this.updateStoredConfig(EXPERIMENT_DELIVERY_CONFIG_KEY, (raw) =>
+			validateStoredConfig(
+				ExperimentDeliveryConfigSchema,
+				update(parseStoredExperimentDeliveryConfig(raw)),
+				'experiment delivery',
+			),
+		);
 	}

 	async readLimitConfigInputs(): Promise<LimitConfigInputs> {
@@ -1149,26 +1438,27 @@ export class InstanceConfigRepository {
 		legal?: Partial<InstanceAppPublicConfig['legal']>;
 		registration?: Partial<InstanceAppPublicConfig['registration']>;
 	}): Promise<InstanceAppPublicConfig> {
-		const current = await this.getAppPublicConfig();
-		const next = decodeAppPublicConfig({
-			branding: {
-				...current.branding,
-				...(config.branding ?? {}),
-			},
-			setup: {
-				...current.setup,
-				...(config.setup ?? {}),
-			},
-			legal: {
-				...current.legal,
-				...(config.legal ?? {}),
-			},
-			registration: {
-				...current.registration,
-				...(config.registration ?? {}),
-			},
+		const next = await this.updateStoredConfig(APP_PUBLIC_CONFIG_KEY, (raw) => {
+			const current = parseStoredAppPublicConfig(raw);
+			return decodeAppPublicConfig({
+				branding: {
+					...current.branding,
+					...(config.branding ?? {}),
+				},
+				setup: {
+					...current.setup,
+					...(config.setup ?? {}),
+				},
+				legal: {
+					...current.legal,
+					...(config.legal ?? {}),
+				},
+				registration: {
+					...current.registration,
+					...(config.registration ?? {}),
+				},
+			});
 		});
-		await this.setConfig(APP_PUBLIC_CONFIG_KEY, JSON.stringify(next));
 		setCachedDateOfBirthCollection(next.registration.collect_date_of_birth);
 		return next;
 	}
@@ -1188,10 +1478,21 @@ export class InstanceConfigRepository {
 		return parseStoredInstancePolicyConfig(raw);
 	}

-	async setInstancePolicyConfig(config: Partial<InstancePolicyConfig>): Promise<InstancePolicyConfig> {
-		const current = await this.readStoredInstancePolicyConfig();
-		const next = decodeInstancePolicyConfig({...current, ...config});
-		await this.setConfig(INSTANCE_POLICY_CONFIG_KEY, JSON.stringify(next));
+	setInstancePolicyConfig(config: Partial<InstancePolicyConfig>): Promise<InstancePolicyConfig> {
+		return this.updateInstancePolicyConfig(() => config);
+	}
+
+	async updateInstancePolicyConfig(
+		plan: (current: InstancePolicyConfig) => Partial<InstancePolicyConfig>,
+	): Promise<InstancePolicyConfig> {
+		const cache = this.configCache;
+		const {result: next, written} = await this.compareAndSetStoredValue(cache, INSTANCE_POLICY_CONFIG_KEY, (raw) => {
+			const current = parseStoredInstancePolicyConfig(raw);
+			const patch = plan(current);
+			const config = decodeInstancePolicyConfig({...current, ...patch});
+			return {value: Object.keys(patch).length === 0 ? null : JSON.stringify(config), result: config};
+		});
+		if (written) await this.publishRefresh(cache.sourceId);
 		setCachedDeferredPhoneGateEnabled(resolveDeferredPhoneGateEnabled(next));
 		return next;
 	}
@@ -1201,37 +1502,37 @@ export class InstanceConfigRepository {
 		return parseStoredInstanceIntegrationsConfig(raw);
 	}

-	async setInstanceIntegrationsConfig(config: InstanceIntegrationsConfigPatch): Promise<InstanceIntegrationsConfig> {
-		const current = await this.getInstanceIntegrationsConfig();
-		const next = decodeInstanceIntegrationsConfig({
-			gif: {
-				...current.gif,
-				...(config.gif ?? {}),
-			},
-			youtube: {
-				...current.youtube,
-				...(config.youtube ?? {}),
-			},
-			captcha: {
-				...current.captcha,
-				...(config.captcha ?? {}),
-			},
-			email: {
-				...current.email,
-				...(config.email ?? {}),
-				smtp: {
-					...current.email.smtp,
-					...(config.email?.smtp ?? {}),
+	setInstanceIntegrationsConfig(config: InstanceIntegrationsConfigPatch): Promise<InstanceIntegrationsConfig> {
+		return this.updateStoredConfig(INSTANCE_INTEGRATIONS_CONFIG_KEY, (raw) => {
+			const current = parseStoredInstanceIntegrationsConfig(raw);
+			return decodeInstanceIntegrationsConfig({
+				gif: {
+					...current.gif,
+					...(config.gif ?? {}),
 				},
-			},
-			bluesky: {
-				...current.bluesky,
-				...(config.bluesky ?? {}),
-				keys: config.bluesky?.keys ?? current.bluesky.keys,
-			},
+				youtube: {
+					...current.youtube,
+					...(config.youtube ?? {}),
+				},
+				captcha: {
+					...current.captcha,
+					...(config.captcha ?? {}),
+				},
+				email: {
+					...current.email,
+					...(config.email ?? {}),
+					smtp: {
+						...current.email.smtp,
+						...(config.email?.smtp ?? {}),
+					},
+				},
+				bluesky: {
+					...current.bluesky,
+					...(config.bluesky ?? {}),
+					keys: config.bluesky?.keys ?? current.bluesky.keys,
+				},
+			});
 		});
-		await this.setConfig(INSTANCE_INTEGRATIONS_CONFIG_KEY, JSON.stringify(next));
-		return next;
 	}

 	async getInstanceMediaConfig(): Promise<InstanceMediaConfig> {
@@ -1239,16 +1540,16 @@ export class InstanceConfigRepository {
 		return parseStoredInstanceMediaConfig(raw);
 	}

-	async setInstanceMediaConfig(config: InstanceMediaConfigPatch): Promise<InstanceMediaConfig> {
-		const current = await this.getInstanceMediaConfig();
-		const next = decodeInstanceMediaConfig({
-			attachment_decay: {
-				...current.attachment_decay,
-				...(config.attachment_decay ?? {}),
-			},
+	setInstanceMediaConfig(config: InstanceMediaConfigPatch): Promise<InstanceMediaConfig> {
+		return this.updateStoredConfig(INSTANCE_MEDIA_CONFIG_KEY, (raw) => {
+			const current = parseStoredInstanceMediaConfig(raw);
+			return decodeInstanceMediaConfig({
+				attachment_decay: {
+					...current.attachment_decay,
+					...(config.attachment_decay ?? {}),
+				},
+			});
 		});
-		await this.setConfig(INSTANCE_MEDIA_CONFIG_KEY, JSON.stringify(next));
-		return next;
 	}

 	async getEffectiveAttachmentDecayConfig(): Promise<InstanceAttachmentDecayEffectiveConfig> {
@@ -1485,15 +1786,15 @@ export class InstanceConfigRepository {
 		return parseStoredRegistrationConfig(raw);
 	}

-	async setRegistrationConfig(config: Partial<InstanceRegistrationConfig>): Promise<InstanceRegistrationConfig> {
-		const current = await this.getRegistrationConfig();
-		const next = decodeRegistrationConfig({
-			mode: config.mode ?? current.mode,
-			admin_registration_urls_enabled:
-				config.admin_registration_urls_enabled ?? current.admin_registration_urls_enabled,
+	setRegistrationConfig(config: Partial<InstanceRegistrationConfig>): Promise<InstanceRegistrationConfig> {
+		return this.updateStoredConfig(REGISTRATION_CONFIG_KEY, (raw) => {
+			const current = parseStoredRegistrationConfig(raw);
+			return decodeRegistrationConfig({
+				mode: config.mode ?? current.mode,
+				admin_registration_urls_enabled:
+					config.admin_registration_urls_enabled ?? current.admin_registration_urls_enabled,
+			});
 		});
-		await this.setConfig(REGISTRATION_CONFIG_KEY, JSON.stringify(next));
-		return next;
 	}

 	async getRegistrationPublicConfig(): Promise<InstanceRegistrationConfig> {
@@ -1534,16 +1835,20 @@ export class InstanceConfigRepository {
 			last_used_at: null,
 			last_used_by_user_id: null,
 		};
-		const registrationUrls = await this.getRegistrationUrls();
-		await this.setRegistrationUrls([registrationUrl, ...registrationUrls]);
+		await this.updateStoredConfig(REGISTRATION_URLS_KEY, (raw) =>
+			validateStoredCollection(
+				StoredRegistrationUrlSchema,
+				[registrationUrl, ...parseStoredCollection(StoredRegistrationUrlSchema, raw, 'registration URLs')],
+				'registration URLs',
+			),
+		);
 		return {registrationUrl: redactRegistrationUrl(registrationUrl), code};
 	}

 	async revokeRegistrationUrl(id: string): Promise<void> {
 		const now = new Date().toISOString();
-		const registrationUrls = await this.getRegistrationUrls();
-		await this.setRegistrationUrls(
-			registrationUrls.map((registrationUrl) =>
+		await this.updateStoredConfig(REGISTRATION_URLS_KEY, (raw) =>
+			parseStoredCollection(StoredRegistrationUrlSchema, raw, 'registration URLs').map((registrationUrl) =>
 				registrationUrl.id === id && !registrationUrl.revoked_at
 					? {...registrationUrl, revoked_at: now}
 					: registrationUrl,
@@ -1556,9 +1861,8 @@ export class InstanceConfigRepository {
 		if (!normalizedCode) return null;
 		const hash = this.hashRegistrationUrlCode(normalizedCode);
 		const now = new Date();
-		const registrationUrls = await this.getRegistrationUrls();
 		return (
-			registrationUrls.find(
+			(await this.fetchRegistrationUrlDefinitions()).find(
 				(registrationUrl) =>
 					(registrationUrl.id === normalizedCode || registrationUrl.code_hash === hash) &&
 					isRegistrationUrlUsable(registrationUrl, now),
@@ -1566,21 +1870,68 @@ export class InstanceConfigRepository {
 		);
 	}

