Add emoji confetti bursts and component playground.

Support app.relay.emoji_confetti on jumbo emoji clicks with canvas physics,
per-emoji particle profiles, and a fixed overlay that does not affect scroll.
Also add a Vite playground for live component previews and theme hover preview.

.gitignore

@@ -4,4 +4,5 @@ node_modules
 devAssets
 
 .DS_Store
-.idea
+.idea
+.cache

package-lock.json

@@ -83,6 +83,7 @@
       },
       "devDependencies": {
         "@esbuild-plugins/node-globals-polyfill": "0.2.3",
+        "@monaco-editor/react": "4.7.0",
         "@rollup/plugin-inject": "5.0.5",
         "@rollup/plugin-wasm": "6.2.2",
         "@types/chroma-js": "3.1.2",
@@ -106,6 +107,7 @@
         "eslint-plugin-jsx-a11y": "6.10.2",
         "eslint-plugin-react": "7.37.5",
         "eslint-plugin-react-hooks": "7.1.1",
+        "monaco-editor": "0.52.2",
         "prettier": "3.9.4",
         "typescript": "6.0.3",
         "vite": "8.1.3",
@@ -2563,6 +2565,31 @@
         "node": ">= 18"
       }
     },
+    "node_modules/@monaco-editor/loader": {
+      "version": "1.7.0",
+      "resolved": "https://registry.npmjs.org/@monaco-editor/loader/-/loader-1.7.0.tgz",
+      "integrity": "sha512-gIwR1HrJrrx+vfyOhYmCZ0/JcWqG5kbfG7+d3f/C1LXk2EvzAbHSg3MQ5lO2sMlo9izoAZ04shohfKLVT6crVA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "state-local": "^1.0.6"
+      }
+    },
+    "node_modules/@monaco-editor/react": {
+      "version": "4.7.0",
+      "resolved": "https://registry.npmjs.org/@monaco-editor/react/-/react-4.7.0.tgz",
+      "integrity": "sha512-cyzXQCtO47ydzxpQtCGSQGOC8Gk3ZUeBXFAxD+CWXYFo5OqZyZUonFl0DwUlTyAfRHntBfw2p3w4s9R6oe1eCA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@monaco-editor/loader": "^1.5.0"
+      },
+      "peerDependencies": {
+        "monaco-editor": ">= 0.25.0 < 1",
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0",
+        "react-dom": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
     "node_modules/@napi-rs/canvas": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/@napi-rs/canvas/-/canvas-1.0.2.tgz",
@@ -8801,6 +8828,13 @@
       "resolved": "https://registry.npmjs.org/modern-ahocorasick/-/modern-ahocorasick-1.1.0.tgz",
       "integrity": "sha512-sEKPVl2rM+MNVkGQt3ChdmD8YsigmXdn5NifZn6jiwn9LRJpWm8F3guhaqrJT/JOat6pwpbXEk6kv+b9DMIjsQ=="
     },
+    "node_modules/monaco-editor": {
+      "version": "0.52.2",
+      "resolved": "https://registry.npmjs.org/monaco-editor/-/monaco-editor-0.52.2.tgz",
+      "integrity": "sha512-GEQWEZmfkOGLdd3XK8ryrfWz3AIP8YymVXiPHEdewrUq7mh0qrKrfHLNCXcbB6sTnMLnOZ3ztSiKcciFUkIJwQ==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/ms": {
       "version": "2.1.3",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
@@ -10157,6 +10191,13 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/state-local": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/state-local/-/state-local-1.0.7.tgz",
+      "integrity": "sha512-HTEHMNieakEnoe33shBYcZ7NX83ACUjCu8c40iOGEZsngj9zRnkqS9j1pqQPXwobB0ZcVTk27REb7COQ0UR59w==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/stop-iteration-iterator": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/stop-iteration-iterator/-/stop-iteration-iterator-1.1.0.tgz",

package.json

@@ -14,7 +14,8 @@
     "check:eslint": "eslint src/*",
     "check:prettier": "prettier --check .",
     "fix:prettier": "prettier --write .",
-    "typecheck": "tsc --noEmit"
+    "typecheck": "tsc --noEmit",
+    "playground": "vite"
   },
   "keywords": [],
   "author": "Ajay Bura",
@@ -94,6 +95,7 @@
   },
   "devDependencies": {
     "@esbuild-plugins/node-globals-polyfill": "0.2.3",
+    "@monaco-editor/react": "4.7.0",
     "@rollup/plugin-inject": "5.0.5",
     "@rollup/plugin-wasm": "6.2.2",
     "@types/chroma-js": "3.1.2",
@@ -117,6 +119,7 @@
     "eslint-plugin-jsx-a11y": "6.10.2",
     "eslint-plugin-react": "7.37.5",
     "eslint-plugin-react-hooks": "7.1.1",
+    "monaco-editor": "0.52.2",
     "prettier": "3.9.4",
     "typescript": "6.0.3",
     "vite": "8.1.3",

playground-liveTsxPlugin.ts

@@ -0,0 +1,149 @@
+import path from 'node:path';
+import fs from 'node:fs';
+import { fileURLToPath } from 'node:url';
+import type { Plugin, ViteDevServer } from 'vite';
+
+export type LiveTsxApi = {
+  getSource: () => string;
+  setSource: (source: string) => void;
+};
+
+const ALLOWED_PREFIXES = ['src/app/components/', 'src/app/features/'];
+
+function resolveAppSourceFile(projectRoot: string, relPath: string): string | null {
+  const normalized = relPath.replace(/\\/g, '/').replace(/^\/+/, '');
+  if (normalized.includes('..') || path.isAbsolute(normalized)) return null;
+  if (!ALLOWED_PREFIXES.some((p) => normalized.startsWith(p))) return null;
+  if (!/\.(tsx|ts)$/.test(normalized)) return null;
+  const abs = path.resolve(projectRoot, normalized);
+  const root = path.resolve(projectRoot);
+  if (!abs.startsWith(root + path.sep) && abs !== root) return null;
+  return abs;
+}
+
+function readBody(req: NodeJS.ReadableStream): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const chunks: Buffer[] = [];
+    req.on('data', (c) => chunks.push(c));
+    req.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
+    req.on('error', reject);
+  });
+}
+
+function bumpLivePreview(server: ViteDevServer | undefined) {
+  if (!server) return;
+  server.ws.send({
+    type: 'custom',
+    event: 'playground:live-updated',
+    data: { revision: Date.now() },
+  });
+}
+
+export function liveTsxPlugin(projectRoot: string, initialSource: string): Plugin {
+  const liveFile = path.resolve(projectRoot, '.cache/playground-live.tsx');
+
+  fs.mkdirSync(path.dirname(liveFile), { recursive: true });
+  fs.writeFileSync(liveFile, initialSource, 'utf8');
+
+  let source = initialSource;
+  let server: ViteDevServer | undefined;
+
+  const api: LiveTsxApi = {
+    getSource: () => source,
+    setSource: (next) => {
+      source = next;
+      fs.writeFileSync(liveFile, next, 'utf8');
+      if (!server) return;
+      for (const m of server.moduleGraph.urlToModuleMap.values()) {
+        if (m.file === liveFile) server.moduleGraph.invalidateModule(m);
+      }
+      const byId = server.moduleGraph.getModuleById(liveFile);
+      if (byId) server.moduleGraph.invalidateModule(byId);
+      bumpLivePreview(server);
+    },
+  };
+
+  return {
+    name: 'playground-live-tsx',
+    configureServer(devServer) {
+      server = devServer;
+      (devServer as ViteDevServer & { playgroundLive?: LiveTsxApi }).playgroundLive = api;
+
+      devServer.middlewares.use('/__playground/live', (req, res, next) => {
+        if (req.method === 'GET') {
+          res.setHeader('Content-Type', 'text/plain; charset=utf-8');
+          res.end(source);
+          return;
+        }
+        if (req.method === 'POST') {
+          void readBody(req).then((body) => {
+            api.setSource(body);
+            res.statusCode = 204;
+            res.end();
+          });
+          return;
+        }
+        next();
+      });
+
+      // Read/write real Cinny component sources (strings, markup, etc.).
+      devServer.middlewares.use('/__playground/source', (req, res, next) => {
+        const url = new URL(req.url ?? '', 'http://playground.local');
+        const rel = url.searchParams.get('path') ?? '';
+        const abs = resolveAppSourceFile(projectRoot, rel);
+        if (!abs) {
+          res.statusCode = 400;
+          res.end('Invalid or disallowed path');
+          return;
+        }
+
+        if (req.method === 'GET') {
+          if (!fs.existsSync(abs)) {
+            res.statusCode = 404;
+            res.end('Not found');
+            return;
+          }
+          res.setHeader('Content-Type', 'text/plain; charset=utf-8');
+          res.end(fs.readFileSync(abs, 'utf8'));
+          return;
+        }
+
+        if (req.method === 'POST') {
+          void readBody(req).then((body) => {
+            fs.mkdirSync(path.dirname(abs), { recursive: true });
+            fs.writeFileSync(abs, body, 'utf8');
+            const mod =
+              server?.moduleGraph.getModuleById(abs) ??
+              [...(server?.moduleGraph.urlToModuleMap.values() ?? [])].find((m) => m.file === abs);
+            if (mod && server) server.moduleGraph.invalidateModule(mod);
+            bumpLivePreview(server);
+            res.statusCode = 204;
+            res.end();
+          });
+          return;
+        }
+
+        next();
+      });
+    },
+    resolveId(id) {
+      const clean = id.split('?')[0];
+      if (
+        clean === '/@playground/live.tsx' ||
+        clean === 'virtual:playground-live' ||
+        clean.endsWith('/.cache/playground-live.tsx')
+      ) {
+        return liveFile;
+      }
+      return undefined;
+    },
+  };
+}
+
+export function readDefaultLiveSource(projectRoot: string): string {
+  return fs.readFileSync(path.join(projectRoot, 'src/playground/defaultLive.tsx'), 'utf8');
+}
+
+export function projectRootDir(): string {
+  return path.dirname(fileURLToPath(import.meta.url));
+}

playground.html

@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Component Playground</title>
+  </head>
+  <body style="margin:0;background:#0f1115;color:#e8eaed">
+    <div id="root"></div>
+    <script type="module" src="./src/playground/main.tsx?v=react-dedupe-1"></script>
+  </body>
+</html>

src/app/components/AccountDataEditor.tsx

@@ -1,5 +1,5 @@
 import React, { FormEventHandler, useCallback, useEffect, useMemo, useRef, useState } from 'react';
-import { Box, Text, IconButton, Input, Button, TextAreaComponent as TextArea, color, Spinner, Chip, Scroll, config } from 'folds';
+import { Box, Text, IconButton, Input, Button, TextArea, color, Spinner, Chip, Scroll, config } from 'folds';
 import { Icon, Icons } from './icons';
 import { MatrixError } from 'matrix-js-sdk';
 import { Cursor } from '../plugins/text-area';
@@ -154,7 +154,7 @@ function AccountDataEdit({
         <Box shrink="No">
           <Text size="L400">JSON Content</Text>
         </Box>
-        <TextAreaComponent
+        <TextArea
           ref={textAreaRef}
           name="contentTextArea"
           style={{

src/app/components/RenderMessageContent.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { KeyboardEvent, MouseEvent } from 'react';
 import { MsgType } from 'matrix-js-sdk';
 import { HTMLReactParserOptions } from 'html-react-parser';
 import { Opts } from 'linkifyjs';
@@ -49,6 +49,12 @@ type RenderMessageContentProps = {
   linkifyOpts: Opts;
   outlineAttachment?: boolean;
   disabledEmbedPatterns?: string[];
+  targetEventId?: string;
+  onJumboEmojiClick?: (
+    targetEventId: string,
+    body: string,
+    event: MouseEvent<HTMLElement> | KeyboardEvent<HTMLElement>
+  ) => void;
 };
 export function RenderMessageContent({
   displayName,
@@ -63,6 +69,8 @@ export function RenderMessageContent({
   linkifyOpts,
   outlineAttachment,
   disabledEmbedPatterns,
+  targetEventId,
+  onJumboEmojiClick,
 }: RenderMessageContentProps) {
   const renderUrlsPreview = (urls: string[]) => {
     let filteredUrls = urls.filter((url) => !testMatrixTo(url));
@@ -100,6 +108,11 @@ export function RenderMessageContent({
       </>
     );
   };
+  const handleJumboEmojiClick =
+    targetEventId && onJumboEmojiClick
+      ? (body: string, event: MouseEvent<HTMLElement> | KeyboardEvent<HTMLElement>) =>
+          onJumboEmojiClick(targetEventId, body, event)
+      : undefined;
   const renderCaption = () => {
     const content: IImageContent = getContent();
     if (content.filename && content.filename !== content.body) {
@@ -182,6 +195,7 @@ export function RenderMessageContent({
       <MText
         edited={edited}
         content={getContent()}
+        onJumboEmojiClick={handleJumboEmojiClick}
         renderBody={(props) => (
           <RenderBody
             {...props}
@@ -201,6 +215,7 @@ export function RenderMessageContent({
         displayName={displayName}
         edited={edited}
         content={getContent()}
+        onJumboEmojiClick={handleJumboEmojiClick}
         renderBody={(props) => (
           <RenderBody
             {...props}
@@ -219,6 +234,7 @@ export function RenderMessageContent({
       <MNotice
         edited={edited}
         content={getContent()}
+        onJumboEmojiClick={handleJumboEmojiClick}
         renderBody={(props) => (
           <RenderBody
             {...props}

src/app/components/message/MsgTypeRenderers.tsx

@@ -27,6 +27,7 @@ import {
   MATRIX_SPOILER_REASON_PROPERTY_NAME,
 } from '../../../types/matrix/common';
 import { StationeryMedia, hashStationerySeed, stationeryMediaRot } from './StationeryMedia';
+import { getJumboEmojiInteractionProps, JumboEmojiClickHandler } from '../../features/room/emoji-confetti/jumboEmojiInteraction';
 import { FALLBACK_MIMETYPE, getBlobSafeMimeType } from '../../utils/mimeTypes';
 import { parseGeoUri, scaleYDimension } from '../../utils/common';
 import { resolveAttachmentBoxSize } from '../../state/mediaDimensionCache';
@@ -78,8 +79,9 @@ type MTextProps = {
   renderBody: (props: RenderBodyProps) => ReactNode;
   renderUrlsPreview?: (urls: string[]) => ReactNode;
   style?: CSSProperties;
+  onJumboEmojiClick?: JumboEmojiClickHandler;
 };
-export function MText({ edited, content, renderBody, renderUrlsPreview, style }: MTextProps) {
+export function MText({ edited, content, renderBody, renderUrlsPreview, style, onJumboEmojiClick }: MTextProps) {
   const { body, formatted_body: customBody } = content;
 
   if (typeof body !== 'string') return <BrokenContent />;
@@ -89,13 +91,20 @@ export function MText({ edited, content, renderBody, renderUrlsPreview, style }:
     : undefined;
   const urlsMatch = renderUrlsPreview && trimmedBody.match(URL_REG);
   const urls = urlsMatch ? [...new Set(urlsMatch)] : undefined;
+  const isJumboEmoji = JUMBO_EMOJI_REG.test(trimmedBody);
+  const jumboEmojiInteraction = getJumboEmojiInteractionProps({
+    body: trimmedBody,
+    isJumboEmoji,
+    onJumboEmojiClick,
+  });
 
   return (
     <>
       <MessageTextBody
         preWrap={typeof customBody !== 'string'}
-        jumboEmoji={JUMBO_EMOJI_REG.test(trimmedBody)}
+        jumboEmoji={isJumboEmoji}
         style={style}
+        {...jumboEmojiInteraction}
       >
         {renderBody({
           body: trimmedBody,
@@ -114,6 +123,7 @@ type MEmoteProps = {
   content: Record<string, unknown>;
   renderBody: (props: RenderBodyProps) => ReactNode;
   renderUrlsPreview?: (urls: string[]) => ReactNode;
+  onJumboEmojiClick?: JumboEmojiClickHandler;
 };
 export function MEmote({
   displayName,
@@ -121,6 +131,7 @@ export function MEmote({
   content,
   renderBody,
   renderUrlsPreview,
+  onJumboEmojiClick,
 }: MEmoteProps) {
   const { body, formatted_body: customBody } = content;
 
