Agent Stream WebSocket

Connect call audio you already carry over a WebSocket (a PBX, a telephony platform such as Twilio, Exotel or Klicko, or your own app) to a 60db voice agent. The agent listens, answers in its voice, uses its tools (your Webhook (JSON) tools and Call transfer) and knowledge base, and can press keys, transfer to a person or hang up. No phone line or UDP ports are needed: everything runs over HTTPS, port 443.

🚀 Quick Start

1. Start the call (from your server)

curl -X POST https://api.60db.ai/agents/$AGENT_ID/stream-calls \
  -H "Authorization: Bearer $SIXTYDB_API_KEY" \
  -H "Content-Type: application/json" -d '{}'

{
  "success": true,
  "data": {
    "call": { "id": "6b1f0c52-…", "direction": "stream", "status": "dialing" },
    "url": "wss://api.60db.ai/ws/agents/stream/6b1f0c52-…?token=…",
    "expires_in": 55
  }
}

The url is single use and valid for 55 seconds. It carries no API key, so you can hand it to the component that streams audio. See Start stream call for overrides and metadata.

2. Connect and stream (Node.js 22+)

const ws = new WebSocket(url);
ws.binaryType = "arraybuffer";

ws.onopen = () => ws.send(JSON.stringify({ event: "start", format: "mulaw" })); // within 10 s

ws.onmessage = ({ data }) => {
  if (typeof data !== "string") return play(new Uint8Array(data));       // agent audio, 20 ms frames
  const m = JSON.parse(data);
  if (m.event === "started") startSending((frame) => ws.send(frame));   // a 160-byte frame every 20 ms
  if (m.event === "clear") flushPlayback();                              // caller cut in: drop unplayed audio
  if (m.event === "transfer") transferCaller(m.destination, m.numbers)
    .then((outcome) => ws.send(JSON.stringify({ event: "transfer_result", outcome })));
  if (m.event === "ended") console.log(m.summary);
};

🔌 Connection

Item	Value
URL	`wss://api.60db.ai/ws/agents/stream/{callId}?token=…` (from step 1)
Auth	The one-time `token` in the URL. The first connection spends it, right or not
First message	Within 10 seconds of connecting
Message size	Under 4 KB
Keep-alive	The server pings every 15 s; a connection silent for 45 s is closed

🎧 Styles

The style is picked from your first message.

Native style

{ "event": "start", "format": "mulaw" }

Format	Samples	Bytes per 20 ms frame
`mulaw`	G.711 μ-law, 8 kHz mono	160
`pcm16`	signed 16-bit little endian, 8 kHz mono	320

You get {"event":"started","call_id":"…","format":"mulaw","frame_bytes":160}, then audio as binary messages in both directions.

Twilio Media Streams style

Send your usual Twilio, Exotel or Klicko messages: no adapter, no change to the request.

{ "event": "connected" }
{ "event": "start", "start": { "streamSid": "MZ…", "mediaFormat": { "encoding": "audio/x-mulaw", "sampleRate": 8000, "channels": 1 } } }
{ "event": "media", "media": { "payload": "<base64 20 ms>" } }

mediaFormat may be nested in start (Twilio) or at the top of it (Klicko).
Encodings: audio/x-mulaw, pcmu, mulaw (μ-law) or audio/x-l16, l16, pcm16, pcm16_8k (PCM16). The rate must be 8000.
pcma and 16 kHz formats close the socket with 1008.
There is no started reply. Audio comes back as {"event":"media","streamSid":"…","streamId":"…","media":{"payload":"…"}}.
mark is ignored. Base64 in JSON is about 1.7 times the native bytes.

