voice-trunks

Create a gateway on a SIP trunk

Adds a gateway address for forwarding inbound calls to this trunk.

Gateways are tried in priority order, lowest first, until one answers. Gateways with equal priority share calls evenly. sip_uri identifies the peer host, while destination_format and origination_format control the called and calling number formats. Both number formats default to E.164.

A SIP URI already registered on this trunk returns 409 Conflict. An invalid SIP URI, a SIP URI carrying a user part, or a malformed number format returns 422. A trunk outside the workspace returns 404 Not Found. A trunk without inbound calling enabled returns 412 Precondition Failed.

A trunk supports at most 20 gateways. Creating another returns 422; delete a gateway before adding its replacement. SIP ports must be between 1 and 65535.

post/v1/voice/trunks/{trunk_id}/gateways

Request

  • Base URL: https://us1.platform.bird.com
  • URL: https://us1.platform.bird.com/v1/voice/trunks/{trunk_id}/gateways
  • Auth: one of:
    • HTTP bearer
    • API key in cookie bird_session

Headers

Idempotency-Keystring

Client-supplied key. On operations supporting request deduplication, a retained response is replayed for duplicate requests with the same key within the idempotency window (3 hours by default). This protection requires a workspace, organization, or staff-account scope. User-only and unscoped unauthenticated operations, streams, and operations with a separate replay contract do not use this response replay.

On a supported operation, if idempotency protection is unavailable before execution, the API returns 503 IdempotencyUnavailable (E01033) without executing this attempt. Retry with backoff using the same key and request. An operation that takes effect before its response is retained can still execute again on retry.

Two distinct 409 errors signal misuse:

  • request_in_progress (E01004): The same key is currently being processed by a concurrent request. Wait briefly and retry. The lock expires within 30 seconds.
  • idempotency_key_reuse (E01005): The same key has already completed against a different request body or method. Generate a new key.

Recommended key format is <event-type>/<entity-id> (for example welcome-user/usr_abc123).

X-Workspace-Idstring

Workspace context for the request. Required for dashboard authentication and master keys. Workspace keys and access tokens already identify their workspace; send that workspace or omit the header. A different one is rejected.

X-Organization-Idstring

Organization context for the request. Required for dashboard authentication. An API key or access token carries its own organization, so send either that organization or no header at all; a different one is rejected.

Request body

sip_uristring required

SIP URI an inbound call to this trunk should be forwarded to. Give the host only, with an optional port: which number is dialed there comes from destination_format, so a URI carrying a user part is rejected.

priorityinteger required

The order gateways are tried in, lowest first. Give two gateways the same priority to share calls between them evenly.

origination_formatstring

How this gateway wants the calling number spelled. Write a template whose {number} stands for the number without its leading +; the result is stated in the P-Asserted-Identity header of the delivered call.

Omit it for E.164, which is +{number}. The template may add digits, letters and the characters -_.!~*'()&=+$,;?/%# around {number}, which may appear at most once, and anything else in braces is rejected so a misspelled placeholder cannot reach a call.

A format with no {number} at all states the same identity on every call, which is what a peer that only accepts one authorized number wants. The call then carries nothing about who really called.

destination_formatstring

How this gateway formats the dialed number. In the template, {number} represents the number without its leading +. The result is placed before the sip_uri host. For example, 1234#{number} formats +31201234567 as sip:1234#31201234567@pbx.example.com:5060.

Omit it for E.164, which is +{number}. A format with no {number} at all sends every number this trunk answers to one fixed number, so 777000447973 reaches sip:777000447973@pbx.example.com:5060 whatever was dialed. The same rules as origination_format apply to what the template may contain.

Example request

{
  "sip_uri": "sip:pbx.example.com:5060",
  "origination_format": "+{number}",
  "destination_format": "1234#{number}"
}

Response

Gateway created.

idstring required
trunk_idstring required
sip_uristring required

SIP URI an inbound call to this trunk is forwarded to. The host only: which number is dialed at that host comes from destination_format, because it changes with every call.

priorityinteger required

The order gateways are tried in, lowest first. Gateways sharing a priority take an equal share of calls, and any of them may be tried first on a given call.

origination_formatstring required

How the calling number is spelled to this gateway, as a template whose {number} stands for the number without its leading +. It is stated in the P-Asserted-Identity header of the delivered call.

A gateway that has not asked for anything else reports +{number}, which is E.164. A format with no {number} states that same identity on every call, whoever called.

destination_formatstring required

How this gateway formats the dialed number. In the template, {number} represents the number without its leading +. The result is placed before the sip_uri host. For example, 1234#{number} formats +31201234567 as sip:1234#31201234567@pbx.example.com:5060.

A gateway that has not asked for anything else reports +{number}, which is E.164. A format with no {number} is dialed as it stands, so every number the trunk answers reaches that one number.

created_atstring date-time required
updated_atstring date-time required

Example response

{
  "id": "vtg_01krdgeqcxet5s7t44vh8rt9mg",
  "trunk_id": "spt_01krdgeqcxet5s7t44vh8rt9mg",
  "sip_uri": "sip:pbx.example.com:5060",
  "origination_format": "+{number}",
  "destination_format": "+{number}",
  "created_at": "2026-05-20T09:14:52Z",
  "updated_at": "2026-05-25T16:42:01Z"
}

Changes

No recorded changes to this operation across all 2 revisions of this API.