@@ -131,20 +142,28 @@ export function MEmote({
     : undefined;
   const urlsMatch = renderUrlsPreview && trimmedBody.match(URL_REG);
   const urls = urlsMatch ? [...new Set(urlsMatch)] : undefined;
+  const isJumboEmoji = JUMBO_EMOJI_REG.test(trimmedBody);
+  const jumboEmojiInteraction = getJumboEmojiInteractionProps({
+    body: trimmedBody,
+    isJumboEmoji,
+    onJumboEmojiClick,
+  });
 
   return (
     <>
       <MessageTextBody
         emote
         preWrap={typeof customBody !== 'string'}
-        jumboEmoji={JUMBO_EMOJI_REG.test(trimmedBody)}
+        jumboEmoji={isJumboEmoji}
       >
         <b>{`${displayName} `}</b>
-        {renderBody({
+        <span {...jumboEmojiInteraction}>
-          body: trimmedBody,
+          {renderBody({
-          customBody: trimmedCustomBody,
+            body: trimmedBody,
-        })}
+            customBody: trimmedCustomBody,
-        {edited && <MessageEditedContent />}
+          })}
+          {edited && <MessageEditedContent />}
+        </span>
       </MessageTextBody>
       {renderUrlsPreview && urls && urls.length > 0 && renderUrlsPreview(urls)}
     </>
@@ -156,8 +175,9 @@ type MNoticeProps = {
   content: Record<string, unknown>;
   renderBody: (props: RenderBodyProps) => ReactNode;
   renderUrlsPreview?: (urls: string[]) => ReactNode;
+  onJumboEmojiClick?: JumboEmojiClickHandler;
 };
-export function MNotice({ edited, content, renderBody, renderUrlsPreview }: MNoticeProps) {
+export function MNotice({ edited, content, renderBody, renderUrlsPreview, onJumboEmojiClick }: MNoticeProps) {
   const { body, formatted_body: customBody } = content;
 
   if (typeof body !== 'string') return <BrokenContent />;
@@ -167,13 +187,20 @@ export function MNotice({ edited, content, renderBody, renderUrlsPreview }: MNot
     : undefined;
   const urlsMatch = renderUrlsPreview && trimmedBody.match(URL_REG);
   const urls = urlsMatch ? [...new Set(urlsMatch)] : undefined;
+  const isJumboEmoji = JUMBO_EMOJI_REG.test(trimmedBody);
+  const jumboEmojiInteraction = getJumboEmojiInteractionProps({
+    body: trimmedBody,
+    isJumboEmoji,
+    onJumboEmojiClick,
+  });
 
   return (
     <>
       <MessageTextBody
         notice
         preWrap={typeof customBody !== 'string'}
-        jumboEmoji={JUMBO_EMOJI_REG.test(trimmedBody)}
+        jumboEmoji={isJumboEmoji}
+        {...jumboEmojiInteraction}
       >
         {renderBody({
           body: trimmedBody,

src/app/components/message/layout/layout.css.ts

@@ -243,6 +243,9 @@ export const MessageTextBody = recipe({
         overflow: 'visible',
         overflowY: 'visible',
         paddingBottom: config.space.S200,
+        cursor: 'pointer',
+        position: 'relative',
+        zIndex: 5,
       },
     },
     emote: {
@@ -263,6 +266,8 @@ globalStyle(`${jumboEmojiClass} .${htmlCss.EmoticonBase}`, {
   padding: 0,
   overflow: 'visible',
   verticalAlign: 'middle',
+  position: 'relative',
+  zIndex: 1,
 });
 
 globalStyle(`${jumboEmojiClass} .${htmlCss.Emoticon.classNames.base}`, {

src/app/features/common-settings/developer-tools/SendRoomEvent.tsx

@@ -1,6 +1,6 @@
 import React, { useCallback, useRef, useState, FormEventHandler, useEffect } from 'react';
 import { MatrixError } from 'matrix-js-sdk';
-import { Box, Chip, IconButton, Text, config, Button, Spinner, color, TextAreaComponent as TextArea, Input } from 'folds';
+import { Box, Chip, IconButton, Text, config, Button, Spinner, color, TextArea, Input } from 'folds';
 import { Icon, Icons } from '../../../components/icons';
 import { Page, PageHeader } from '../../../components/page';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
@@ -171,7 +171,7 @@ export function SendRoomEvent({ type, stateKey, requestClose }: SendRoomEventPro
             <Box shrink="No">
               <Text size="L400">JSON Content</Text>
             </Box>
-            <TextAreaComponent
+            <TextArea
               ref={textAreaRef}
               name="contentTextArea"
               style={{ fontFamily: 'monospace' }}

src/app/features/common-settings/developer-tools/StateEventEditor.tsx

@@ -1,5 +1,5 @@
 import React, { FormEventHandler, useCallback, useEffect, useMemo, useRef, useState } from 'react';
-import { Box, Text, IconButton, Chip, Scroll, config, TextAreaComponent as TextArea, color, Spinner, Button } from 'folds';
+import { Box, Text, IconButton, Chip, Scroll, config, TextArea, color, Spinner, Button } from 'folds';
 import { Icon, Icons } from '../../../components/icons';
 import { MatrixError } from 'matrix-js-sdk';
 import { Page, PageHeader } from '../../../components/page';
@@ -153,7 +153,7 @@ function StateEventEdit({ type, stateKey, content, requestClose }: StateEventEdi
         <Box shrink="No">
           <Text size="L400">JSON Content</Text>
         </Box>
-        <TextAreaComponent
+        <TextArea
           ref={textAreaRef}
           name="contentTextArea"
           style={{ fontFamily: 'monospace' }}

src/app/features/room/RoomTimeline.tsx

@@ -137,6 +137,8 @@ import {
   PAARROT_CAROUSEL_TOTAL_PROPERTY_NAME,
   PAARROT_CAROUSEL_UUID_PROPERTY_NAME,
 } from '../../../types/matrix/common';
+import { EmojiConfettiOverlay } from './emoji-confetti/EmojiConfettiOverlay';
+import { useJumboEmojiConfetti } from './emoji-confetti/useJumboEmojiConfetti';
 
 /** Information about a call member event for grouping */
 interface CallEventInfo {
@@ -582,6 +584,8 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
   );
   const [showHiddenEvents] = useSetting(settingsAtom, 'showHiddenEvents');
   const [showDeveloperTools] = useSetting(settingsAtom, 'developerTools');
+  const { bursts: emojiConfettiBursts, removeBurst: removeEmojiConfettiBurst, handleJumboEmojiClick } =
+    useJumboEmojiConfetti(room);
 
   const [hour24Clock] = useSetting(settingsAtom, 'hour24Clock');
   const [dateFormatString] = useSetting(settingsAtom, 'dateFormatString');
@@ -1597,6 +1601,8 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
                 linkifyOpts={linkifyOpts}
                 outlineAttachment={messageLayout === MessageLayout.Bubble}
                 disabledEmbedPatterns={combinedEmbedFilters}
+                targetEventId={mEventId}
+                onJumboEmojiClick={handleJumboEmojiClick}
               />
             )}
           </Message>
@@ -1705,6 +1711,8 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
                       linkifyOpts={linkifyOpts}
                       outlineAttachment={messageLayout === MessageLayout.Bubble}
                       disabledEmbedPatterns={combinedEmbedFilters}
+                      targetEventId={mEventId}
+                      onJumboEmojiClick={handleJumboEmojiClick}
                     />
                   );
                 }
@@ -2002,6 +2010,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
         // Return special marker for call event (will be handled by eventRenderer)
         return 'CALL_EVENT_PENDING' as unknown as React.ReactNode;
       },
+      [MessageEvent.RelayEmojiConfetti]: () => null,
     },
     (mEventId, mEvent, item) => {
       if (!showHiddenEvents) return null;
@@ -2704,6 +2713,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
           </Box>
         </TimelineFloat>
       )}
+      <EmojiConfettiOverlay bursts={emojiConfettiBursts} onBurstComplete={removeEmojiConfettiBurst} />
     </Box>
   );
 }

src/app/features/room/ThreadView.tsx

@@ -65,6 +65,8 @@ import * as roomViewCss from './RoomViewFollowing.css';
 import { Message, Reactions, EncryptedContent } from './message';
 import { Reply } from '../../components/message';
 import { RenderMessageContent } from '../../components/RenderMessageContent';
+import { EmojiConfettiOverlay } from './emoji-confetti/EmojiConfettiOverlay';
+import { useJumboEmojiConfetti } from './emoji-confetti/useJumboEmojiConfetti';
 import {
   LINKIFY_OPTS,
   factoryRenderLinkifyWithMention,
@@ -156,6 +158,8 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
   const [hour24Clock] = useSetting(settingsAtom, 'hour24Clock');
   const [dateFormatString] = useSetting(settingsAtom, 'dateFormatString');
   const [hideActivity] = useSetting(settingsAtom, 'hideActivity');
+  const { bursts: emojiConfettiBursts, removeBurst: removeEmojiConfettiBurst, handleJumboEmojiClick } =
+    useJumboEmojiConfetti(room);
 
   const showUrlPreview = room.hasEncryptionStateEvent() ? encUrlPreview : urlPreview;
   const direct = useIsDirectRoom();
@@ -638,6 +642,8 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
                 linkifyOpts={linkifyOpts}
                 outlineAttachment={messageLayout === MessageLayout.Bubble}
                 disabledEmbedPatterns={combinedEmbedFilters}
+                targetEventId={mEventId}
+                onJumboEmojiClick={handleJumboEmojiClick}
               />
             )}
           </EncryptedContent>
@@ -654,6 +660,8 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
             linkifyOpts={linkifyOpts}
             outlineAttachment={messageLayout === MessageLayout.Bubble}
             disabledEmbedPatterns={combinedEmbedFilters}
+            targetEventId={mEventId}
+            onJumboEmojiClick={handleJumboEmojiClick}
           />
         )}
       </Message>
@@ -759,6 +767,10 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
               {events.map((evt, idx, arr) => renderEvent(evt, idx, arr))}
             </Box>
           </Scroll>
+          <EmojiConfettiOverlay
+            bursts={emojiConfettiBursts}
+            onBurstComplete={removeEmojiConfettiBurst}
+          />
         </Box>
         <div className={roomViewCss.RoomViewBottomFloat}>
           <RoomViewTyping room={room} />

src/app/features/room/emoji-confetti/EmojiConfettiBurstCanvas.tsx

@@ -0,0 +1,180 @@
+import React, { useEffect, useMemo, useRef, useState } from 'react';
+import { createPortal } from 'react-dom';
+import { EmojiConfettiBurst } from './types';
+import { findJumboEmojiElement, getLocalBurstCanvasSize } from './findJumboMount';
+import {
+  BurstParticle,
+  drawBurstParticles,
+  spawnEmojiBurst,
+  stepBurstParticles,
+} from './emojiBurstEngine';
+
+const MAX_DPR = 2;
+
+type EmojiConfettiBurstCanvasProps = {
+  burst: EmojiConfettiBurst;
+  onComplete: (burstId: string) => void;
+};
+
+export function EmojiConfettiBurstCanvas({ burst, onComplete }: EmojiConfettiBurstCanvasProps) {
+  const canvasRef = useRef<HTMLCanvasElement>(null);
+  const layerRef = useRef<HTMLDivElement>(null);
+  const particlesRef = useRef<BurstParticle[]>([]);
+  const frameRef = useRef<number | null>(null);
+  const lastFrameTimeRef = useRef<number | null>(null);
+  const spawnedRef = useRef(false);
+  const onCompleteRef = useRef(onComplete);
+  onCompleteRef.current = onComplete;
+
+  const canvasSize = getLocalBurstCanvasSize(burst.origin.maskRadius ?? 36);
+  const localOrigin = useMemo(
+    () => ({
+      x: canvasSize / 2,
+      y: canvasSize / 2,
+      maskRadius: burst.origin.maskRadius ?? 36,
+    }),
+    [burst.origin.maskRadius, canvasSize]
+  );
+
+  const updateLayerPosition = () => {
+    const layer = layerRef.current;
+    if (!layer) return false;
+
+    const jumbo = findJumboEmojiElement(burst.targetEventId);
+    if (!jumbo) return false;
+
+    const rect = jumbo.getBoundingClientRect();
+    layer.style.left = `${rect.left + rect.width / 2 - canvasSize / 2}px`;
+    layer.style.top = `${rect.top + rect.height / 2 - canvasSize / 2}px`;
+    return true;
+  };
+
+  useEffect(() => {
+    const onScrollOrResize = () => {
+      updateLayerPosition();
+    };
+
+    window.addEventListener('scroll', onScrollOrResize, true);
+    window.addEventListener('resize', onScrollOrResize);
+
+    return () => {
+      window.removeEventListener('scroll', onScrollOrResize, true);
+      window.removeEventListener('resize', onScrollOrResize);
+    };
+  }, [burst.targetEventId, canvasSize]);
+
+  useEffect(() => {
+    if (!canvasRef.current || spawnedRef.current) return undefined;
+
+    const reducedMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
+    if (reducedMotion) {
+      onCompleteRef.current(burst.id);
+      return undefined;
+    }
+
+    let frameCleanup: (() => void) | undefined;
+
+    const start = (): boolean => {
+      if (spawnedRef.current || !canvasRef.current) return false;
+      if (!updateLayerPosition()) return false;
+
+      spawnedRef.current = true;
+      const canvas = canvasRef.current;
+      const context = canvas.getContext('2d');
+      if (!context) return false;
+
+      const dpr = Math.min(window.devicePixelRatio || 1, MAX_DPR);
+      canvas.width = Math.round(canvasSize * dpr);
+      canvas.height = Math.round(canvasSize * dpr);
+      canvas.style.width = `${canvasSize}px`;
+      canvas.style.height = `${canvasSize}px`;
+
+      spawnEmojiBurst(
+        particlesRef.current,
+        burst.id,
+        localOrigin,
+        burst.emojis[0] ?? '🎉',
+        performance.now()
+      );
+
+      const tick = (now: number) => {
+        updateLayerPosition();
+
+        const last = lastFrameTimeRef.current ?? now;
+        const dtSeconds = Math.min((now - last) / 1000, 0.05);
+        lastFrameTimeRef.current = now;
+
+        stepBurstParticles(particlesRef.current, now, dtSeconds);
+
+        context.setTransform(1, 0, 0, 1, 0, 0);
+        context.clearRect(0, 0, canvas.width, canvas.height);
+
+        if (particlesRef.current.length > 0) {
+          drawBurstParticles(context, particlesRef.current, dpr, now);
+          frameRef.current = requestAnimationFrame(tick);
+          return;
+        }
+
+        onCompleteRef.current(burst.id);
+        frameRef.current = null;
+        lastFrameTimeRef.current = null;
+      };
+
+      lastFrameTimeRef.current = performance.now();
+      frameRef.current = requestAnimationFrame(tick);
+
+      frameCleanup = () => {
+        if (frameRef.current !== null) {
+          cancelAnimationFrame(frameRef.current);
+          frameRef.current = null;
+        }
+      };
+
+      return true;
+    };
+
+    if (start()) {
+      return frameCleanup;
+    }
+
+    let attempt = 0;
+    const retry = window.setInterval(() => {
+      attempt += 1;
+      if (start() || attempt >= 10) {
+        window.clearInterval(retry);
+        if (attempt >= 10 && !spawnedRef.current) {
+          onCompleteRef.current(burst.id);
+        }
+      }
+    }, 50);
+
+    return () => {
+      window.clearInterval(retry);
+      frameCleanup?.();
+    };
+  }, [burst.emojis, burst.id, burst.targetEventId, canvasSize, localOrigin]);
+
+  return createPortal(
+    <div
+      ref={layerRef}
+      aria-hidden
+      style={{
+        position: 'fixed',
+        width: canvasSize,
+        height: canvasSize,
+        pointerEvents: 'none',
+        zIndex: 4,
+      }}
+    >
+      <canvas
+        ref={canvasRef}
+        style={{
+          position: 'absolute',
+          inset: 0,
+          pointerEvents: 'none',
+        }}
+      />
+    </div>,
+    document.body
+  );
+}

src/app/features/room/emoji-confetti/EmojiConfettiOverlay.tsx

@@ -0,0 +1,24 @@
+import React from 'react';
+import { EmojiConfettiBurst } from './types';
+import { EmojiConfettiBurstCanvas } from './EmojiConfettiBurstCanvas';
+
+type EmojiConfettiOverlayProps = {
+  bursts: EmojiConfettiBurst[];
+  onBurstComplete: (burstId: string) => void;
+};
+
+export function EmojiConfettiOverlay({ bursts, onBurstComplete }: EmojiConfettiOverlayProps) {
+  if (bursts.length === 0) return null;
+
+  return (
+    <>
+      {bursts.map((burst) => (
+        <EmojiConfettiBurstCanvas
+          key={burst.id}
+          burst={burst}
+          onComplete={onBurstComplete}
+        />
+      ))}
+    </>
+  );
+}

src/app/features/room/emoji-confetti/burstOrigin.ts

@@ -0,0 +1,74 @@
+export type BurstPoint = {
+  x: number;
+  y: number;
+  maskRadius?: number;
+};
+
+export function getBurstPointFromElement(element: Element): BurstPoint {
+  const rect = element.getBoundingClientRect();
+  return {
+    x: rect.left + rect.width / 2,
+    y: rect.top + rect.height / 2,
+    maskRadius: Math.max(rect.width, rect.height) * 0.5,
+  };
+}
+
+export function getElementCenter(element: Element): BurstPoint {
+  return getBurstPointFromElement(element);
+}
+
+export function findEmojiOriginInMessage(
+  targetEventId: string,
+  emoji: string
+): BurstPoint | undefined {
+  const message = document.querySelector(`[data-message-id="${CSS.escape(targetEventId)}"]`);
+  if (!message) return undefined;
+
+  const matches = message.querySelectorAll('[data-emoticon]');
+  for (const element of matches) {
+    if (element.getAttribute('data-emoticon') === emoji) {
+      return getBurstPointFromElement(element);
+    }
+  }
+
+  return undefined;
+}
+
+export function getMessageFallbackOrigin(targetEventId: string): BurstPoint | undefined {
+  const message = document.querySelector(`[data-message-id="${CSS.escape(targetEventId)}"]`);
+  if (!message) return undefined;
+
+  const jumboBody = message.querySelector('[data-jumbo-emoji]');
+  if (jumboBody) {
+    return getBurstPointFromElement(jumboBody);
+  }
+
+  const body = message.querySelector('[data-message-body]');
+  if (body) {
+    return getBurstPointFromElement(body);
+  }
+
+  return getBurstPointFromElement(message);
+}
+
+export function resolveBurstOrigin(
+  targetEventId: string | undefined,
+  emojis: string[],
+  explicitOrigin?: BurstPoint
+): BurstPoint {
+  if (explicitOrigin) return explicitOrigin;
+
+  const primaryEmoji = emojis[0];
+  if (targetEventId && primaryEmoji) {
+    const emojiOrigin = findEmojiOriginInMessage(targetEventId, primaryEmoji);
+    if (emojiOrigin) return emojiOrigin;
+
+    const messageOrigin = getMessageFallbackOrigin(targetEventId);
+    if (messageOrigin) return messageOrigin;
+  }
+
+  return {
+    x: window.innerWidth / 2,
+    y: window.innerHeight * 0.35,
+  };
+}

