Session Launch

SessionLaunchResponse

Both /v1/sessions and /v1/browser-sessions return this shape (201, Cache-Control: no-store, private). See /openapi/sessions.json for the machine-readable contract.

{
"session": {
  "id": "sess_…",
  "experienceId": "exp_…",
  "experienceRevisionId": "…",
  "expiresAt": "2026-08-11T12:30:00.000Z",
  "locale": "en-GB",
  "mode": "conversation",
  "status": "active",
  "capabilities": {
    "speech": { "input": true, "output": true, "externalAudio": false },
    "conversation": { "managed": true },
    "avatar": { "enabled": true },
    "tools": { "enabled": false }
  }
},
"launch": "eyJ…"
}

Top-level fields

Field	Type	Description
session	object	Minimal public session facts
launch	string	Asymmetrically signed opaque bootstrap — do not parse

session fields

Field	Type	Description
id	string	Session id
experienceId	string	Experience being run
experienceRevisionId	string	Published revision id
expiresAt	string	ISO 8601 expiry
locale	string	BCP 47 locale
mode	string	conversation | presenter
capabilities	object	Boolean flags for avatar, speech I/O, tools, external audio

Runtime internals (transport, pipeline, renderer, sessionToken, characters) are not part of the public API — they live only inside opaque launch.