📨 Messages

From the agent

Message	Meaning
`started`	The call began (native style only)
`media` / binary	The agent’s audio, paced in real time
`{"event":"clear"}`	The caller cut in: drop agent audio you have not played yet
`{"event":"dtmf","digits":"5"}`	The agent pressed a key on the caller’s phone (agent setting `dtmf: true`)
`{"event":"transfer","destination":"Sales","numbers":["+919800000001"]}`	Put the caller through to a person; the first number is the one to try first
`{"event":"hangup"}`	The agent is hanging up
`{"event":"ended","summary":{…}}`	The call is over: turns, sentiment, transfer, interruptions, VAD, latency. The socket then closes with `1000`

From you

Message	Meaning
binary / `media`	Caller audio. Send in real time, and send silence while the caller is quiet
`{"event":"dtmf","digits":"5#"}`	The caller pressed keys: `0-9`, `*`, `#`, `A-D`, up to 32 (Twilio style also accepts `{"dtmf":{"digit":"5"}}`)
`{"event":"transfer_result","outcome":"joined"}`	How a transfer went: `joined`, `busy`, `declined`, `no_answer` or `failed`, within 10 s
`{"event":"stop"}`	The caller hung up. Closing the socket does the same

Tools During a Stream Call

A stream call uses the agent’s tools exactly like a phone call. Add them on the agent (dashboard → agent → Tools & webhooks → Add tool, or tools / transfer_targets in the API).

Webhook (JSON) tools

Your own functions, such as checking availability or booking a table. They do not go over this socket. 60db calls your server directly:

Define the tool on the agent with a JSON Schema, and set the agent’s Tool webhook (tool_webhook_url):

{
  "name": "book_table",
  "description": "Book a table once the caller gives a date, time and party size.",
  "parameters": {
    "type": "object",
    "properties": {
      "date": { "type": "string", "description": "YYYY-MM-DD" },
      "time": { "type": "string", "description": "HH:MM, 24-hour" },
      "guests": { "type": "integer", "minimum": 1 }
    },
    "required": ["date", "time", "guests"]
  }
}

During the call, when the agent uses it, 60db sends a signed POST to your tool_webhook_url with the tool name and arguments (headers X-60db-Signature, X-60db-Timestamp).
Reply with any JSON object within about 6 seconds, e.g. { "booked": true, "table": 12 }. The agent turns it into its spoken answer. A slow or failed reply reaches the agent as {"error": "tool_unavailable", …}, so it can apologise.

The request and reply formats, signature checks and example servers (Node.js, Python) are in Agent Tools and Webhooks. An agent with tools must have a tool_webhook_url, or starting the call returns 400 VALIDATION_ERROR (field: tool_webhook_url).

Call transfer tool

Built in: no webhook needed. Set transfer_targets on the agent (or in overrides for one call). When the caller asks for a person, the agent says a short line and this socket receives:

{ "event": "transfer", "destination": "Sales", "numbers": ["+919800000001"] }

Put the caller through on your platform, then reply within 10 seconds with {"event":"transfer_result","outcome":"joined"} (or busy, declined, no_answer, failed). See Call transfer.

Keypad

With call_defaults.dtmf: true the agent can press keys ({"event":"dtmf","digits":"1"} arrives on this socket) and collect the caller’s keys (send {"event":"dtmf","digits":"5#"}).

❌ Close Codes

Code	Meaning
`1000`	The call ended normally
`1002`	A malformed or unknown message (native style)
`1008`	Invalid or used URL, no valid first message within 10 s, or an unsupported audio format
`1009`	A message over 4 KB
`1011`	The call service failed

📊 Limits and Pricing

Item	Value
Live stream calls	3 at once per workspace (including calls waiting for their socket)
Call length	`max_duration_secs`, 10 to 900 (default 180)
Price	AI credits only, about $0.016 per minute of conversation. No line charge

After the call, find it in Agents → History (label Stream), or use Get call, Get transcript and Get recording.

​Agent Stream WebSocket

​🚀 Quick Start

​1. Start the call (from your server)

​2. Connect and stream (Node.js 22+)

​🔌 Connection

​🎧 Styles

​Native style

​Twilio Media Streams style

​📨 Messages

​From the agent

​From you

​Tools During a Stream Call

​Webhook (JSON) tools

​Call transfer tool

​Keypad

​❌ Close Codes

​📊 Limits and Pricing