src/app/features/room/emoji-confetti/emojiBurstEngine.ts

@@ -0,0 +1,357 @@
+import { BurstPoint } from './burstOrigin';
+import {
+  BurstMotionStyle,
+  EmojiBurstProfile,
+  getEmojiBurstProfile,
+  pickParticleEmoji,
+  sampleBurstAngle,
+} from './emojiParticleProfiles';
+
+/** Particles spawn over this window. */
+export const BURST_SPAWN_MS = 500;
+/** Global fade runs from 0.5s → 2s after burst start. */
+export const BURST_FADE_START_MS = 500;
+export const BURST_FADE_END_MS = 2000;
+export const BURST_TOTAL_MS = BURST_FADE_END_MS;
+
+export type BurstParticle = {
+  burstId: string;
+  burstStartMs: number;
+  emoji: string;
+  fontSize: number;
+  spawnX: number;
+  spawnY: number;
+  maskRadius: number;
+  x: number;
+  y: number;
+  vx: number;
+  vy: number;
+  bornAt: number;
+  rotation: number;
+  spin: number;
+  peakScale: number;
+  style: BurstMotionStyle;
+  gravity: number;
+  drag: number;
+  phase: number;
+  twinkle?: boolean;
+  wobble?: boolean;
+  orbitRadius: number;
+  orbitSpeed: number;
+  orbitAngle: number;
+  bounceDamping: number;
+  bouncesLeft: number;
+};
+
+const EMOJI_CACHE_PX = 64;
+const EMOJI_CACHE_SCALE = 2;
+const MAX_DPR = 2;
+const POP_IN_MS = 70;
+
+const emojiCanvasCache = new Map<string, HTMLCanvasElement>();
+
+function easeOutBack(t: number): number {
+  const c1 = 1.70158;
+  const c3 = c1 + 1;
+  return 1 + c3 * (t - 1) ** 3 + c1 * (t - 1) ** 2;
+}
+
+function easeOutCubic(t: number): number {
+  return 1 - (1 - t) ** 3;
+}
+
+function lerp(min: number, max: number): number {
+  return min + Math.random() * (max - min);
+}
+
+function getEmojiCanvas(emoji: string): HTMLCanvasElement {
+  const dpr = Math.min(window.devicePixelRatio || 1, MAX_DPR);
+  const cacheKey = `${emoji}:${dpr}`;
+  const cached = emojiCanvasCache.get(cacheKey);
+  if (cached) return cached;
+
+  const fontSize = Math.ceil(EMOJI_CACHE_PX * dpr);
+  const size = Math.ceil(fontSize * EMOJI_CACHE_SCALE);
+  const canvas = document.createElement('canvas');
+  canvas.width = size;
+  canvas.height = size;
+
+  const context = canvas.getContext('2d');
+  if (context) {
+    context.textAlign = 'center';
+    context.textBaseline = 'middle';
+    context.font = `${fontSize}px "Apple Color Emoji", "Segoe UI Emoji", "Noto Color Emoji", sans-serif`;
+    context.fillText(emoji, size / 2, size / 2);
+  }
+
+  emojiCanvasCache.set(cacheKey, canvas);
+  return canvas;
+}
+
+function emergeOpacity(
+  x: number,
+  y: number,
+  spawnX: number,
+  spawnY: number,
+  maskRadius: number
+): number {
+  const dist = Math.hypot(x - spawnX, y - spawnY);
+  const inner = maskRadius * 0.55;
+  const outer = maskRadius * 1.05;
+  if (dist <= inner) return 0;
+  if (dist >= outer) return 1;
+  return (dist - inner) / (outer - inner);
+}
+
+function spawnParticle(
+  particles: BurstParticle[],
+  burstId: string,
+  burstStartMs: number,
+  point: BurstPoint,
+  primaryEmoji: string,
+  profile: EmojiBurstProfile,
+  bornAt: number,
+  options?: { hero?: boolean }
+) {
+  const hero = options?.hero ?? false;
+  const angle = sampleBurstAngle(profile);
+  const speed = hero
+    ? lerp(profile.speedMin * 0.65, profile.speedMax * 0.55)
+    : lerp(profile.speedMin, profile.speedMax);
+  const launchUp = lerp(profile.launchUpMin, profile.launchUpMax);
+  const maskRadius = point.maskRadius ?? 28;
+  const jitter = hero ? 3 : 12;
+  const emoji = pickParticleEmoji(profile, primaryEmoji);
+
+  let vx = Math.cos(angle) * speed + (Math.random() - 0.5) * 60;
+  let vy = Math.sin(angle) * speed - launchUp;
+
+  if (profile.style === 'spiral') {
+    vx *= 0.35;
+    vy *= 0.35;
+  }
+
+  if (profile.style === 'sparkle') {
+    vx *= 0.75;
+    vy *= 0.75;
+  }
+
+  particles.push({
+    burstId,
+    burstStartMs,
+    emoji,
+    fontSize: hero
+      ? lerp(profile.heroFontSizeMin, profile.heroFontSizeMax)
+      : lerp(profile.fontSizeMin, profile.fontSizeMax),
+    spawnX: point.x,
+    spawnY: point.y,
+    maskRadius,
+    x: point.x + (Math.random() - 0.5) * jitter,
+    y: point.y + (Math.random() - 0.5) * jitter,
+    vx,
+    vy,
+    bornAt,
+    rotation: (Math.random() - 0.5) * 40,
+    spin: lerp(profile.spinMin, profile.spinMax),
+    peakScale: hero ? 1.1 + Math.random() * 0.2 : 0.9 + Math.random() * 0.4,
+    style: profile.style,
+    gravity: profile.gravity,
+    drag: profile.drag,
+    phase: Math.random() * Math.PI * 2,
+    twinkle: profile.twinkle,
+    wobble: profile.wobble,
+    orbitRadius: hero ? 8 : 14 + Math.random() * 28,
+    orbitSpeed: (Math.random() < 0.5 ? -1 : 1) * (1.8 + Math.random() * 2.4),
+    orbitAngle: Math.random() * Math.PI * 2,
+    bounceDamping: 0.42 + Math.random() * 0.18,
+    bouncesLeft: profile.style === 'bounce' ? 2 : 0,
+  });
+}
+
+/** Fountain from behind the emoji for 0.5s, fade 0.5s→2s. */
+export function spawnEmojiBurst(
+  particles: BurstParticle[],
+  burstId: string,
+  point: BurstPoint,
+  emoji: string,
+  now = performance.now()
+) {
+  const profile = getEmojiBurstProfile(emoji);
+  const burstStartMs = now;
+
+  spawnParticle(particles, burstId, burstStartMs, point, emoji, profile, burstStartMs, {
+    hero: true,
+  });
+
+  const particleCount = profile.particleCount;
+  for (let i = 0; i < particleCount; i += 1) {
+    const slot = i / particleCount;
+    const bornAt =
+      burstStartMs + slot * BURST_SPAWN_MS + Math.random() * (BURST_SPAWN_MS / particleCount);
+    spawnParticle(particles, burstId, burstStartMs, point, emoji, profile, bornAt);
+  }
+}
+
+function stepSpiralParticle(particle: BurstParticle, dtSeconds: number) {
+  particle.orbitRadius += 42 * dtSeconds;
+  particle.orbitAngle += particle.orbitSpeed * dtSeconds;
+  particle.x = particle.spawnX + Math.cos(particle.orbitAngle) * particle.orbitRadius;
+  particle.y =
+    particle.spawnY + Math.sin(particle.orbitAngle) * particle.orbitRadius * 0.65 + particle.vy * dtSeconds * 8;
+  particle.vy += particle.gravity * dtSeconds * 0.35;
+  particle.rotation += particle.spin * dtSeconds;
+}
+
+function stepBounceParticle(particle: BurstParticle, dtSeconds: number, dragFactor: number) {
+  particle.vy += particle.gravity * dtSeconds;
+  particle.vx *= dragFactor;
+  particle.vy *= dragFactor;
+  particle.x += particle.vx * dtSeconds;
+  particle.y += particle.vy * dtSeconds;
+  particle.rotation += particle.spin * dtSeconds;
+
+  if (particle.bouncesLeft > 0 && particle.vy > 0 && particle.y >= particle.spawnY + 6) {
+    particle.y = particle.spawnY + 6;
+    particle.vy = -Math.abs(particle.vy) * particle.bounceDamping;
+    particle.vx *= 0.82;
+    particle.bouncesLeft -= 1;
+    particle.spin += (Math.random() - 0.5) * 120;
+  }
+}
+
+function stepDefaultParticle(particle: BurstParticle, dtSeconds: number, dragFactor: number) {
+  particle.vy += particle.gravity * dtSeconds;
+  particle.vx *= dragFactor;
+  particle.vy *= dragFactor;
+  particle.x += particle.vx * dtSeconds;
+  particle.y += particle.vy * dtSeconds;
+  particle.rotation += particle.spin * dtSeconds;
+}
+
+export function stepBurstParticles(
+  particles: BurstParticle[],
+  now: number,
+  dtSeconds: number
+): void {
+  for (let i = particles.length - 1; i >= 0; i -= 1) {
+    const particle = particles[i];
+    const burstElapsed = now - particle.burstStartMs;
+
+    if (burstElapsed > BURST_TOTAL_MS) {
+      particles[i] = particles[particles.length - 1];
+      particles.pop();
+      continue;
+    }
+
+    const ageMs = now - particle.bornAt;
+    if (ageMs < 0) continue;
+
+    const dragFactor = particle.drag ** (dtSeconds * 60);
+
+    switch (particle.style) {
+      case 'spiral':
+        stepSpiralParticle(particle, dtSeconds);
+        break;
+      case 'bounce':
+        stepBounceParticle(particle, dtSeconds, dragFactor);
+        break;
+      default:
+        stepDefaultParticle(particle, dtSeconds, dragFactor);
+        break;
+    }
+
+    particle.phase += dtSeconds * (particle.twinkle ? 9 : 5);
+  }
+}
+
+type DrawState = {
+  x: number;
+  y: number;
+  scale: number;
+  opacity: number;
+  rotation: number;
+};
+
+function particleDrawState(particle: BurstParticle, now: number): DrawState | null {
+  const burstElapsed = now - particle.burstStartMs;
+  if (burstElapsed > BURST_TOTAL_MS) return null;
+
+  const ageMs = now - particle.bornAt;
+  if (ageMs < 0) return null;
+
+  let scale = particle.peakScale;
+  let opacity = emergeOpacity(
+    particle.x,
+    particle.y,
+    particle.spawnX,
+    particle.spawnY,
+    particle.maskRadius
+  );
+
+  if (opacity <= 0) return null;
+
+  if (ageMs < POP_IN_MS) {
+    const pop = easeOutBack(ageMs / POP_IN_MS);
+    scale = 0.1 + pop * particle.peakScale;
+    opacity *= pop;
+  }
+
+  if (particle.twinkle) {
+    opacity *= 0.55 + 0.45 * Math.sin(particle.phase * 1.6);
+  }
+
+  if (particle.wobble) {
+    scale *= 1 + 0.12 * Math.sin(particle.phase * 2.2);
+  }
+
+  if (particle.style === 'sparkle' && burstElapsed < BURST_FADE_START_MS) {
+    scale *= 0.85 + 0.3 * Math.sin(particle.phase * 3);
+  }
+
+  if (burstElapsed >= BURST_FADE_START_MS) {
+    const fadeT = (burstElapsed - BURST_FADE_START_MS) / (BURST_FADE_END_MS - BURST_FADE_START_MS);
+    opacity *= 1 - easeOutCubic(Math.min(1, fadeT));
+    scale *= 1 - easeOutCubic(Math.min(1, fadeT)) * 0.2;
+  }
+
+  if (opacity <= 0.02) return null;
+
+  return {
+    x: particle.x,
+    y: particle.y,
+    scale,
+    opacity,
+    rotation: particle.rotation,
+  };
+}
+
+export function drawBurstParticles(
+  context: CanvasRenderingContext2D,
+  particles: BurstParticle[],
+  dpr: number,
+  now: number
+) {
+  for (const particle of particles) {
+    const state = particleDrawState(particle, now);
+    if (!state) continue;
+
+    context.globalAlpha = state.opacity;
+
+    const emojiCanvas = getEmojiCanvas(particle.emoji);
+    const drawSize = particle.fontSize * state.scale * EMOJI_CACHE_SCALE;
+    const halfSize = drawSize / 2;
+    const radians = (state.rotation * Math.PI) / 180;
+    const cos = Math.cos(radians) * dpr;
+    const sin = Math.sin(radians) * dpr;
+
+    context.setTransform(cos, sin, -sin, cos, state.x * dpr, state.y * dpr);
+    context.drawImage(emojiCanvas, -halfSize, -halfSize, drawSize, drawSize);
+  }
+
+  context.globalAlpha = 1;
+  context.setTransform(dpr, 0, 0, dpr, 0, 0);
+}
+
+export function hasBurstParticles(particles: BurstParticle[], burstId: string): boolean {
+  return particles.some((particle) => particle.burstId === burstId);
+}

src/app/features/room/emoji-confetti/emojiParticleProfiles.ts

@@ -0,0 +1,391 @@
+export type BurstMotionStyle =
+  | 'explode'
+  | 'bounce'
+  | 'rise'
+  | 'sparkle'
+  | 'splash'
+  | 'spiral'
+  | 'punch'
+  | 'scatter'
+  | 'shower';
+
+export type EmojiBurstProfile = {
+  style: BurstMotionStyle;
+  particleCount: number;
+  gravity: number;
+  drag: number;
+  speedMin: number;
+  speedMax: number;
+  launchUpMin: number;
+  launchUpMax: number;
+  spinMin: number;
+  spinMax: number;
+  fontSizeMin: number;
+  fontSizeMax: number;
+  heroFontSizeMin: number;
+  heroFontSizeMax: number;
+  companions?: string[];
+  companionChance?: number;
+  /** Bias burst angle in radians. 0 = right, -π/2 = up. */
+  angleBias?: number;
+  /** Limit spawn to a cone (radians). Omit for full 360°. */
+  angleSpread?: number;
+  twinkle?: boolean;
+  wobble?: boolean;
+};
+
+const DEFAULT_PROFILE: EmojiBurstProfile = {
+  style: 'explode',
+  particleCount: 36,
+  gravity: 400,
+  drag: 0.935,
+  speedMin: 240,
+  speedMax: 560,
+  launchUpMin: 40,
+  launchUpMax: 130,
+  spinMin: -180,
+  spinMax: 180,
+  fontSizeMin: 14,
+  fontSizeMax: 26,
+  heroFontSizeMin: 26,
+  heroFontSizeMax: 34,
+};
+
+const PROFILE_OVERRIDES: Record<string, Partial<EmojiBurstProfile>> = {
+  '😆': {
+    style: 'bounce',
+    particleCount: 28,
+    gravity: 520,
+    speedMin: 180,
+    speedMax: 360,
+    launchUpMin: 120,
+    launchUpMax: 220,
+    spinMin: -240,
+    spinMax: 240,
+    wobble: true,
+  },
+  '😂': {
+    style: 'bounce',
+    particleCount: 30,
+    gravity: 500,
+    speedMin: 160,
+    speedMax: 340,
+    launchUpMin: 110,
+    launchUpMax: 210,
+    spinMin: -220,
+    spinMax: 220,
+    wobble: true,
+  },
+  '🤣': {
+    style: 'bounce',
+    particleCount: 32,
+    gravity: 480,
+    speedMin: 200,
+    speedMax: 380,
+    launchUpMin: 130,
+    launchUpMax: 240,
+    wobble: true,
+  },
+  '🔥': {
+    style: 'rise',
+    particleCount: 24,
+    gravity: -120,
+    drag: 0.96,
+    speedMin: 80,
+    speedMax: 200,
+    launchUpMin: 60,
+    launchUpMax: 160,
+    spinMin: -90,
+    spinMax: 90,
+    fontSizeMin: 16,
+    fontSizeMax: 28,
+    twinkle: true,
+    wobble: true,
+    companions: ['✨'],
+    companionChance: 0.35,
+  },
+  '❤️': {
+    style: 'rise',
+    particleCount: 22,
+    gravity: -80,
+    drag: 0.97,
+    speedMin: 60,
+    speedMax: 150,
+    launchUpMin: 40,
+    launchUpMax: 110,
+    spinMin: -40,
+    spinMax: 40,
+    fontSizeMin: 14,
+    fontSizeMax: 24,
+    companions: ['💕', '💖'],
+    companionChance: 0.4,
+  },
+  '💕': {
+    style: 'rise',
+    particleCount: 20,
+    gravity: -70,
+    drag: 0.97,
+    speedMin: 50,
+    speedMax: 140,
+    launchUpMin: 35,
+    launchUpMax: 100,
+    spinMin: -35,
+    spinMax: 35,
+  },
+  '💖': {
+    style: 'rise',
+    particleCount: 20,
+    gravity: -90,
+    drag: 0.968,
+    speedMin: 55,
+    speedMax: 150,
+    launchUpMin: 45,
+    launchUpMax: 115,
+    twinkle: true,
+  },
+  '⭐': {
+    style: 'sparkle',
+    particleCount: 26,
+    gravity: 40,
+    drag: 0.94,
+    speedMin: 100,
+    speedMax: 260,
+    launchUpMin: 20,
+    launchUpMax: 80,
+    spinMin: -120,
+    spinMax: 120,
+    twinkle: true,
+    companions: ['✨'],
+    companionChance: 0.5,
+  },
+  '✨': {
+    style: 'sparkle',
+    particleCount: 30,
+    gravity: 30,
+    drag: 0.945,
+    speedMin: 90,
+    speedMax: 240,
+    launchUpMin: 15,
+    launchUpMax: 70,
+    spinMin: -200,
+    spinMax: 200,
+    twinkle: true,
+  },
+  '💀': {
+    style: 'scatter',
+    particleCount: 20,
+    gravity: 620,
+    drag: 0.92,
+    speedMin: 200,
+    speedMax: 420,
+    launchUpMin: 20,
+    launchUpMax: 90,
+    spinMin: -360,
+    spinMax: 360,
+    fontSizeMin: 16,
+    fontSizeMax: 28,
+  },
+  '🎉': {
+    style: 'shower',
+    particleCount: 40,
+    gravity: 280,
+    drag: 0.93,
+    speedMin: 200,
+    speedMax: 480,
+    launchUpMin: 80,
+    launchUpMax: 200,
+    companions: ['🎊', '✨', '🎈'],
+    companionChance: 0.45,
+  },
+  '🎊': {
+    style: 'shower',
+    particleCount: 38,
+    gravity: 260,
+    drag: 0.932,
+    speedMin: 190,
+    speedMax: 460,
+    launchUpMin: 70,
+    launchUpMax: 190,
+    companions: ['🎉', '✨'],
+    companionChance: 0.4,
+  },
+  '👏': {
+    style: 'punch',
+    particleCount: 18,
+    gravity: 320,
+    speedMin: 220,
+    speedMax: 400,
+    launchUpMin: 30,
+    launchUpMax: 100,
+    angleBias: -Math.PI / 2,
+    angleSpread: Math.PI * 0.85,
+    spinMin: -100,
+    spinMax: 100,
+  },
+  '👍': {
+    style: 'punch',
+    particleCount: 14,
+    gravity: 380,
+    speedMin: 260,
+    speedMax: 440,
+    launchUpMin: 100,
+    launchUpMax: 200,
+    angleBias: -Math.PI / 2,
+    angleSpread: Math.PI * 0.55,
+    spinMin: -60,
+    spinMax: 60,
+  },
+  '💯': {
+    style: 'punch',
+    particleCount: 16,
+    gravity: 300,
+    speedMin: 200,
+    speedMax: 380,
+    launchUpMin: 140,
+    launchUpMax: 240,
+    angleBias: -Math.PI / 2,
+    angleSpread: Math.PI * 0.45,
+    fontSizeMin: 16,
+    fontSizeMax: 30,
+    wobble: true,
+  },
+  '💦': {
+    style: 'splash',
+    particleCount: 32,
+    gravity: 540,
+    drag: 0.925,
+    speedMin: 280,
+    speedMax: 520,
+    launchUpMin: 160,
+    launchUpMax: 300,
+    spinMin: -140,
+    spinMax: 140,
+    angleBias: -Math.PI / 2,
+    angleSpread: Math.PI * 1.1,
+  },
+  '🌊': {
+    style: 'splash',
+    particleCount: 28,
+    gravity: 420,
+    drag: 0.93,
+    speedMin: 220,
+    speedMax: 460,
+    launchUpMin: 100,
+    launchUpMax: 220,
+    angleBias: -Math.PI / 2,
+    angleSpread: Math.PI,
+    companions: ['💧'],
+    companionChance: 0.3,
+  },
+  '⚡': {
+    style: 'scatter',
+    particleCount: 14,
+    gravity: 180,
+    drag: 0.88,
+    speedMin: 380,
+    speedMax: 680,
+    launchUpMin: 10,
+    launchUpMax: 60,
+    spinMin: -30,
+    spinMax: 30,
+    fontSizeMin: 18,
+    fontSizeMax: 32,
+    angleSpread: Math.PI * 1.2,
+  },
+  '🌀': {
+    style: 'spiral',
+    particleCount: 24,
+    gravity: 60,
+    drag: 0.96,
+    speedMin: 120,
+    speedMax: 260,
+    launchUpMin: 0,
+    launchUpMax: 40,
+    spinMin: -420,
+    spinMax: 420,
+  },
+  '🤯': {
+    style: 'explode',
+    particleCount: 34,
+    gravity: 360,
+    speedMin: 280,
+    speedMax: 580,
+    launchUpMin: 60,
+    launchUpMax: 160,
+    companions: ['💥', '✨', '⭐'],
+    companionChance: 0.5,
+  },
+  '😭': {
+    style: 'splash',
+    particleCount: 26,
+    gravity: 480,
+    drag: 0.94,
+    speedMin: 140,
+    speedMax: 300,
+    launchUpMin: 40,
+    launchUpMax: 120,
+    angleBias: Math.PI / 2,
+    angleSpread: Math.PI * 0.7,
+    companions: ['💧'],
+    companionChance: 0.55,
+  },
+  '🥳': {
+    style: 'shower',
+    particleCount: 36,
+    gravity: 250,
+    speedMin: 180,
+    speedMax: 440,
+    launchUpMin: 90,
+    launchUpMax: 210,
+    companions: ['🎉', '🎊', '🎈'],
+    companionChance: 0.4,
+  },
+  '🐱': {
+    style: 'bounce',
+    particleCount: 20,
+    gravity: 440,
+    speedMin: 150,
+    speedMax: 320,
+    launchUpMin: 90,
+    launchUpMax: 180,
+    spinMin: -160,
+    spinMax: 160,
+  },
+  '🐶': {
+    style: 'bounce',
+    particleCount: 20,
+    gravity: 460,
+    speedMin: 160,
+    speedMax: 330,
+    launchUpMin: 85,
+    launchUpMax: 175,
+    wobble: true,
+  },
+};
+
+export function getEmojiBurstProfile(emoji: string): EmojiBurstProfile {
+  const override = PROFILE_OVERRIDES[emoji];
+  if (!override) return DEFAULT_PROFILE;
+  return { ...DEFAULT_PROFILE, ...override };
+}
+
+export function pickParticleEmoji(profile: EmojiBurstProfile, primaryEmoji: string): string {
+  if (!profile.companions?.length || !profile.companionChance) {
+    return primaryEmoji;
+  }
+  if (Math.random() >= profile.companionChance) {
+    return primaryEmoji;
+  }
+  const companion = profile.companions[Math.floor(Math.random() * profile.companions.length)];
+  return companion ?? primaryEmoji;
+}
+
+export function sampleBurstAngle(profile: EmojiBurstProfile): number {
+  if (profile.angleSpread === undefined) {
+    return Math.random() * Math.PI * 2;
+  }
+
+  const bias = profile.angleBias ?? -Math.PI / 2;
+  const halfSpread = profile.angleSpread / 2;
+  return bias + (Math.random() - 0.5) * profile.angleSpread * (0.6 + Math.random() * 0.4);
+}