-	async recordRegistrationUrlUse(id: string, userId: string): Promise<void> {
-		const now = new Date().toISOString();
-		const registrationUrls = await this.getRegistrationUrls();
-		await this.setRegistrationUrls(
-			registrationUrls.map((registrationUrl) =>
-				registrationUrl.id === id
-					? {
-							...registrationUrl,
-							use_count: registrationUrl.use_count + 1,
-							last_used_at: now,
-							last_used_by_user_id: userId,
-						}
-					: registrationUrl,
-			),
-		);
+	async claimRegistrationUrlUse(registrationUrlId: string, userId: string): Promise<RegistrationUrlClaim | null> {
+		const cache = this.configCache;
+		let claimed: {result: RegistrationUrlClaim | null; written: boolean};
+		try {
+			claimed = await this.compareAndSetStoredValue<RegistrationUrlClaim | null>(
+				cache,
+				REGISTRATION_URLS_KEY,
+				(raw) => {
+					const registrationUrls = parseStoredCollection(StoredRegistrationUrlSchema, raw, 'registration URLs');
+					const now = new Date();
+					const claimable = registrationUrls.find(
+						(registrationUrl) =>
+							registrationUrl.id === registrationUrlId && isRegistrationUrlUsable(registrationUrl, now),
+					);
+					if (!claimable) return {value: null, result: null};
+					const next = registrationUrls.map((registrationUrl) =>
+						registrationUrl === claimable
+							? {
+									...registrationUrl,
+									use_count: registrationUrl.use_count + 1,
+									last_used_at: now.toISOString(),
+									last_used_by_user_id: userId,
+								}
+							: registrationUrl,
+					);
+					return {
+						value: JSON.stringify(validateStoredCollection(StoredRegistrationUrlSchema, next, 'registration URLs')),
+						result: {registration_url_id: registrationUrlId, user_id: userId},
+					};
+				},
+			);
+		} catch (error) {
+			if (error instanceof InstanceConfigWriteConflictError) throw new ServiceUnavailableError();
+			throw error;
+		}
+		if (claimed.written) await this.publishRefresh(cache.sourceId);
+		return claimed.result;
+	}
+
+	async releaseRegistrationUrlUse(claim: RegistrationUrlClaim): Promise<void> {
+		const cache = this.configCache;
+		try {
+			const {written} = await this.compareAndSetStoredValue<null>(cache, REGISTRATION_URLS_KEY, (raw) => {
+				const registrationUrls = parseStoredCollection(StoredRegistrationUrlSchema, raw, 'registration URLs');
+				const released = registrationUrls.find(
+					(registrationUrl) => registrationUrl.id === claim.registration_url_id && registrationUrl.use_count > 0,
+				);
+				if (!released) return {value: null, result: null};
+				const next = registrationUrls.map((registrationUrl) =>
+					registrationUrl === released
+						? {...registrationUrl, use_count: registrationUrl.use_count - 1}
+						: registrationUrl,
+				);
+				return {value: JSON.stringify(next), result: null};
+			});
+			if (written) await this.publishRefresh(cache.sourceId);
+		} catch (error) {
+			Logger.warn(
+				{registrationUrlId: claim.registration_url_id, userId: claim.user_id, error},
+				'Releasing a registration URL use failed',
+			);
+		}
 	}

 	async getPendingRegistrations(): Promise<Array<InstancePendingRegistration>> {
@@ -1591,104 +1942,82 @@ export class InstanceConfigRepository {
 	}

 	async addPendingRegistration(pendingRegistration: InstancePendingRegistration): Promise<void> {
-		const pendingRegistrations = await this.getPendingRegistrations();
-		const next = [
-			pendingRegistration,
-			...pendingRegistrations.filter((entry) => entry.user_id !== pendingRegistration.user_id),
-		];
-		await this.setPendingRegistrations(next);
+		await this.updateStoredConfig(REGISTRATION_PENDING_APPROVALS_KEY, (raw) =>
+			validateStoredCollection(
+				StoredPendingRegistrationSchema,
+				[
+					pendingRegistration,
+					...parseStoredCollection(StoredPendingRegistrationSchema, raw, 'pending registrations').filter(
+						(entry) => entry.user_id !== pendingRegistration.user_id,
+					),
+				],
+				'pending registrations',
+			),
+		);
 	}

 	async removePendingRegistration(userId: string): Promise<void> {
-		const pendingRegistrations = await this.getPendingRegistrations();
-		await this.setPendingRegistrations(pendingRegistrations.filter((entry) => entry.user_id !== userId));
+		await this.updateStoredConfig(REGISTRATION_PENDING_APPROVALS_KEY, (raw) =>
+			parseStoredCollection(StoredPendingRegistrationSchema, raw, 'pending registrations').filter(
+				(entry) => entry.user_id !== userId,
+			),
+		);
 	}

 	async getSsoConfig(options?: {includeSecret?: boolean}): Promise<InstanceSsoConfig> {
-		const configs = await this.getAllConfigs();
-		const flags = readStoredSsoFlags(configs);
-		const read = (key: string): string | null => {
-			const v = configs.get(key);
-			if (!v) return null;
-			const trimmed = v.trim();
-			return trimmed.length === 0 ? null : trimmed;
-		};
-		const allowedDomains = parseStoredSsoAllowedEmailDomains(configs.get('sso_allowed_domains'));
-		const clientSecret = read('sso_client_secret');
-		return {
-			...flags,
-			displayName: read('sso_display_name'),
-			issuer: read('sso_issuer'),
-			authorizationUrl: read('sso_authorization_url'),
-			tokenUrl: read('sso_token_url'),
-			userInfoUrl: read('sso_userinfo_url'),
-			jwksUrl: read('sso_jwks_url'),
-			clientId: read('sso_client_id'),
-			clientSecret: options?.includeSecret ? clientSecret : undefined,
-			clientSecretSet: Boolean(clientSecret),
-			scope: read('sso_scope'),
-			allowedEmailDomains: allowedDomains,
-			redirectUri: null,
-		};
+		return readStoredSsoConfig(await this.getAllConfigs(), options);
 	}

 	async setSsoConfig(config: Partial<InstanceSsoConfig>): Promise<InstanceSsoConfig> {
-		const current = await this.getSsoConfig({includeSecret: true});
-		const definedConfig = Object.fromEntries(
-			Object.entries(config).filter(([, value]) => value !== undefined),
-		) as Partial<InstanceSsoConfig>;
-		const next: InstanceSsoConfig = {
-			...current,
-			...definedConfig,
-			clientSecret: config.clientSecret !== undefined ? config.clientSecret : current.clientSecret,
-		};
-		if (config.enabled === true && config.enforced === undefined && !current.enabled) {
-			next.enforced = true;
-		}
-		let allowedEmailDomains: Array<string>;
-		try {
-			allowedEmailDomains = normalizeSsoAllowedEmailDomains(next.allowedEmailDomains);
-		} catch (error) {
-			if (next.enabled) {
-				throw error;
-			}
-			Logger.warn({error}, 'Clearing invalid SSO allowed domain config while SSO is disabled');
-			allowedEmailDomains = [];
-		}
-		const entries: Array<[string, string]> = [
-			['sso_enabled', next.enabled ? 'true' : 'false'],
-			['sso_enforced', next.enforced ? 'true' : 'false'],
-			['sso_display_name', next.displayName ?? ''],
-			['sso_issuer', next.issuer ?? ''],
-			['sso_authorization_url', next.authorizationUrl ?? ''],
-			['sso_token_url', next.tokenUrl ?? ''],
-			['sso_userinfo_url', next.userInfoUrl ?? ''],
-			['sso_jwks_url', next.jwksUrl ?? ''],
-			['sso_client_id', next.clientId ?? ''],
-			['sso_scope', next.scope ?? ''],
-			['sso_allowed_domains', JSON.stringify(allowedEmailDomains)],
-			['sso_auto_provision', next.autoProvision ? 'true' : 'false'],
-			['sso_redirect_uri', ''],
+		const configs = await this.getAllConfigs();
+		const current = readStoredSsoConfig(configs, {includeSecret: true});
+		const enabled = config.enabled ?? current.enabled;
+		const allowedEmailDomains =
+			config.allowedEmailDomains === undefined
+				? undefined
+				: normalizeSsoAllowedEmailDomainsForWrite(config.allowedEmailDomains, enabled);
+		const rows: Array<SsoRowWrite> = [
+			ssoRow('sso_enabled', config.enabled, current.enabled, formatSsoBoolean),
+			ssoRow('sso_enforced', config.enforced, current.enforced, formatSsoBoolean),
+			ssoRow('sso_display_name', config.displayName, current.displayName, formatSsoString),
+			ssoRow('sso_issuer', config.issuer, current.issuer, formatSsoString),
+			ssoRow('sso_authorization_url', config.authorizationUrl, current.authorizationUrl, formatSsoString),
+			ssoRow('sso_token_url', config.tokenUrl, current.tokenUrl, formatSsoString),
+			ssoRow('sso_userinfo_url', config.userInfoUrl, current.userInfoUrl, formatSsoString),
+			ssoRow('sso_jwks_url', config.jwksUrl, current.jwksUrl, formatSsoString),
+			ssoRow('sso_client_id', config.clientId, current.clientId, formatSsoString),
+			ssoRow('sso_scope', config.scope, current.scope, formatSsoString),
+			ssoRow('sso_allowed_domains', allowedEmailDomains, current.allowedEmailDomains, formatSsoDomains),
+			ssoRow('sso_auto_provision', config.autoProvision, current.autoProvision, formatSsoBoolean),
+			ssoRow('sso_redirect_uri', undefined, null, formatSsoString),
 		];
 		if (config.clientSecret !== undefined) {
-			entries.push(['sso_client_secret', config.clientSecret ?? '']);
+			rows.push(ssoRow('sso_client_secret', config.clientSecret, current.clientSecret ?? null, formatSsoString));
 		}
-		await this.setConfigs(entries);
+		const cache = this.configCache;
+		const results = await Promise.allSettled(
+			rows
+				.filter((row) => row.value !== undefined || !configs.has(row.key))
+				.map((row) =>
+					this.compareAndSetStoredValue(cache, row.key, (raw) => ({value: nextSsoRowValue(row, raw), result: null})),
+				),
+		);
+		const errors: Array<unknown> = results.flatMap((result) => (result.status === 'rejected' ? [result.reason] : []));
+		if (results.some((result) => result.status === 'fulfilled' && result.value.written)) {
+			try {
+				await this.publishRefresh(cache.sourceId);
+			} catch (error) {
+				errors.push(error);
+			}
+		}
+		if (errors.length === 1) throw errors[0];
+		if (errors.length > 1) throw new AggregateError(errors, 'Failed to write or publish the SSO config');
 		return this.getSsoConfig({includeSecret: true});
 	}

