fix(voice): stop screen shares failing to reach their viewers (#2835)

2026-10-07 19:22:14 +09:00 · 2026-09-19 02:17:25 +02:00
parent f32356801d
commit bc47a724af
119 changed files with 27942 additions and 12524 deletions
@@ -35,6 +35,7 @@ Missing settings use the defaults documented below. Invalid stored configuration
 | sso | [SSO configuration](#sso-configuration-object) object | Single sign-on settings |
 | gateway_rollout | [Gateway rollout configuration](#gateway-rollout-configuration-object) object | Gateway admission and dispatch tuning |
 | voice_noise_suppression | [voice noise suppression configuration](#voice-noise-suppression-configuration-object) object | Client-side noise suppression rollout |
+| screen_share_delivery | [screen share delivery configuration](#screen-share-delivery-configuration-object) object | Adaptive screen share delivery rollout |
 | experiment_delivery | [experiment delivery configuration](#experiment-delivery-configuration-object) object | Cadence every client polls the experiments route on |
 | registration | [registration configuration](#registration-configuration-object) object | Registration policy, issued URLs, and pending registrations |
 | self_hosted | boolean | Whether the deployment runs in self-hosted mode |
@@ -121,6 +122,29 @@ Every field is present on read. An absent document or missing field uses the def

 How often a client revalidates this rollout is not set here. It is set once for every experiment in the [experiment delivery configuration](#experiment-delivery-configuration-object) below.

+## Screen share delivery configuration object
+
+The instance rollout of adaptive screen share delivery. [Experiments](/http-api/experiments/) defines what a client resolves from it and what each arm does.
+
+### Structure
+
+| Field | Type | Description |
+| --- | --- | --- |
+| enabled | boolean | Whether the rollout runs at all (default false) |
+| config_version | integer | Revision counter, raised by Fluxer and never accepted from a request |
+| rollout_basis_points | integer | Share of accounts the rollout selects, in basis points (0-10000, default 0) |
+| rollout_salt | string | Salt of the sampling hash (1-64 characters, default `screen-share-delivery-v1`) |
+| included_user_ids | array[snowflake] | Accounts the rollout always selects, up to 1000 entries (default empty) |
+| excluded_user_ids | array[snowflake] | Accounts the rollout never selects, up to 1000 entries (default empty) |
+
+Every field is present on read. An absent document or missing field uses the defaults above.
+
+`excluded_user_ids` is applied before `included_user_ids`, so the rollout never selects an account in both.
+
+A client reads this rollout once, when a screen share starts, and holds that answer for the life of the share. Turning the rollout off leaves a share that is already running on the arm it started on.
+
+How often a client revalidates this rollout is not set here. It is set once for every experiment in the [experiment delivery configuration](#experiment-delivery-configuration-object) below.
+
 ## Experiment delivery configuration object

 How often a client polls [Get experiment assignments](/http-api/experiments/#get-experiment-assignments), and how widely those polls are spread. The setting is instance-wide and applies to every experiment at once, so adding an experiment adds no second cadence to tune.
@@ -529,6 +553,7 @@ The body has one optional object for each section. Fluxer leaves an absent secti
 | sso?<sup>1</sup> | object | Every [SSO configuration](#sso-configuration-object) field except `client_secret_set` and `redirect_uri`, plus `client_secret` |
 | gateway_rollout? | object | Any subset of the [Gateway rollout configuration](#gateway-rollout-configuration-object) fields, each bound as documented there |
 | voice_noise_suppression? | object | Any subset of the [noise suppression](#voice-noise-suppression-configuration-object) fields |
+| screen_share_delivery? | object | Any subset of the [screen share delivery](#screen-share-delivery-configuration-object) fields |
 | experiment_delivery? | object | Any subset of the [experiment delivery](#experiment-delivery-configuration-object) fields |
 | registration? | object | `mode` and `admin_registration_urls_enabled` |
 | app_public?<sup>2</sup> | object | `branding`, `setup`, `legal`, and `registration` sub-objects, each merged field by field |
@@ -542,6 +567,8 @@ The body has one optional object for each section. Fluxer leaves an absent secti

 `voice_noise_suppression` takes every [voice noise suppression configuration](#voice-noise-suppression-configuration-object) field except `config_version`, each bound as documented there. Fluxer raises `config_version` by one on each request that supplies at least one of them. A section that is absent, or present with no field set, writes nothing and leaves `config_version` alone.

+`screen_share_delivery` takes every [screen share delivery configuration](#screen-share-delivery-configuration-object) field except `config_version`, each bound as documented there. Fluxer raises `config_version` by one on each request that supplies at least one of them. A section that is absent, or present with no field set, writes nothing and leaves `config_version` alone.
+
 `experiment_delivery` takes both [experiment delivery configuration](#experiment-delivery-configuration-object) fields, each bound as documented there. It is a section of its own, so a write to it changes no `config_version` and changes no assignment, only the cadence on which clients ask for one.