src/app/features/room/emoji-confetti/findJumboMount.ts

@@ -0,0 +1,11 @@
+export function findJumboEmojiElement(targetEventId: string): HTMLElement | null {
+  const message = document.querySelector(`[data-message-id="${CSS.escape(targetEventId)}"]`);
+  if (!message) return null;
+
+  const jumbo = message.querySelector('[data-jumbo-emoji]');
+  return jumbo instanceof HTMLElement ? jumbo : null;
+}
+
+export function getLocalBurstCanvasSize(maskRadius: number): number {
+  return Math.max(300, Math.round(maskRadius * 6.5));
+}

src/app/features/room/emoji-confetti/jumboEmojiInteraction.ts

@@ -0,0 +1,34 @@
+import { KeyboardEvent, MouseEvent } from 'react';
+
+export type JumboEmojiClickHandler = (body: string, event: MouseEvent<HTMLElement> | KeyboardEvent<HTMLElement>) => void;
+
+export function getJumboEmojiInteractionProps({
+  body,
+  isJumboEmoji,
+  onJumboEmojiClick,
+}: {
+  body: string;
+  isJumboEmoji: boolean;
+  onJumboEmojiClick?: JumboEmojiClickHandler;
+}) {
+  if (!isJumboEmoji || !onJumboEmojiClick) {
+    return {};
+  }
+
+  const activate = (event: MouseEvent<HTMLElement> | KeyboardEvent<HTMLElement>) => {
+    if ('key' in event) {
+      if (event.key !== 'Enter' && event.key !== ' ') return;
+      event.preventDefault();
+    }
+    event.stopPropagation();
+    onJumboEmojiClick(body, event);
+  };
+
+  return {
+    role: 'button' as const,
+    tabIndex: 0,
+    title: 'Throw emoji confetti',
+    onClick: activate,
+    onKeyDown: activate,
+  };
+}

src/app/features/room/emoji-confetti/resolveClickedEmoji.ts

@@ -0,0 +1,54 @@
+import { KeyboardEvent, MouseEvent } from 'react';
+import { extractJumboEmojis } from './sendEmojiConfetti';
+import { BurstPoint, getBurstPointFromElement } from './burstOrigin';
+
+export function resolveClickedEmoji(
+  event: MouseEvent<HTMLElement> | KeyboardEvent<HTMLElement>,
+  fallbackBody: string
+): { emoji: string; origin: BurstPoint } | null {
+  const currentTarget = event.currentTarget as HTMLElement;
+  const target = event.target as HTMLElement;
+  const emoticonEl = target.closest('[data-emoticon]') ?? currentTarget.querySelector('[data-emoticon]');
+  if (emoticonEl instanceof HTMLElement) {
+    const emoji = emoticonEl.getAttribute('data-emoticon');
+    if (emoji) {
+      return {
+        emoji,
+        origin: getBurstPointFromElement(emoticonEl),
+      };
+    }
+  }
+
+  if (!currentTarget.closest('[data-jumbo-emoji]') && !currentTarget.hasAttribute('data-jumbo-emoji')) {
+    return null;
+  }
+
+  const emojis = extractJumboEmojis(fallbackBody);
+  if (emojis.length === 0) return null;
+
+  if ('clientX' in event) {
+    return {
+      emoji: emojis[0],
+      origin: {
+        x: event.clientX,
+        y: event.clientY,
+      },
+    };
+  }
+
+  const firstEmoticon = currentTarget.querySelector('[data-emoticon]');
+  if (firstEmoticon instanceof HTMLElement) {
+    const emoji = firstEmoticon.getAttribute('data-emoticon');
+    if (emoji) {
+      return {
+        emoji,
+        origin: getBurstPointFromElement(firstEmoticon),
+      };
+    }
+  }
+
+  return {
+    emoji: emojis[0],
+    origin: getBurstPointFromElement(currentTarget),
+  };
+}

src/app/features/room/emoji-confetti/sendEmojiConfetti.ts

@@ -0,0 +1,42 @@
+import { MatrixClient } from 'matrix-js-sdk';
+import { EMOJI_REG_G, JUMBO_EMOJI_REG } from '../../../utils/regex';
+import { trimReplyFromBody } from '../../../utils/room';
+import { emojis } from '../../../plugins/emoji';
+import { EMOJI_CONFETTI_EVENT_TYPE, EmojiConfettiContent } from './types';
+
+const SHORTCODE_PATTERN = /:([^\s:]+):/g;
+
+export function extractJumboEmojis(body: string): string[] {
+  const trimmedBody = trimReplyFromBody(body).trim();
+  if (!JUMBO_EMOJI_REG.test(trimmedBody)) return [];
+
+  const found: string[] = [];
+
+  for (const match of trimmedBody.matchAll(EMOJI_REG_G)) {
+    const emoji = match[1];
+    if (emoji) found.push(emoji);
+  }
+
+  for (const match of trimmedBody.matchAll(SHORTCODE_PATTERN)) {
+    const shortcode = match[1];
+    const resolved = emojis.find((emoji) => emoji.shortcode === shortcode);
+    if (resolved) found.push(resolved.unicode);
+  }
+
+  return found.length > 0 ? found : ['🎉'];
+}
+
+export function sendEmojiConfettiEvent(
+  mx: MatrixClient,
+  roomId: string,
+  targetEventId: string,
+  emojis: string[]
+) {
+  const content: EmojiConfettiContent = {
+    emojis,
+    msgtype: EMOJI_CONFETTI_EVENT_TYPE,
+    target_event_id: targetEventId,
+  };
+
+  return mx.sendEvent(roomId, EMOJI_CONFETTI_EVENT_TYPE as never, content);
+}

src/app/features/room/emoji-confetti/types.ts

@@ -0,0 +1,16 @@
+import type { BurstPoint } from './burstOrigin';
+
+export const EMOJI_CONFETTI_EVENT_TYPE = 'app.relay.emoji_confetti';
+
+export type EmojiConfettiContent = {
+  emojis?: string[];
+  msgtype?: string;
+  target_event_id?: string;
+};
+
+export type EmojiConfettiBurst = {
+  id: string;
+  targetEventId: string;
+  emojis: string[];
+  origin: BurstPoint;
+};

src/app/features/room/emoji-confetti/useEmojiConfetti.ts

@@ -0,0 +1,137 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { MatrixEvent, Room, RoomEvent } from 'matrix-js-sdk';
+import { BurstPoint, resolveBurstOrigin } from './burstOrigin';
+import {
+  EMOJI_CONFETTI_EVENT_TYPE,
+  EmojiConfettiBurst,
+  EmojiConfettiContent,
+} from './types';
+
+function scheduleBurstFromValues(
+  burstId: string,
+  emojis: string[],
+  targetEventId: string | undefined,
+  onBurst: (burst: EmojiConfettiBurst) => void,
+  attempt = 0,
+  explicitOrigin?: BurstPoint
+) {
+  const targetElement =
+    targetEventId &&
+    document.querySelector(`[data-message-id="${CSS.escape(targetEventId)}"]`);
+
+  if (targetEventId && !targetElement && attempt < 8) {
+    window.setTimeout(
+      () =>
+        scheduleBurstFromValues(
+          burstId,
+          emojis,
+          targetEventId,
+          onBurst,
+          attempt + 1,
+          explicitOrigin
+        ),
+      50
+    );
+    return;
+  }
+
+  onBurst({
+    id: burstId,
+    targetEventId: targetEventId ?? '',
+    emojis: emojis.length > 0 ? emojis : ['🎉'],
+    origin: resolveBurstOrigin(targetEventId, emojis, explicitOrigin),
+  });
+}
+
+function scheduleBurst(
+  event: MatrixEvent,
+  onBurst: (burst: EmojiConfettiBurst) => void,
+  attempt = 0
+) {
+  const eventId = event.getId();
+  if (!eventId) return;
+
+  const { emojis, targetEventId } = parseEmojiConfettiContent(event.getContent());
+  scheduleBurstFromValues(eventId, emojis, targetEventId, onBurst, attempt);
+}
+
+function parseEmojiConfettiContent(content: unknown): { emojis: string[]; targetEventId?: string } {
+  const confettiContent = content as EmojiConfettiContent;
+  const emojis = Array.isArray(confettiContent.emojis)
+    ? confettiContent.emojis.filter((emoji): emoji is string => typeof emoji === 'string' && emoji.length > 0)
+    : [];
+
+  return {
+    emojis: emojis.length > 0 ? emojis : ['🎉'],
+    targetEventId:
+      typeof confettiContent.target_event_id === 'string'
+        ? confettiContent.target_event_id
+        : undefined,
+  };
+}
+
+export function useEmojiConfetti(room: Room) {
+  const [bursts, setBursts] = useState<EmojiConfettiBurst[]>([]);
+  const seenEventIdsRef = useRef(new Set<string>());
+  const ownEventIdsRef = useRef(new Set<string>());
+
+  const addBurst = useCallback((burst: EmojiConfettiBurst) => {
+    setBursts((current) => [...current, burst]);
+  }, []);
+
+  const registerOwnEventId = useCallback((eventId: string) => {
+    ownEventIdsRef.current.add(eventId);
+  }, []);
+
+  const queueBurst = useCallback((event: MatrixEvent) => {
+    const eventId = event.getId();
+    if (!eventId || seenEventIdsRef.current.has(eventId)) return;
+
+    seenEventIdsRef.current.add(eventId);
+
+    if (ownEventIdsRef.current.has(eventId)) {
+      ownEventIdsRef.current.delete(eventId);
+      return;
+    }
+
+    scheduleBurst(event, addBurst);
+  }, [addBurst]);
+
+  const triggerLocalBurst = useCallback(
+    (targetEventId: string, emojis: string[], origin?: BurstPoint) => {
+      const burstId = `local-${targetEventId}-${Date.now()}`;
+      scheduleBurstFromValues(burstId, emojis, targetEventId, addBurst, 0, origin);
+    },
+    [addBurst]
+  );
+
+  useEffect(() => {
+    const handleTimeline: (
+      event: MatrixEvent,
+      eventRoom: Room | undefined,
+      toStartOfTimeline?: boolean,
+      removed?: boolean
+    ) => void = (event, eventRoom, toStartOfTimeline, removed) => {
+      if (removed || toStartOfTimeline || eventRoom?.roomId !== room.roomId) return;
+      if (event.getType() !== EMOJI_CONFETTI_EVENT_TYPE) return;
+
+      queueBurst(event);
+    };
+
+    room.on(RoomEvent.Timeline, handleTimeline);
+    return () => {
+      room.off(RoomEvent.Timeline, handleTimeline);
+    };
+  }, [queueBurst, room]);
+
+  const removeBurst = useCallback((burstId: string) => {
+    setBursts((current) => current.filter((burst) => burst.id !== burstId));
+  }, []);
+
+  return {
+    bursts,
+    removeBurst,
+    triggerLocalBurst,
+    registerOwnEventId,
+  };
+}

src/app/features/room/emoji-confetti/useJumboEmojiConfetti.ts

@@ -0,0 +1,37 @@
+import { KeyboardEvent, MouseEvent, useCallback } from 'react';
+import { Room } from 'matrix-js-sdk';
+import { useMatrixClient } from '../../../hooks/useMatrixClient';
+import { resolveClickedEmoji } from './resolveClickedEmoji';
+import { sendEmojiConfettiEvent } from './sendEmojiConfetti';
+import { useEmojiConfetti } from './useEmojiConfetti';
+
+export function useJumboEmojiConfetti(room: Room) {
+  const mx = useMatrixClient();
+  const { bursts, removeBurst, triggerLocalBurst, registerOwnEventId } = useEmojiConfetti(room);
+
+  const handleJumboEmojiClick = useCallback(
+    (targetEventId: string, body: string, event: MouseEvent<HTMLElement> | KeyboardEvent<HTMLElement>) => {
+      const clicked = resolveClickedEmoji(event, body);
+      if (!clicked) return;
+
+      const emojis = [clicked.emoji];
+
+      triggerLocalBurst(targetEventId, emojis, clicked.origin);
+      sendEmojiConfettiEvent(mx, room.roomId, targetEventId, emojis)
+        .then((response) => {
+          const eventId = response?.event_id;
+          if (eventId) registerOwnEventId(eventId);
+        })
+        .catch((error) => {
+          console.error('[emoji-confetti] Failed to send confetti event:', error);
+        });
+    },
+    [mx, registerOwnEventId, room.roomId, triggerLocalBurst]
+  );
+
+  return {
+    bursts,
+    removeBurst,
+    handleJumboEmojiClick,
+  };
+}