-	private async setRegistrationUrls(registrationUrls: Array<InstanceRegistrationUrl>): Promise<void> {
-		const validated = validateStoredCollection(StoredRegistrationUrlSchema, registrationUrls, 'registration URLs');
-		await this.setConfig(REGISTRATION_URLS_KEY, JSON.stringify(validated));
-	}
-
-	private async setPendingRegistrations(pendingRegistrations: Array<InstancePendingRegistration>): Promise<void> {
-		const validated = validateStoredCollection(
-			StoredPendingRegistrationSchema,
-			pendingRegistrations,
-			'pending registrations',
-		);
-		await this.setConfig(REGISTRATION_PENDING_APPROVALS_KEY, JSON.stringify(validated));
+	private async fetchRegistrationUrlDefinitions(): Promise<Array<InstanceRegistrationUrl>> {
+		const raw = await this.fetchConfigFromDatabase(REGISTRATION_URLS_KEY);
+		return parseStoredCollection(StoredRegistrationUrlSchema, raw, 'registration URLs');
 	}

 	private hashRegistrationUrlCode(code: string): string {
@@ -8,6 +8,7 @@ import type {LimitConfigService} from '@app/api/limits/LimitConfigService';
 import {InMemoryCassandraQueryExecutor} from '@app/api/test/InMemoryCassandraQueryExecutor';
 import {MockKVProvider} from '@app/api/test/mocks/MockKVProvider';
 import type {HonoEnv} from '@app/api/types/HonoEnv';
+import {DEFAULT_DOMAIN_MIGRATION_CONFIG} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
 import {Hono} from 'hono';
 import {afterEach, describe, expect, it} from 'vitest';

@@ -96,4 +97,36 @@ describe('InstanceController discovery captcha', () => {
 			turnstile_site_key: 'turnstile-site-key',
 		});
 	});
+
+	it('publishes the domain migration kill switch and anonymous rollout without the targeting lists', async () => {
+		const repository = createRepository();
+		const app = createApp(repository);
+
+		const initial = await app.request('http://localhost/.well-known/fluxer');
+		expect(((await initial.json()) as {domain_migration: unknown}).domain_migration).toEqual({
+			enabled: false,
+			anonymous_rollout_basis_points: 0,
+			rollout_salt: 'domain-migration-v1',
+			standalone_forwarding: false,
+		});
+
+		await repository.setDomainMigrationConfig({
+			...DEFAULT_DOMAIN_MIGRATION_CONFIG,
+			enabled: true,
+			config_version: 2,
+			rollout_basis_points: 100,
+			anonymous_rollout_basis_points: 1500,
+			included_user_ids: ['1400000000000000001'],
+			standalone_forwarding: true,
+		});
+
+		const updated = await app.request('http://localhost/.well-known/fluxer');
+		expect(updated.headers.get('etag')).not.toBe(initial.headers.get('etag'));
+		expect(((await updated.json()) as {domain_migration: unknown}).domain_migration).toEqual({
+			enabled: true,
+			anonymous_rollout_basis_points: 1500,
+			rollout_salt: 'domain-migration-v1',
+			standalone_forwarding: true,
+		});
+	});
 });
@@ -16,6 +16,7 @@ import type {HonoEnv} from '@app/api/types/HonoEnv';
 import {API_CODE_VERSION} from '@fluxer/constants/src/AppConstants';
 import {buildDiscoveryResponse, type DiscoveryStaticInput} from '@fluxer/instance_bootstrap/src/BuildDiscovery';
 import type {InstanceAppPublic} from '@fluxer/instance_bootstrap/src/Types';
+import {toDomainMigrationDiscovery} from '@fluxer/schema/src/domains/admin/DomainMigrationSchemas';
 import {WellKnownFluxerResponse} from '@fluxer/schema/src/domains/instance/InstanceSchemas';
 import type {Hono} from 'hono';

@@ -102,15 +103,16 @@ export function InstanceController(app: Hono<HonoEnv>) {
 			const limits = ctx.get('limitConfigService').getConfigWireFormat();
 			const sso = await ctx.get('ssoService').getPublicStatus();
 			const instanceConfigRepository = ctx.get('instanceConfigRepository');
-			const [registration, community, services, appPublicConfig, captcha, email] = await Promise.all([
+			const [registration, community, services, appPublicConfig, captcha, email, domainMigration] = await Promise.all([
 				instanceConfigRepository.getRegistrationPublicConfig(),
 				instanceConfigRepository.getInstanceCommunityPublicConfig(),
 				instanceConfigRepository.getResolvedServicesConfig(),
 				instanceConfigRepository.getAppPublicConfig(),
 				instanceConfigRepository.getEffectiveCaptchaConfig(),
 				instanceConfigRepository.getEffectiveEmailConfig(),
+				instanceConfigRepository.getDomainMigrationConfig(),
 			]);
-			const response = buildDiscoveryResponse(
+			const discovery = buildDiscoveryResponse(
 				buildDiscoveryStaticInput(
 					gifService,
 					{
@@ -133,6 +135,7 @@ export function InstanceController(app: Hono<HonoEnv>) {
 					limits,
 				},
 			);
+			const response = {...discovery, domain_migration: toDomainMigrationDiscovery(domainMigration)};
 			discoveryValidators = nextDiscoveryValidators(response, discoveryValidators);
 			ctx.header('ETag', discoveryValidators.etag);
 			ctx.header('Last-Modified', discoveryValidators.lastModified.toUTCString());
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import type {LegacyPushServiceDeliveryWire} from '@fluxer/schema/src/domains/admin/PushRelaySchemas';
+import type {INatsConnectionManager} from '@pkgs/nats/src/INatsConnectionManager';
+
+const textEncoder = new TextEncoder();
+
+const PUSH_SERVICE_DELIVERY_CONFIG_NATS_SUBJECT = 'config.push.delivery';
+
+interface PushServiceDeliveryConfigNatsMessage {
+	type: 'push_service_delivery_config';
+	config: LegacyPushServiceDeliveryWire;
+}
+
+export class PushRelayConfigPublisher {
+	constructor(private readonly connectionManager: INatsConnectionManager) {}
+
+	async publish(config: LegacyPushServiceDeliveryWire): Promise<void> {
+		if (this.connectionManager.isClosed()) {
+			await this.connectionManager.connect();
+		}
+		const connection = this.connectionManager.getConnection();
+		const message: PushServiceDeliveryConfigNatsMessage = {
+			type: 'push_service_delivery_config',
+			config,
+		};
+		connection.publish(PUSH_SERVICE_DELIVERY_CONFIG_NATS_SUBJECT, textEncoder.encode(JSON.stringify(message)));
+		await connection.flush();
+	}
+}
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {getKvMeta} from '@app/api/database/CassandraMetaRegistry';
+import type {CassandraQueryExecutorForTesting} from '@app/api/database/CassandraQueryExecution';
+import type {CassandraParams, KvQueryMeta, PreparedQuery} from '@app/api/database/CassandraTypes';
+import type {InstanceConfigurationRow} from '@app/api/database/types/InstanceConfigTypes';
+import {InstanceConfiguration} from '@app/api/Tables';
+
+type InstanceConfigWriteEvent = 'read' | 'write' | 'write rejected';
+
+interface WriteGate {
+	size: number;
+	paused: Array<() => void>;
+}
+
+const FETCH_ROW_QUERY = InstanceConfiguration.selectCql({
+	where: InstanceConfiguration.where.eq('key'),
+	limit: 1,
+});
+
+export class InstanceConfigWriteRaceExecutor implements CassandraQueryExecutorForTesting {
+	readonly events: Array<InstanceConfigWriteEvent> = [];
+	private watchedKey: string | null = null;
+	private gate: WriteGate | null = null;
+	private beforeEachWrite: (() => Promise<void>) | null = null;
+
+	constructor(private readonly base: CassandraQueryExecutorForTesting) {}
+
+	watch(key: string): void {
+		this.watchedKey = key;
+		this.events.length = 0;
+	}
+
+	pauseWritesUntil(size: number): void {
+		this.gate = {size, paused: []};
+	}
+
+	competeBeforeEachWrite(write: () => Promise<void>): void {
+		this.beforeEachWrite = write;
+	}
+
+	async writeDirectly(key: string, value: string): Promise<void> {
+		await this.base.executeQuery(InstanceConfiguration.upsertAll({key, value, updated_at: new Date()}));
+	}
+
+	async readDirectly(key: string): Promise<string | null> {
+		const [row] = await this.base.executeQuery<InstanceConfigurationRow>({cql: FETCH_ROW_QUERY, params: {key}});
+		return row?.value ?? null;
+	}
+
+	async executeQuery<T = Record<string, unknown>, P extends CassandraParams = CassandraParams>(
+		query: PreparedQuery<P>,
+	): Promise<Array<T>> {
+		const meta = query.kvMeta ?? getKvMeta(query.cql);
+		if (this.watchedKey === null || !this.isWatched(meta, query.params)) {
+			return this.base.executeQuery<T, P>(query);
+		}
+		if (meta?.action === 'select') {
+			this.events.push('read');
+			return this.base.executeQuery<T, P>(query);
+		}
+		await this.passGate();
+		await this.beforeEachWrite?.();
+		const rows = await this.base.executeQuery<T, P>(query);
+		const applied = (rows[0] as {'[applied]'?: unknown} | undefined)?.['[applied]'];
+		this.events.push(applied === false ? 'write rejected' : 'write');
+		return rows;
+	}
+
+	executeBatch(queries: Array<{query: string; params: object; meta?: KvQueryMeta}>, atomic?: boolean): Promise<void> {
+		return this.base.executeBatch(queries, atomic);
+	}
+
+	reset(): void {
+		this.base.reset?.();
+		this.watchedKey = null;
+		this.gate = null;
+		this.beforeEachWrite = null;
+		this.events.length = 0;
+	}
+
+	async shutdown(): Promise<void> {
+		await this.base.shutdown?.();
+	}
+
+	private isWatched(meta: KvQueryMeta | null | undefined, params: CassandraParams): boolean {
+		return meta?.table.name === InstanceConfiguration.name && params.key === this.watchedKey;
+	}
+
+	private async passGate(): Promise<void> {
+		const gate = this.gate;
+		if (gate === null) return;
+		await new Promise<void>((release) => {
+			gate.paused.push(release);
+			if (gate.paused.length < gate.size) return;
+			this.gate = null;
+			for (const release of gate.paused) release();
+		});
+	}
+}
@@ -1,11 +1,17 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

+import {Config} from '@app/api/Config';
 import {InvalidApiOriginError} from '@fluxer/errors/src/domains/core/InvalidApiOriginError';
 import type {Context, Next} from 'hono';

+const LEGACY_APP_ORIGINS = ['https://web.fluxer.app', 'https://web.canary.fluxer.app'];
+
 export async function BlockAppOriginMiddleware(ctx: Context, next: Next) {
 	const origin = ctx.req.header('origin');
-	if (origin === 'https://web.fluxer.app' || origin === 'https://web.canary.fluxer.app') {
+	if (
+		origin !== undefined &&
+		(LEGACY_APP_ORIGINS.includes(origin) || Config.endpoints.webAppOrigins.includes(origin))
+	) {
 		throw new InvalidApiOriginError();
 	}
 	await next();
@@ -1,7 +1,11 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

