Open-source AI phone API for voice agents. Give Claude, Cursor, OpenClaw, or any LLM a real phone number — outbound/inbound calls, SMS, transcripts, MCP, DTMF/IVR. FastAPI + SignalWire + Deepgram. Self-hostable alternative to Twilio, Vapi, and Retell. Maintained by AgentLineHQ on GitHub, where it has earned 52 stars from the community.