src/app/features/settings/general/General.tsx

@@ -8,6 +8,7 @@ import React, {
 } from 'react';
 import dayjs from 'dayjs';
 import { as, Box, Button, Chip, color, config, Header, IconButton, Input, Menu, MenuItem, PopOut, RectCords, Scroll, Switch, Text, toRem } from 'folds';
+import { useSetAtom } from 'jotai';
 import { Icon, Icons } from '../../../components/icons';
 import { HexColorPicker } from 'react-colorful';
 import { isKeyHotkey } from 'is-hotkey';
@@ -24,6 +25,7 @@ import {
   LightTheme,
   Theme,
   ThemeKind,
+  themePreviewIdAtom,
   useSystemThemeKind,
   useThemeNames,
   useThemes,
@@ -41,28 +43,49 @@ type ThemeSelectorProps = {
   onSelect: (theme: Theme) => void;
 };
 const ThemeSelector = as<'div', ThemeSelectorProps>(
-  ({ themeNames, themes, selected, onSelect, ...props }, ref) => (
+  ({ themeNames, themes, selected, onSelect, ...props }, ref) => {
-    <Menu {...props} ref={ref}>
+    const setPreviewId = useSetAtom(themePreviewIdAtom);
-      <Box direction="Column" gap="100" style={{ padding: config.space.S100 }}>
+
-        {themes.map((theme) => (
+    useEffect(
-          <MenuItem
+      () => () => {
-            key={theme.id}
+        setPreviewId(undefined);
-            size="300"
+      },
-            variant={theme.id === selected.id ? 'Primary' : 'Surface'}
+      [setPreviewId]
-            radii="300"
+    );
-            onClick={() => onSelect(theme)}
+
-          >
+    const clearPreview = () => setPreviewId(undefined);
-            <Text size="T300">{themeNames[theme.id] ?? theme.id}</Text>
+    const previewTheme = (theme: Theme) => setPreviewId(theme.id);
-          </MenuItem>
+
-        ))}
+    return (
-      </Box>
+      <Menu
-    </Menu>
+        {...props}
-  )
+        ref={ref}
+        onMouseLeave={clearPreview}
+      >
+        <Box direction="Column" gap="100" style={{ padding: config.space.S100 }}>
+          {themes.map((theme) => (
+            <MenuItem
+              key={theme.id}
+              size="300"
+              variant={theme.id === selected.id ? 'Primary' : 'Surface'}
+              radii="300"
+              onMouseEnter={() => previewTheme(theme)}
+              onFocus={() => previewTheme(theme)}
+              onClick={() => onSelect(theme)}
+            >
+              <Text size="T300">{themeNames[theme.id] ?? theme.id}</Text>
+            </MenuItem>
+          ))}
+        </Box>
+      </Menu>
+    );
+  }
 );
 
 function SelectTheme({ disabled }: { disabled?: boolean }) {
   const themes = useThemes();
   const themeNames = useThemeNames();
+  const setPreviewId = useSetAtom(themePreviewIdAtom);
   const [themeId, setThemeId] = useSetting(settingsAtom, 'themeId');
   const [menuCords, setMenuCords] = useState<RectCords>();
   const selectedTheme = themes.find((theme) => theme.id === themeId) ?? LightTheme;
@@ -72,10 +95,16 @@ function SelectTheme({ disabled }: { disabled?: boolean }) {
   };
 
   const handleThemeSelect = (theme: Theme) => {
+    setPreviewId(undefined);
     setThemeId(theme.id);
     setMenuCords(undefined);
   };
 
+  const closeMenu = () => {
+    setPreviewId(undefined);
+    setMenuCords(undefined);
+  };
+
   return (
     <>
       <Button
@@ -99,7 +128,7 @@ function SelectTheme({ disabled }: { disabled?: boolean }) {
           <FocusTrap
             focusTrapOptions={{
               initialFocus: false,
-              onDeactivate: () => setMenuCords(undefined),
+              onDeactivate: closeMenu,
               clickOutsideDeactivates: true,
               isKeyForward: (evt: KeyboardEvent) =>
                 evt.key === 'ArrowDown' || evt.key === 'ArrowRight',
@@ -125,6 +154,7 @@ function SystemThemePreferences() {
   const themeKind = useSystemThemeKind();
   const themeNames = useThemeNames();
   const themes = useThemes();
+  const setPreviewId = useSetAtom(themePreviewIdAtom);
   const [lightThemeId, setLightThemeId] = useSetting(settingsAtom, 'lightThemeId');
   const [darkThemeId, setDarkThemeId] = useSetting(settingsAtom, 'darkThemeId');
 
@@ -145,15 +175,27 @@ function SystemThemePreferences() {
   };
 
   const handleLightThemeSelect = (theme: Theme) => {
+    setPreviewId(undefined);
     setLightThemeId(theme.id);
     setLTCords(undefined);
   };
 
   const handleDarkThemeSelect = (theme: Theme) => {
+    setPreviewId(undefined);
     setDarkThemeId(theme.id);
     setDTCords(undefined);
   };
 
+  const closeLightMenu = () => {
+    setPreviewId(undefined);
+    setLTCords(undefined);
+  };
+
+  const closeDarkMenu = () => {
+    setPreviewId(undefined);
+    setDTCords(undefined);
+  };
+
   return (
     <Box wrap="Wrap" gap="400">
       <SettingTile
@@ -179,7 +221,7 @@ function SystemThemePreferences() {
           <FocusTrap
             focusTrapOptions={{
               initialFocus: false,
-              onDeactivate: () => setLTCords(undefined),
+              onDeactivate: closeLightMenu,
               clickOutsideDeactivates: true,
               isKeyForward: (evt: KeyboardEvent) =>
                 evt.key === 'ArrowDown' || evt.key === 'ArrowRight',
@@ -220,7 +262,7 @@ function SystemThemePreferences() {
           <FocusTrap
             focusTrapOptions={{
               initialFocus: false,
-              onDeactivate: () => setDTCords(undefined),
+              onDeactivate: closeDarkMenu,
               clickOutsideDeactivates: true,
               isKeyForward: (evt: KeyboardEvent) =>
                 evt.key === 'ArrowDown' || evt.key === 'ArrowRight',

src/app/features/settings/notifications/SystemNotification.tsx

@@ -172,6 +172,7 @@ type PushStatus = {
   endpoint: string;
   distributors: string[];
   lastFailure: string;
+  autoStartBlocked: boolean;
 };
 
 /** Android-only section showing UnifiedPush registration status and controls. */
@@ -196,6 +197,7 @@ function AndroidPushNotifications() {
             endpoint: s.endpoint || '',
             distributors,
             lastFailure: s.lastFailure || '',
+            autoStartBlocked: Boolean(s.autoStartBlocked),
           }
         : undefined
     );
@@ -246,6 +248,13 @@ function AndroidPushNotifications() {
         </Text>
       );
     }
+    if (status.lastFailure === 'AUTO_START_BLOCKED' || status.autoStartBlocked) {
+      return (
+        <Text as="span" style={{ color: color.Critical.Main }} size="T200">
+          Phone is blocking auto-start for Paarrot. Open App Boot / Auto-start settings, allow Paarrot (and ntfy), then tap Reset.
+        </Text>
+      );
+    }
     if (status.lastFailure) {
       return (
         <Text as="span" style={{ color: color.Critical.Main }} size="T200">

src/app/hooks/useTheme.ts

@@ -1,4 +1,5 @@
 import { lightTheme } from 'folds';
+import { atom, useAtomValue } from 'jotai';
 import { createContext, useContext, useEffect, useMemo, useState } from 'react';
 import { onDarkFontWeight, onLightFontWeight } from '../../config.css';
 import { butterTheme, catppuccinMochaTheme, darkTheme, discordTheme, discordDarkerTheme, mochaTheme, silverTheme, stationeryDarkTheme, stationeryTheme, twilightTheme } from '../../colors.css';
@@ -6,6 +7,9 @@ import { settingsAtom } from '../state/settings';
 import { useSetting } from '../state/hooks/settings';
 import { pluginRegistry } from '../features/settings/plugins/PluginAPI';
 
+/** Ephemeral theme id while hovering theme options in settings (not persisted). */
+export const themePreviewIdAtom = atom<string | undefined>(undefined);
+
 export enum ThemeKind {
   Light = 'light',
   Dark = 'dark',
@@ -190,6 +194,16 @@ export const useActiveTheme = (): Theme => {
   return selectedTheme;
 };
 
+/** Active theme, or hover-preview theme when browsing the theme menu. */
+export const useDisplayTheme = (): Theme => {
+  const activeTheme = useActiveTheme();
+  const themes = useThemes();
+  const previewId = useAtomValue(themePreviewIdAtom);
+
+  if (!previewId) return activeTheme;
+  return themes.find((theme) => theme.id === previewId) ?? activeTheme;
+};
+
 const ThemeContext = createContext<Theme | null>(null);
 export const ThemeContextProvider = ThemeContext.Provider;
 

src/app/pages/ThemeManager.tsx

@@ -5,7 +5,7 @@ import {
   LightTheme,
   ThemeContextProvider,
   ThemeKind,
-  useActiveTheme,
+  useDisplayTheme,
   useSystemThemeKind,
 } from '../hooks/useTheme';
 import { useSetting } from '../state/hooks/settings';
@@ -29,21 +29,21 @@ export function UnAuthRouteThemeManager() {
 }
 
 export function AuthRouteThemeManager({ children }: { children: ReactNode }) {
-  const activeTheme = useActiveTheme();
+  const displayTheme = useDisplayTheme();
   const [monochromeMode] = useSetting(settingsAtom, 'monochromeMode');
 
   useEffect(() => {
     document.body.className = '';
     document.body.classList.add(configClass, varsClass);
 
-    document.body.classList.add(...activeTheme.classNames);
+    document.body.classList.add(...displayTheme.classNames);
 
     if (monochromeMode) {
       document.body.style.filter = 'grayscale(1)';
     } else {
       document.body.style.filter = '';
     }
-  }, [activeTheme, monochromeMode]);
+  }, [displayTheme, monochromeMode]);
 
-  return <ThemeContextProvider value={activeTheme}>{children}</ThemeContextProvider>;
+  return <ThemeContextProvider value={displayTheme}>{children}</ThemeContextProvider>;
 }

src/app/plugins/react-custom-html-parser.tsx

@@ -188,7 +188,7 @@ export const scaleSystemEmoji = (text: string): (string | JSX.Element)[] =>
     text,
     EMOJI_REG_G,
     (match, pushIndex) => (
-      <span key={`scaleSystemEmoji-${pushIndex}`} className={css.EmoticonBase}>
+      <span key={`scaleSystemEmoji-${pushIndex}`} className={css.EmoticonBase} data-emoticon={match[0]}>
         <span className={css.Emoticon()} title={getShortcodeFor(getHexcodeForEmoji(match[0]))}>
           {match[0]}
         </span>
@@ -551,8 +551,15 @@ export const getReactCustomHtmlParser = (
             );
           }
           if (htmlSrc && 'data-mx-emoticon' in props) {
+            const emoticonLabel =
+              (typeof props.alt === 'string' && props.alt) ||
+              (typeof props.title === 'string' && props.title) ||
+              undefined;
             return (
-              <span className={css.EmoticonBase}>
+              <span
+                className={css.EmoticonBase}
+                {...(emoticonLabel ? { 'data-emoticon': emoticonLabel } : {})}
+              >
                 <span className={css.Emoticon()}>
                   <AuthenticatedImg {...props} className={css.EmoticonImg} src={htmlSrc} />
                 </span>

src/app/utils/backgroundSync.ts

@@ -16,6 +16,8 @@ type UnifiedPushStatus = {
   distributor: string;
   distributors: string[] | string;
   lastFailure?: string;
+  /** OEM App Boot / AUTO_START is blocking distributor broadcasts (e.g. TCL). */
+  autoStartBlocked?: boolean;
 };
 
 type UnifiedPushEndpointEvent = {

src/playground/App.tsx

@@ -0,0 +1,365 @@
+import { useDeferredValue, useEffect, useMemo, useState, useTransition } from 'react';
+import Editor, { loader } from '@monaco-editor/react';
+import * as monaco from 'monaco-editor';
+import './monacoSetup';
+import { getCatalog, harnessForModule, type CatalogEntry } from './catalog';
+import { DEFAULT_SOURCE } from './defaultSource';
+import { loadManualSession, type ManualSessionInput } from './liveClient';
+import { PlaygroundProviders } from './mocks/PlaygroundProviders';
+import { PreviewErrorBoundary } from './PreviewErrorBoundary';
+import { ResizableStage } from './ResizableStage';
+import { LivePreview } from './LivePreview';
+import { usePlaygroundMatrix } from './usePlaygroundMatrix';
+
+// Use the npm monaco build — the CDN AMD loader breaks UMD deps like sanitize-html.
+loader.config({ monaco });
+
+type EditorTab = 'component' | 'harness';
+
+async function pushLiveSource(source: string) {
+  await fetch('/__playground/live', {
+    method: 'POST',
+    headers: { 'Content-Type': 'text/plain; charset=utf-8' },
+    body: source,
+  });
+}
+
+async function fetchComponentSource(filePath: string): Promise<string> {
+  const res = await fetch(`/__playground/source?path=${encodeURIComponent(filePath)}`);
+  if (!res.ok) throw new Error(`Failed to load ${filePath}: ${res.status}`);
+  return res.text();
+}
+
+async function pushComponentSource(filePath: string, source: string) {
+  await fetch(`/__playground/source?path=${encodeURIComponent(filePath)}`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'text/plain; charset=utf-8' },
+    body: source,
+  });
+}
+
+export function App() {
+  const catalog = useMemo(() => getCatalog(), []);
+  const [filter, setFilter] = useState('');
+  const [harnessSource, setHarnessSource] = useState(DEFAULT_SOURCE);
+  const [componentSource, setComponentSource] = useState<string>('');
+  const [editorTab, setEditorTab] = useState<EditorTab>('harness');
+  const [selected, setSelected] = useState<CatalogEntry | null>(null);
+  const [loadError, setLoadError] = useState<string | null>(null);
+  const [showTokenForm, setShowTokenForm] = useState(false);
+  const [manual, setManual] = useState<ManualSessionInput>(() => {
+    const saved = loadManualSession();
+    return (
+      saved ?? {
+        baseUrl: 'https://matrix.org',
+        userId: '@you:matrix.org',
+        deviceId: 'PLAYGROUND',
+        accessToken: '',
+      }
+    );
+  });
+  const deferredHarness = useDeferredValue(harnessSource);
+  const deferredComponent = useDeferredValue(componentSource);
+  const [, startTransition] = useTransition();
+  const matrix = usePlaygroundMatrix();
+
+  useEffect(() => {
+    fetch('/__playground/live')
+      .then((r) => r.text())
+      .then((text) => {
+        if (text.trim()) setHarnessSource(text);
+      })
+      .catch(() => undefined);
+  }, []);
+
+  useEffect(() => {
+    const handle = window.setTimeout(() => {
+      void pushLiveSource(deferredHarness);
+    }, 250);
+    return () => window.clearTimeout(handle);
+  }, [deferredHarness]);
+
+  // Upgrade stale RoomInput harness (bare <RoomInput /> or mocks.room) to useRoom().
+  useEffect(() => {
+    if (!selected?.importPath.endsWith('/RoomInput')) return;
+    if (harnessSource.includes('useRoom()')) return;
+    setHarnessSource(harnessForModule(selected.importPath));
+  }, [selected, harnessSource]);
+
+  // Writes the real component file — strings/markup edits land in src/app/…
+  useEffect(() => {
+    if (!selected || editorTab !== 'component') return;
+    if (!deferredComponent) return;
+    const handle = window.setTimeout(() => {
+      void pushComponentSource(selected.filePath, deferredComponent).catch((err) => {
+        setLoadError(err instanceof Error ? err.message : String(err));
+      });
+    }, 400);
+    return () => window.clearTimeout(handle);
+  }, [deferredComponent, editorTab, selected]);
+
+  const filtered = useMemo(() => {
+    const q = filter.trim().toLowerCase();
+    if (!q) return catalog;
+    return catalog.filter((e) => e.label.toLowerCase().includes(q));
+  }, [catalog, filter]);
+
+  const openEntry = (entry: CatalogEntry) => {
+    setSelected(entry);
+    setLoadError(null);
+    setEditorTab('component');
+    startTransition(() => {
+      setHarnessSource(harnessForModule(entry.importPath));
+    });
+    void fetchComponentSource(entry.filePath)
+      .then((text) => setComponentSource(text))
+      .catch((err) => {
+        setComponentSource('');
+        setLoadError(err instanceof Error ? err.message : String(err));
+      });
+  };
+
+  const liveReady = matrix.mode === 'live' && matrix.status === 'ready' && matrix.client;
+  const previewClient = liveReady ? matrix.client! : undefined;
+  const previewRoom = liveReady ? matrix.room ?? undefined : undefined;
+
+  const editorValue = editorTab === 'component' ? componentSource : harnessSource;
+  const editorPath =
+    editorTab === 'component' && selected
+      ? selected.filePath
+      : 'playground-live.tsx';
+
+  return (
+    <div className="app">
+      <header className="topbar">
+        <div>
+          <strong>Component Playground</strong>
+          <span className="muted">
+            {' '}
+            — Component tab edits real source · Harness tab only mounts it
+          </span>
+        </div>
+        <div className="topbar-actions">
+          <button
+            type="button"
+            className="ghost"
+            onClick={() => {
+              setSelected(null);
+              setComponentSource('');
+              setEditorTab('harness');
+              setHarnessSource(DEFAULT_SOURCE);
+            }}
+          >
+            Reset message preview
+          </button>
+        </div>
+      </header>
+
+      <div className="conn-bar">
+        <div className="conn-modes">
+          <button
+            type="button"
+            className={matrix.mode === 'mock' ? 'conn-btn active' : 'conn-btn'}
+            onClick={() => matrix.useMocks()}
+          >
+            Mocks
+          </button>
+          <button
+            type="button"
+            className={matrix.mode === 'live' ? 'conn-btn active' : 'conn-btn'}
+            disabled={matrix.status === 'connecting'}
+            onClick={() => {
+              void matrix.connectLive();
+            }}
+            title={
+              matrix.hasPaarrotSession
+                ? `Use logged-in session ${matrix.paarrotUserId}`
+                : 'Needs Paarrot login on this origin, or a pasted token'
+            }
+          >
+            {matrix.status === 'connecting' ? 'Connecting…' : 'Paarrot session'}
+          </button>
+          <button
+            type="button"
+            className="conn-btn"
+            onClick={() => setShowTokenForm((v) => !v)}
+          >
+            Token…
+          </button>
+        </div>
+
+        <div className="conn-status">
+          {matrix.mode === 'mock' && <span className="muted">Using lightweight mocks</span>}
+          {matrix.mode === 'live' && matrix.status === 'connecting' && (
+            <span className="muted">Syncing (memory store, no crypto)…</span>
+          )}
+          {matrix.mode === 'live' && matrix.status === 'ready' && (
+            <span className="conn-ok">{matrix.sessionLabel}</span>
+          )}
+          {matrix.mode === 'live' && matrix.status === 'error' && (
+            <span className="conn-err">{matrix.error}</span>
+          )}
+          {!matrix.hasPaarrotSession && matrix.mode !== 'live' && (
+            <span className="muted">Tip: log into Paarrot at / first, then hit Paarrot session</span>
+          )}
+        </div>
+
+        {liveReady && matrix.rooms.length > 0 && (
+          <label className="conn-room">
+            Room
+            <select
+              value={matrix.room?.roomId ?? ''}
+              onChange={(e) => matrix.selectRoom(e.target.value)}
+            >
+              {matrix.rooms.map((r) => (
+                <option key={r.roomId} value={r.roomId}>
+                  {r.name || r.roomId}
+                </option>
+              ))}
+            </select>
+          </label>
+        )}
+      </div>
+
+      {showTokenForm && (
+        <form
+          className="token-form"
+          onSubmit={(e) => {
+            e.preventDefault();
+            setShowTokenForm(false);
+            void matrix.connectLive(manual);
+          }}
+        >
+          <input
+            placeholder="Homeserver URL"
+            value={manual.baseUrl}
+            onChange={(e) => setManual((m) => ({ ...m, baseUrl: e.target.value }))}
+          />
+          <input
+            placeholder="@user:server"
+            value={manual.userId}
+            onChange={(e) => setManual((m) => ({ ...m, userId: e.target.value }))}
+          />
+          <input
+            placeholder="Device ID"
+            value={manual.deviceId}
+            onChange={(e) => setManual((m) => ({ ...m, deviceId: e.target.value }))}
+          />
+          <input
+            placeholder="Access token"
+            value={manual.accessToken}
+            onChange={(e) => setManual((m) => ({ ...m, accessToken: e.target.value }))}
+          />
+          <button type="submit" className="ghost">
+            Connect
+          </button>
+        </form>
+      )}
+
+      <div className="panes">
+        <aside className="pane catalog-pane">
+          <div className="pane-label">Cinny modules ({filtered.length})</div>
+          <input
+            className="filter"
+            placeholder="Filter components…"
+            value={filter}
+            onChange={(e) => setFilter(e.target.value)}
+          />
+          <div className="catalog-list">
+            {filtered.map((entry) => (
+              <button
+                key={entry.id}
+                type="button"
+                className={selected?.id === entry.id ? 'catalog-item active' : 'catalog-item'}
+                onClick={() => openEntry(entry)}
+                title={entry.filePath}
+              >
+                {entry.label}
+              </button>
+            ))}
+          </div>
+        </aside>
+
+        <section className="pane editor-pane">
+          <div className="pane-label editor-tabs">
+            <button
+              type="button"
+              className={editorTab === 'component' ? 'tab active' : 'tab'}
+              disabled={!selected}
+              onClick={() => setEditorTab('component')}
+              title={selected ? `Edit ${selected.filePath}` : 'Pick a module first'}
+            >
+              Component
+            </button>
+            <button
+              type="button"
+              className={editorTab === 'harness' ? 'tab active' : 'tab'}
+              onClick={() => setEditorTab('harness')}
+            >
+              Harness
+            </button>
+            <span className="muted tab-hint">
+              {editorTab === 'component' && selected
+                ? `writes ${selected.filePath}`
+                : 'mount-only · not saved'}
+            </span>
+          </div>
+          {loadError && <pre className="error-block editor-error">{loadError}</pre>}
+          <Editor
+            height="100%"
+            defaultLanguage="typescript"
+            path={editorPath}
+            theme="vs-dark"
+            value={editorValue}
+            onChange={(value) => {
+              const next = value ?? '';
+              if (editorTab === 'component') setComponentSource(next);
+              else setHarnessSource(next);
+            }}
+            options={{
+              minimap: { enabled: false },
+              fontSize: 13,
+              fontFamily: 'ui-monospace, SFMono-Regular, Menlo, Consolas, monospace',
+              scrollBeyondLastLine: false,
+              wordWrap: 'on',
+              tabSize: 2,
+              automaticLayout: true,
+              padding: { top: 12 },
+              readOnly: editorTab === 'component' && !selected,
+            }}
+            beforeMount={(monaco) => {
+              monaco.languages.typescript.typescriptDefaults.setCompilerOptions({
+                jsx: monaco.languages.typescript.JsxEmit.ReactJSX,
+                target: monaco.languages.typescript.ScriptTarget.ES2020,
+                allowNonTsExtensions: true,
+                esModuleInterop: true,
+                moduleResolution: monaco.languages.typescript.ModuleResolutionKind.NodeJs,
+                paths: {
+                  '@cinny/*': ['*'],
+                  '@playground/mocks': ['*'],
+                },
+              });
+              monaco.languages.typescript.typescriptDefaults.setDiagnosticsOptions({
+                noSemanticValidation: true,
+                noSyntaxValidation: false,
+              });
+            }}
+          />
+        </section>
+
+        <section className="pane preview-pane">
+          <div className="pane-label">Preview</div>
+          <div className="preview-body">
+            <ResizableStage>
+              <PlaygroundProviders client={previewClient} room={previewRoom}>
+                <PreviewErrorBoundary resetKey={`${deferredHarness}:${selected?.filePath ?? ''}`}>
+                  <LivePreview />
+                </PreviewErrorBoundary>
+              </PlaygroundProviders>
+            </ResizableStage>
+          </div>
+        </section>
+      </div>
+    </div>
+  );
+}

