refactor(inbox): record voice notes client-side, drop server ffmpeg

Follow-up to #259. Voice notes are encoded to Ogg/Opus in the browser via
opus-recorder (small WASM encoder, lazy-loaded on record), so there's no
server-side transcode and nothing to provision on the host. The server
stores the .ogg like any other attachment; WhatsApp renders it as a voice
note.

- Composer: MediaRecorder + /api/whatsapp/transcode-audio replaced with
  opus-recorder. Encoder worker vendored at public/opus/encoderWorker.min.js
  (no install-time download to fail), ignored by eslint + prettier.
- Removed the transcode route, the audio-transcode lib + tests, the
  ffmpeg-static dep + ambient types, the FFMPEG_PATH env doc, and the
  unused transcodeAudio rate limit.
- Added opus-recorder ambient types.

Still behind the 'chat_media' beta flag with per-kind size caps.
typecheck/lint/build green; 414 tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.env.local.example

@@ -83,9 +83,3 @@ NEXT_PUBLIC_SITE_URL=https://crm.example.com
 # Set this in CI and local development so you can exercise the full
 # template UI without a real WABA. Leave unset (or "false") in prod.
 # WHATSAPP_TEMPLATES_DRY_RUN=true
-
-# Override the ffmpeg binary used by POST /api/whatsapp/transcode-audio
-# (voice notes are remuxed to OGG/Opus before being sent to Meta). By
-# default the bundled `ffmpeg-static` binary is used; set this only if
-# that binary can't run on your host and you have a system ffmpeg.
-#   FFMPEG_PATH=/usr/bin/ffmpeg

.prettierignore

@@ -7,3 +7,4 @@ next-env.d.ts
 package-lock.json
 # Generated / vendored
 supabase/migrations
+public/opus

eslint.config.mjs

@@ -12,6 +12,8 @@ const eslintConfig = defineConfig([
     "out/**",
     "build/**",
     "next-env.d.ts",
+    // Vendored minified opus-recorder encoder worker (served statically).
+    "public/opus/**",
   ]),
 ]);
 

