diff --git a/fluxer_app/src/features/lexical/composer/useLexicalAutocomplete.ts b/fluxer_app/src/features/lexical/composer/useLexicalAutocomplete.ts
index 18bdb4fc8..20434234f 100644
--- a/fluxer_app/src/features/lexical/composer/useLexicalAutocomplete.ts
+++ b/fluxer_app/src/features/lexical/composer/useLexicalAutocomplete.ts
@@ -57,6 +57,7 @@ import type {GuildMember} from '@app/features/member/models/GuildMember';
 import GuildMembers from '@app/features/member/state/GuildMembers';
 import type {SearchContext} from '@app/features/member/state/MemberSearch';
 import * as HighlightCommands from '@app/features/messaging/commands/HighlightCommands';
+import * as MessageCommands from '@app/features/messaging/commands/MessageCommands';
 import * as ReactionCommands from '@app/features/messaging/commands/ReactionCommands';
 import Messages from '@app/features/messaging/state/MessagingMessages';
 import {
@@ -77,6 +78,7 @@ import {
 } from '@app/features/messaging/utils/AutocompleteOptionBuilders';
 import {isAutocompleteTriggerAllowed, type TriggerType} from '@app/features/messaging/utils/AutocompleteTriggerPolicy';
 import {toReactionEmoji} from '@app/features/messaging/utils/MessageReactionUtils';
+import {getReactionShorthandTargetId} from '@app/features/messaging/utils/ReactionShorthandUtils';
 import {
 	type AutocompleteTrigger,
 	detectAutocompleteTrigger,
@@ -705,10 +707,10 @@ export function useLexicalAutocomplete({
 			const matchStart = getComposerAutocompleteReplacementStart(currentTextUpToCursor, trigger.type, trigger.match);
 			if (trigger.type === 'emojiReaction' && isEmoji(option)) {
 				if (channel != null) {
-					const messages = Messages.getMessages(channel.id).toArray();
-					const mostRecent = messages[messages.length - 1];
-					if (mostRecent != null) {
-						ReactionCommands.addReaction(i18n, channel.id, mostRecent.id, toReactionEmoji(option.emoji));
+					const targetId = getReactionShorthandTargetId(channel.id);
+					if (targetId !== null) {
+						ReactionCommands.addReaction(i18n, channel.id, targetId, toReactionEmoji(option.emoji));
+						MessageCommands.stopReply(channel.id);
 					}
 				}
 				handle.clear();
diff --git a/fluxer_app/src/features/messaging/hooks/useTextareaSubmit.ts b/fluxer_app/src/features/messaging/hooks/useTextareaSubmit.ts
index f9a83023b..dc69421b9 100644
--- a/fluxer_app/src/features/messaging/hooks/useTextareaSubmit.ts
+++ b/fluxer_app/src/features/messaging/hooks/useTextareaSubmit.ts
@@ -20,6 +20,7 @@ import GuildMembers from '@app/features/member/state/GuildMembers';
 import MemberSidebar from '@app/features/member/state/MemberSidebar';
 import * as DraftCommands from '@app/features/messaging/commands/DraftCommands';
 import * as MessageCommands from '@app/features/messaging/commands/MessageCommands';
+import * as ReactionCommands from '@app/features/messaging/commands/ReactionCommands';
 import type {Message} from '@app/features/messaging/models/MessagingMessage';
 import type {MentionConfirmationInfo, MentionType} from '@app/features/messaging/state/MentionConfirmationStateMachine';
 import Messages from '@app/features/messaging/state/MessagingMessages';
@@ -29,6 +30,10 @@ import {
 	isAttachmentOnlyMessage,
 } from '@app/features/messaging/utils/MessageEditContentUtils';
 import {canSubmitMessage, hasVisibleMessageContent} from '@app/features/messaging/utils/MessageRequestUtils';
+import {
+	getReactionShorthandTargetId,
+	parseReactionShorthand,
+} from '@app/features/messaging/utils/ReactionShorthandUtils';
 import * as ReplaceCommandUtils from '@app/features/messaging/utils/ReplaceCommandUtils';
 import {resolveTypedEmojiShortcodes} from '@app/features/messaging/utils/TypedEmojiShortcodeUtils';
 import Permission from '@app/features/permissions/state/Permission';
@@ -458,6 +463,20 @@ export const useTextareaSubmit = ({
 			parsedCommand = lexicalCommand.command;
 		}
 		const replaceCommand = ReplaceCommandUtils.parseReplaceCommand(actualContent);
+		const reactionShorthand =
+			editingMessage === null && uploadAttachmentsLength === 0 && !hasPendingSticker
+				? parseReactionShorthand(resolvedContent)
+				: null;
+		const reactionTargetId = reactionShorthand === null ? null : getReactionShorthandTargetId(channelId);
+		if (reactionShorthand !== null && reactionTargetId !== null) {
+			ReactionCommands.addReaction(i18n, channelId, reactionTargetId, reactionShorthand);
+			setValue('');
+			clearSegments();
+			DraftCommands.deleteDraft(channelId);
+			TypingUtils.clear(channelId);
+			MessageCommands.stopReply(channelId);
+			return;
+		}
 		if (
 			shouldBlockSubmissionForSlowmode(
 				isSlowmodeActive,
diff --git a/fluxer_app/src/features/messaging/utils/ReactionShorthandUtils.ts b/fluxer_app/src/features/messaging/utils/ReactionShorthandUtils.ts
new file mode 100644
index 000000000..27fa9f629
--- /dev/null
+++ b/fluxer_app/src/features/messaging/utils/ReactionShorthandUtils.ts
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import UnicodeEmojis from '@app/features/expressions/utils/UnicodeEmojis';
+import MessageReply from '@app/features/messaging/state/MessageReply';
+import Messages from '@app/features/messaging/state/MessagingMessages';
+import {type ReactionEmoji, toReactionEmoji} from '@app/features/messaging/utils/MessageReactionUtils';
+
+const REACTION_SHORTHAND_PATTERN = /^\+(\S+)$/u;
+const CUSTOM_EMOJI_MARKDOWN_PATTERN = /^<(a)?:([a-zA-Z0-9_+-]{2,}):(\d+)>$/;
+const SHORTCODE_PATTERN = /^:([^\s:]+):$/;
+
+export function parseReactionShorthand(content: string): ReactionEmoji | null {
+	const match = REACTION_SHORTHAND_PATTERN.exec(content.trim());
+	if (match === null) {
+		return null;
+	}
+	const token = match[1];
+	const customMatch = CUSTOM_EMOJI_MARKDOWN_PATTERN.exec(token);
+	if (customMatch !== null) {
+		return {id: customMatch[3], name: customMatch[2], animated: customMatch[1] === 'a'};
+	}
+	const shortcodeMatch = SHORTCODE_PATTERN.exec(token);
+	if (shortcodeMatch !== null) {
+		const emoji = UnicodeEmojis.findEmojiByShortcodeName(shortcodeMatch[1]);
+		return emoji === null ? null : toReactionEmoji(emoji);
+	}
+	const name = UnicodeEmojis.nameForSurrogate(token, false);
+	if (name === '') {
+		return null;
+	}
+	return {name: UnicodeEmojis.surrogateForName(name, token)};
+}
+
+export function getReactionShorthandTargetId(channelId: string): string | null {
+	const reply = MessageReply.getReplyingMessage(channelId);
+	if (reply !== null) {
+		return reply.messageId;
+	}
+	const messages = Messages.getMessages(channelId).toArray();
+	return messages[messages.length - 1]?.id ?? null;
+}