Register Call
Mint a **short-lived, single-use access token** for opening a realtime
[Agent WebSocket](/atoms/api-reference/api-reference/realtime-agent/realtime-agent)
connection. This is the **recommended** way to start a session from a
browser or other client-side app: your API key stays server-side, and
the browser only ever sees the short-lived token. (Server-side or
trusted clients may instead connect to the WebSocket with a raw API key
directly.)
Flow:
1. Call this endpoint with your API key and the `agent_id` (plus optional
`mode` and per-call `variables`). All session configuration is fixed
here — it is baked into the returned token.
2. Open a WebSocket to `wss://api.smallest.ai/atoms/v1/agent/connect?token=<access_token>`.
No `agent_id`, `mode`, or `variables` query params are needed on the
WebSocket — they come from the token.
The token is valid for `expires_in` seconds (30) and can be used for a
single connection. Request a fresh token for each connection.
Authentication
AuthorizationBearer
API key from the console ApiKey collection, sent as Bearer token. Also accepts session cookies for browser-based auth.
Request
This endpoint expects an object.
agent_id
The Atoms agent to connect to.
mode
Session mode. webcall = full voice pipeline (audio in +
audio out). chat = text-only pipeline. Defaults to webcall.
Allowed values:
variables
Per-call prompt variables that override the agent's
`defaultVariables` for this session only. Values must be
`string`, `number`, or `boolean`. Reserved system-variable
keys (`call_id`, `conversation_type`, `agent_number`,
`user_number`, `current_date`, `current_time`, `current_day`,
`agent_gender`, `default_language`, `supported_languages`,
`timezone`) are populated by the server and stripped if
supplied.
Response
Access token created.
status
data
Errors
400
Bad Request Error
401
Unauthorized Error
404
Not Found Error
500
Internal Server Error