package-lock.json

@@ -20,9 +20,9 @@
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",
         "date-fns": "^4.4.0",
-        "ffmpeg-static": "^5.3.0",
         "lucide-react": "^1.18.0",
         "next": "16.2.6",
+        "opus-recorder": "^8.0.5",
         "react": "19.2.4",
         "react-dom": "19.2.4",
         "recharts": "^3.8.1",
@@ -550,21 +550,6 @@
       "integrity": "sha512-IvcV6FduIIAmLwnH+yun+QtV36SC7mERqa86aClNqmMN09WhmPPYU8ckHrZBozErf+UvHPWOTJYaGYiIcs0DgA==",
       "license": "MIT"
     },
-    "node_modules/@derhuerst/http-basic": {
-      "version": "8.2.4",
-      "resolved": "https://registry.npmjs.org/@derhuerst/http-basic/-/http-basic-8.2.4.tgz",
-      "integrity": "sha512-F9rL9k9Xjf5blCz8HsJRO4diy111cayL2vkY2XE4r4t3n0yPXVYy3KD3nJ1qbrSn9743UWSXH4IwuCa/HWlGFw==",
-      "license": "MIT",
-      "dependencies": {
-        "caseless": "^0.12.0",
-        "concat-stream": "^2.0.0",
-        "http-response-object": "^3.0.1",
-        "parse-cache-control": "^1.0.1"
-      },
-      "engines": {
-        "node": ">=6.0.0"
-      }
-    },
     "node_modules/@dnd-kit/accessibility": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/@dnd-kit/accessibility/-/accessibility-3.1.1.tgz",
@@ -4222,12 +4207,6 @@
         "node": "^6 || ^7 || ^8 || ^9 || ^10 || ^11 || ^12 || >=13.7"
       }
     },
-    "node_modules/buffer-from": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.2.tgz",
-      "integrity": "sha512-E+XQCRwSbaaiChtv6k6Dwgc+bx+Bs6vuKJHHl5kox/BaKbhiXzqQOwK4cO22yElGp2OCmjwVhT3HmxgyPGnJfQ==",
-      "license": "MIT"
-    },
     "node_modules/bundle-name": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/bundle-name/-/bundle-name-4.1.0.tgz",
@@ -4329,12 +4308,6 @@
       ],
       "license": "CC-BY-4.0"
     },
-    "node_modules/caseless": {
-      "version": "0.12.0",
-      "resolved": "https://registry.npmjs.org/caseless/-/caseless-0.12.0.tgz",
-      "integrity": "sha512-4tYFyifaFfGacoiObjJegolkwSU4xQNGbVgUiNYVUxbQ2x2lUsFvY4hVgVzGiIe6WLOPqycWXA40l+PWsxthUw==",
-      "license": "Apache-2.0"
-    },
     "node_modules/chai": {
       "version": "6.2.2",
       "resolved": "https://registry.npmjs.org/chai/-/chai-6.2.2.tgz",
@@ -4464,21 +4437,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/concat-stream": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/concat-stream/-/concat-stream-2.0.0.tgz",
-      "integrity": "sha512-MWufYdFw53ccGjCA+Ol7XJYpAlW6/prSMzuPOTRnJGcGzuhLn4Scrz7qf6o8bROZ514ltazcIFJZevcfbo0x7A==",
-      "engines": [
-        "node >= 6.0"
-      ],
-      "license": "MIT",
-      "dependencies": {
-        "buffer-from": "^1.0.0",
-        "inherits": "^2.0.3",
-        "readable-stream": "^3.0.2",
-        "typedarray": "^0.0.6"
-      }
-    },
     "node_modules/content-disposition": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-1.1.0.tgz",
@@ -6020,47 +5978,6 @@
         "node": "^12.20 || >= 14.13"
       }
     },
-    "node_modules/ffmpeg-static": {
-      "version": "5.3.0",
-      "resolved": "https://registry.npmjs.org/ffmpeg-static/-/ffmpeg-static-5.3.0.tgz",
-      "integrity": "sha512-H+K6sW6TiIX6VGend0KQwthe+kaceeH/luE8dIZyOP35ik7ahYojDuqlTV1bOrtEwl01sy2HFNGQfi5IDJvotg==",
-      "hasInstallScript": true,
-      "license": "GPL-3.0-or-later",
-      "dependencies": {
-        "@derhuerst/http-basic": "^8.2.0",
-        "env-paths": "^2.2.0",
-        "https-proxy-agent": "^5.0.0",
-        "progress": "^2.0.3"
-      },
-      "engines": {
-        "node": ">=16"
-      }
-    },
-    "node_modules/ffmpeg-static/node_modules/agent-base": {
-      "version": "6.0.2",
-      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-6.0.2.tgz",
-      "integrity": "sha512-RZNwNclF7+MS/8bDg70amg32dyeZGZxiDuQmZxKLAlQjr3jGyLx+4Kkk58UO7D2QdgFIQCovuSuZESne6RG6XQ==",
-      "license": "MIT",
-      "dependencies": {
-        "debug": "4"
-      },
-      "engines": {
-        "node": ">= 6.0.0"
-      }
-    },
-    "node_modules/ffmpeg-static/node_modules/https-proxy-agent": {
-      "version": "5.0.1",
-      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-5.0.1.tgz",
-      "integrity": "sha512-dFcAjpTQFgoLMzC2VwU+C/CbS7uRL0lWmxDITmqm7C+7F0Odmj6s9l6alZc6AELXhrnggM2CeWSXHGOdX2YtwA==",
-      "license": "MIT",
-      "dependencies": {
-        "agent-base": "6",
-        "debug": "4"
-      },
-      "engines": {
-        "node": ">= 6"
-      }
-    },
     "node_modules/figures": {
       "version": "6.1.0",
       "resolved": "https://registry.npmjs.org/figures/-/figures-6.1.0.tgz",
@@ -6607,21 +6524,6 @@
         "url": "https://opencollective.com/express"
       }
     },
-    "node_modules/http-response-object": {
-      "version": "3.0.2",
