Hi, ive attempted to create a sip trunk to ringcentral with this

curl -X POST "https://api.vapi.ai/credential" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <API_KEY>" \
  -d '{
    "provider": "byo-sip-trunk",
    "name": "RingCentral Trunk",
    "gateways": [{
      "ip": "<OUTBOUNT_PROXY>",
      "port": <OUTBOUNT_PROXY_PORT>,
      "netmask": 32,
      "inboundEnabled": true,
      "outboundEnabled": true
    }],
    "outboundLeadingPlusEnabled": false,
    "outboundAuthenticationPlan": {
      "authUsername": "<USER_NAME>",
      "authPassword": "<PASSWORD>",
      "sipRegisterPlan": {
        "domain": "sip.ringcentral.com",
        "username": "<AUTHORIZATION_ID>",
        "realm": "sip.ringcentral.com",
        "publicIpInContactEnabled": true
      }
    }
  }'

but i always get this

{
  "message": "Couldn't validate SIP trunk credential. SIP gateway creation failed.",
  "error": "Bad Request",
  "statusCode": 400
}

That 400 error usually means the trunk isn’t registering correctly with RingCentral, often due to an auth mismatch, wrong proxy/port, or realm misconfiguration. If the SIP REGISTER returns 401 or 403, the credential validation will instantly fail. I can help you quickly identify where the registration is breaking and adjust the config properly. Are you using their SIP trunking product or just registering a standard extension? @User

i have an existing phone number in ringcentral that i want to reuse for the vapi agent

@aafsgdrgdrgdgr have you figured this out?