ConferenceCaptioning

ConfCapMcp

A read-only MCP server for ConferenceCaptioning. It lets an AI assistant read your stream's live captions and translations, your saved transcripts and your audience questions, using a developer API key you create in the portal.

Privacy: everything a tool returns is sent to the AI model you connected. If you promised attendees that captions stay private, check that model provider's terms first.

Setup

1. In the portal (https://app.deafassistant.com), open Advanced Settings and choose Create Developer API Key. Copy the key (it is shown once). It is read-only, and you can delete it any time.
2. Build: npm install && npm run build.
3. Add the server to your client. Claude Desktop (claude_desktop_config.json) or any stdio MCP client:

{  "mcpServers": {    "confcap": {      "command": "node",      "args": ["/path/to/ConfCapMcp/dist/src/index.js"],      "env": { "CONFCAP_KEY": "cck_...", "CONFCAP_STREAM": "yourstream" }    }  }}

Claude Code: claude mcp add confcap -e CONFCAP_KEY=cck_... -e CONFCAP_STREAM=yourstream -- node /path/to/ConfCapMcp/dist/src/index.js

Keep the key out of source control. See the Developer API docs.

Hosted mode

MCP_TRANSPORT=http PORT=8787 node dist/src/index.js runs a stateless streamable-HTTP endpoint (POST /mcp, GET /healthz) instead of stdio. Each request carries its own key (Authorization: Bearer cck_...), optionally X-Confcap-Stream and X-Confcap-Auth. Nothing is stored; callers never share cached text; 60 requests a minute per caller. Self-hosting as a systemd service behind nginx, with memory and CPU caps, is in deploy/README.md.

Connect a client to the hosted server (nothing to install)

The hosted endpoint is https://mcp.deafassistant.com/mcp. Create a key in the portal (step 1 above), then:

• Claude Code: claude mcp add --transport http confcap https://mcp.deafassistant.com/mcp --header "Authorization: Bearer cck_..." (add --header "X-Confcap-Stream: yourstream" to set a default stream).
• Claude Desktop (tested): Settings > Connectors > Add > Add custom connector. Name ConferenceCaptioning, MCP server URL https://mcp.deafassistant.com/mcp, then Continue. It reports "no sign-in" (we do not use OAuth); open Request headers, add the header Authorization with the value Bearer followed by your key, and click Add. Then start a chat and ask "what can the ConferenceCaptioning connector do".
• Any other client with remote MCP and custom headers: the same URL with the header Authorization: Bearer cck_.... Clients that only offer OAuth sign-in cannot send a static header yet.
• Clients that only speak stdio: npx mcp-remote https://mcp.deafassistant.com/mcp --header "Authorization: Bearer cck_..." bridges to the hosted URL.

The key is sent on every request, so treat the client's config file like a password file. Check the connection with HOSTED_URL=https://mcp.deafassistant.com node scripts/live-smoke.mjs (needs a portal login and FIREBASE_API_KEY, see below).

Listing in the MCP Registry

server.json describes the hosted server for the official MCP Registry (a remote, streamable-http server that needs an Authorization header). It is published by the "Publish to the MCP Registry" workflow (.github/workflows/publish-registry.yml) through GitHub's OIDC login, because an organization namespace (io.github.TheFirstPrototype) cannot be published from a laptop's mcp-publisher login github. Push a tag such as v0.1.0 (the tag becomes the version), or run the workflow by hand. The registry checks that you control the namespace, not the server URL.

Tools

Also: resources confcap://stream/{name}/status and confcap://stream/{name}/transcript/{id}, and prompts meeting_minutes, triage_questions, catch_me_up, translate_summary.

Good to know:

• Translations are a window of recent text that is re-translated as people speak. Saved transcripts are in the spoken language only; ask the assistant to translate them.
• Only some streams store history, and only sessions of 100 characters or more.
• Speech and questions come back wrapped in <untrusted-text>: other people wrote them, so a model should treat them as data, never as instructions.

Safety properties (all tested)

• Only GET requests. The server has no code path that writes or deletes, and the key is read-only on the server as well.
• Credentials come only from the environment, never from tool arguments. They are redacted from errors and never logged.
• The account uid and the admin code are never used or sent.
• Calls to one stream are spaced at one per second and overall at five per second; 429 and 5xx are retried with backoff.
• Two server instances never share cached text.

Live smoke test (stdio, or HOSTED_URL=https://... node scripts/live-smoke.mjs for the hosted endpoint)

Runs the built server against the real API with a throwaway key (created and deleted by the script), calls every tool read-only, and checks that neither the key nor the account uid appears in any output.

npm run buildFIREBASE_API_KEY='portal Firebase web apiKey' T_EMAIL='<portal login of an account that owns a stream>' T_PASS='<password>' npm run live-smoke

Optional: SMOKE_STREAM (default: the account's first stream), API_BASE_URL. Exit code 0 means it passed. Never commit the password. The related checks are ConfCapApi/scripts/live_developer_keys_check.py (API) and ConfCapPortal/e2e (portal UI).

Development

npm test builds and runs the tests (a real local mock API, the protocol through the SDK's in-memory transport, and mutation-style checks described in test/). The server uses the v1.x SDK, which supports the 2025-11-25 MCP spec.