-      "resolved": "https://registry.npmjs.org/http-response-object/-/http-response-object-3.0.2.tgz",
-      "integrity": "sha512-bqX0XTF6fnXSQcEJ2Iuyr75yVakyjIDCqroJQ/aHfSdlM743Cwqoi2nDYMzLGWUcuTWGWy8AAvOKXTfiv6q9RA==",
-      "license": "MIT",
-      "dependencies": {
-        "@types/node": "^10.0.3"
-      }
-    },
-    "node_modules/http-response-object/node_modules/@types/node": {
-      "version": "10.17.60",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-10.17.60.tgz",
-      "integrity": "sha512-F0KIgDJfy2nA3zMLmWGKxcH2ZVEtCZXHHdOQs2gSaQ27+lNeEfGxzkIw90aXswATX7AZ33tahPbzy6KAfUreVw==",
-      "license": "MIT"
-    },
     "node_modules/https-proxy-agent": {
       "version": "7.0.6",
       "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-7.0.6.tgz",
@@ -8436,6 +8338,12 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/opus-recorder": {
+      "version": "8.0.5",
+      "resolved": "https://registry.npmjs.org/opus-recorder/-/opus-recorder-8.0.5.tgz",
+      "integrity": "sha512-tBRXc9Btds7i3bVfA7d5rekAlyOcfsivt5vSIXHxRV1Oa+s6iXFW8omZ0Lm3ABWotVcEyKt96iIIUcgbV07YOw==",
+      "license": "MIT"
+    },
     "node_modules/ora": {
       "version": "8.2.0",
       "resolved": "https://registry.npmjs.org/ora/-/ora-8.2.0.tgz",
@@ -8533,11 +8441,6 @@
         "node": ">=6"
       }
     },
-    "node_modules/parse-cache-control": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/parse-cache-control/-/parse-cache-control-1.0.1.tgz",
-      "integrity": "sha512-60zvsJReQPX5/QP0Kzfd/VrpjScIQ7SHBW6bFCYfEP+fp0Eppr1SHhIO5nd1PjZtvclzSzES9D/p5nFJurwfWg=="
-    },
     "node_modules/parse-json": {
       "version": "5.2.0",
       "resolved": "https://registry.npmjs.org/parse-json/-/parse-json-5.2.0.tgz",
@@ -8826,15 +8729,6 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
-    "node_modules/progress": {
-      "version": "2.0.3",
-      "resolved": "https://registry.npmjs.org/progress/-/progress-2.0.3.tgz",
-      "integrity": "sha512-7PiHtLll5LdnKIMw100I+8xJXR5gW2QwWYkT6iJva0bXitZKa/XMrSbdmg3r2Xnaidz9Qumd0VPaMrZlF9V9sA==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.4.0"
-      }
-    },
     "node_modules/prompts": {
       "version": "2.4.2",
       "resolved": "https://registry.npmjs.org/prompts/-/prompts-2.4.2.tgz",
@@ -9001,20 +8895,6 @@
         }
       }
     },
-    "node_modules/readable-stream": {
-      "version": "3.6.2",
-      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.6.2.tgz",
-      "integrity": "sha512-9u/sniCrY3D5WdsERHzHE4G2YCXqoG5FTHUiCC4SIbr6XcLZBY05ya9EKjYek9O5xOAwjGq+1JdGBAS7Q9ScoA==",
-      "license": "MIT",
-      "dependencies": {
-        "inherits": "^2.0.3",
-        "string_decoder": "^1.1.1",
-        "util-deprecate": "^1.0.1"
-      },
-      "engines": {
-        "node": ">= 6"
-      }
-    },
     "node_modules/recast": {
       "version": "0.23.11",
       "resolved": "https://registry.npmjs.org/recast/-/recast-0.23.11.tgz",
@@ -9325,26 +9205,6 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
-    "node_modules/safe-buffer": {
-      "version": "5.2.1",
-      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
-      "integrity": "sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==",
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/feross"
-        },
-        {
-          "type": "patreon",
-          "url": "https://www.patreon.com/feross"
-        },
-        {
-          "type": "consulting",
-          "url": "https://feross.org/support"
-        }
-      ],
-      "license": "MIT"
-    },
     "node_modules/safe-push-apply": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/safe-push-apply/-/safe-push-apply-1.0.0.tgz",
@@ -9856,15 +9716,6 @@
         "node": ">= 0.4"
       }
     },
-    "node_modules/string_decoder": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.3.0.tgz",
-      "integrity": "sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA==",
-      "license": "MIT",
-      "dependencies": {
-        "safe-buffer": "~5.2.0"
-      }
-    },
     "node_modules/string-width": {
       "version": "7.2.0",
       "resolved": "https://registry.npmjs.org/string-width/-/string-width-7.2.0.tgz",
@@ -10418,12 +10269,6 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
-    "node_modules/typedarray": {
-      "version": "0.0.6",
-      "resolved": "https://registry.npmjs.org/typedarray/-/typedarray-0.0.6.tgz",
-      "integrity": "sha512-/aCDEGatGvZ2BIk+HmLf4ifCJFwvKFNb9/JeZPMulfgFracn9QFcAf5GO8B/mweUjSoblS5In0cWhqpfs/5PQA==",
-      "license": "MIT"
-    },
     "node_modules/typescript": {
       "version": "6.0.3",
       "resolved": "https://registry.npmjs.org/typescript/-/typescript-6.0.3.tgz",