src/playground/LivePreview.tsx

@@ -0,0 +1,59 @@
+import { useEffect, useState } from 'react';
+
+/**
+ * Dynamically remounts the Vite virtual live module when the harness changes.
+ */
+export function LivePreview() {
+  const [revision, setRevision] = useState(0);
+  const [Comp, setComp] = useState<React.ComponentType | null>(null);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    const onUpdate = () => setRevision((n) => n + 1);
+    const handler = () => onUpdate();
+
+    // Vite custom event from liveTsxPlugin
+    if (import.meta.hot) {
+      import.meta.hot.on('playground:live-updated', handler);
+    }
+
+    return () => {
+      if (import.meta.hot) {
+        import.meta.hot.off('playground:live-updated', handler);
+      }
+    };
+  }, []);
+
+  useEffect(() => {
+    let cancelled = false;
+    setError(null);
+    setComp(null);
+
+    import(/* @vite-ignore */ `/@playground/live.tsx?t=${revision}`)
+      .then((mod) => {
+        if (cancelled) return;
+        const candidate = mod.default;
+        if (typeof candidate !== 'function') {
+          setError('Live module must `export default` a React component.');
+          return;
+        }
+        setComp(() => candidate);
+      })
+      .catch((err: unknown) => {
+        if (cancelled) return;
+        const message =
+          err instanceof Error
+            ? `${err.message}\n\n${err.stack ?? ''}`
+            : String(err);
+        setError(message);
+      });
+
+    return () => {
+      cancelled = true;
+    };
+  }, [revision]);
+
+  if (error) return <pre className="error-block">{error}</pre>;
+  if (!Comp) return <div className="muted">Compiling harness…</div>;
+  return <Comp />;
+}

src/playground/PreviewErrorBoundary.tsx

@@ -0,0 +1,40 @@
+import React, { Component, type ErrorInfo, type ReactNode } from 'react';
+
+type Props = {
+  resetKey: string;
+  children: ReactNode;
+};
+
+type State = {
+  error: string | null;
+};
+
+export class PreviewErrorBoundary extends Component<Props, State> {
+  state: State = { error: null };
+
+  static getDerivedStateFromError(error: Error): State {
+    return {
+      error: `${error.message}\n\n${error.stack ?? ''}`,
+    };
+  }
+
+  componentDidCatch(error: Error, info: ErrorInfo) {
+    console.error('[playground preview]', error, info);
+    this.setState({
+      error: `${error.message}\n\n${error.stack ?? ''}\n\n${info.componentStack ?? ''}`,
+    });
+  }
+
+  componentDidUpdate(prevProps: Props) {
+    if (prevProps.resetKey !== this.props.resetKey && this.state.error) {
+      this.setState({ error: null });
+    }
+  }
+
+  render() {
+    if (this.state.error) {
+      return <pre className="error-block">{this.state.error}</pre>;
+    }
+    return this.props.children;
+  }
+}

src/playground/ResizableStage.tsx

@@ -0,0 +1,86 @@
+import { useCallback, useEffect, useRef, useState, type CSSProperties } from 'react';
+
+type Props = {
+  children: React.ReactNode;
+};
+
+const MIN = 160;
+const MAX = 1200;
+
+export function ResizableStage({ children }: Props) {
+  const [size, setSize] = useState({ width: 520, height: 480 });
+  const dragRef = useRef<{
+    edge: 'e' | 's' | 'se';
+    startX: number;
+    startY: number;
+    startW: number;
+    startH: number;
+  } | null>(null);
+
+  const onPointerMove = useCallback((e: PointerEvent) => {
+    const drag = dragRef.current;
+    if (!drag) return;
+    const dx = e.clientX - drag.startX;
+    const dy = e.clientY - drag.startY;
+    setSize((prev) => {
+      let width = prev.width;
+      let height = prev.height;
+      if (drag.edge === 'e' || drag.edge === 'se') {
+        width = clamp(drag.startW + dx, MIN, MAX);
+      }
+      if (drag.edge === 's' || drag.edge === 'se') {
+        height = clamp(drag.startH + dy, MIN, MAX);
+      }
+      return { width, height };
+    });
+  }, []);
+
+  const onPointerUp = useCallback(() => {
+    dragRef.current = null;
+    window.removeEventListener('pointermove', onPointerMove);
+    window.removeEventListener('pointerup', onPointerUp);
+  }, [onPointerMove]);
+
+  const startDrag = (edge: 'e' | 's' | 'se') => (e: React.PointerEvent) => {
+    e.preventDefault();
+    dragRef.current = {
+      edge,
+      startX: e.clientX,
+      startY: e.clientY,
+      startW: size.width,
+      startH: size.height,
+    };
+    window.addEventListener('pointermove', onPointerMove);
+    window.addEventListener('pointerup', onPointerUp);
+  };
+
+  useEffect(() => () => onPointerUp(), [onPointerUp]);
+
+  const stageStyle: CSSProperties = {
+    width: size.width,
+    height: size.height,
+  };
+
+  return (
+    <div className="stage-wrap">
+      <div className="stage-meta">
+        {size.width} × {size.height}
+      </div>
+      <div className="stage" style={stageStyle}>
+        <div className="stage-canvas">{children}</div>
+        <button type="button" className="handle handle-e" aria-label="Resize width" onPointerDown={startDrag('e')} />
+        <button type="button" className="handle handle-s" aria-label="Resize height" onPointerDown={startDrag('s')} />
+        <button
+          type="button"
+          className="handle handle-se"
+          aria-label="Resize both"
+          onPointerDown={startDrag('se')}
+        />
+      </div>
+    </div>
+  );
+}
+
+function clamp(n: number, min: number, max: number) {
+  return Math.min(max, Math.max(min, n));
+}

src/playground/catalog.ts

@@ -0,0 +1,128 @@
+/**
+ * Path list of Cinny UI modules the playground can open.
+ */
+const componentModules = import.meta.glob(
+  [
+    '../app/components/**/*.{tsx,ts}',
+    '../app/features/**/*.{tsx,ts}',
+  ],
+  { eager: false }
+);
+
+export type CatalogEntry = {
+  id: string;
+  label: string;
+  importPath: string;
+  /** Path under cinny/, e.g. src/app/components/.../Foo.tsx */
+  filePath: string;
+};
+
+function toFilePath(viteKey: string): string | null {
+  const normalized = viteKey.replace(/\\/g, '/');
+  let rel = normalized;
+  const appIdx = rel.indexOf('/app/');
+  if (appIdx !== -1) {
+    rel = `src${rel.slice(appIdx)}`;
+  } else if (rel.startsWith('../app/')) {
+    rel = `src/${rel.slice('../'.length)}`;
+  } else if (rel.startsWith('../')) {
+    rel = `src/app/${rel.slice('../'.length)}`;
+  } else {
+    return null;
+  }
+  if (!/\.(tsx|ts)$/.test(rel)) return null;
+  return rel;
+}
+
+function toImportPath(viteKey: string): string | null {
+  const normalized = viteKey.replace(/\\/g, '/');
+  let rel = normalized;
+  const appIdx = rel.indexOf('/app/');
+  if (appIdx !== -1) {
+    rel = rel.slice(appIdx + '/app/'.length);
+  } else if (rel.startsWith('../')) {
+    rel = rel.replace(/^\.\.\//, '');
+  }
+  rel = rel.replace(/\.(tsx|ts)$/, '');
+  if (rel.endsWith('.css') || rel.includes('.css')) return null;
+  return `@cinny/app/${rel}`;
+}
+
+function toLabel(importPath: string): string {
+  return importPath.replace(/^@cinny\//, '');
+}
+
+export function getCatalog(): CatalogEntry[] {
+  const entries: CatalogEntry[] = [];
+  for (const key of Object.keys(componentModules)) {
+    if (/\.css(\.ts)?$/.test(key)) continue;
+    if (/\.test\./.test(key) || /\.spec\./.test(key)) continue;
+    // Prefer UI modules — plain .ts files are usually helpers/hooks, not preview targets.
+    if (key.endsWith('.ts') && !key.endsWith('.tsx')) continue;
+    const importPath = toImportPath(key);
+    const filePath = toFilePath(key);
+    if (!importPath || !filePath) continue;
+    entries.push({
+      id: key,
+      label: toLabel(importPath),
+      importPath,
+      filePath,
+    });
+  }
+  return entries.sort((a, b) => a.label.localeCompare(b.label));
+}
+
+/**
+ * Generated harness source. Prefer a clean named import the user can edit.
+ */
+export function harnessForModule(importPath: string): string {
+  const nameGuess =
+    importPath
+      .split('/')
+      .pop()
+      ?.replace(/[^a-zA-Z0-9_$]/g, '') || 'Component';
+
+  if (nameGuess === 'RoomInput') {
+    return `/**
+ * Preview harness for ${importPath}
+ *
+ * Uses the room from PlaygroundProviders (mock or live Paarrot session).
+ * Switch to the Component tab to edit the real source.
+ */
+import { useRef } from 'react';
+import { RoomInput } from '${importPath}';
+import { useEditor } from '@cinny/app/components/editor';
+import { useRoom } from '@cinny/app/hooks/useRoom';
+
+export default function Preview() {
+  const editor = useEditor();
+  const dropRef = useRef<HTMLDivElement>(null);
+  const room = useRoom();
+
+  return (
+    <div ref={dropRef} style={{ width: '100%' }}>
+      <RoomInput
+        editor={editor}
+        fileDropContainerRef={dropRef}
+        roomId={room.roomId}
+        room={room}
+      />
+    </div>
+  );
+}
+`;
+  }
+
+  return `/**
+ * Preview harness for ${importPath}
+ *
+ * This only mounts the component. To edit labels/strings/markup, switch to the
+ * Component tab (writes the real source file under src/app/…).
+ */
+import { ${nameGuess} } from '${importPath}';
+
+export default function Preview() {
+  return <${nameGuess} />;
+}
+`;
+}

src/playground/defaultLive.tsx

@@ -0,0 +1,43 @@
+/**
+ * Live preview harness — edit freely. Nothing is saved.
+ *
+ * - Import any Cinny module via `@cinny/...`
+ * - Use mocks / PlaygroundProviders from `@playground/mocks`
+ * - `export default` the component to render in the stage
+ */
+import { Message } from '@cinny/app/features/room/message';
+import { MessageLayout } from '@cinny/app/state/settings';
+import { Box, Text } from 'folds';
+import { mocks } from '@playground/mocks';
+
+export default function Preview() {
+  const room = mocks.room;
+  const mEvent = mocks.event;
+
+  return (
+    <Box direction="Column" gap="200" style={{ width: '100%', maxWidth: 520 }}>
+      <Text size="T200" priority="300">
+        Preview harness — swap imports to any `@cinny/...` export
+      </Text>
+      <Message
+        room={room}
+        mEvent={mEvent}
+        collapse={false}
+        highlight={false}
+        messageLayout={MessageLayout.Modern}
+        messageSpacing="400"
+        canDelete
+        canSendReaction
+        canPinEvent
+        hour24Clock={false}
+        dateFormatString="D MMM YYYY"
+        onUserClick={() => undefined}
+        onUsernameClick={() => undefined}
+        onReplyClick={() => undefined}
+        onReactionToggle={() => undefined}
+      >
+        <Text style={{ margin: 0 }}>{mEvent.getContent().body}</Text>
+      </Message>
+    </Box>
+  );
+}

src/playground/defaultSource.ts

@@ -0,0 +1,3 @@
+import defaultLive from './defaultLive.tsx?raw';
+
+export const DEFAULT_SOURCE = defaultLive;