+import {createHmac} from 'node:crypto';
 import {Config} from '@app/api/Config';
+import {ANONYMOUS_EXPERIMENT_TARGETING, resolveExperimentTargeting} from '@app/api/experiment/ExperimentTargeting';
 import type {InstanceCaptchaEffectiveConfig} from '@app/api/instance/InstanceConfigRepository';
+import {Logger} from '@app/api/Logger';
+import {getKVClient} from '@app/api/middleware/ServiceRegistry';
 import type {User} from '@app/api/models/User';
 import {accountPolicyContactHasCapability} from '@app/api/risk/AccountPolicyService';
 import type {HonoEnv} from '@app/api/types/HonoEnv';
@@ -9,12 +13,44 @@ import {Headers} from '@fluxer/constants/src/Headers';
 import {UserFlags} from '@fluxer/constants/src/UserConstants';
 import {CaptchaRequiredError, InvalidCaptchaError} from '@fluxer/errors/src/CaptchaErrors';
 import {extractClientIp} from '@fluxer/ip_utils/src/ClientIp';
+import {type AltchaCaptchaConfig, altchaCaptchaAppliesTo} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
 import type {InstanceCaptchaProvider} from '@fluxer/schema/src/domains/instance/InstanceSchemas';
 import {createCaptchaProvider} from '@pkgs/captcha/src/CaptchaProviderFactory';
 import type {ICaptchaProvider} from '@pkgs/captcha/src/ICaptchaProvider';
+import {AltchaProvider} from '@pkgs/captcha/src/providers/AltchaProvider';
 import type {Context} from 'hono';
 import {createMiddleware} from 'hono/factory';

+const ALTCHA_SPENT_CHALLENGE_KEY_PREFIX = 'captcha:altcha:spent:';
+
+function deriveAltchaSecret(label: string): string {
+	return createHmac('sha256', Config.auth.sudoModeSecret).update(label).digest('hex');
+}
+
+function createAltchaProvider(config: AltchaCaptchaConfig): AltchaProvider {
+	return new AltchaProvider({
+		hmacSignatureSecret: deriveAltchaSecret('fluxer-altcha-challenge-signature-v1'),
+		hmacKeySignatureSecret: deriveAltchaSecret('fluxer-altcha-key-signature-v1'),
+		cost: config.cost,
+		maxCounter: config.max_counter,
+		claimChallenge: (signature, ttlSeconds) =>
+			getKVClient().setnx(`${ALTCHA_SPENT_CHALLENGE_KEY_PREFIX}${signature}`, '1', ttlSeconds),
+		logger: Logger,
+	});
+}
+
+async function altchaChallengeData(altcha: AltchaProvider | null): Promise<Record<string, unknown> | undefined> {
+	if (!altcha) return undefined;
+	return {captcha_provider: 'altcha', altcha_challenge: await altcha.createChallenge()};
+}
+
+async function resolveAltchaProvider(ctx: Context<HonoEnv>, user: User | undefined): Promise<AltchaProvider | null> {
+	const config = await ctx.get('instanceConfigRepository').getAltchaCaptchaConfig();
+	const targeting = user ? await resolveExperimentTargeting(user, [config]) : ANONYMOUS_EXPERIMENT_TARGETING;
+	if (!altchaCaptchaAppliesTo(config, user ? user.id.toString() : null, targeting)) return null;
+	return createAltchaProvider(config);
+}
+
 function resolveProviderSecret(
 	config: InstanceCaptchaEffectiveConfig,
 	provider: InstanceCaptchaProvider,
@@ -58,11 +94,19 @@ export async function verifyCaptchaToken(ctx: Context<HonoEnv>): Promise<void> {
 	if (accountPolicyContactHasCapability(user?.email, 'captcha_exempt')) return;
 	if (userHasCaptchaExemptFlag(user)) return;
 	if (await requestUserHasCaptchaExemptFlag(ctx)) return;
+	const altcha = await resolveAltchaProvider(ctx, user);
 	const token = ctx.req.header(Headers.X_CAPTCHA_TOKEN);
 	if (!token) {
-		throw new CaptchaRequiredError();
+		throw new CaptchaRequiredError(await altchaChallengeData(altcha));
 	}
-	const provider = resolveCaptchaProvider(captchaConfig, ctx.req.header(Headers.X_CAPTCHA_TYPE));
+	const requestedType = ctx.req.header(Headers.X_CAPTCHA_TYPE);
+	if (requestedType === 'altcha') {
+		if (!altcha || !(await altcha.verify({token}))) {
+			throw new InvalidCaptchaError(await altchaChallengeData(altcha));
+		}
+		return;
+	}
+	const provider = resolveCaptchaProvider(captchaConfig, requestedType);
 	const isValid = await provider.verify({
 		token,
 		remoteIp:
@@ -72,7 +116,7 @@ export async function verifyCaptchaToken(ctx: Context<HonoEnv>): Promise<void> {
 			}) ?? undefined,
 	});
 	if (!isValid) {
-		throw new InvalidCaptchaError();
+		throw new InvalidCaptchaError(await altchaChallengeData(altcha));
 	}
 }

@@ -15,6 +15,7 @@ interface RequireClientIpOptions {

 const defaultExemptPaths: Array<string> = [
 	'/_health',
+	'/internal',
 	'/webhooks/livekit',
 	'/test',
 	'/connections/bluesky/client-metadata.json',
@@ -51,6 +51,7 @@ import {createUsersServiceClient} from '@app/api/infrastructure/UsersServiceClie
 import {VirusScanService} from '@app/api/infrastructure/VirusScanService';
 import {GatewayRolloutConfigPublisher} from '@app/api/instance/GatewayRolloutConfigPublisher';
 import {InstanceConfigRepository} from '@app/api/instance/InstanceConfigRepository';
+import {PushRelayConfigPublisher} from '@app/api/instance/PushRelayConfigPublisher';
 import {InviteRepository} from '@app/api/invite/InviteRepository';
 import {Logger} from '@app/api/Logger';
 import {LimitConfigService} from '@app/api/limits/LimitConfigService';
@@ -155,6 +156,18 @@ export const getGatewayRolloutConfigPublisher = singleton(
 			}),
 		),
 );
+
+export const getPushRelayConfigPublisher = singleton(
+	() =>
+		new PushRelayConfigPublisher(
+			new NatsConnectionManager({
+				url: Config.nats.coreUrl,
+				token: Config.nats.authToken || undefined,
+				name: 'fluxer-api-push-relay-config',
+			}),
+		),
+);
+
 export const getVisionarySlotRepository = singleton(() => new VisionarySlotRepository());
 export const getCacheService: () => ICacheService = singleton(() => new KVCacheProvider({client: getKVClient()}));
 export const getRateLimitService = singleton(() => new RateLimitService(getKVClient()));
@@ -5,7 +5,7 @@ import {Logger} from '@app/api/Logger';
 import {hashAuthToken, recordAbuseSignal} from '@app/api/middleware/AbusiveIpAutoBanner';
 import type {User} from '@app/api/models/User';
 import type {HonoEnv} from '@app/api/types/HonoEnv';
-import {requireRequestClientIp} from '@app/api/utils/RequestClientIp';
+import {getRequestClientIp} from '@app/api/utils/RequestClientIp';
 import {stripApiPrefix} from '@app/api/utils/RequestPathUtils';
 import type {Context} from 'hono';
 import {createMiddleware} from 'hono/factory';
@@ -60,7 +60,7 @@ function setUserInContext(ctx: Context<HonoEnv>, user: User, trackActivity: bool
 	ctx.set('user', user);
 	if (trackActivity) {
 		const now = new Date();
-		const ip = requireRequestClientIp(ctx);
+		const ip = getRequestClientIp(ctx);
 		const kvActivityTracker = ctx.get('kvActivityTracker');
 		const userActivityBuffer = ctx.get('userActivityBuffer');
 		userActivityBuffer.recordActivity(user.id, now, ip);
@@ -77,7 +77,7 @@ export const UserMiddleware = createMiddleware<HonoEnv>(async (ctx, next) => {
 	}
 	const rawAuthHeader = ctx.req.header('Authorization');
 	const parsed = parseAuthHeader(rawAuthHeader);
-	const resolvedClientIp = requireRequestClientIp(ctx);
+	const resolvedClientIp = getRequestClientIp(ctx);
 	ctx.set('oauthBearerToken', undefined);
 	ctx.set('oauthBearerApplicationId', undefined);
 	ctx.set('oauthBearerAllowed', false);
@@ -8,6 +8,7 @@ import type {
 import {CaptchaMiddleware} from '@app/api/middleware/CaptchaMiddleware';
 import type {HonoEnv} from '@app/api/types/HonoEnv';
 import {AppErrorHandler} from '@fluxer/errors/src/domains/core/ErrorHandlers';
+import {DEFAULT_ALTCHA_CAPTCHA_CONFIG} from '@fluxer/schema/src/domains/admin/AltchaCaptchaSchemas';
 import {Hono} from 'hono';
 import {afterEach, beforeEach, describe, expect, it} from 'vitest';

@@ -25,6 +26,7 @@ function createHarness(
 ): (headers: Record<string, string>) => Promise<Response> {
 	const repository = {
 		getEffectiveCaptchaConfig: async () => captcha,
+		getAltchaCaptchaConfig: async () => DEFAULT_ALTCHA_CAPTCHA_CONFIG,
 	} as unknown as InstanceConfigRepository;
 	const app = new Hono<HonoEnv>();
 	app.use(async (ctx, next) => {
@@ -22,6 +22,7 @@ function createHarness(path = 'http://localhost/v1/messages'): Harness {
 		return ctx.text('ok');
 	});
 	app.get('/_health', (ctx) => ctx.text('OK'));
+	app.get('/internal/rpc', (ctx) => ctx.text('OK'));
 	app.onError(AppErrorHandler);
 	return {
 		request: async (headers) => app.request(path, {headers}),
@@ -80,6 +81,12 @@ describe('RequireClientIpMiddleware', () => {
 		expect(response.status).toBe(200);
 	});