package.json

@@ -50,9 +50,9 @@
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "date-fns": "^4.4.0",
-    "ffmpeg-static": "^5.3.0",
     "lucide-react": "^1.18.0",
     "next": "16.2.6",
+    "opus-recorder": "^8.0.5",
     "react": "19.2.4",
     "react-dom": "19.2.4",
     "recharts": "^3.8.1",

src/app/api/whatsapp/transcode-audio/route.ts

@@ -1,148 +0,0 @@
-import { NextResponse } from 'next/server'
-import { execFile } from 'node:child_process'
-import { mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
-import { tmpdir } from 'node:os'
-import { join } from 'node:path'
-import ffmpegStatic from 'ffmpeg-static'
-import { createClient } from '@/lib/supabase/server'
-import {
-  checkRateLimit,
-  rateLimitResponse,
-  RATE_LIMITS,
-} from '@/lib/rate-limit'
-import { buildFfmpegArgs } from '@/lib/whatsapp/audio-transcode'
-import { hasBetaFeature, CHAT_MEDIA_BETA } from '@/lib/auth/beta-features'
-
-// ffmpeg + temp-file I/O need the Node runtime (not Edge).
-export const runtime = 'nodejs'
-
-// Recorded clips are short voice notes — same 16 MB ceiling as the
-// chat-media bucket so we reject anything that couldn't be stored anyway.
-const MAX_INPUT_BYTES = 16 * 1024 * 1024
-
-/**
- * Resolve the ffmpeg binary path. `ffmpeg-static` ships a per-platform
- * binary and exports its absolute path; `FFMPEG_PATH` overrides it for
- * hosts where the bundled binary can't run (e.g. a system ffmpeg).
- */
-function resolveFfmpegPath(): string | null {
-  return process.env.FFMPEG_PATH || ffmpegStatic || null
-}
-
-function runFfmpeg(binary: string, args: string[]): Promise<void> {
-  return new Promise((resolve, reject) => {
-    execFile(binary, args, { timeout: 30_000 }, (error, _stdout, stderr) => {
-      if (error) {
-        reject(new Error(stderr?.toString().slice(-500) || error.message))
-        return
-      }
-      resolve()
-    })
-  })
-}
-
-/**
- * POST /api/whatsapp/transcode-audio
- *
- * Accepts a recorded audio clip (multipart form field `file`, typically
- * Chromium's WebM/Opus) and returns OGG/Opus bytes that Meta accepts and
- * WhatsApp renders as a playable voice note. The client only calls this
- * when its recording isn't already a Meta-accepted format — Firefox
- * records OGG and Safari records MP4/AAC, which skip the round-trip.
- *
- * The route does NOT upload anywhere: it returns the bytes and the client
- * uploads them to the account-scoped chat-media bucket (same RLS path as
- * every other attachment).
- */
-export async function POST(request: Request) {
-  try {
-    const supabase = await createClient()
-    const {
-      data: { user },
-      error: authError,
-    } = await supabase.auth.getUser()
-    if (authError || !user) {
-      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
-    }
-
-    const limit = checkRateLimit(`transcode:${user.id}`, RATE_LIMITS.transcodeAudio)
-    if (!limit.success) {
-      return rateLimitResponse(limit)
-    }
-
-    // Voice notes are part of the beta-gated media feature — only opted-in
-    // accounts may transcode (mirrors the send route + client gate).
-    const { data: profile } = await supabase
-      .from('profiles')
-      .select('beta_features')
-      .eq('user_id', user.id)
-      .maybeSingle()
-    if (!hasBetaFeature(profile?.beta_features, CHAT_MEDIA_BETA)) {
-      return NextResponse.json(
-        { error: 'Voice notes are not enabled for your account.' },
-        { status: 403 },
-      )
-    }
-
-    const ffmpegPath = resolveFfmpegPath()
-    if (!ffmpegPath) {
-      console.error('[transcode-audio] ffmpeg binary not found')
-      return NextResponse.json(
-        { error: 'Audio transcoding is unavailable on this server.' },
-        { status: 500 },
-      )
-    }
-
-    const form = await request.formData()
-    const file = form.get('file')
-    if (!(file instanceof File)) {
-      return NextResponse.json(
-        { error: 'Expected a `file` form field.' },
-        { status: 400 },
-      )
-    }
-    if (file.size === 0) {
-      return NextResponse.json({ error: 'Empty audio file.' }, { status: 400 })
-    }
-    if (file.size > MAX_INPUT_BYTES) {
-      return NextResponse.json(
-        { error: 'Audio clip exceeds the 16 MB limit.' },
-        { status: 400 },
-      )
-    }
-
-    // Stage input + output in a per-request temp dir so concurrent
-    // transcodes never collide, and clean it up no matter what.
-    const dir = await mkdtemp(join(tmpdir(), 'wacrm-audio-'))
-    const inputPath = join(dir, 'in')
-    const outputPath = join(dir, 'out.ogg')
-    try {
-      await writeFile(inputPath, Buffer.from(await file.arrayBuffer()))
-      await runFfmpeg(ffmpegPath, buildFfmpegArgs(inputPath, outputPath))
-      const ogg = await readFile(outputPath)
-      if (ogg.byteLength > MAX_INPUT_BYTES) {
-        return NextResponse.json(
-          { error: 'Transcoded audio exceeds the 16 MB limit.' },
-          { status: 400 },
-        )
-      }
-      return new Response(new Uint8Array(ogg), {
-        status: 200,
-        headers: {
-          'Content-Type': 'audio/ogg',
-          'Cache-Control': 'no-store',
-        },
-      })
-    } finally {
-      await rm(dir, { recursive: true, force: true }).catch(() => {})
-    }
-  } catch (error) {
-    const message =
-      error instanceof Error ? error.message : 'Audio transcoding failed'
-    console.error('[transcode-audio] failed:', message)
-    return NextResponse.json(
-      { error: 'Failed to process the recording.' },
-      { status: 500 },
-    )
-  }
-}

