MeetVcon

Chrome extension that transcribes Google Meet calls using the browser's built-in captions and POSTs each transcript as an IETF vCon (Virtualized Conversation) JSON document to a user-configured HTTPS webhook.

• No external speech-to-text. No Whisper, no Deepgram, no Google STT API. Transcription quality is whatever Meet's browser captions provide.
• No bot joins your call. A floating panel reads captions from the DOM.
• No third-party servers. The transcript leaves your device only when it's POSTed to the webhook you configure.
• Standard format. Receivers consume application/vcon+json, the emerging standard for interoperable conversation data.

See PRD.md for the full product specification.

Features

• Captions auto-enable. On joining a call, MeetVcon turns Meet's captions on for you and re-enables them within ~10 seconds if they get turned off mid-call (rate-limited; respects an explicit user opt-out).
• Two delivery modes.
  • end_of_call (default): one POST per call, on hangup.
  • periodic_snapshot: every N minutes (1–60), POST a cumulative snapshot using the same vCon UUID. Survives tab crashes; supports near-real-time receivers.
• Reliable delivery. Exponential-backoff retry queue (30s → 24h), persisted across service-worker restarts. Snapshot dedup so stale retries don't clobber fresh data.
• Authenticated webhooks. Optional Bearer token and optional HMAC-SHA256 body signature.
• Capturer attribution. Each vCon includes the Chrome profile email of the user who ran the extension (toggleable).
• In-call status panel with capture indicator and one-click opt-out / try-again.
• Popup UI. Pending-delivery queue (Retry / Download vCon / Discard) and recent-meetings list.

Install (developer mode)

The extension is not yet published on the Chrome Web Store. To run it:

1. Clone this repo (or download the source zip):

   git clone https://github.com/sippulse/meetvcon.git

2. Open chrome://extensions (or edge://extensions, brave://extensions).
3. Toggle Developer mode in the top right.
4. Click Load unpacked and select the cloned meetvcon/ directory.
5. Pin the extension from the toolbar puzzle-piece menu.

For detailed steps, how to update (git pull + reload), uninstall, and troubleshooting, see INSTALL.md.

Configure

Right-click the MeetVcon icon → Options.

Field	Required	Description
Webhook URL	yes	HTTPS endpoint that receives the vCon payloads.
Bearer token	no	Sent as Authorization: Bearer <token> if set.
HMAC signing secret	no	If set, payloads are signed: X-MeetVcon-Signature: sha256=<hex> (HMAC-SHA256 over the raw body).
Delivery mode	yes	end_of_call (default) or periodic_snapshot.
Snapshot interval	conditional	Minutes between snapshots, when in periodic_snapshot mode (1–60, default 5).
Include capturer email	no	When on (default), the Chrome profile email is included in attachments[0].body.captured_by_user.email.

Click Send test payload to verify your receiver gets a vCon before joining a real call.

vCon payload shape

Conforms to draft-ietf-vcon-vcon-container. Minimum example:

{
  "vcon": "0.0.1",
  "uuid": "018f3a1c-...",
  "created_at": "2026-04-30T14:32:11Z",
  "subject": "Weekly sync",
  "parties": [
    { "name": "Flavio Costa" },
    { "name": "Jane Doe" }
  ],
  "dialog": [
    { "type": "text", "start": "2026-04-30T14:32:15Z",
      "duration": 4.2, "parties": [0],
      "body": "Thanks everyone for joining." }
  ],
  "analysis": [],
  "attachments": [
    {
      "type": "meeting_metadata",
      "encoding": "json",
      "body": {
        "platform": "google_meet",
        "meeting_code": "abc-defg-hij",
        "meeting_url": "https://meet.google.com/abc-defg-hij",
        "captured_by": "MeetVcon/0.1.0",
        "captions_enabled": true,
        "delivery_kind": "final",
        "captured_by_user": {
          "email": "you@example.com",
          "id": "1234567890abcdef"
        }
      }
    }
  ]
}

Webhook receiver: minimal example

Any HTTPS endpoint will work. A throwaway Node.js receiver for testing:

import http from "node:http";
http
  .createServer((req, res) => {
    let body = "";
    req.on("data", (c) => (body += c));
    req.on("end", () => {
      console.log(req.method, req.url, req.headers["x-meetvcon-delivery"]);
      console.log(JSON.parse(body));
      res.writeHead(200).end("ok");
    });
  })
  .listen(8443);

Expose it over HTTPS for testing with ngrok http 8443, then paste the ngrok URL into MeetVcon's options page.

Architecture

┌──────────────────────────┐     ┌──────────────────────┐     ┌─────────────────┐
│ Content script           │     │ Service worker (MV3) │     │ Options / popup │
│ (meet.google.com)        │     │                      │     │                 │
│                          │     │  - delivery queue    │     │  - webhook URL  │
│  - DOM caption scraper   │────▶│  - retry/backoff     │     │  - bearer token │
│  - in-call UI panel      │     │  - HMAC signing      │     │  - HMAC secret  │
│  - end-of-call detector  │     │  - snapshot alarms   │     │  - test send    │
│  - captions watchdog     │     │  - identity API      │     │  - queue mgmt   │
└──────────────────────────┘     └──────────┬───────────┘     └─────────────────┘
                                            │
                                            ▼
                                     HTTPS POST (vCon)
                                            │
                                            ▼
                                  user's configured endpoint

Project layout

manifest.json                          MV3 manifest
PRD.md                                 product spec
CHANGELOG.md
LICENSE
src/
  lib/
    logger.js                          shared [MeetVcon] logger
    selectors.js                       Meet DOM selectors (multilingual)
    storage.js                         chrome.storage helpers
    vcon.js                            vCon assembler
  content/
    captions-watchdog.js               auto-enable + monitoring
    transcript-capture.js              caption DOM observer
    in-call-panel.js                   floating status overlay
    panel.css
    main.js                            content-script orchestrator
  background/
    service-worker.js                  delivery + retry + alarms
  options/                             webhook config
  popup/                               queue + recent-meetings UI
.github/
  ISSUE_TEMPLATE/
  PULL_REQUEST_TEMPLATE.md

Privacy

• Transcripts never leave the device until POSTed to your webhook.
• No telemetry, no analytics, no third-party services.
• No external STT or LLM. Transcription is whatever Meet's browser captions produce.
• Webhook URL, bearer token, and HMAC secret are stored exclusively in chrome.storage.local and are never hardcoded in source.

Legal & consent

Recording or transcribing a meeting may be subject to consent requirements in your jurisdiction (e.g., two-party-consent states in the US, GDPR in the EU). The in-call panel is non-removable during capture so participants can see that transcription is active. You are responsible for obtaining participant consent where required.

Contributing

Issues and PRs welcome. The most common breakage is a Google Meet DOM change. If captions stop being captured, look first at src/lib/selectors.js.

For security issues, email security@sippulse.com instead of opening a public issue.

License

MIT © 2026 SipPulse.