Getting started with AgentStream

Get audio flowing between a live call and your server in minutes.

Prerequisites

• Exotel account with AgentStream enabled (sign up)
• API Key, API Token, Account SID — Authentication
• An ExoPhone (virtual number)
• A publicly reachable WebSocket endpoint (wss://)

Step 1 — Run an echo server

# echo.py — works on Python 3.8+
import asyncio, json, websockets

async def handle(ws):
    stream_sid = None
    async for msg in ws:
        ev = json.loads(msg)
        event = ev.get("event")
        if event == "start":
            stream_sid = ev["start"]["stream_sid"]
            print("stream started", stream_sid)
        elif event == "media":
            await ws.send(json.dumps({
                "event": "media",
                "stream_sid": stream_sid,
                "media": {"payload": ev["media"]["payload"]},
            }))
        elif event == "stop":
            break

async def main():
    async with websockets.serve(handle, "0.0.0.0", 5001):
        print("listening on :5001")
        await asyncio.Future()

asyncio.run(main())

pip install websockets
python echo.py
# expose with ngrok (or similar): ngrok http 5001
# use the wss:// URL as StreamUrl

Step 2 — Connect Voice AI (outbound)

export EXOTEL_API_KEY="your_api_key"
export EXOTEL_API_TOKEN="your_api_token"
export EXOTEL_ACCOUNT_SID="your_account_sid"
# India: api.in.exotel.com · Singapore: api.exotel.com
export EXOTEL_SUBDOMAIN="api.in.exotel.com"

curl -u "$EXOTEL_API_KEY:$EXOTEL_API_TOKEN" -X POST \
  "https://$EXOTEL_SUBDOMAIN/v1/Accounts/$EXOTEL_ACCOUNT_SID/Calls/connect" \
  -F "From=+919876543210" \
  -F "CallerId=YOUR_EXOPHONE" \
  -F "StreamUrl=wss://YOUR_PUBLIC_HOST/media" \
  -F "StreamType=bidirectional"

Answer the phone — you should hear your own audio echoed back.

Step 3 — Confirm success

Check	Expected
API response	call.sid present, status queued / in-progress
Server logs	start then continuous media events
Call audio	Echo (or your TTS) audible

Next paths

Goal	Go to
Unsure which API to use	What to use when
IVR / agent handoff	Connect with Flow
Build a real bot	WebSocket protocol
Monitor live streams	WSS errors & monitoring

Samples

Example servers and SDKs: github.com/exotel