API reference

Carrier SIP trunks

Create and manage SIP trunks — the connections to carriers, SBCs, or your own PBX — with source-IP allowlists and test calling.

SIP trunk resource

SipTrunkjson

{
  "data": {
    "id": "ST…",
    "type": "sip_trunk",
    "attributes": {
      "name": "Carrier SBC",
      "region": "hydrogen",
      "inbound_source_ips": ["203.0.113.10"],
      "created_at": "…"
    }
  }
}

Create a trunk

POST/carrier/v1/sip_trunks

Parameter	Type	Description
`data.type` required	`string`	`sip_trunk`
`data.attributes.name` required	`string`	Trunk name.
`data.attributes.region` optional	`string`	Platform region.
`data.attributes.inbound_source_ips` required	`array`	Allowed source IPs for inbound traffic.

The inbound_source_ips allowlist is a hard security boundary. Only traffic from these IPs is accepted — omit it and the trunk is a direct-to-PSTN abuse vector.

List trunks

GET/carrier/v1/sip_trunks

Return all trunks on the carrier.

Fetch a trunk

GET/carrier/v1/sip_trunks/{id}

Return a single trunk.

Update a trunk

PATCH/carrier/v1/sip_trunks/{id}

Change the name, region, or inbound source IPs.

Test call

POST/carrier/v1/sip_trunks/{id}/test_call

Place a test call through the trunk to verify routing and media.

Parameter	Type	Description
`to` required	`string`	Destination number.
`from` required	`string`	Caller ID to use.

Delete a trunk

DELETE/carrier/v1/sip_trunks/{id}

Delete the trunk. Accounts assigned to it fall back to automatic routing.

See the SIP trunks guide for setup and troubleshooting.