src/components/inbox/message-composer.tsx

@@ -108,14 +108,10 @@ function formatDuration(seconds: number): string {
   return `${m}:${s.toString().padStart(2, "0")}`;
 }
 
-/** A recording can skip the transcode round-trip only if it's already
+/** Worker that encodes mic input to Ogg/Opus entirely in the browser
- *  OGG/Opus — the one format WhatsApp reliably renders as a voice note
+ *  (vendored from opus-recorder into /public). Recording client-side in a
- *  with a waveform. Everything else (Chromium WebM, Safari MP4/AAC) is
+ *  Meta-accepted format means no server ffmpeg / transcode step. */
- *  remuxed server-side so the voice-note UX is consistent across
+const OPUS_ENCODER_PATH = "/opus/encoderWorker.min.js";
- *  browsers, not a plain audio attachment on some of them. */
-function isOggOpus(mime: string): boolean {
-  return mime.split(";")[0].trim().toLowerCase() === "audio/ogg";
-}
 
 export function MessageComposer({
   conversationId,
@@ -151,12 +147,11 @@ export function MessageComposer({
     void deleteAccountMedia(CHAT_MEDIA_BUCKET, path).catch(() => {});
   }, []);
 
-  // Voice recording state.
+  // Voice recording state. The recorder encodes Ogg/Opus in-browser
+  // (opus-recorder) so there's no server-side transcode.
   const [recording, setRecording] = useState(false);
   const [recordSeconds, setRecordSeconds] = useState(0);
-  const recorderRef = useRef<MediaRecorder | null>(null);
+  const recorderRef = useRef<import("opus-recorder").default | null>(null);
-  const chunksRef = useRef<Blob[]>([]);
-  const streamRef = useRef<MediaStream | null>(null);
   const cancelledRef = useRef(false);
   const timerRef = useRef<ReturnType<typeof setInterval> | null>(null);
 
@@ -185,7 +180,9 @@ export function MessageComposer({
   useEffect(() => {
     return () => {
       clearTimer();
-      streamRef.current?.getTracks().forEach((t) => t.stop());
+      cancelledRef.current = true;
+      // stop() releases the mic stream + audio context inside opus-recorder.
+      void recorderRef.current?.stop().catch(() => {});
       removeStaged(draftRef.current?.path);
     };
   }, [clearTimer, removeStaged]);
@@ -269,41 +266,29 @@ export function MessageComposer({
     [stageUpload],
   );
 
-  // ---- Voice recording ----------------------------------------------
+  // ---- Voice recording (client-side Ogg/Opus, no server transcode) ---
 