+	it('leaves internal service to service calls alone', async () => {
+		const harness = createHarness('http://localhost/internal/rpc');
+		const response = await harness.request({});
+		expect(response.status).toBe(200);
+	});
+
 	it('passes every request through in test mode', async () => {
 		Config.dev.testModeEnabled = true;
 		const harness = createHarness();
@@ -12,6 +12,8 @@ export class WebAuthnCredential {
 	readonly createdAt: Date;
 	readonly lastUsedAt: Date | null;
 	readonly version: number;
+	readonly rpId: string | null;
+	readonly supersededBy: string | null;

 	constructor(row: WebAuthnCredentialRow) {
 		this.credentialId = row.credential_id;
@@ -22,6 +24,8 @@ export class WebAuthnCredential {
 		this.createdAt = row.created_at;
 		this.lastUsedAt = row.last_used_at ?? null;
 		this.version = row.version;
+		this.rpId = row.rp_id ?? null;
+		this.supersededBy = row.superseded_by ?? null;
 	}

 	toRow(userId: UserID): WebAuthnCredentialRow {
@@ -35,6 +39,8 @@ export class WebAuthnCredential {
 			created_at: this.createdAt,
 			last_used_at: this.lastUsedAt,
 			version: this.version,
+			rp_id: this.rpId,
+			superseded_by: this.supersededBy,
 		};
 	}
 }
@@ -204,9 +204,7 @@ function buildApnsPayload(payload: Record<string, unknown>): Record<string, unkn
 	if (badge !== undefined) {
 		aps.badge = badge;
 	}
-	if (imageUrl) {
-		aps['mutable-content'] = 1;
-	}
+	aps['mutable-content'] = 1;
 	return {
 		...data,
 		title,
@@ -139,7 +139,7 @@ describe('ApnsPushService', () => {
 			notification: {title: 'Alice', body: 'Hello', icon: 'https://cdn.example/avatar.png'},
 		});
 		expect(payload.image_url).toBeUndefined();
-		expect(payload.aps).not.toHaveProperty('mutable-content');
+		expect(payload.aps).toHaveProperty('mutable-content', 1);
 		expect(payload.author_avatar_url).toBe('https://cdn.example/avatar.png');
 	});
 	it('imports the APNs signing key once per PEM and rejects a truncated one every time', async () => {
@@ -104,6 +104,10 @@ export const AuthRateLimitConfigs = {
 		bucket: 'mfa:webauthn:two_factor',
 		config: {limit: 10, windowMs: ms('1 minute')},
 	} as RouteRateLimitConfig,
+	MFA_WEBAUTHN_MIGRATION: {
+		bucket: 'mfa:webauthn:migration',
+		config: {limit: 20, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
 	PHONE_SEND_VERIFICATION: {
 		bucket: 'phone:send_verification',
 		config: {limit: 5, windowMs: ms('1 minute')},
@@ -132,6 +136,34 @@ export const AuthRateLimitConfigs = {
 		bucket: 'auth:handoff:cancel',
 		config: {limit: 10, windowMs: ms('1 minute')},
 	} as RouteRateLimitConfig,
+	AUTH_ORIGIN_HANDOFF_CREATE: {
+		bucket: 'auth:origin_handoff:create',
+		config: {limit: 3, windowMs: ms('10 minutes')},
+	} as RouteRateLimitConfig,
+	AUTH_ORIGIN_HANDOFF_REDEEM: {
+		bucket: 'auth:origin_handoff:redeem',
+		config: {limit: 10, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
+	AUTH_PASSKEY_BRIDGE_START: {
+		bucket: 'auth:passkey_bridge:start',
+		config: {limit: 10, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
+	AUTH_PASSKEY_BRIDGE_CEREMONY: {
+		bucket: 'auth:passkey_bridge:ceremony',
+		config: {limit: 20, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
+	AUTH_PASSKEY_BRIDGE_REDEEM: {
+		bucket: 'auth:passkey_bridge:redeem',
+		config: {limit: 60, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
+	USER_PASSKEY_BRIDGE_START: {
+		bucket: 'mfa:passkey_bridge:start',
+		config: {limit: 10, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
+	USER_PASSKEY_BRIDGE_REDEEM: {
+		bucket: 'mfa:passkey_bridge:redeem',
+		config: {limit: 60, windowMs: ms('1 minute')},
+	} as RouteRateLimitConfig,
 	SUDO_WEBAUTHN_OPTIONS: {
 		bucket: 'sudo:webauthn:options',
 		config: {limit: 10, windowMs: ms('1 minute')},
@@ -15,53 +15,6 @@ import {ReadStateService} from '@app/api/read_state/ReadStateService';
 import {BadGatewayError} from '@fluxer/errors/src/domains/core/BadGatewayError';
 import {describe, expect, it, vi} from 'vitest';

-describe('ReadStateService.bulkIncrementMentionCounts', () => {
-	it('invalidates badge counts for touched users in a single bulk call', async () => {
-		const channelId = createChannelID(2n);
-		const messageId = createMessageID(3n);
-		const touched: Array<{userId: UserID; channelId: ChannelID}> = [
-			{userId: createUserID(10n), channelId},
-			{userId: createUserID(11n), channelId},
-			{userId: createUserID(10n), channelId: createChannelID(4n)},
-		];
-		const repository = {
-			bulkIncrementMentionCounts: vi.fn().mockResolvedValue(touched),
-		} as unknown as IReadStateRepository;
-		const invalidatePushBadgeCounts = vi.fn().mockResolvedValue(undefined);
-		const invalidatePushBadgeCount = vi.fn().mockResolvedValue(undefined);
-		const gatewayService = {
-			invalidatePushBadgeCounts,
-			invalidatePushBadgeCount,
-		} as unknown as IGatewayService;
-		const service = new ReadStateService(repository, gatewayService);
-
-		await service.bulkIncrementMentionCounts([
-			{userId: createUserID(10n), channelId, messageId},
-			{userId: createUserID(11n), channelId, messageId},
-			{userId: createUserID(12n), channelId, messageId},
-		]);
-
-		expect(invalidatePushBadgeCount).not.toHaveBeenCalled();
-		expect(invalidatePushBadgeCounts).toHaveBeenCalledTimes(1);
-		expect(invalidatePushBadgeCounts).toHaveBeenCalledWith({userIds: [createUserID(10n), createUserID(11n)]});
-	});
-
-	it('skips the bulk call when no read state was touched', async () => {
-		const repository = {
-			bulkIncrementMentionCounts: vi.fn().mockResolvedValue([]),
-		} as unknown as IReadStateRepository;
-		const invalidatePushBadgeCounts = vi.fn().mockResolvedValue(undefined);
-		const gatewayService = {invalidatePushBadgeCounts} as unknown as IGatewayService;
-		const service = new ReadStateService(repository, gatewayService);
-
-		await service.bulkIncrementMentionCounts([
-			{userId: createUserID(10n), channelId: createChannelID(2n), messageId: createMessageID(3n)},
-		]);
-
-		expect(invalidatePushBadgeCounts).not.toHaveBeenCalled();
-	});
-});
-
 const USER_ID = createUserID(20n);
 const CHANNEL_ID = createChannelID(21n);
 const MESSAGE_ID = createMessageID(22n);
@@ -78,7 +31,7 @@ function makeReadState(channelId: ChannelID, messageId: MessageID, mentionCount
 }

 describe('ReadStateService gateway side effects after the write', () => {
-	it('returns the committed read state when the badge invalidation fails', async () => {
+	it('returns the committed read state when clearing push notifications fails', async () => {
 		const stored: Array<{channelId: ChannelID; messageId: MessageID}> = [];
 		const repository = {
 			upsertReadState: vi.fn(async (_userId: UserID, channelId: ChannelID, messageId: MessageID) => {
@@ -87,8 +40,7 @@ describe('ReadStateService gateway side effects after the write', () => {
 			}),
 		} as unknown as IReadStateRepository;
 		const gatewayService = {
-			invalidatePushBadgeCount: vi.fn().mockRejectedValue(new BadGatewayError()),
-			clearPushChannelNotifications: vi.fn().mockResolvedValue(undefined),
+			clearPushChannelNotifications: vi.fn().mockRejectedValue(new BadGatewayError()),
 			dispatchPresence: vi.fn().mockResolvedValue(undefined),
 		} as unknown as IGatewayService;
 		const service = new ReadStateService(repository, gatewayService);
@@ -113,7 +65,6 @@ describe('ReadStateService gateway side effects after the write', () => {
 			),
 		} as unknown as IReadStateRepository;
 		const gatewayService = {
-			invalidatePushBadgeCount: vi.fn().mockResolvedValue(undefined),
 			clearPushChannelNotifications: vi.fn().mockResolvedValue(undefined),
 			dispatchPresence: vi.fn().mockRejectedValue(new BadGatewayError()),
 		} as unknown as IGatewayService;
@@ -138,7 +89,6 @@ describe('ReadStateService gateway side effects after the write', () => {
 			}),
 		} as unknown as IReadStateRepository;
 		const gatewayService = {
-			invalidatePushBadgeCount: vi.fn().mockResolvedValue(undefined),
 			clearPushChannelNotifications: vi.fn().mockResolvedValue(undefined),
 			dispatchPresence: vi.fn().mockRejectedValue(new BadGatewayError()),
 		} as unknown as IGatewayService;
@@ -156,42 +106,13 @@ describe('ReadStateService gateway side effects after the write', () => {
 		expect(stored).toEqual(['21', '23']);
 	});

-	it('deletes the read state when the badge invalidation fails', async () => {
-		const deleteReadState = vi.fn().mockResolvedValue(undefined);
-		const repository = {deleteReadState} as unknown as IReadStateRepository;
-		const gatewayService = {
-			invalidatePushBadgeCount: vi.fn().mockRejectedValue(new BadGatewayError()),
-		} as unknown as IGatewayService;
-		const service = new ReadStateService(repository, gatewayService);
-
-		await expect(service.deleteReadState({userId: USER_ID, channelId: CHANNEL_ID})).resolves.toBeUndefined();
-
-		expect(deleteReadState).toHaveBeenCalledWith(USER_ID, CHANNEL_ID);
-	});
-
-	it('increments the mention count when the badge invalidation fails', async () => {
-		const incrementReadStateMentions = vi.fn().mockResolvedValue(makeReadState(CHANNEL_ID, MESSAGE_ID, 1));
-		const repository = {incrementReadStateMentions} as unknown as IReadStateRepository;
-		const gatewayService = {
-			invalidatePushBadgeCount: vi.fn().mockRejectedValue(new BadGatewayError()),
-		} as unknown as IGatewayService;
-		const service = new ReadStateService(repository, gatewayService);
-
-		await expect(
-			service.incrementMentionCount({userId: USER_ID, channelId: CHANNEL_ID, messageId: MESSAGE_ID}),
-		).resolves.toBeUndefined();
-
-		expect(incrementReadStateMentions).toHaveBeenCalledTimes(1);
-	});
-
-	it('returns the bulk acknowledged states when the badge invalidation fails', async () => {
+	it('returns the bulk acknowledged states when clearing push notifications fails', async () => {
 		const updated = [makeReadState(CHANNEL_ID, MESSAGE_ID)];
 		const repository = {
 			bulkAckMessages: vi.fn().mockResolvedValue(updated),
 		} as unknown as IReadStateRepository;
 		const gatewayService = {
-			invalidatePushBadgeCount: vi.fn().mockRejectedValue(new BadGatewayError()),
-			clearPushChannelNotifications: vi.fn().mockResolvedValue(undefined),
+			clearPushChannelNotifications: vi.fn().mockRejectedValue(new BadGatewayError()),
 			dispatchPresence: vi.fn().mockResolvedValue(undefined),
 		} as unknown as IGatewayService;
 		const service = new ReadStateService(repository, gatewayService);
@@ -34,7 +34,6 @@ export class ReadStateService {
 			undefined,
 			manual ?? false,
 		);
-		await this.invalidatePushBadgeCount(userId);
 		if (!silent) {
 			await this.clearPushChannelNotifications({userId, channelId, messageId});
 		}
@@ -115,7 +114,6 @@ export class ReadStateService {
 		try {
 			const updatedReadStates = await this.repository.bulkAckMessages(userId, readStates);
 			const readStatesByChannel = new Map(updatedReadStates.map((readState) => [readState.channelId, readState]));
-			await this.invalidatePushBadgeCount(userId);
 			await Promise.all(
 				readStates.map(({channelId, messageId}) =>
 					Promise.all([
@@ -145,7 +143,6 @@ export class ReadStateService {

