call4me MCP server

call4me

https://call4.me

Your coding agent (Claude Code, Codex, Claude Desktop, ChatGPT) gets one new tool: make a phone call. Prepaid credits from $10 via Stripe Checkout, reloading monthly by default; one MCP URL with the key in it.

How a call works

agent ──MCP──▶ worker ──POST /v2/calls──▶ Telnyx ──PSTN──▶ business
                  ▲                          │ media stream (PCMU, bidirectional RTP)
                  │ webhooks                 ▼
                  └──────────────── VoiceSession (Durable Object) ◀──WS──▶ GPT-Live (gpt-live-1, audio/pcmu 8k)
                                                                           └─ back office (Responses model):
                                                                              end_call · ask_user · press_digits

no recording notice, no end-of-call read-back; honest if sincerely asked whether it's an AI.

• src/server/voice/prompt.ts: what the caller is told. The product lives here: no opening disclosure,

verified to call from. Telnyx keeps one verified-number list for our whole carrier account, so verified_numbers ties each to the one call4me account that submitted a fresh code for it; a number Telnyx already lists as verified is never handed to another account. A call from an own number (from) only reaches businesses in its country, and still rings the user from a call4me number.

• src/server/voice/session.ts: the audio relay and back-office functions.
• src/server/services/dialer.ts: placing calls, per-account numbers, answering callbacks.
• src/server/services/numbers.ts: the account's call4me numbers, and the user's own numbers

• src/server/mcp/server.ts: the MCP tools.

The app does not request recording when dialing or answering. Existing recordings stored by Telnyx can be played or opened from the signed in call page after a call ends, or retrieved using call4megetrecordings({ callid }) over MCP, or GET /api/calls/{callid}/recordings with a call4me API key or OAuth token in the Bearer header. Both check account ownership before contacting Telnyx and return fresh download links without storing them. Empty results can mean processing is pending or no recording was saved. Links may expire and should only be shared with the account owner.

Trunk recordings use call leg IDs. A separate provider ID table receives these from verified webhooks; existing calls resolve them from an exact control ID match in Telnyx webhook history. The app never guesses a match from phone numbers or timestamps. If provider history has expired and no mapping was saved, only recordings directly associated with the control ID can be found.

The recording lookup never contacts the voice session or changes prompts, live tools, audio, or Telnyx recording settings. Existing call status and transcript responses are unchanged.

The recording API's OpenAPI document is served at /api/openapi.json. Run npm run openapi:generate to regenerate openapi.json from the shared MCP and HTTP schemas. CI checks the generated artifact for drift. Run npm test, npm run check, npm run lint, and npx wrangler deploy --dry-run before deploying through git.

Menu recovery tracks fresh phone prompts separately from transcript timestamps and remembers accepted keypad submissions. Repeated menus, invalid input, and recorded instruction dead ends can restart the existing back office after the recording goes quiet. It waits for pending tools and their continuations, avoids interrupting holds or a person answering, and asks the model to choose a supported route from the heard options rather than blindly replaying digits.

Shortened. The full README is on GitHub.