+  // The encoded Ogg/Opus file from opus-recorder → upload as an audio
+  // draft. WhatsApp renders Ogg/Opus as a playable voice note.
   const finalizeRecording = useCallback(
-    async (blob: Blob, mime: string) => {
+    async (bytes: Uint8Array) => {
+      // Uint8Array is a valid BlobPart at runtime; the cast sidesteps the
+      // lib.dom ArrayBufferLike-vs-ArrayBuffer generic mismatch.
+      const file = new File([bytes as unknown as BlobPart], `voice-${Date.now()}.ogg`, {
+        type: "audio/ogg",
+      });
+      if (file.size === 0) return; // cancelled / empty take
+      if (file.size > MEDIA_MAX_BYTES_BY_KIND.audio) {
+        toast.error("Recording is too long (over 16 MB).");
+        return;
+      }
       setBusy(true);
       try {
-        let file: File;
-        if (isOggOpus(mime)) {
-          // Firefox records OGG/Opus directly — upload as-is.
-          file = new File([blob], `voice-${Date.now()}.ogg`, { type: "audio/ogg" });
-        } else {
-          // Chromium (WebM) and Safari (MP4) are remuxed to OGG/Opus so
-          // WhatsApp renders a voice note, not a plain audio attachment.
-          const form = new FormData();
-          form.append("file", blob, "recording");
-          const res = await fetch("/api/whatsapp/transcode-audio", {
-            method: "POST",
-            body: form,
-          });
-          if (!res.ok) {
-            const payload = await res.json().catch(() => ({}));
-            throw new Error(payload?.error || `Transcode failed (HTTP ${res.status})`);
-          }
-          const ogg = await res.blob();
-          file = new File([ogg], `voice-${Date.now()}.ogg`, { type: "audio/ogg" });
-        }
-        if (file.size > MEDIA_MAX_BYTES_BY_KIND.audio) {
-          toast.error("Recording is too long (over 16 MB).");
-          return;
-        }
         const { publicUrl, path } = await uploadAccountMedia(CHAT_MEDIA_BUCKET, file);
         removeStaged(draftRef.current?.path);
         setDraft({ kind: "audio", mediaUrl: publicUrl, path, filename: file.name, caption: "" });
       } catch (err) {
-        toast.error(err instanceof Error ? err.message : "Could not process the recording.");
+        toast.error(err instanceof Error ? err.message : "Upload failed.");
       } finally {
         setBusy(false);
       }
@@ -313,41 +298,34 @@ export function MessageComposer({
 
   const startRecording = useCallback(async () => {
     if (inputsDisabled || busy || recording) return;
-    if (typeof MediaRecorder === "undefined" || !navigator.mediaDevices?.getUserMedia) {
+    if (!navigator.mediaDevices?.getUserMedia || typeof AudioContext === "undefined") {
       toast.error("Voice recording isn't supported in this browser.");
       return;
     }
     try {
-      const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
+      // Lazy-load the encoder (≈400 KB worker) only when the user records,
-      streamRef.current = stream;
+      // keeping it out of the main bundle.
-      // Prefer a Meta-accepted container (Firefox supports ogg/opus) so
+      const { default: Recorder } = await import("opus-recorder");
-      // we can skip the transcode round-trip; Chromium falls back to webm.
+      const recorder = new Recorder({
-      const preferred = ["audio/ogg;codecs=opus", "audio/webm;codecs=opus", "audio/webm"];
+        encoderPath: OPUS_ENCODER_PATH,
-      const mimeType = preferred.find((t) => MediaRecorder.isTypeSupported(t)) || "";
+        numberOfChannels: 1,
-      const recorder = new MediaRecorder(stream, mimeType ? { mimeType } : undefined);
+        encoderApplication: 2048, // VOIP — tuned for speech
-      chunksRef.current = [];
+        encoderSampleRate: 48000,
+        streamPages: false, // one callback with the complete file on stop
+      });
       cancelledRef.current = false;
-      recorder.ondataavailable = (e) => {
+      recorder.ondataavailable = (bytes) => {
-        if (e.data.size > 0) chunksRef.current.push(e.data);
-      };
-      recorder.onstop = () => {
-        stream.getTracks().forEach((t) => t.stop());
-        streamRef.current = null;
-        const chunks = chunksRef.current;
-        chunksRef.current = [];
         if (cancelledRef.current) return;
-        const type = recorder.mimeType || mimeType || "audio/webm";
+        void finalizeRecording(bytes);
-        const blob = new Blob(chunks, { type });
-        if (blob.size > 0) void finalizeRecording(blob, type);
       };
       recorderRef.current = recorder;
-      recorder.start();
+      await recorder.start();
       setRecording(true);
       setRecordSeconds(0);
       timerRef.current = setInterval(() => setRecordSeconds((s) => s + 1), 1000);
     } catch {
-      streamRef.current?.getTracks().forEach((t) => t.stop());
+      void recorderRef.current?.stop().catch(() => {});
-      streamRef.current = null;
+      recorderRef.current = null;
       toast.error("Microphone access denied or unavailable.");
     }
   }, [inputsDisabled, busy, recording, finalizeRecording]);
@@ -355,18 +333,18 @@ export function MessageComposer({
   const stopRecording = useCallback(() => {
     clearTimer();
     setRecording(false);
-    recorderRef.current?.stop();
+    void recorderRef.current?.stop().catch(() => {});
   }, [clearTimer]);
 