 <sup>3</sup> A secret such as `klipy_api_key`, `api_key`, `hcaptcha_secret_key`, `turnstile_secret_key`, or the SMTP `password` is written when supplied and left alone when absent. `integrations.bluesky.keys` is the only way to write the Bluesky signing keys counted as `bluesky.key_count`. It takes up to 8 entries of `kid` (1-255 characters) and nullable `private_key` (up to 10000 characters), and replaces the stored key set outright
@@ -578,7 +605,7 @@ Fluxer skips URL validation while the merged configuration leaves single sign-on
 | 400 | [error response](/admin-api/#error-response) | A policy transition is refused, returned as `INSTANCE_POLICY_TRANSITION_NOT_ALLOWED` |

 :::caution[Sections are applied one after another]
-The order is `gateway_rollout`, `voice_noise_suppression`, `experiment_delivery`, `sso`, `registration`, `app_public` branding, legal, and registration fields, `integrations`, `media`, `policy`, and finally `app_public.setup`. A failure part way through leaves the earlier sections written.
+The order is `gateway_rollout`, `voice_noise_suppression`, `screen_share_delivery`, `experiment_delivery`, `sso`, `registration`, `app_public` branding, legal, and registration fields, `integrations`, `media`, `policy`, and finally `app_public.setup`. A failure part way through leaves the earlier sections written.
 :::

 ### Side effects
@@ -1,12 +1,12 @@
 ---
 # SPDX-License-Identifier: AGPL-3.0-or-later
 title: Experiments
-description: The experiment assignments envelope, the revalidation and polling contract, and the noise suppression experiment.
+description: The experiment assignments envelope, the revalidation and polling contract, and the experiments this server defines.
 ---

 import RouteHeader from '@/components/RouteHeader.astro';

-An experiment is an instance-wide rollout that an operator configures. For each account, Fluxer works out from that configuration whether the account is in the rollout and which settings the account receives. The single route on this page resolves every experiment the server defines and returns them in one envelope, together with the polling cadence they share. `voice_noise_suppression` is the only experiment defined today, and [Voice](/voice/) defines the placement protocol its assignment applies to.
+An experiment is an instance-wide rollout that an operator configures. For each account, Fluxer works out from that configuration whether the account is in the rollout and which settings the account receives. The single route on this page resolves every experiment the server defines and returns them in one envelope, together with the polling cadence they share. This server defines `voice_noise_suppression`, whose placement protocol [Voice](/voice/) defines, and `screen_share_delivery`, which selects whether a client adapts its own screen share after it starts.

 Every assignment is advice. A client that ignores one behaves as it does with the rollout off, and no route and no Gateway event reports what a client actually ran.

@@ -33,10 +33,11 @@ One entry per experiment. The envelope reports this object even when it is empty
 | Field | Type | Description |
 | --- | --- | --- |
 | voice_noise_suppression? | [noise suppression assignment](#noise-suppression-assignment-object) object | The caller's noise suppression assignment |
+| screen_share_delivery? | [screen share delivery assignment](#screen-share-delivery-assignment-object) object | The caller's screen share delivery assignment |

 Ignore unknown experiments and treat a missing experiment as off.

-This server version writes `voice_noise_suppression` on every response, including while the rollout is disabled. The disabled value is the first [resolution outcome](#resolution-outcomes) below, which reports `enabled` false and the stored `config_version`, so a client that compares `config_version` with the value from its previous response can see that an operator saved the noise suppression configuration, even while the rollout stays disabled, and needs no second request for it.
+This server version writes `voice_noise_suppression` and `screen_share_delivery` on every response, including while a rollout is disabled. The disabled value is the first [resolution outcome](#resolution-outcomes) below, which reports `enabled` false and the stored `config_version`, so a client that compares `config_version` with the value from its previous response can see that an operator saved the configuration, even while the rollout stays disabled, and needs no second request for it.

 ## Noise suppression backends

@@ -102,6 +103,33 @@ One backend replacement scoped to one guild. While the caller is connected to a

 An override naming a backend that is absent from `enabled_backends` is dropped before the response is written, so every entry is runnable.

+## Screen share delivery assignment object
+
+One resolution of the instance screen share delivery rollout against one account. Every field is present whenever the key is written.
+
+The rollout selects whether a client adapts its own screen share after the share starts. A drawn client measures what its encoder sends, steps the share down a resolution and frame rate ladder while the encoder cannot keep up, probes back up when it can, remembers the rung it settled on for each codec, and reports what is going out to the sharer. A client that is not drawn publishes the target the account's settings ask for and holds it for the life of the share. Both arms recover a screen share whose encoder stalls. Neither arm changes what the API returns, and no route reports which arm a client ran.
+
+### Structure
+
+| Field | Type | Description |
+| --- | --- | --- |
+| enabled | boolean | Whether the rollout is running on this instance |
+| config_version | integer | The revision of the instance configuration this assignment was resolved from |
+| user_targeted | boolean | Whether the caller is inside the rollout |
+| source | ?string | Which rule targeted the caller, one of `user_rule` or `canary`, and null where the caller is not targeted |
+
+### Delivery resolution outcomes
+
+The outcomes below set `user_targeted` to false, and they differ in what else they report.
+
+1. The rollout is off. `enabled` is false and `source` is null.
+2. The operator has excluded the caller. `enabled` is true and `source` is null.
+3. The caller was not drawn. `enabled` is true and `source` is null.
+
+A caller is drawn either by the operator's allowlist, which sets `source` to `user_rule`, or by the sampled share of the account population, which sets `source` to `canary`. The blocklist is read before the allowlist, so an account named in both is not drawn.
+
+`config_version` reports the stored revision in all outcomes, the rollout being off included. A client branches on `user_targeted` alone, and reads the assignment once when a share starts rather than while one is running.
+
 ## Get experiment assignments

 <RouteHeader method="GET" path="/v1/experiments" bot />