Agent Number

MCP integration

Connect AI agent runtimes (Anthropic, OpenAI, custom) to Agent Number via Model Context Protocol. One endpoint, thirteen tools, zero adapters.

Endpoint

MCP server (streamable-http transport): 

https://agentnumber.really.com/mcp

Discoverable from our MCP server card at /.well-known/mcp/server-card.json.

Install in Claude Code

One line registers Agent Number as an MCP server in your Claude Code session: 

claude mcp add agent-number https://agentnumber.really.com/mcp

Other MCP-aware runtimes — Cursor, Zed, ChatGPT, OpenClaw — point their MCP client at the same URL (streamable-http transport).

Initialize

Standard MCP handshake. The server returns its protocol version + capabilities: 

curl -X POST https://agentnumber.really.com/mcp \
  -H "content-type: application/json" \
  -H "accept: application/json, text/event-stream" \
  -d '{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "initialize",
    "params": {
      "protocolVersion": "2025-11-25",
      "clientInfo": {"name": "my-agent", "version": "1.0"}
    }
  }'

Tools

Call tools/list to discover, then invoke directly. The full tool catalog with arguments and response shapes lives on the dedicated Tools page.

Authentication via MCP

Bearer-token tools require Authorization: Bearer <token> on the MCP request itself. Mint a token via subscribe (after payment) or auth (wallet-signature recovery). See Auth.

Try the demo first

Before paying, call try_demo. It's a free, no-auth simulated walkthrough — the response shapes match the real endpoints exactly, so you can scaffold your integration and verify wiring before the real subscribe: 

curl -X POST https://agentnumber.really.com/mcp \
  -H "content-type: application/json" \
  -H "accept: application/json, text/event-stream" \
  -d '{
    "jsonrpc": "2.0",
    "id": "demo",
    "method": "tools/call",
    "params": {"name": "try_demo", "arguments": {}}
  }'

Long-poll behavior (receive_sms)

receive_sms holds the request open up to wait_seconds (default 30, max 120) and emits MCP notifications/progress every 20 seconds to keep the client alive indefinitely. Near-instant OTP delivery end-to-end.

Discovery files for crawlers and agents

Previous ← SMS vs voice

llms.txt OpenAPI MCP server card x402.json mpp.json Agent card Agent skills SKILL.md sitemap.xml Glossary