 	async deleteReadState({userId, channelId}: {userId: UserID; channelId: ChannelID}): Promise<void> {
 		await this.repository.deleteReadState(userId, channelId);
-		await this.invalidatePushBadgeCount(userId);
 	}

 	async incrementMentionCount({
@@ -157,11 +154,7 @@ export class ReadStateService {
 		channelId: ChannelID;
 		messageId: MessageID;
 	}): Promise<void> {
-		const readState = await this.repository.incrementReadStateMentions(userId, channelId, messageId, 1);
-		if (readState == null) {
-			return;
-		}
-		await this.invalidatePushBadgeCount(userId);
+		await this.repository.incrementReadStateMentions(userId, channelId, messageId, 1);
 	}

 	async bulkIncrementMentionCounts(
@@ -175,15 +168,7 @@ export class ReadStateService {
 			return;
 		}
 		try {
-			const appliedUpdates = await this.repository.bulkIncrementMentionCounts(updates);
-			const uniqueUserIds = Array.from(new Set(appliedUpdates.map((update) => update.userId)));
-			if (uniqueUserIds.length === 0) {
-				return;
-			}
-			await this.gatewayService.invalidatePushBadgeCounts({userIds: uniqueUserIds}).catch((error) => {
-				Logger.error({userCount: uniqueUserIds.length, error}, 'Failed to invalidate push badge counts');
-				return null;
-			});
+			await this.repository.bulkIncrementMentionCounts(updates);
 		} catch (error) {
 			Logger.error({error}, 'Bulk increment mention counts failed');
 			throw error;
@@ -196,13 +181,6 @@ export class ReadStateService {
 		await this.dispatchPinsAck({userId, channelId, timestamp});
 	}

-	private async invalidatePushBadgeCount(userId: UserID): Promise<void> {
-		await this.gatewayService.invalidatePushBadgeCount({userId}).catch((error) => {
-			Logger.error({userId: userId.toString(), error}, 'Failed to invalidate push badge count');
-			return null;
-		});
-	}
-
 	private async dispatchMessageAck(params: {
 		userId: UserID;
 		channelId: ChannelID;
@@ -1,6 +1,29 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

 import {Config} from '@app/api/Config';
+import {PHONE_REQUIREMENT_FLAGS, SuspiciousActivityFlags} from '@fluxer/constants/src/UserConstants';
+
+const EMAIL_ONLY_EQUIVALENTS: ReadonlyArray<readonly [number, number]> = [
+	[SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL_OR_VERIFIED_PHONE, SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL],
+	[SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL_OR_REVERIFIED_PHONE, SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL],
+	[
+		SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL_OR_VERIFIED_PHONE,
+		SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL,
+	],
+	[
+		SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL_OR_REVERIFIED_PHONE,
+		SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL,
+	],
+];
+
+const PHONE_OFFERING_FLAGS = EMAIL_ONLY_EQUIVALENTS.reduce((mask, [either]) => mask | either, PHONE_REQUIREMENT_FLAGS);
+
+function withoutPhoneOfferingFlags(flagBits: number): number {
+	return EMAIL_ONLY_EQUIVALENTS.reduce(
+		(next, [either, emailOnly]) => ((flagBits & either) !== 0 ? next | emailOnly : next),
+		flagBits & ~PHONE_OFFERING_FLAGS,
+	);
+}

 function normalizeCountryCode(countryCode: string | null | undefined): string | null {
 	const trimmed = countryCode?.trim();
@@ -17,6 +40,25 @@ export function countryRequiresInboundPhoneVerification(countryCode: string | nu
 	return configuredCountrySet(Config.abusePolicy.inboundPhoneCountryCodes).has(normalized);
 }

+export function phoneFlaggingAllowedForCountry(countryCode: string | null | undefined): boolean {
+	const {enabled, exemptCountryCodes} = Config.abusePolicy.phoneFlagging;
+	if (!enabled) return false;
+	const normalized = normalizeCountryCode(countryCode);
+	if (!normalized) return true;
+	return !configuredCountrySet(exemptCountryCodes).has(normalized);
+}
+
+export async function stripDisallowedPhoneFlags(
+	flagBits: number,
+	resolveCountryCode: () => Promise<string | null>,
+): Promise<number> {
+	if ((flagBits & PHONE_OFFERING_FLAGS) === 0) return flagBits;
+	const {enabled, exemptCountryCodes} = Config.abusePolicy.phoneFlagging;
+	if (enabled && exemptCountryCodes.length === 0) return flagBits;
+	if (enabled && phoneFlaggingAllowedForCountry(await resolveCountryCode())) return flagBits;
+	return withoutPhoneOfferingFlags(flagBits);
+}
+
 export function phoneRequiresInboundVerification(
 	phone: string,
 	prefixes: ReadonlyArray<string> = Config.abusePolicy.phoneVerification.inboundRequiredPrefixes,
@@ -1,34 +1,69 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later

 import {Config} from '@app/api/Config';
+import {parseIpBanEntry, tryParseSingleIp} from '@app/api/utils/IpRangeUtils';
+import type {IpAddressFamily} from '@fluxer/ip_utils/src/IpAddress';
 import {getSameIpDecisionKey} from '@fluxer/ip_utils/src/IpAddress';

-let exemptDecisionKeys: ReadonlySet<string> | null = null;
+interface ExemptRange {
+	family: IpAddressFamily;
+	start: bigint;
+	end: bigint;
+}

-function getExemptDecisionKeys(): ReadonlySet<string> {
-	if (exemptDecisionKeys) {
-		return exemptDecisionKeys;
+interface IpBanExemptions {
+	decisionKeys: ReadonlySet<string>;
+	ranges: ReadonlyArray<ExemptRange>;
+}
+
+let exemptions: IpBanExemptions | null = null;
+
+function getExemptions(): IpBanExemptions {
+	if (exemptions) {
+		return exemptions;
 	}
-	const keys = new Set<string>();
-	for (const ip of Config.ipBanExemptIps) {
-		const key = getSameIpDecisionKey(ip);
-		if (!key) {
-			throw new Error(`Invalid IP ban exemption in API config: ${ip}`);
+	const decisionKeys = new Set<string>();
+	const ranges: Array<ExemptRange> = [];
+	for (const entry of Config.ipBanExemptIps) {
+		if (entry.includes('/')) {
+			const range = parseIpBanEntry(entry);
+			if (range?.type !== 'range') {
+				throw new Error(`Invalid IP ban exemption in API config: ${entry}`);
+			}
+			ranges.push({family: range.family, start: range.start, end: range.end});
+			continue;
 		}
-		keys.add(key);
+		const key = getSameIpDecisionKey(entry);
+		if (!key) {
+			throw new Error(`Invalid IP ban exemption in API config: ${entry}`);
+		}
+		decisionKeys.add(key);
 	}
-	exemptDecisionKeys = keys;
-	return keys;
+	exemptions = {decisionKeys, ranges};
+	return exemptions;
 }

 export function isIpBanExempt(ip: string | null | undefined): boolean {
 	if (!ip) {
 		return false;
 	}
+	const {decisionKeys, ranges} = getExemptions();
 	const key = getSameIpDecisionKey(ip);
-	return key !== null && getExemptDecisionKeys().has(key);
+	if (key !== null && decisionKeys.has(key)) {
+		return true;
+	}
+	if (ranges.length === 0) {
+		return false;
+	}
+	const parsed = tryParseSingleIp(ip);
+	if (!parsed) {
+		return false;
+	}
+	return ranges.some(
+		(range) => range.family === parsed.family && parsed.value >= range.start && parsed.value <= range.end,
+	);
 }