   const cancelRecording = useCallback(() => {
     cancelledRef.current = true;
     clearTimer();
     setRecording(false);
-    recorderRef.current?.stop();
+    void recorderRef.current?.stop().catch(() => {});
   }, [clearTimer]);
 
   // Auto-stop at the cap so a forgotten recording can't blow the
-  // upload/transcode limits.
+  // upload size limit.
   useEffect(() => {
     if (recording && recordSeconds >= MAX_RECORDING_SECONDS) {
       stopRecording();

src/lib/rate-limit.ts

@@ -125,10 +125,6 @@ export const RATE_LIMITS = {
    *  fidget with reactions and a single "swap" is actually two calls
    *  (remove + add) under the hood. */
   react: { limit: 120, windowMs: 60_000 },
-  /** Voice-note transcode (WebM/Opus → OGG/Opus). One call per recorded
-   *  clip; tighter than send because each spawns an ffmpeg process. 20/min
-   *  is far above any human recording cadence. */
-  transcodeAudio: { limit: 20, windowMs: 60_000 },
   /** Invitation peek (public, per-IP). 30/min lets a forwarded link
    *  retry a handful of times under flaky connectivity without
    *  enabling brute-force token enumeration. With 256-bit tokens the

src/lib/whatsapp/audio-transcode.test.ts

@@ -1,43 +0,0 @@
-import { describe, expect, it } from "vitest";
-import {
-  buildFfmpegArgs,
-  isMetaAcceptedAudio,
-  META_ACCEPTED_AUDIO_MIME,
-} from "./audio-transcode";
-
-describe("isMetaAcceptedAudio", () => {
-  it("accepts the Meta-supported audio types", () => {
-    for (const mime of META_ACCEPTED_AUDIO_MIME) {
-      expect(isMetaAcceptedAudio(mime)).toBe(true);
-    }
-  });
-
-  it("strips the codec suffix before matching", () => {
-    expect(isMetaAcceptedAudio("audio/ogg;codecs=opus")).toBe(true);
-    expect(isMetaAcceptedAudio("audio/mp4; codecs=mp4a.40.2")).toBe(true);
-  });
-
-  it("rejects WebM (Chromium's MediaRecorder default) — needs transcode", () => {
-    expect(isMetaAcceptedAudio("audio/webm")).toBe(false);
-    expect(isMetaAcceptedAudio("audio/webm;codecs=opus")).toBe(false);
-  });
-
-  it("rejects empty / nullish input", () => {
-    expect(isMetaAcceptedAudio("")).toBe(false);
-    expect(isMetaAcceptedAudio(undefined)).toBe(false);
-    expect(isMetaAcceptedAudio(null)).toBe(false);
-  });
-});
-
-describe("buildFfmpegArgs", () => {
-  it("targets OGG/Opus mono and overwrites the output", () => {
-    const args = buildFfmpegArgs("/tmp/in", "/tmp/out.ogg");
-    expect(args).toContain("-y");
-    expect(args).toEqual(expect.arrayContaining(["-i", "/tmp/in"]));
-    expect(args).toEqual(expect.arrayContaining(["-c:a", "libopus"]));
-    expect(args).toEqual(expect.arrayContaining(["-f", "ogg"]));
-    expect(args).toEqual(expect.arrayContaining(["-ac", "1"]));
-    // Output path is last so ffmpeg treats it as the destination.
-    expect(args[args.length - 1]).toBe("/tmp/out.ogg");
-  });
-});

