#telephony

The embedded telephony data plane for Go. Place and answer calls on any SIP trunk — or be the trunk — with carrier failover, full SIP-signaling visibility, and call audio delivered as PCM frames on a channel, ready for STT or a voice agent. Battle-tested across 500,000+ production calls.

Phone calls for every other language: one self-hosted binary turns SIP calls into WebSocket audio + REST call control. Twilio-compatible framing, so existing voice apps port over with the URL swapped.

The same phone line for Rust — SIP and RTP implemented from scratch, zero telephony crate dependencies. Call audio as crossbeam channels of PCM frames; powers xbridge in production.

In-process SIP server for Go tests. Real SIP over loopback — no Docker, no Asterisk, no hardcoded ports.

A real PBX in one docker run — Asterisk with a web UI for extensions, trunks and dialplans. The five-minute test bench for anything you build with xphone or xbridge.

TTS APIs speak HTTP. Voice apps speak WebSocket. This bridges the gap.