src/playground/liveClient.ts

@@ -0,0 +1,151 @@
+import {
+  ClientEvent,
+  createClient,
+  MemoryStore,
+  SyncState,
+  type MatrixClient,
+  type Room,
+} from 'matrix-js-sdk';
+import { getCurrentSession, type Session } from '@cinny/app/state/sessions';
+
+export type LiveConnectMode = 'mock' | 'live';
+
+export type ManualSessionInput = {
+  baseUrl: string;
+  userId: string;
+  deviceId: string;
+  accessToken: string;
+};
+
+const MANUAL_SESSION_KEY = 'playgroundManualSession';
+
+/** Session already used by Paarrot/Cinny on this origin (localStorage). */
+export function peekPaarrotSession(): Session | undefined {
+  return getCurrentSession();
+}
+
+export function loadManualSession(): ManualSessionInput | null {
+  try {
+    const raw = sessionStorage.getItem(MANUAL_SESSION_KEY);
+    if (!raw) return null;
+    const parsed = JSON.parse(raw) as ManualSessionInput;
+    if (parsed?.baseUrl && parsed?.userId && parsed?.deviceId && parsed?.accessToken) {
+      return parsed;
+    }
+  } catch {
+    /* ignore */
+  }
+  return null;
+}
+
+export function saveManualSession(input: ManualSessionInput | null) {
+  if (!input) {
+    sessionStorage.removeItem(MANUAL_SESSION_KEY);
+    return;
+  }
+  sessionStorage.setItem(MANUAL_SESSION_KEY, JSON.stringify(input));
+}
+
+function normalizeSession(input: Session | ManualSessionInput): Session {
+  return {
+    baseUrl: input.baseUrl.replace(/\/$/, ''),
+    userId: input.userId,
+    deviceId: input.deviceId,
+    accessToken: input.accessToken,
+  };
+}
+
+function resolveSession(explicit?: Session | ManualSessionInput): Session {
+  if (explicit) return normalizeSession(explicit);
+
+  const fromPaarrot = peekPaarrotSession();
+  if (fromPaarrot) return normalizeSession(fromPaarrot);
+
+  const manual = loadManualSession();
+  if (manual) return normalizeSession(manual);
+
+  throw new Error(
+    'No Paarrot session found. Log in at / (same origin), or paste homeserver + token in the playground.'
+  );
+}
+
+function waitForPrepared(mx: MatrixClient, timeoutMs = 90_000): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const finish = (ok: boolean, err?: Error) => {
+      clearTimeout(timer);
+      mx.off(ClientEvent.Sync, onSync);
+      if (ok) resolve();
+      else reject(err ?? new Error('Sync failed'));
+    };
+
+    const timer = window.setTimeout(
+      () => finish(false, new Error('Timed out waiting for Matrix sync')),
+      timeoutMs
+    );
+
+    const onSync = (state: SyncState | null) => {
+      if (state === SyncState.Prepared || state === SyncState.Syncing) {
+        finish(true);
+      }
+    };
+
+    mx.on(ClientEvent.Sync, onSync);
+    const cur = mx.getSyncState();
+    if (cur === SyncState.Prepared || cur === SyncState.Syncing) {
+      finish(true);
+    }
+  });
+}
+
+/**
+ * Live Matrix client for the playground.
+ * Uses MemoryStore so it won't fight Paarrot's IndexedDB sync/crypto stores.
+ * Skips Rust crypto — encrypted timelines won't decrypt, but profiles/rooms/settings APIs work.
+ */
+export async function connectLiveMatrixClient(
+  session?: Session | ManualSessionInput
+): Promise<MatrixClient> {
+  const finalSession = resolveSession(session);
+
+  const mx = createClient({
+    baseUrl: finalSession.baseUrl,
+    accessToken: finalSession.accessToken,
+    userId: finalSession.userId,
+    deviceId: finalSession.deviceId,
+    store: new MemoryStore({ localStorage: globalThis.localStorage }),
+    timelineSupport: true,
+  });
+
+  mx.setMaxListeners(50);
+  await mx.startClient({
+    lazyLoadMembers: true,
+    initialSyncLimit: 20,
+  });
+  await waitForPrepared(mx);
+  return mx;
+}
+
+export function stopLiveMatrixClient(mx: MatrixClient | null | undefined) {
+  if (!mx) return;
+  try {
+    mx.stopClient();
+  } catch {
+    /* ignore */
+  }
+}
+
+export function listJoinedRooms(mx: MatrixClient): Room[] {
+  return mx
+    .getRooms()
+    .filter((r) => r.getMyMembership() === 'join')
+    .sort((a, b) => (a.name || a.roomId).localeCompare(b.name || b.roomId));
+}
+
+export function pickDefaultRoom(mx: MatrixClient, preferredId?: string): Room | undefined {
+  const rooms = listJoinedRooms(mx);
+  if (preferredId) {
+    const hit = rooms.find((r) => r.roomId === preferredId);
+    if (hit) return hit;
+  }
+  return rooms[0];
+}

src/playground/main.tsx

@@ -0,0 +1,49 @@
+import { StrictMode, Component, type ErrorInfo, type ReactNode } from 'react';
+import { createRoot } from 'react-dom/client';
+import 'folds/dist/style.css';
+import { configClass, varsClass } from 'folds';
+import { App } from './App';
+import './styles.css';
+
+document.body.classList.add(configClass, varsClass);
+
+// Playground shares the Cinny origin — drop any SW/caches so stale shims cannot stick.
+if ('serviceWorker' in navigator) {
+  void navigator.serviceWorker.getRegistrations().then((regs) => {
+    for (const reg of regs) void reg.unregister();
+  });
+}
+if (typeof caches !== 'undefined') {
+  void caches.keys().then((keys) => Promise.all(keys.map((k) => caches.delete(k))));
+}
+
+class BootErrorBoundary extends Component<{ children: ReactNode }, { error: string | null }> {
+  state = { error: null as string | null };
+
+  static getDerivedStateFromError(error: Error) {
+    return { error: error.message };
+  }
+
+  componentDidCatch(error: Error, info: ErrorInfo) {
+    console.error('[playground boot]', error, info);
+  }
+
+  render() {
+    if (this.state.error) {
+      return (
+        <pre style={{ padding: 24, color: '#ffb4b4', whiteSpace: 'pre-wrap' }}>
+          {this.state.error}
+        </pre>
+      );
+    }
+    return this.props.children;
+  }
+}
+
+createRoot(document.getElementById('root')!).render(
+  <StrictMode>
+    <BootErrorBoundary>
+      <App />
+    </BootErrorBoundary>
+  </StrictMode>
+);

src/playground/mocks/PlaygroundProviders.tsx

@@ -0,0 +1,106 @@
+import { ReactNode, useEffect, useMemo, useState } from 'react';
+import { Provider as JotaiProvider } from 'jotai';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import { MemoryRouter } from 'react-router-dom';
+import {
+  Box,
+  OverlayContainerProvider,
+  PopOutContainerProvider,
+  TooltipContainerProvider,
+  configClass,
+  varsClass,
+} from 'folds';
+import { MatrixClientProvider } from '@cinny/app/hooks/useMatrixClient';
+import { RoomProvider, IsDirectRoomProvider } from '@cinny/app/hooks/useRoom';
+import { SpecVersionsProvider } from '@cinny/app/hooks/useSpecVersions';
+import { DarkTheme, ThemeContextProvider } from '@cinny/app/hooks/useTheme';
+import {
+  PowerLevelsContextProvider,
+  type IPowerLevels,
+} from '@cinny/app/hooks/usePowerLevels';
+import { ContainerColor } from '@cinny/app/styles/ContainerColor.css';
+import type { MatrixClient, Room } from 'matrix-js-sdk';
+import { MOCK_POWER_LEVELS, createMockRoom, mocks } from './matrix';
+
+type Props = {
+  children: ReactNode;
+  client?: MatrixClient;
+  room?: Room;
+  isDirect?: boolean;
+  powerLevels?: IPowerLevels;
+};
+
+const SPEC_VERSIONS = {
+  versions: ['v1.11', 'v1.12'],
+  unstable_features: {
+    'org.matrix.msc3916.stable': true,
+  },
+};
+
+/**
+ * Wraps a preview in the providers Cinny UI pieces usually expect.
+ * Overlay/popout/tooltip portals stay inside the stage (not the full window).
+ */
+export function PlaygroundProviders({
+  children,
+  client,
+  room,
+  isDirect = false,
+  powerLevels = MOCK_POWER_LEVELS as IPowerLevels,
+}: Props) {
+  const [portal, setPortal] = useState<HTMLDivElement | null>(null);
+  const queryClient = useMemo(() => new QueryClient(), []);
+  const resolvedClient = client ?? mocks.client;
+  // Always provide a room with `.client` set — RoomInput/useStateEvent require it.
+  const resolvedRoom = useMemo(() => {
+    if (room) return room;
+    return createMockRoom({ client: resolvedClient });
+  }, [room, resolvedClient]);
+
+  useEffect(() => {
+    document.body.classList.add(configClass, varsClass, ...DarkTheme.classNames);
+  }, []);
+
+  return (
+    <div className="preview-frame">
+      <ThemeContextProvider value={DarkTheme}>
+        <TooltipContainerProvider value={portal ?? undefined}>
+          <PopOutContainerProvider value={portal ?? undefined}>
+            <OverlayContainerProvider value={portal ?? undefined}>
+              <QueryClientProvider client={queryClient}>
+                <JotaiProvider>
+                  <MemoryRouter>
+                    <SpecVersionsProvider value={SPEC_VERSIONS}>
+                      <MatrixClientProvider value={resolvedClient}>
+                        <RoomProvider value={resolvedRoom}>
+                          <IsDirectRoomProvider value={isDirect}>
+                            <PowerLevelsContextProvider value={powerLevels}>
+                              <Box
+                                className={ContainerColor({ variant: 'Surface' })}
+                                style={{
+                                  width: '100%',
+                                  minHeight: '100%',
+                                  height: '100%',
+                                  padding: 16,
+                                  borderRadius: 8,
+                                }}
+                              >
+                                {children}
+                              </Box>
+                            </PowerLevelsContextProvider>
+                          </IsDirectRoomProvider>
+                        </RoomProvider>
+                      </MatrixClientProvider>
+                    </SpecVersionsProvider>
+                  </MemoryRouter>
+                </JotaiProvider>
+              </QueryClientProvider>
+            </OverlayContainerProvider>
+          </PopOutContainerProvider>
+        </TooltipContainerProvider>
+      </ThemeContextProvider>
+      {/* Host for folds Overlay/Dialog portals — contained by .preview-frame */}
+      <div className="preview-portal" ref={setPortal} />
+    </div>
+  );
+}

src/playground/mocks/index.ts

@@ -0,0 +1,2 @@
+export { mocks, createMockMatrixClient, createMockRoom, createMockMatrixEvent, MOCK_POWER_LEVELS } from './matrix';
+export { PlaygroundProviders } from './PlaygroundProviders';

src/playground/mocks/matrix.ts

@@ -0,0 +1,245 @@
+import type { MatrixClient, MatrixEvent, Room } from 'matrix-js-sdk';
+import { MessageEvent, StateEvent } from '@cinny/types/matrix/room';
+import type { IPowerLevels } from '@cinny/app/hooks/usePowerLevels';
+
+type AnyFn = (...args: never[]) => unknown;
+
+function fn<T extends AnyFn>(impl?: T): T {
+  return (impl ?? ((() => undefined) as T)) as T;
+}
+
+export const MOCK_USER_ID = '@alice:example.org';
+export const MOCK_OTHER_USER_ID = '@bob:example.org';
+export const MOCK_ROOM_ID = '!room:example.org';
+export const MOCK_EVENT_ID = '$event:example.org';
+
+/** Default power levels — user can send messages / invite. */
+export const MOCK_POWER_LEVELS: IPowerLevels = {
+  users_default: 0,
+  state_default: 50,
+  events_default: 0,
+  invite: 0,
+  redact: 50,
+  kick: 50,
+  ban: 50,
+  historical: 0,
+  events: {
+    'm.room.message': 0,
+    'm.reaction': 0,
+  },
+  users: {
+    [MOCK_USER_ID]: 100,
+  },
+  notifications: {
+    room: 50,
+  },
+};
+
+function mockStateEvent(type: string, content: Record<string, unknown>, stateKey = ''): MatrixEvent {
+  return {
+    getId: () => `$${type}`,
+    getSender: () => MOCK_USER_ID,
+    getTs: () => Date.now(),
+    getType: () => type,
+    getContent: () => content,
+    getWireContent: () => content,
+    isRedacted: () => false,
+    getStateKey: () => stateKey,
+    isEncrypted: () => false,
+    getRoomId: () => MOCK_ROOM_ID,
+    event: { sender: MOCK_USER_ID },
+  } as unknown as MatrixEvent;
+}
+
+/** Lightweight MatrixEvent stand-in for UI previews. */
+export function createMockMatrixEvent(
+  overrides: Partial<{
+    id: string;
+    sender: string;
+    body: string;
+    ts: number;
+    type: string;
+    redacted: boolean;
+    content: Record<string, unknown>;
+  }> = {}
+): MatrixEvent {
+  const id = overrides.id ?? MOCK_EVENT_ID;
+  const sender = overrides.sender ?? MOCK_OTHER_USER_ID;
+  const content = {
+    body: overrides.body ?? 'Hello from the playground preview.',
+    msgtype: 'm.text',
+    ...(overrides.content ?? {}),
+  };
+  const ts = overrides.ts ?? Date.now() - 60_000;
+  const type = overrides.type ?? MessageEvent.RoomMessage;
+  const redacted = overrides.redacted ?? false;
+
+  return {
+    getId: () => id,
+    getSender: () => sender,
+    getTs: () => ts,
+    getType: () => type,
+    getContent: () => (redacted ? {} : content),
+    getWireContent: () => content,
+    isRedacted: () => redacted,
+    getStateKey: () => undefined,
+    isEncrypted: () => false,
+    threadRootId: undefined,
+    getRoomId: () => MOCK_ROOM_ID,
+  } as unknown as MatrixEvent;
+}
+
+/** Lightweight Room stand-in. */
+export function createMockRoom(
+  overrides: Partial<{
+    roomId: string;
+    name: string;
+    client: MatrixClient;
+    members: Record<string, { displayName?: string; avatarMxc?: string }>;
+    powerLevels: IPowerLevels;
+  }> = {}
+): Room {
+  const roomId = overrides.roomId ?? MOCK_ROOM_ID;
+  const members = {
+    [MOCK_USER_ID]: { displayName: 'Alice' },
+    [MOCK_OTHER_USER_ID]: { displayName: 'Bob' },
+    ...(overrides.members ?? {}),
+  };
+  const powerLevels = overrides.powerLevels ?? MOCK_POWER_LEVELS;
+
+  const stateByType: Record<string, MatrixEvent> = {
+    [StateEvent.RoomPowerLevels]: mockStateEvent(
+      StateEvent.RoomPowerLevels,
+      powerLevels as unknown as Record<string, unknown>
+    ),
+    [StateEvent.RoomCreate]: mockStateEvent(StateEvent.RoomCreate, {
+      room_version: '11',
+      creator: MOCK_USER_ID,
+    }),
+    [StateEvent.RoomPinnedEvents]: mockStateEvent(StateEvent.RoomPinnedEvents, { pinned: [] }),
+  };
+
+  const getStateEvents = ((type: string, stateKey?: string) => {
+    const ev = stateByType[type];
+    if (stateKey !== undefined) return ev ?? null;
+    return ev ? [ev] : [];
+  }) as Room['currentState']['getStateEvents'];
+
+  const liveState = {
+    getStateEvents,
+  };
+
+  const client = overrides.client ?? ({
+    on: fn(() => undefined),
+    removeListener: fn(() => undefined),
+    once: fn(() => undefined),
+    off: fn(() => undefined),
+  } as unknown as MatrixClient);
+
+  return {
+    roomId,
+    name: overrides.name ?? 'Preview Room',
+    client,
+    getMyMembership: () => 'join',
+    getMember: (userId: string) => {
+      const m = members[userId];
+      if (!m) return null;
+      return {
+        userId,
+        name: m.displayName ?? userId,
+        rawDisplayName: m.displayName ?? userId,
+        getAvatarUrl: () => null,
+        getMxcAvatarUrl: () => m.avatarMxc ?? null,
+      };
+    },
+    getCanonicalAlias: () => null,
+    getAltAliases: () => [],
+    getTimelineForEvent: () => null,
+    getLiveTimeline: () => ({
+      getTimelineSet: () => ({ relations: { getChildEventsForEvent: () => null } }),
+      getEvents: () => [],
+      getState: () => liveState,
+    }),
+    currentState: {
+      getStateEvents,
+    },
+  } as unknown as Room;
+}
+
+/** Lightweight MatrixClient stand-in used by MatrixClientProvider. */
+export function createMockMatrixClient(
+  overrides: Partial<{ userId: string }> = {}
+): MatrixClient {
+  const userId = overrides.userId ?? MOCK_USER_ID;
+  const users = new Map<
+    string,
+    {
+      userId: string;
+      presence: string;
+      presenceStatusMsg?: string;
+      currentlyActive: boolean;
+      getLastActiveTs: () => number;
+      on: AnyFn;
+      removeListener: AnyFn;
+      once: AnyFn;
+      off: AnyFn;
+    }
+  >();
+
+  const ensureUser = (id: string) => {
+    if (!users.has(id)) {
+      users.set(id, {
+        userId: id,
+        presence: 'online',
+        currentlyActive: true,
+        getLastActiveTs: () => Date.now(),
+        on: fn(() => undefined),
+        removeListener: fn(() => undefined),
+        once: fn(() => undefined),
+        off: fn(() => undefined),
+      });
+    }
+    return users.get(id)!;
+  };
+  ensureUser(userId);
+  ensureUser(MOCK_OTHER_USER_ID);
+
+  const client = {
+    getUserId: () => userId,
+    getSafeUserId: () => userId,
+    getDomain: () => 'example.org',
+    getUser: (id: string) => ensureUser(id),
+    getRoom: (id: string | undefined) =>
+      id ? createMockRoom({ roomId: id, client: client as MatrixClient }) : null,
+    getRooms: () => [createMockRoom({ client: client as MatrixClient })],
+    isRoomEncrypted: () => false,
+    getAccountData: () => undefined,
+    sendEvent: fn(async () => ({ event_id: '$sent' })),
+    sendStateEvent: fn(async () => ({ event_id: '$state' })),
+    redactEvent: fn(async () => ({ event_id: '$redact' })),
+    reportEvent: fn(async () => ({})),
+    downloadKeys: fn(async () => ({})),
+    mxcUrlToHttp: (mxc: string) => mxc,
+    on: fn(() => undefined),
+    removeListener: fn(() => undefined),
+    once: fn(() => undefined),
+  } as unknown as MatrixClient;
+
+  return client;
+}
+
+const defaultClient = createMockMatrixClient();
+
+export const mocks = {
+  userId: MOCK_USER_ID,
+  otherUserId: MOCK_OTHER_USER_ID,
+  roomId: MOCK_ROOM_ID,
+  eventId: MOCK_EVENT_ID,
+  powerLevels: MOCK_POWER_LEVELS,
+  client: defaultClient,
+  room: createMockRoom({ client: defaultClient }),
+  event: createMockMatrixEvent(),
+  createClient: createMockMatrixClient,
+  createRoom: createMockRoom,
+  createEvent: createMockMatrixEvent,
+};

