AlterPhone MCP

Let your AI assistant make real phone calls.

AlterPhone MCP is a hosted Model Context Protocol server. Connect it to Claude, ChatGPT, Cursor, Claude Code or any other MCP client, and the assistant can dial a real phone number, hold a spoken conversation in one of 12 languages, and report back what was said: book or reschedule appointments, ask a business a question, negotiate, confirm an order, screen a caller, run a survey.

Server URL: https://mcp.alterphone.app/mcp (Streamable HTTP)
Registry name: app.alterphone/phone-calls in the official MCP Registry
Auth: OAuth 2.1 with PKCE and dynamic client registration. Sign in with Google or Apple on first use.
Billing: prepaid credits, 100 credits per US dollar, per started minute at the destination rate (about 8 credits per minute to the US). Same account and balance as the AlterPhone app.

Full details, tools and supported countries: https://alterphone.app/mcp.html

Quick start

Claude (claude.ai and Claude Desktop)

Settings → Connectors → Add custom connector → enter https://mcp.alterphone.app/mcp → complete the sign-in.

ChatGPT

Settings → Connectors → create a connector with the server URL https://mcp.alterphone.app/mcp → complete the sign-in. Custom MCP connectors require developer mode on your plan.

Claude Code

Terminal

claude mcp add --transport http -s user alterphone https://mcp.alterphone.app/mcp

Cursor, Windsurf and other clients with an MCP config file

config.json

{
  "mcpServers": {
    "alterphone": {
      "url": "https://mcp.alterphone.app/mcp"
    }
  }
}

Clients that only run local (stdio) servers

This package is a thin bridge for that case. It delegates to mcp-remote, which performs the browser sign-in, caches the tokens locally and forwards every message to the hosted server:

config.json

{
  "mcpServers": {
    "alterphone": {
      "command": "npx",
      "args": ["-y", "alterphone-mcp"]
    }
  }
}

Requires Node.js 18 or newer. Set ALTERPHONE_MCP_URL to point the bridge at a different server.

Tools

Tool	Description
`have_conversation`	Dial a number and pursue an objective autonomously. Streams the transcript and returns the collected answers and a summary. The main tool.
`place_call`	Dial a number, optionally with a greeting, for turn-by-turn control.
`speak_and_listen`	Say something and return what the other party replied.
`listen`	Wait for the other party to speak and return the transcript.
`hangup`	End the call.
`get_balance`	Read the prepaid credit balance.
`purchase_credits`	Top up with the saved payment method, within a daily cap.

Every tool carries readOnlyHint / destructiveHint annotations.

Safety and limits

Outbound calls only, to the US, Canada, the UK, Germany, France, Italy, Spain, the Netherlands, Belgium, Portugal, Poland, Romania, Turkey, Russia, India, Australia, Saudi Arabia, the UAE, Egypt, Morocco, Algeria, Tunisia and Libya.
Emergency, premium-rate and satellite numbers are refused before dialing. Conversation plans are screened for fraud, harassment, impersonation and other prohibited uses.
One active call per account. Transcripts are kept for 24 hours; see section 12 of the privacy policy.

For developers

OAuth discovery: https://mcp.alterphone.app/.well-known/oauth-protected-resource; authorization server https://alterphone.app.
Scopes: calls:write, balance:read, credits:purchase.
REST description of the call service, for integrations that do not speak MCP: https://calls.alterphone.app/openapi.json
Machine-readable summary: https://alterphone.app/llms.txt

Support

support@alterphone.app · Terms of service

License

MIT