> For AI agents: the documentation index is at https://platform.detectif.ai/llms.txt. Every page is also available as Markdown by adding `.md` to its path.

# FreeSWITCH

Fork a FreeSWITCH channel's audio to a WebSocket relay with an audio-fork module, and forward it to Noesis.

FreeSWITCH can fork a channel's audio to a WebSocket with an audio-fork module, such as `mod_audio_fork`. The module sends 16-bit PCM as binary frames, after an optional JSON metadata message. Run a relay that forwards the frames to Noesis.

## 1. Fork the callee's audio to your relay

Start the fork on the channel of the person you called, for example from `fs_cli` or the event socket, once the call is answered:

```fs_cli
uuid_audio_fork <uuid> start wss://relay.example.com/freeswitch mono 16k {"call_id":"<uuid>"}
```

`mono` sends that channel's audio only, and `16k` sets 16 kHz. Check your module's documentation for its exact options; other audio-fork modules work the same way.

## 2. Forward the audio to Noesis

The relay uses `noesis_relay.py` from the [relay helper](https://platform.detectif.ai/docs/noesis/websocket-client/#relay-helper):

```python
# freeswitch_relay.py: FreeSWITCH audio fork -> your server -> Noesis
import asyncio, json

import websockets

from noesis_relay import NoesisCall

async def on_answer(event):
    if event["type"] == "classification":
        print(event["call_id"], event["label"])     # your own logic

async def handle(fork):
    call = None
    try:
        async for message in fork:
            if call is None:                        # metadata, if the fork sends it first
                meta = json.loads(message) if isinstance(message, str) else {}
                call = NoesisCall(on_answer, encoding="pcm_s16le", sample_rate=16000,
                                  call_id=meta.get("call_id"))
                await call.open()
            if isinstance(message, bytes):
                await call.send(message)            # 16-bit PCM
    except websockets.ConnectionClosed:
        pass
    if call is not None:
        await call.close()

async def main():
    async with websockets.serve(handle, "0.0.0.0", 8080):
        await asyncio.Future()                      # run until stopped

asyncio.run(main())
```

For an `8k` fork, use `sample_rate=8000`. To not record calls, create each call with `record="false"` as well.