WebRTC

Last updated September 4, 2026

WebRTC peer connection establishment

# GET /legs/{id}/ice-candidates

Get server-side ICE candidates for a WebRTC leg (trickle ICE)

Parameters

Name	In	Type		Description
`id`	path	string	required	Leg ID

Responses

200 Buffered ICE candidates

Field	Type		Description
`candidates`	array[object]	required
`done`	boolean	required

400 Leg is not a WebRTC leg

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

404 Leg not found

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

# POST /legs/{id}/ice-candidates

Send a remote ICE candidate to a WebRTC leg (trickle ICE)

Parameters

Name	In	Type		Description
`id`	path	string	required	Leg ID

Responses

200 Candidate added

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`status`	string	required

400 Invalid JSON or leg is not a WebRTC leg

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

404 Leg not found

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

500 Failed to add ICE candidate

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

# POST /webrtc/offer

Establish a WebRTC leg via SDP offer/answer

Request Body

Field	Type		Description
`sdp`	string	required	SDP offer from the browser
`app_id`	string	optional	Application identifier. Carried through to all events emitted for this leg, and matched against the VSI `app_id` filter.
`custom_data`	any	optional	Opaque application JSON attached to the leg. Any JSON value is accepted (object, array, string, number, boolean). It is echoed on the leg view and carried at the top level of every event published for this leg, so external state can be correlated without keeping a leg_id lookup table. Capped by CUSTOM_DATA_MAX_BYTES (default 1024 bytes, 0 = unlimited).

Responses

200 SDP answer with leg ID

Field	Type		Description
`leg_id`	string	required
`sdp`	string	required

400 Invalid JSON or invalid SDP offer

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

500 Peer connection, track creation, or answer generation failed

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

Schemas

Objects used by the WebRTC endpoints above.

Error

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`error`	string	required	Error message

ICECandidateInit

Field	Type		Description
`candidate`	string	required	ICE candidate string
`sdpMid`	string	optional	Media stream identification tag
`sdpMLineIndex`	integer	optional	Index of the media description

StatusResponse

Field	Type		Description
`instance_id`	string	optional	Instance identifier
`status`	string	required

WebRTCCandidatesResult

Field	Type		Description
`candidates`	array[object]	required
`done`	boolean	required

WebRTCOfferRequest

Field	Type		Description
`sdp`	string	required	SDP offer from the browser
`app_id`	string	optional	Application identifier. Carried through to all events emitted for this leg, and matched against the VSI `app_id` filter.
`custom_data`	any	optional	Opaque application JSON attached to the leg. Any JSON value is accepted (object, array, string, number, boolean). It is echoed on the leg view and carried at the top level of every event published for this leg, so external state can be correlated without keeping a leg_id lookup table. Capped by CUSTOM_DATA_MAX_BYTES (default 1024 bytes, 0 = unlimited).

WebRTCOfferResult

Field	Type		Description
`leg_id`	string	required
`sdp`	string	required