CallAgentVoice agents that answer the phone

A voice AI platform, a SIP PBX and an AI contact centre in one system. Describe an assistant, attach tools and knowledge, point a number at it — every call is transcribed, recorded, priced and replayable.

Quickstart

How a call works

What is not built

A pipeline you can see

Transport, transcription, endpointing, model, tools, synthesis, playback — each stage timed separately, coloured consistently, and visible per turn in the call timeline.

The seven stages

Interruption as a first-class problem

Four separate waits chosen by what the caller's last words looked like, phrase lists that decide what counts as an interruption, and a measured stop-audio latency. Barge-in is tuned, not hoped for.

Turn taking & barge-in

Your own trunks, your own numbers

FreeSWITCH terminates SIP directly, so a BYO trunk is a first-class path — registration or IP auth, per-trunk codecs and DTMF, four test endpoints, and an honest account of where the path currently stops.

SIP trunking

MCP servers, attached whole

Connect an MCP server and its tools arrive as one attachment with per-tool risk tiers and a confirmation policy — not twenty separate tools pasted into the assistant.

MCP servers

Escalation without re-dialling

Queues, operators, skills, ring groups, IVRs and time conditions. The handover redirects the caller's existing leg — nobody's phone rings twice — and the operator's screen already has the transcript and the reason.

Contact centre

Money you can audit

An insert-only credit ledger, per-component metering at decimal(20,8), and a cost row that records what the provider charged as well as what you were charged — with unpriced stages marked rather than guessed.

Analytics & cost

Start here

If you want to…	Go to
Understand what this is before writing code	Introduction
Get an assistant published and a number pointed at it	Quickstart
Run the whole stack on your laptop	Install
Know which key goes where	Authentication
Call the REST API	API reference — 305 operations, generated from the spec
Manage assistants in git	Config as code
Arrive from Asterisk, FreePBX or 3CX	Coming from a PBX
Understand an error at 2am	When something fails
Know what is actually built	What is not built

A note on this documentation

Every page here was written against the code, not against a plan. Where something is partial the page says which part; where it is not built the page says so instead of describing it in the present tense.

That is not a slogan — it is load-bearing. Five things in this product look finished and are not:

Twilio is the only carrier proven to carry a call into the AI pipeline.
No SIP trunk call has ever reached an assistant, though trunk authentication is proven against a real SIP peer.
Speech-to-speech is stored, published and ignored by the live call session.
Post-call analysis never runs, which also means no structured-output extraction.
No provider adapter has been run against a live vendor, so "verified" means reviewed, not tested.

The full list, with the code behind each claim, is on What is not built. If you find that page disagreeing with the code, the page is the bug.