session.initialize

voice → application

Negotiate the audio codec and initialize a real-time voice session.

Parameters

Field	Type	Presence	Constraints	Description
application	AppInfo	required	—	Application that owns the call flow.
call	CallInfo	required	—	Call being bridged into the session.
audio_codec_offerings	AudioCodec[]	required	—	Audio codecs offered by the voice peer.
metadata	object	nullable	—	Free-form session metadata; the field is present and may be null.

Result

Field	Type	Presence	Constraints	Description
audio_codec	AudioCodec	nullable	—	Selected codec; the field is present and may be null.

Referenced types

AppInfo

Field	Type	Presence	Constraints	Description
id	string	required	—	Application or graph-node identifier.

AudioCodec

Field	Type	Presence	Constraints	Description
id	string	required	—	Codec identifier such as L16/8000/1.
name	string	required	—	Codec name such as L16.
sample_rate	integer	required	—	Sample rate in hertz.
bit_depth	integer	required	—	Number of bits per sample.
channels	integer	required	—	Number of audio channels.

CallInfo

Field	Type	Presence	Constraints	Description
id	string	required	—	Call identifier.
session_id	string	required	—	Session identifier owned by the voice peer.
from	string	required	—	Caller address or number.
to	string	required	—	Callee address or number.

Example: canonical

Parameters

{
  "application": {
    "id": "app-1"
  },
  "call": {
    "id": "call-1",
    "session_id": "session-1",
    "from": "+12025550100",
    "to": "+12025550101"
  },
  "audio_codec_offerings": [
    {
      "id": "L16/8000/1",
      "name": "L16",
      "sample_rate": 8000,
      "bit_depth": 16,
      "channels": 1
    }
  ],
  "metadata": null
}

Result

{
  "audio_codec": null
}