src/playground/monacoSetup.ts

@@ -0,0 +1,12 @@
+import editorWorker from 'monaco-editor/esm/vs/editor/editor.worker?worker';
+import jsonWorker from 'monaco-editor/esm/vs/language/json/json.worker?worker';
+import tsWorker from 'monaco-editor/esm/vs/language/typescript/ts.worker?worker';
+
+// Vite-friendly Monaco workers (no AMD CDN loader).
+self.MonacoEnvironment = {
+  getWorker(_workerId: string, label: string) {
+    if (label === 'json') return new jsonWorker();
+    if (label === 'typescript' || label === 'javascript') return new tsWorker();
+    return new editorWorker();
+  },
+};

src/playground/shims/loglevel.js

@@ -0,0 +1,65 @@
+/**
+ * Standalone loglevel stand-in for the playground.
+ * Avoids Vite CJS interop fights with the real package; matrix-js-sdk only needs
+ * getLogger / levels / methodFactory / setLevel / rebuild.
+ */
+
+const levels = {
+  TRACE: 0,
+  DEBUG: 1,
+  INFO: 2,
+  WARN: 3,
+  ERROR: 4,
+  SILENT: 5,
+};
+
+const loggers = new Map();
+
+function defaultMethodFactory(methodName) {
+  return (...args) => {
+    const supported =
+      methodName === 'error' ||
+      methodName === 'warn' ||
+      methodName === 'trace' ||
+      methodName === 'info' ||
+      methodName === 'debug';
+    if (supported) console[methodName](...args);
+    else console.log(...args);
+  };
+}
+
+function createLogger(name) {
+  const logger = {
+    name,
+    prefix: undefined,
+    methodFactory: defaultMethodFactory,
+    getChild: undefined,
+    setLevel(_level, _persist) {},
+    getLevel() {
+      return levels.WARN;
+    },
+    setDefaultLevel() {},
+    enableAll() {},
+    disableAll() {},
+    rebuild() {
+      for (const methodName of ['trace', 'debug', 'info', 'warn', 'error']) {
+        logger[methodName] = logger.methodFactory(methodName, levels.DEBUG, name);
+      }
+    },
+  };
+  logger.rebuild();
+  // matrix-js-sdk expects console-like `.log` (e.g. logger.log.bind(logger)).
+  logger.log = logger.info;
+  return logger;
+}
+
+const loglevel = createLogger('root');
+loglevel.levels = levels;
+loglevel.getLogger = (name) => {
+  const key = String(name ?? 'default');
+  if (!loggers.has(key)) loggers.set(key, createLogger(key));
+  return loggers.get(key);
+};
+loglevel.methodFactory = defaultMethodFactory;
+
+export default loglevel;

src/playground/styles.css

@@ -0,0 +1,414 @@
+:root {
+  color-scheme: dark;
+  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, sans-serif;
+  background: #0f1115;
+  color: #e8eaed;
+}
+
+* {
+  box-sizing: border-box;
+}
+
+html,
+body,
+#root {
+  margin: 0;
+  height: 100%;
+}
+
+.app {
+  height: 100%;
+  display: grid;
+  grid-template-rows: auto auto auto 1fr;
+}
+
+.conn-bar {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 12px 16px;
+  padding: 8px 14px;
+  border-bottom: 1px solid #232833;
+  background: #12161d;
+}
+
+.conn-modes {
+  display: flex;
+  gap: 6px;
+}
+
+.conn-btn {
+  border: 1px solid #2f3640;
+  background: transparent;
+  color: #c7ced8;
+  border-radius: 8px;
+  padding: 5px 10px;
+  cursor: pointer;
+  font-size: 12px;
+}
+
+.conn-btn:hover:not(:disabled) {
+  background: #1c2230;
+}
+
+.conn-btn.active {
+  background: #243147;
+  border-color: #3d7eff;
+  color: #fff;
+}
+
+.conn-btn:disabled {
+  opacity: 0.6;
+  cursor: wait;
+}
+
+.conn-status {
+  flex: 1;
+  min-width: 180px;
+  font-size: 12px;
+}
+
+.conn-ok {
+  color: #7dcea0;
+}
+
+.conn-err {
+  color: #ffb4b4;
+}
+
+.conn-room {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 12px;
+  color: #9aa3af;
+}
+
+.conn-room select {
+  max-width: 240px;
+  border: 1px solid #2f3640;
+  border-radius: 8px;
+  background: #0c0e12;
+  color: #e8eaed;
+  padding: 5px 8px;
+}
+
+.token-form {
+  display: grid;
+  grid-template-columns: repeat(4, minmax(120px, 1fr)) auto;
+  gap: 8px;
+  padding: 8px 14px 10px;
+  border-bottom: 1px solid #232833;
+  background: #0f131a;
+}
+
+.token-form input {
+  border: 1px solid #2f3640;
+  border-radius: 8px;
+  background: #0c0e12;
+  color: #e8eaed;
+  padding: 7px 10px;
+  font-size: 12px;
+  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+}
+
+@media (max-width: 1100px) {
+  .token-form {
+    grid-template-columns: 1fr;
+  }
+}
+
+.topbar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  padding: 10px 14px;
+  border-bottom: 1px solid #232833;
+  background: #141820;
+}
+
+.topbar-actions {
+  display: flex;
+  gap: 8px;
+}
+
+.muted {
+  color: #9aa3af;
+  font-size: 13px;
+}
+
+.ghost {
+  border: 1px solid #2f3640;
+  background: transparent;
+  color: #e8eaed;
+  border-radius: 8px;
+  padding: 6px 10px;
+  cursor: pointer;
+}
+
+.ghost:hover {
+  background: #1c2230;
+}
+
+.panes {
+  display: grid;
+  grid-template-columns: minmax(200px, 280px) 1.2fr 1fr;
+  min-height: 0;
+}
+
+.pane {
+  min-width: 0;
+  min-height: 0;
+  display: grid;
+  grid-template-rows: auto 1fr;
+  border-right: 1px solid #232833;
+}
+
+.pane:last-child {
+  border-right: 0;
+}
+
+.pane-label {
+  padding: 8px 12px;
+  font-size: 11px;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: #8b949e;
+  border-bottom: 1px solid #232833;
+  background: #12161d;
+}
+
+.catalog-pane {
+  grid-template-rows: auto auto 1fr;
+  background: #10141b;
+}
+
+.filter {
+  margin: 8px 10px;
+  border: 1px solid #2f3640;
+  border-radius: 8px;
+  background: #0c0e12;
+  color: #e8eaed;
+  padding: 8px 10px;
+  font-size: 13px;
+}
+
+.catalog-list {
+  overflow: auto;
+  padding: 4px 6px 12px;
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+}
+
+.catalog-item {
+  text-align: left;
+  border: 0;
+  background: transparent;
+  color: #c7ced8;
+  border-radius: 6px;
+  padding: 7px 8px;
+  font-size: 12px;
+  cursor: pointer;
+  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+}
+
+.catalog-item:hover {
+  background: #1a2130;
+}
+
+.catalog-item.active {
+  background: #243147;
+  color: #fff;
+}
+
+.editor-pane {
+  background: #1e1e1e;
+  grid-template-rows: auto 1fr;
+}
+
+.editor-tabs {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  text-transform: none;
+  letter-spacing: 0;
+}
+
+.tab {
+  border: 1px solid #2f3640;
+  background: transparent;
+  color: #9aa3af;
+  border-radius: 6px;
+  padding: 3px 8px;
+  font-size: 11px;
+  cursor: pointer;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+}
+
+.tab:hover:not(:disabled) {
+  background: #1c2230;
+  color: #e8eaed;
+}
+
+.tab.active {
+  background: #243147;
+  border-color: #3d7eff;
+  color: #fff;
+}
+
+.tab:disabled {
+  opacity: 0.4;
+  cursor: not-allowed;
+}
+
+.tab-hint {
+  margin-left: auto;
+  font-size: 11px;
+  text-transform: none;
+  letter-spacing: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  max-width: 55%;
+}
+
+.editor-error {
+  margin: 8px 12px;
+  max-width: none;
+}
+
+.preview-pane {
+  background: #0f1115;
+}
+
+.preview-body {
+  overflow: auto;
+  padding: 24px;
+  display: grid;
+  place-items: center;
+}
+
+.stage-wrap {
+  display: grid;
+  gap: 8px;
+  justify-items: center;
+}
+
+.stage-meta {
+  font-size: 12px;
+  color: #8b949e;
+  font-variant-numeric: tabular-nums;
+}
+
+.stage {
+  position: relative;
+  background:
+    linear-gradient(45deg, #161a22 25%, transparent 25%),
+    linear-gradient(-45deg, #161a22 25%, transparent 25%),
+    linear-gradient(45deg, transparent 75%, #161a22 75%),
+    linear-gradient(-45deg, transparent 75%, #161a22 75%);
+  background-size: 20px 20px;
+  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
+  background-color: #0c0e12;
+  border: 1px solid #2a3140;
+  border-radius: 10px;
+  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
+  /* Contain folds position:fixed overlays inside the stage. */
+  transform: translateZ(0);
+  overflow: hidden;
+}
+
+.stage-canvas {
+  width: 100%;
+  height: 100%;
+  overflow: auto;
+  padding: 12px;
+  display: grid;
+  place-items: stretch;
+  align-content: stretch;
+}
+
+.preview-frame {
+  position: relative;
+  width: 100%;
+  height: 100%;
+  min-height: 200px;
+  /* Nested containing block so Overlay fixed coords map to the frame. */
+  transform: translateZ(0);
+  overflow: hidden;
+  border-radius: 8px;
+}
+
+.preview-portal {
+  position: absolute;
+  inset: 0;
+  z-index: 30;
+  pointer-events: none;
+}
+
+.preview-portal > * {
+  pointer-events: auto;
+}
+
+.handle {
+  position: absolute;
+  padding: 0;
+  border: 0;
+  background: #3d7eff;
+  opacity: 0.85;
+}
+
+.handle:hover {
+  opacity: 1;
+}
+
+.handle-e {
+  top: 12px;
+  right: -4px;
+  width: 8px;
+  height: calc(100% - 24px);
+  cursor: ew-resize;
+  border-radius: 999px;
+}
+
+.handle-s {
+  left: 12px;
+  bottom: -4px;
+  height: 8px;
+  width: calc(100% - 24px);
+  cursor: ns-resize;
+  border-radius: 999px;
+}
+
+.handle-se {
+  right: -5px;
+  bottom: -5px;
+  width: 12px;
+  height: 12px;
+  cursor: nwse-resize;
+  border-radius: 3px;
+}
+
+.error-block {
+  margin: 0;
+  max-width: 560px;
+  white-space: pre-wrap;
+  word-break: break-word;
+  padding: 14px 16px;
+  border-radius: 10px;
+  background: #2a1215;
+  border: 1px solid #5c1f28;
+  color: #ffb4b4;
+  font-size: 13px;
+  line-height: 1.45;
+}
+
+@media (max-width: 1100px) {
+  .panes {
+    grid-template-columns: 1fr;
+    grid-template-rows: 180px 1fr 1fr;
+  }
+}

src/playground/usePlaygroundMatrix.ts

@@ -0,0 +1,123 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import type { MatrixClient, Room } from 'matrix-js-sdk';
+import {
+  connectLiveMatrixClient,
+  listJoinedRooms,
+  loadManualSession,
+  peekPaarrotSession,
+  pickDefaultRoom,
+  saveManualSession,
+  stopLiveMatrixClient,
+  type LiveConnectMode,
+  type ManualSessionInput,
+} from './liveClient';
+
+type LiveState = {
+  mode: LiveConnectMode;
+  status: 'idle' | 'connecting' | 'ready' | 'error';
+  error: string | null;
+  client: MatrixClient | null;
+  room: Room | null;
+  rooms: Room[];
+  sessionLabel: string | null;
+};
+
+const initial: LiveState = {
+  mode: 'mock',
+  status: 'idle',
+  error: null,
+  client: null,
+  room: null,
+  rooms: [],
+  sessionLabel: null,
+};
+
+export function usePlaygroundMatrix() {
+  const [state, setState] = useState<LiveState>(initial);
+  const clientRef = useRef<MatrixClient | null>(null);
+  const roomIdRef = useRef<string | undefined>(undefined);
+  const paarrotSession = peekPaarrotSession();
+  const hasPaarrotSession = Boolean(paarrotSession);
+  const hasManualSession = Boolean(loadManualSession());
+
+  const teardown = useCallback(() => {
+    stopLiveMatrixClient(clientRef.current);
+    clientRef.current = null;
+  }, []);
+
+  useEffect(() => () => teardown(), [teardown]);
+
+  const selectRoom = useCallback((roomId: string) => {
+    roomIdRef.current = roomId;
+    setState((prev) => {
+      if (!prev.client) return prev;
+      const room = pickDefaultRoom(prev.client, roomId) ?? null;
+      return { ...prev, room };
+    });
+  }, []);
+
+  const connectLive = useCallback(
+    async (manual?: ManualSessionInput) => {
+      teardown();
+      setState((prev) => ({
+        ...prev,
+        mode: 'live',
+        status: 'connecting',
+        error: null,
+        client: null,
+        room: null,
+        rooms: [],
+        sessionLabel: null,
+      }));
+
+      try {
+        if (manual) saveManualSession(manual);
+        const mx = await connectLiveMatrixClient(manual);
+        clientRef.current = mx;
+        const rooms = listJoinedRooms(mx);
+        const room = pickDefaultRoom(mx, roomIdRef.current) ?? null;
+        if (room) roomIdRef.current = room.roomId;
+
+        const hs =
+          peekPaarrotSession()?.baseUrl ??
+          loadManualSession()?.baseUrl ??
+          '';
+        setState({
+          mode: 'live',
+          status: 'ready',
+          error: null,
+          client: mx,
+          room,
+          rooms,
+          sessionLabel: `${mx.getUserId() ?? '?'} · ${hs}`,
+        });
+      } catch (err) {
+        clientRef.current = null;
+        setState({
+          ...initial,
+          mode: 'live',
+          status: 'error',
+          error: err instanceof Error ? err.message : String(err),
+        });
+      }
+    },
+    [teardown]
+  );
+
+  const useMocks = useCallback(() => {
+    teardown();
+    roomIdRef.current = undefined;
+    setState(initial);
+  }, [teardown]);
+
+  return {
+    ...state,
+    hasPaarrotSession,
+    hasManualSession,
+    paarrotUserId: paarrotSession?.userId ?? null,
+    paarrotBaseUrl: paarrotSession?.baseUrl ?? null,
+    connectLive,
+    useMocks,
+    selectRoom,
+  };
+}

src/playground/vite-env.d.ts

@@ -0,0 +1,11 @@
+/// <reference types="vite/client" />
+
+declare module '*?raw' {
+  const content: string;
+  default content;
+}
+
+declare module '/@playground/live.tsx' {
+  const Comp: React.ComponentType;
+  export default Comp;
+}

src/types/matrix/room.ts

@@ -58,6 +58,9 @@ export enum MessageEvent {
   Sticker = 'm.sticker',
   RoomRedaction = 'm.room.redaction',
   Reaction = 'm.reaction',
+
+  /** Relay emoji confetti burst tied to a target message */
+  RelayEmojiConfetti = 'app.relay.emoji_confetti',
 }
 
 export enum RoomType {

vite.config.js

@@ -10,6 +10,9 @@ import { VitePWA } from 'vite-plugin-pwa';
 import fs from 'fs';
 import path from 'path';
 import buildConfig from './build.config';
+import { liveTsxPlugin, readDefaultLiveSource } from './playground-liveTsxPlugin';
+
+const projectRoot = path.resolve();
 
 const copyFiles = {
   targets: [
@@ -217,6 +220,30 @@ export default defineConfig({
   publicDir: false,
   base: buildConfig.base,
   assetsInclude: ['**/*.ogg', '**/*.mp3', '**/*.wav'],
+  resolve: {
+    // Keep a single React instance — dual copies cause resolveDispatcher() === null.
+    dedupe: ['react', 'react-dom'],
+    alias: [
+      { find: '@cinny', replacement: path.resolve(projectRoot, 'src') },
+      {
+        find: '@playground/mocks',
+        replacement: path.resolve(projectRoot, 'src/playground/mocks/index.ts'),
+      },
+      // Exact match only — do not rewrite loglevel/lib/...
+      {
+        find: /^loglevel$/,
+        replacement: path.resolve(projectRoot, 'src/playground/shims/loglevel.js'),
+      },
+      {
+        find: /^react$/,
+        replacement: path.resolve(projectRoot, 'node_modules/react'),
+      },
+      {
+        find: /^react-dom$/,
+        replacement: path.resolve(projectRoot, 'node_modules/react-dom'),
+      },
+    ],
+  },
   server: {
     port: 38347,
     host: '0.0.0.0',
@@ -232,6 +259,7 @@ export default defineConfig({
     serverMatrixSdkCryptoWasm('/node_modules/.vite/deps/pkg/matrix_sdk_crypto_wasm_bg.wasm'),
     serveGifWorker(),
     servePublicAssets(),
+    liveTsxPlugin(projectRoot, readDefaultLiveSource(projectRoot)),
     topLevelAwait({
       // The export name of top-level await promise for each chunk module
       promiseExportName: '__tla',
@@ -258,6 +286,16 @@ export default defineConfig({
     }),
   ],
   optimizeDeps: {
+    include: [
+      'react',
+      'react-dom',
+      'react/jsx-runtime',
+      'react/jsx-dev-runtime',
+      'loglevel',
+      'matrix-js-sdk',
+      '@monaco-editor/react',
+    ],
+    needsInterop: ['loglevel'],
     rolldownOptions: {
       define: {
         global: 'globalThis',
@@ -277,6 +315,10 @@ export default defineConfig({
     sourcemap: true,
     copyPublicDir: false,
     rollupOptions: {
+      input: {
+        main: path.resolve(projectRoot, 'index.html'),
+        playground: path.resolve(projectRoot, 'playground.html'),
+      },
       plugins: [inject({ Buffer: ['buffer', 'Buffer'] })],
     },
   },