How to give Claude or any MCP agent a phone number

An MCP server turns a telephony API into tools an AI agent can call. With the right server installed, Claude Code or Claude Desktop can buy a number, send a text, or place a call from a chat. This guide compares the telephony MCP servers available today and shows how to install each one. Facts come from each vendor's docs, checked on October 8, 2026.

What each server can do

Generic tools. Telnyx and Retell expose three tools: list endpoints, get an endpoint's schema, and invoke an endpoint. The agent can reach the whole API this way, but it must find the right endpoint first. Dedicated tools such as AgentPhone's send_message are easier for a model to use correctly.

AgentPhone

AgentPhone's server has 28 tools, including buy_number, send_message (SMS or iMessage), get_messages, make_call, attach_number, and set_webhook. Numbers are US and Canada.

Claude Code:

claude mcp add --transport http agentphone https://mcp.agentphone.ai/mcp

This signs in through your browser. To use an API key instead, add --header "Authorization: Bearer YOUR_API_KEY". In Claude Desktop, open Settings > Connectors > Add custom connector and paste the URL. Numbers cost $3 per month and SMS costs $0.02 per segment. Docs.

Telnyx

Telnyx's remote server at https://api.telnyx.com/v2/mcp gives the agent the full Telnyx API: search numbers, buy them, send messages, and control calls. invoke_api_endpoint can change state and spend money, so scope your API key with care.

In Claude Desktop, add it as a custom connector under Settings > Connectors, then grant access in the Telnyx Portal. Telnyx also ships a local server:

claude mcp add telnyx_mcp_api --env TELNYX_API_KEY="YOUR_KEY" -- npx -y telnyx-mcp

The local package runs in "code mode": a docs search tool plus a tool that runs Telnyx SDK code in a sandbox. Docs.

Retell

claude mcp add --transport http retell https://mcp.retellai.com \
  --header "Authorization: Bearer $RETELL_API_KEY"

The server can import, provision, and list phone numbers and create calls. Use it when your voice agent already runs on Retell. Docs.

Bland

claude mcp add --transport http bland https://api.bland.ai/v1/mcp \
  --header "Authorization: Bearer $BLAND_API_KEY"

To sign in without a key, add the server without the header, then run claude mcp login bland. Bland marks create_call as destructive. It also has wait_for_call and get_call_log, so an agent can place a call and read the result. Docs.

Bland also sells an Agent Phone Plan that an agent can sign up for itself: one US number with calls and texts for $29.99 per month, capped at 50 calls and 100 texts per day.

Vapi

Vapi's hosted server is at https://mcp.vapi.ai/mcp with a Bearer Vapi API key. It can create assistants and calls and list phone numbers. It cannot buy or import numbers and has no SMS tool. Get a number in the dashboard first. See connect a phone number to Vapi. Docs.

Twilio

Twilio's official MCP server (public beta) is read-only. It searches Twilio's documentation and does not execute API calls. It cannot send SMS, make calls, or buy numbers.

claude mcp add --transport http twilio-docs https://mcp.twilio.com/docs

Twilio's older @twilio-alpha/mcp package exposes the Twilio API as tools, but Twilio calls it a proof of concept. Limit it to the services you need with --services or --tags. Docs.

Safety rules for agents with a phone

A phone number lets an agent reach real people and spend real money. Set limits before you hand it over.

• Use a scoped key. Give the agent a key for a sub-account or a project with a spend cap, not your main account key.
• Require approval for outbound actions. Claude Code asks before each tool call by default. Keep that on for send_message, make_call, and buy_number.
• Respect consent. In the US, texting or calling people with an automated system or AI voice needs their consent. Business texts from local numbers need A2P 10DLC registration.
• Never use agent numbers for verification bypass. Using a number to receive one-time codes for accounts you do not own breaks most terms of service.
• Log everything. Keep a record of each message and call the agent made.

Where Numbers for Agents fits

Numbers for Agents is building a number API designed for agents: numbers, SMS, signed webhooks, SIP, and raw WebSocket audio for teams that run their own voice stack. It is in private beta. Join the waitlist below to get access.

FAQ

Can Claude make phone calls?

Yes, through an MCP server. Install a telephony MCP server such as AgentPhone, Bland, Retell, or Vapi in Claude Code or Claude Desktop. Claude can then place calls through that provider's tools. The provider runs the voice on the call.

Can Claude send a text message?

Yes. With AgentPhone's MCP server, Claude can send SMS with send_message. With Telnyx's remote MCP server, Claude can call the messaging API. You need a number on that account first.

Does Twilio have an MCP server?

Yes, but the official one only searches Twilio's docs. The @twilio-alpha/mcp package can call the Twilio API, and Twilio labels it a proof of concept.

Is it safe to give an AI agent a phone number?

It is safe with limits: a scoped API key, a spend cap, approval for outbound messages and calls, and consent from the people the agent contacts.