src/lib/whatsapp/audio-transcode.ts

@@ -1,63 +0,0 @@
-/**
- * Pure helpers for the voice-note transcode flow. Kept free of Node /
- * ffmpeg imports so they can be unit-tested without spawning a process —
- * the route handler (`/api/whatsapp/transcode-audio`) does the actual
- * spawning.
- */
-
-/**
- * Audio MIME types Meta accepts for OUTBOUND messages on the WhatsApp
- * Cloud API. Anything outside this set must be transcoded before send.
- * Notably absent: `audio/webm` (Chromium's default MediaRecorder output)
- * — which is exactly why the transcode step exists.
- *
- * https://developers.facebook.com/docs/whatsapp/cloud-api/reference/media#supported-media-types
- */
-export const META_ACCEPTED_AUDIO_MIME = new Set<string>([
-  "audio/aac",
-  "audio/mp4",
-  "audio/mpeg",
-  "audio/amr",
-  "audio/ogg", // Opus only — the codec MediaRecorder + ffmpeg produce here
-]);
-
-/**
- * Whether a recorded clip's MIME type can be sent to Meta as-is. The
- * client only round-trips through the transcode route when this is false.
- * The codec suffix (e.g. `audio/ogg;codecs=opus`) is stripped before the
- * lookup.
- */
-export function isMetaAcceptedAudio(mimeType: string | undefined | null): boolean {
-  if (!mimeType) return false;
-  const base = mimeType.split(";")[0]!.trim().toLowerCase();
-  return META_ACCEPTED_AUDIO_MIME.has(base);
-}
-
-/**
- * ffmpeg arguments to remux/encode an arbitrary recorded clip into
- * OGG/Opus — the format WhatsApp renders as a playable voice note.
- *
- * We re-encode to libopus rather than `-c:a copy` so the output is valid
- * regardless of the input container/codec (Chromium gives WebM/Opus,
- * older browsers may give other codecs). Opus at 48k mono is the voice-
- * note sweet spot and keeps the file tiny.
- */
-export function buildFfmpegArgs(inputPath: string, outputPath: string): string[] {
-  return [
-    "-y", // overwrite output if it exists
-    "-i",
-    inputPath,
-    "-vn", // no video stream
-    "-c:a",
-    "libopus",
-    "-b:a",
-    "32k",
-    "-ar",
-    "48000",
-    "-ac",
-    "1",
-    "-f",
-    "ogg",
-    outputPath,
-  ];
-}

src/types/ffmpeg-static.d.ts

@@ -1,7 +0,0 @@
-// `ffmpeg-static` ships no type declarations. Its default export is the
-// absolute path to the bundled ffmpeg binary (or null if unavailable on
-// the current platform).
-declare module "ffmpeg-static" {
-  const ffmpegPath: string | null;
-  export default ffmpegPath;
-}

src/types/opus-recorder.d.ts

@@ -0,0 +1,31 @@
+// `opus-recorder` ships no type declarations. We use a small subset of its
+// API: construct a Recorder, start()/stop(), and receive the encoded
+// Ogg/Opus file via `ondataavailable`. See https://github.com/chris-rudmin/opus-recorder
+declare module "opus-recorder" {
+  interface RecorderConfig {
+    /** URL of the encoder worker (served from /public). */
+    encoderPath?: string;
+    /** Media track constraints, or `true` for default audio. */
+    mediaTrackConstraints?: MediaTrackConstraints | boolean;
+    /** 1 = mono, 2 = stereo. */
+    numberOfChannels?: number;
+    /** 2048 = Voice, 2049 = Full Band Audio, 2051 = Restricted Low Delay. */
+    encoderApplication?: number;
+    /** 8000 | 12000 | 16000 | 24000 | 48000. */
+    encoderSampleRate?: number;
+    /** Target bitrate in bits/sec. */
+    encoderBitRate?: number;
+    /** When false (default), ondataavailable fires once with the full file. */
+    streamPages?: boolean;
+  }
+
+  export default class Recorder {
+    constructor(config?: RecorderConfig);
+    /** Fired with the encoded audio bytes (full Ogg/Opus file when streamPages is false). */
+    ondataavailable: ((data: Uint8Array) => void) | null;
+    start(): Promise<void>;
+    stop(): Promise<void>;
+    /** Browser support probe exposed as a static on the class. */
+    static isRecordingSupported(): boolean;
+  }
+}