AgentPhone

• ▸Instant US/Canadian phone number provisioning via one API call
• ▸Two voice modes: hosted (built-in AI handles calls end-to-end from a system prompt) or webhook (caller speech transcribed and sent to your own backend)
• ▸Unified webhook event model: one agent.message event format for both SMS and voice
• ▸Stateful conversations: messages and calls auto-thread into durable conversation history
• ▸Real-time transcription and live transcript streaming via SSE
• ▸Per-agent webhook routing, HMAC-signed webhooks with idempotency headers and retry backoff
• ▸MCP server with 26 tools for managing numbers, SMS, calls, agents, conversations, and webhooks
• ▸Agent self-signup flow: an agent can provision an account, number, and API key via a human-verified OTP flow with no human web signup

Authentication

Bearer token (API key) in the Authorization header

Base URL

https://api.agentphone.ai/v1

Notable endpoints

• GET /v1/agents/voices - list available voices
• GET/POST /v1/agents - list/create agents
• GET/DELETE /v1/agents/{agent_id} - get/delete an agent
• POST /v0/agent/sign-up and /v0/agent/verify - agent self-signup with OTP, provisions account + number + agent + API key
• PATCH /v1/agents/:id - switch voiceMode between hosted and webhook

Machine-readable spec

OpenAPI spec retrieved

Published by the vendor themselves — not community forks.

• AgentPhone Claude Code Skill

  Official skill for using AgentPhone directly from Claude Code, per the docs llms.txt index.

AgentPhone gives an AI agent a phone identity: a provisioned number that can send/receive SMS, MMS, and iMessage, and place or receive voice calls, with conversations threaded into durable history. Voice can run fully hosted (AgentPhone's own LLM handles the call from a system prompt) or via a webhook that forwards transcribed speech to the developer's own backend/LLM.

Developers and GTM/AI-agent builders who want their agents to have a real phone identity for outbound follow-up, 2FA/verification inboxes, or voice conversations, without building telephony infrastructure themselves.

There is no separate sandbox environment - new accounts get $5.00 of free credit that the vendor says covers roughly the first month of one phone number plus some SMS/voice usage, meaning testing happens against production from day one. We could not retrieve a pricing page (no `pricing`-kind excerpt was in evidence), so teams cannot evaluate ongoing per-number or per-minute costs without contacting the vendor or signing up.

No curated rival set covers this tool yet, so these are simply other tools in the same architectural layer and product form. Treat it as a starting point, not a shortlist.

• Full MCP tool name list (count of 26 stated, individual names not enumerated in evidence)
• Company/funding background beyond the operating entity name (Relay Innovations, Inc.)
• Published pricing was not available in the reviewed source set; confirm current commercial terms with the vendor.