 export function resetIpBanExemptionsForTesting(): void {
-	exemptDecisionKeys = null;
+	exemptions = null;
 }
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {Config} from '@app/api/Config';
+import {phoneFlaggingAllowedForCountry, stripDisallowedPhoneFlags} from '@app/api/risk/AbusePolicy';
+import {SuspiciousActivityFlags} from '@fluxer/constants/src/UserConstants';
+import {afterEach, beforeEach, describe, expect, it, vi} from 'vitest';
+
+const PHONE_AND_EMAIL =
+	SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL |
+	SuspiciousActivityFlags.REQUIRE_VERIFIED_PHONE |
+	SuspiciousActivityFlags.REQUIRE_INBOUND_PHONE_VERIFICATION;
+
+describe('phone flagging policy', () => {
+	const original = {...Config.abusePolicy.phoneFlagging};
+
+	beforeEach(() => {
+		Config.abusePolicy.phoneFlagging = {enabled: true, exemptCountryCodes: []};
+	});
+
+	afterEach(() => {
+		Config.abusePolicy.phoneFlagging = original;
+	});
+
+	it('keeps phone flags by default without resolving the country', async () => {
+		const resolveCountryCode = vi.fn(async () => 'NG');
+		expect(await stripDisallowedPhoneFlags(PHONE_AND_EMAIL, resolveCountryCode)).toBe(PHONE_AND_EMAIL);
+		expect(resolveCountryCode).not.toHaveBeenCalled();
+		expect(phoneFlaggingAllowedForCountry('NG')).toBe(true);
+	});
+
+	it('strips only phone flags when disabled', async () => {
+		Config.abusePolicy.phoneFlagging = {enabled: false, exemptCountryCodes: []};
+		const resolveCountryCode = vi.fn(async () => 'NG');
+		expect(await stripDisallowedPhoneFlags(PHONE_AND_EMAIL, resolveCountryCode)).toBe(
+			SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL,
+		);
+		expect(resolveCountryCode).not.toHaveBeenCalled();
+		expect(phoneFlaggingAllowedForCountry('NG')).toBe(false);
+		expect(phoneFlaggingAllowedForCountry(null)).toBe(false);
+	});
+
+	it('strips phone flags for exempt countries only', async () => {
+		Config.abusePolicy.phoneFlagging = {enabled: true, exemptCountryCodes: [' br', 'PT']};
+		expect(await stripDisallowedPhoneFlags(PHONE_AND_EMAIL, async () => 'BR')).toBe(
+			SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL,
+		);
+		expect(await stripDisallowedPhoneFlags(PHONE_AND_EMAIL, async () => 'ng')).toBe(PHONE_AND_EMAIL);
+		expect(await stripDisallowedPhoneFlags(PHONE_AND_EMAIL, async () => null)).toBe(PHONE_AND_EMAIL);
+		expect(phoneFlaggingAllowedForCountry('pt')).toBe(false);
+		expect(phoneFlaggingAllowedForCountry('NG')).toBe(true);
+	});
+
+	it('replaces email or phone flags with their email only equivalent', async () => {
+		Config.abusePolicy.phoneFlagging = {enabled: false, exemptCountryCodes: []};
+		expect(
+			await stripDisallowedPhoneFlags(
+				SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL_OR_VERIFIED_PHONE |
+					SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL_OR_REVERIFIED_PHONE,
+				async () => null,
+			),
+		).toBe(SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL);
+		expect(
+			await stripDisallowedPhoneFlags(
+				SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL_OR_VERIFIED_PHONE |
+					SuspiciousActivityFlags.REQUIRE_INBOUND_PHONE_VERIFICATION,
+				async () => null,
+			),
+		).toBe(SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL);
+		Config.abusePolicy.phoneFlagging = {enabled: true, exemptCountryCodes: ['BR']};
+		expect(
+			await stripDisallowedPhoneFlags(
+				SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL_OR_REVERIFIED_PHONE,
+				async () => 'BR',
+			),
+		).toBe(SuspiciousActivityFlags.REQUIRE_REVERIFIED_EMAIL);
+	});
+
+	it('skips the country lookup when no phone flags are present', async () => {
+		Config.abusePolicy.phoneFlagging = {enabled: true, exemptCountryCodes: ['BR']};
+		const resolveCountryCode = vi.fn(async () => 'BR');
+		expect(await stripDisallowedPhoneFlags(SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL, resolveCountryCode)).toBe(
+			SuspiciousActivityFlags.REQUIRE_VERIFIED_EMAIL,
+		);
+		expect(resolveCountryCode).not.toHaveBeenCalled();
+	});
+});
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {getConfig} from '@app/api/Config';
+import {isIpBanExempt, resetIpBanExemptionsForTesting} from '@app/api/risk/IpBanExemptions';
+import {afterEach, beforeEach, describe, expect, it} from 'vitest';
+
+describe('isIpBanExempt', () => {
+	let originalExemptIps: Array<string>;
+
+	beforeEach(() => {
+		const config = getConfig();
+		originalExemptIps = config.ipBanExemptIps;
+		config.ipBanExemptIps = ['198.51.100.7', '2001:db8:6::', '2001:db8:1200:1000::/56', '203.0.113.0/24'];
+		resetIpBanExemptionsForTesting();
+	});
+
+	afterEach(() => {
+		getConfig().ipBanExemptIps = originalExemptIps;
+		resetIpBanExemptionsForTesting();
+	});
+
+	it('matches a bare IPv4 address exactly', () => {
+		expect(isIpBanExempt('198.51.100.7')).toBe(true);
+		expect(isIpBanExempt('198.51.100.8')).toBe(false);
+	});
+
+	it('matches a bare IPv6 address on its /64', () => {
+		expect(isIpBanExempt('2001:db8:6::abcd')).toBe(true);
+		expect(isIpBanExempt('2001:db8:7::1')).toBe(false);
+	});
+
+	it('matches every address inside a CIDR range', () => {
+		expect(isIpBanExempt('2001:db8:1200:1000::1')).toBe(true);
+		expect(isIpBanExempt('2001:db8:1200:10ff:ffff:ffff:ffff:ffff')).toBe(true);
+		expect(isIpBanExempt('2001:db8:1200:1100::1')).toBe(false);
+		expect(isIpBanExempt('2001:db8:1200:fff::1')).toBe(false);
+		expect(isIpBanExempt('203.0.113.200')).toBe(true);
+		expect(isIpBanExempt('::ffff:203.0.113.200')).toBe(true);
+		expect(isIpBanExempt('203.0.114.1')).toBe(false);
+	});
+
+	it('does not match empty or unparsable input', () => {
+		expect(isIpBanExempt(null)).toBe(false);
+		expect(isIpBanExempt('')).toBe(false);
+		expect(isIpBanExempt('not-an-ip')).toBe(false);
+	});
+});
@@ -3,6 +3,7 @@
 import {createHash} from 'node:crypto';
 import type {ApiContext} from '@app/api/ApiContext';
 import * as AuthSession from '@app/api/auth/AuthSession';
+import {visibleWebAuthnCredentials} from '@app/api/auth/services/PasskeyRelyingParty';
 import type {ChannelID, GuildID, UserID} from '@app/api/BrandedTypes';
 import {
 	createChannelID,
@@ -75,6 +76,7 @@ import {
 	mapUserGuildSettingsToResponse,
 	mapUserSettingsToResponse,
 	mapUserToPrivateResponse,
+	mapWebAuthnCredentialToResponse,
 } from '@app/api/user/UserMappers';
 import {isUserAdult} from '@app/api/utils/AgeUtils';
 import {deriveDominantAvatarColor} from '@app/api/utils/AvatarColorUtils';
@@ -635,6 +637,13 @@ export class RpcService {
 					data: {config: rolloutConfig},
 				};
 			}
+			case 'get_push_service_delivery_config': {
+				const config = await this.instanceConfigRepository.getLegacyPushServiceDeliveryWire();
+				return {
+					type: 'get_push_service_delivery_config',
+					data: {config},
+				};
+			}
 			default: {
 				const exhaustiveCheck: never = request;
 				throw new Error(
@@ -1184,12 +1193,9 @@ export class RpcService {
 			longitude: geoipLongitude,
 			rtc_regions: rtcRegions,
 			webauthn_credentials: timeRpcStepSync(responseBuildSteps, 'map_webauthn_credentials', () =>
-				userData.webAuthnCredentials.map((cred) => ({
-					id: cred.credentialId,
-					name: cred.name,
-					created_at: cred.createdAt.toISOString(),
-					last_used_at: cred.lastUsedAt?.toISOString() ?? null,
-				})),
+				visibleWebAuthnCredentials(userData.webAuthnCredentials).map((cred) =>
+					mapWebAuthnCredentialToResponse(cred, Config.auth.passkeys.rpId),
+				),
 			),
 			version,
 		};
@@ -10,7 +10,7 @@ import type {UserCacheService} from '@app/api/infrastructure/UserCacheService';
 import {Logger} from '@app/api/Logger';
 import type {RequestCache} from '@app/api/middleware/RequestCacheMiddleware';
 import type {User} from '@app/api/models/User';
-import {countryRequiresInboundPhoneVerification} from '@app/api/risk/AbusePolicy';
+import {countryRequiresInboundPhoneVerification, phoneFlaggingAllowedForCountry} from '@app/api/risk/AbusePolicy';
 import {
 	createRpcTimingNode,
 	RpcTimingRecorder,
@@ -311,6 +311,17 @@ export class RpcSessionStartService {
 		) {
 			return null;
 		}
+		if (
+			!timeRpcStepSync(timingSteps, 'check_phone_flagging_allowed', () =>
+				phoneFlaggingAllowedForCountry(geoipCountryIso),
+			)
+		) {
+			Logger.info(
+				{userId: user.id.toString(), countryIso: geoipCountryIso},
+				'Skipping configured-country inbound phone requirement: phone flagging disabled for this country',
+			);
+			return null;
+		}
 		if (
 			timeRpcStepSync(timingSteps, 'check_not_suspicious_flag', () => (user.flags & UserFlags.NOT_SUSPICIOUS) !== 0n)
 		) {
@@ -52,7 +52,8 @@ function snowflakeSeconds(snowflake: string): number {

 function buildSort(sortBy: string, sortOrder: 'asc' | 'desc' | undefined): Array<string> | undefined {
 	if (sortBy === 'relevance') return undefined;
-	return [`${sortBy}:${sortOrder ?? 'desc'}`, 'id:desc'];
+	const direction = sortOrder ?? 'desc';
+	return [`${sortBy}:${direction}`, `id:${direction}`];
 }

