Raw WebSocket

If you control the media (FreeSWITCH, Asterisk, LiveKit, Pipecat, your own SIP stack), open a socket and send binary audio frames. Decision events come back on the same socket.

wss://api.patchamd.com/v1/stream?encoding=mulaw&sample_rate=8000
Authorization: Bearer pamd_live_…

Query	Values
encoding	mulaw, alaw or linear16 (16-bit little-endian PCM)
sample_rate	8000 (default), 16000, 24000, 44100, 48000
transcripts	1 to also receive transcript events with the words heard so far
webhook_url	optional: also send amd.decided there

Can't set headers? Mint a URL with POST /v1/streams and "encoding": "mulaw" — the returned url carries the token and the codec.

Protocol

1. Connect when the call is answered. The first audio frame starts the clock.
2. Send the callee's audio only (not your own outbound audio), ideally in 20 ms frames, in real time.
3. Receive events:

{"type":"connected","detection_id":"det_…"}
{"type":"started","detection_id":"det_…","carrier":"raw","encoding":"mulaw/8000"}
{"type":"transcript","detection_id":"det_…","text":"Hello?","finished":true}
{"type":"decision","detection_id":"det_…","result":"human","reason":"person_waiting","at_ms":1620,"heard":"Hello?"}

4. After decision the server closes the socket with code 1000. To stop early (the callee hung up), send {"type":"stop"} or close the socket; nothing is billed without a decision.

Example (Node)

import WebSocket from 'ws';

const ws = new WebSocket('wss://api.patchamd.com/v1/stream?encoding=mulaw&sample_rate=8000', {
  headers: { authorization: `Bearer ${process.env.PATCH_AMD_KEY}` },
});
ws.on('open', () => call.on('audio', frame => ws.send(frame)));
ws.on('message', data => {
  const event = JSON.parse(data);
  if (event.type === 'decision') route(event.result);
});

Close codes

Code	Meaning
1000	Decided
4401	Bad credentials in a Twilio start message
4408	No audio within 90 s of connecting
4429	Concurrent stream limit reached

Bad credentials on connect are rejected before the upgrade with HTTP 401; a reused token with 409; rate limits with 429.