 function buildTimestampSort(filters: MessageSearchFilters | AuditLogSearchFilters): Array<string> | undefined {
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
HampusandGitHub	eaee820216	feat(experiments): target rollouts by guild and premium status (#3012 )	2026-09-28 14:34:19 +02:00
HampusandGitHub	564c5ae164	feat(profile): move profile timezone from staff to an experiment (#3011 )	2026-09-28 12:57:26 +02:00
HampusandGitHub	dd8ed6f205	fix(app): react at once when picking a +: autocomplete emoji (#3010 )	2026-09-28 12:30:45 +02:00
HampusandGitHub	ed8c412415	perf(gateway): make channel moves cheap in large guilds (#3008 )	2026-09-28 02:07:47 +02:00
HampusandGitHub	12417a6942	fix(app): keep the caret after inserted emoji (#3007 )	2026-09-28 01:56:08 +02:00
HampusandGitHub	d05f6c9aaa	fix(gateway): push held users whose sessions end during grace (#3006 )	2026-09-28 01:47:55 +02:00
HampusandGitHub	0ca035c547	fix(messages): accept null version on legacy message rows (#3004 )	2026-09-28 01:10:52 +02:00
HampusandGitHub	dfd46ccc2c	ci(gateway): drop cached gateway build output before compiling (#3003 )	2026-09-28 01:08:52 +02:00
HampusandGitHub	f6df3169ca	fix(app): use +:shortcode: for reactions, no space before emoji (#3001 )	2026-09-28 00:48:23 +02:00
HampusandGitHub	5b280898c5	refactor(push): retire the push service delivery experiment (#3000 )	2026-09-28 00:45:22 +02:00
HampusandGitHub	2a9e25c788	fix(dev): drop the stray -- from the tunnel public URL hint (#2999 )	2026-09-28 00:43:32 +02:00
HampusandGitHub	463c03fb6d	feat(app): make +emoji react on send and target replies (#2998 )	2026-09-28 00:08:40 +02:00
HampusandGitHub	153dad11e1	feat(installer): let upgrades copy the uploads uncompressed (#2995 )	2026-09-27 23:51:24 +02:00
HampusandGitHub	e2d05a44a8	fix(push): stop retrying relay rate limit refusals (#2993 )	2026-09-27 23:29:27 +02:00
HampusandGitHub	30ba55bd4d	fix(gateway): parse push relay hosts as binaries (#2989 )	2026-09-27 21:22:45 +02:00
HampusandGitHub	9def9fbef6	feat(api): accept CIDR ranges in FLUXER_API_IP_BAN_EXEMPT_IPS (#2988 )	2026-09-27 21:19:35 +02:00
HampusandGitHub	fa3fd0027c	fix(i18n): translate the push relay notice strings (#2987 )	2026-09-27 21:15:33 +02:00
HampusandGitHub	7e1b934637	feat(captcha): add ALTCHA proof-of-work captcha experiment (#2986 )	2026-09-27 21:02:55 +02:00
HampusandGitHub	33a118d12a	docs(readme): list the Google Play beta first for Android (#2985 )	2026-09-27 20:49:39 +02:00
HampusandGitHub	01f53a168d	feat(push): gate relay delivery on operator consent (#2984 )	2026-09-27 20:33:10 +02:00
HampusandGitHub	336b8b7dcd	fix(forward): make an @silent comment silence the forward too (#2983 )	2026-09-27 20:13:14 +02:00
HampusandGitHub	48d0034239	fix(app-proxy): trust the Play app signing certificate (#2982 )	2026-09-27 19:37:40 +02:00
HampusandGitHub	677ef8491e	fix(desktop): back off failed app loads and offer a retry (#2980 )	2026-09-27 16:18:01 +02:00
HampusandGitHub	6a6119ed1e	fix(push): preview forwarded message content (#2979 )	2026-09-27 13:33:22 +02:00
HampusandGitHub	931327d1dc	fix(push): stop sending notifications for system messages (#2978 )	2026-09-27 13:33:18 +02:00
HampusandGitHub	858a2d9e2b	fix(oauth): stop granting scopes the user turned off (#2968 )	2026-09-26 13:48:23 +02:00
HampusandGitHub	841fb7af41	feat(auth): migrate passkeys to fluxer.com (#2964 )	2026-09-25 22:33:50 +02:00
HampusandGitHub	08e65d41c0	fix(api): clear the perks-sanitized latch when premium returns (#2963 )	2026-09-25 20:13:00 +02:00
HampusandGitHub	f76c4dc041	fix(api): cancel only the subscription the refund belongs to (#2962 )	2026-09-25 20:10:54 +02:00
HampusandGitHub	f1f8ba2031	fix(app): add copy link to link channel context menus (#2959 )	2026-09-25 18:16:20 +02:00
HampusandGitHub	5ab8d745c0	fix(i18n): correct the fluxer.com migration translations (#2958 )	2026-09-25 17:46:07 +02:00
HampusandGitHub	ff62bc89a4	feat(app): add passkey popup bridge for password managers (#2957 )	2026-09-25 17:43:19 +02:00
HampusandGitHub	838bbdb5ec	fix(app): only start the domain migration when the app opens (#2956 )	2026-09-25 16:44:58 +02:00
HampusandGitHub	1c36a59b2c	feat(app): rework quick switcher ranking and show origin icons (#2953 )	2026-09-25 13:59:25 +02:00
HampusandGitHub	6730a242db	feat(web): prepare the fluxer.com domain migration (#2952 )	2026-09-25 13:43:34 +02:00
HampusandGitHub	e62ae77643	refactor(config): trim the default passkey origin list (#2951 )	2026-09-25 13:42:02 +02:00
HampusandGitHub	f4f39e6a89	feat(app): show where forward destinations come from (#2950 )	2026-09-25 13:12:17 +02:00
HampusandGitHub	00bf74cef5	fix(app): handle swapped overwrites when comparing channels (#2949 )	2026-09-24 23:38:04 +02:00
HampusandGitHub	c1c45d835f	fix(app): only parse markdown in rich embeds (#2948 )	2026-09-24 22:50:34 +02:00
HampusandGitHub	bbfe809bef	fix(app): crop animated images on web with libwebp (#2947 )	2026-09-24 22:45:53 +02:00
HampusandGitHub	e0843ac4f5	fix(app): keep guild folder expansion state local (#2944 )	2026-09-24 17:52:33 +02:00
HampusandGitHub	43741cdad8	fix(gateway): always trim the connect snapshot for guild connects (#2943 )	2026-09-24 17:09:48 +02:00
HampusandGitHub	b8e3807262	Revert "fix(push): deliver direct messages without holding them" (#2942 )	2026-09-24 17:09:44 +02:00
HampusandGitHub	3304f01a84	chore(i18n): recompile uk error catalog (#2941 )	2026-09-24 17:09:36 +02:00
fluxer-weblate[bot]andGitHub	2ba463235b	chore(i18n): update translations from Weblate (#2909 )	2026-09-24 16:25:26 +02:00
fluxer-weblate[bot]andGitHub	15136fed59	chore(i18n): update translations from Weblate (#2923 )	2026-09-24 16:25:05 +02:00
HampusandGitHub	6013581dd9	fix(push): deliver direct messages without holding them (#2938 )	2026-09-24 16:21:42 +02:00
HampusandGitHub	7a91f128e9	fix(app-proxy): drop link preview metadata on self-hosted (#2936 )	2026-09-24 16:07:00 +02:00
HampusandGitHub	963ffc5550	feat(push): scope read clears to the enrolled cohort (#2935 )	2026-09-24 15:15:45 +02:00
HampusandGitHub	a90991612c	fix(gateway): truncate reads on an expired outbox entry (#2934 )	2026-09-24 15:04:24 +02:00
HampusandGitHub	50ad23b760	fix(api): run the notification extension on every iOS alert (#2933 )	2026-09-24 15:04:01 +02:00
HampusandGitHub	425dab983b	fix(push): restore iOS avatars and stop misrouting relay endpoints (#2932 )	2026-09-24 15:03:32 +02:00
HampusandGitHub	a0825e77c4	feat(voice): ship the screen share delivery rework to everyone (#2931 )	2026-09-24 14:57:40 +02:00
HampusandGitHub	88038a1d5b	fix(voice): stop direct input capturing microphones in stereo (#2929 )	2026-09-24 14:51:05 +02:00
HampusandGitHub	c2c0fdb445	fix(app): make corner volume control the focused stream (#2928 )	2026-09-24 14:04:05 +02:00
HampusandGitHub	dcd5f09d6a	feat(api): add env toggles for automatic phone flagging (#2927 )	2026-09-24 03:36:35 +02:00
HampusandGitHub	590b1f36fd	docs(downloads): document the canary apt and dnf repositories (#2926 )	2026-09-24 03:29:52 +02:00
HampusandGitHub	168ac727f1	fix(desktop): set the deb package synopsis (#2925 )	2026-09-24 03:29:33 +02:00
HampusandGitHub	deb86dd92e	fix(admin): format users list search hint (#2924 )	2026-09-24 02:12:37 +02:00
omsterandGitHub	7ccec4d3b8	feat(admin): hint text for * search in user page (#2922 )	2026-09-24 01:56:17 +02:00
omsterandGitHub	2f38bcdf26	fix(admin): ordering fixes for admin user search and meilisearch (#2920 )	2026-09-24 01:45:56 +02:00
HampusandGitHub	f2785941aa	fix(app): point self-hosted users at their instance admins (#2921 )	2026-09-24 01:42:33 +02:00
HampusandGitHub	ea9f83a443	fix(push): keep read-state clears alive as long as the alert (#2919 )	2026-09-24 01:26:18 +02:00
HampusandGitHub	bd6ca7290e	fix(api): allow deleting messages without send permission (#2918 )	2026-09-24 01:14:01 +02:00
HampusandGitHub	b85e975fb5	feat(push): deliver our own relay endpoints in process (#2917 )	2026-09-24 01:07:09 +02:00
HampusandGitHub	b6e504f68c	fix(push): keep device tokens out of logs (#2916 )	2026-09-24 00:33:50 +02:00
HampusandGitHub	5fde6eb484	feat(push): ring Android calls and harden the relay (#2915 )	2026-09-24 00:07:15 +02:00
HampusandGitHub	b16989d567	feat(push): ring incoming calls on Apple PushKit devices (#2911 )	2026-09-23 20:21:08 +02:00
HampusandGitHub	c9754ac11a	fix(api): exempt internal rpc from the client ip check (#2910 )	2026-09-23 18:03:36 +02:00
fluxer-weblate[bot]andGitHub	f34e4a5115	chore(i18n): update translations from Weblate (#2903 )	2026-09-23 17:28:25 +02:00
fluxer-weblate[bot]andGitHub	44b3615298	chore(i18n): update translations from Weblate (#2904 )	2026-09-23 17:27:59 +02:00
HampusandGitHub	211e98307d	perf(push): cache endpoint guard dns verdicts (#2907 )	2026-09-23 17:27:19 +02:00
HampusandGitHub	18c303abf6	feat(push): relay notifications as encrypted web push (#2906 )	2026-09-23 14:04:55 +02:00
JiraliteandGitHub	7021a58090	fix: allow copying message snapshots (#2905 )	2026-09-23 14:01:10 +02:00
WagnerandGitHub	320725a587	fix(desktop): capture full pipewire quantum on linux (#2481 )	2026-09-22 21:37:20 +02:00
fluxer-weblate[bot]andGitHub	8450edc072	chore(i18n): update translations from Weblate (#2895 )	2026-09-22 21:28:24 +02:00
omsterandGitHub	a1e2bf2c8d	feat(dev/linux): select the wayland backend when reachable in the native desktop app (#2899 ) Signed-off-by: omstr <[email protected]>	2026-09-22 21:27:59 +02:00
HampusandGitHub	82b2f4ec5e	fix(app): put jxl and other image attachments in the mosaic (#2902 )	2026-09-22 21:18:39 +02:00
HampusandGitHub	c92e5d03a7	fix(api): accept any image or video attachment as embed media (#2901 )	2026-09-22 21:18:35 +02:00
HampusandGitHub	91340c5c84	fix(markdown): compile the parser wasm asynchronously (#2900 )	2026-09-22 19:58:38 +02:00
HampusandGitHub	045dd5d027	test(api): make the harvest token tamper test deterministic (#2894 )	2026-09-22 02:20:18 +02:00
HampusandGitHub	a21b9c4659	docs(readme): clean up the download prose (#2893 )	2026-09-22 02:08:42 +02:00
HampusandGitHub	4b1b869802	docs(readme): point Linux installs at Flathub (#2892 )	2026-09-22 02:04:06 +02:00
HampusandGitHub	1ab7e7dfcc	fix(api): unfurl links to a self-hosted instance's own domain (#2891 )	2026-09-22 02:00:51 +02:00
HampusandGitHub	31c53d2dff	fix(app): stop pending stickers from reloading the channel (#2890 )	2026-09-22 02:00:26 +02:00