Hi everyone, I’ve been trying to integrate RingCentral with Vapi so that calls arriving on a specific RingCentral extension can be forwarded to a Vapi AI agent, but I’m running into difficulties getting it to work. I tried using SIP trunk configuration in Vapi following the SIP docs, but it doesn’t seem to work with RingCentral. From an older thread I found, Vapi doesn’t support direct SIP registration with RingCentral and recommends using an intermediary SIP provider like Twilio or Plivo. I’d really appreciate clear answers to the following: Is it possible to integrate RingCentral directly with Vapi via SIP? Or is an intermediary SIP provider required to make this work? Is there any specific documentation / step-by-step guide for this setup? Thanks in advance!

Direct SIP integration with RingCentral is not supported by Vapi. To connect RingCentral with Vapi, you need to use an intermediary SIP provider like Twilio or Plivo. Here’s a quick example of how to register a phone number with Vapi after setting up your intermediary SIP trunk:

bash
curl -X POST "https://api.vapi.ai/phone-number" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_VAPI_PRIVATE_KEY" \
  -d '{
    "provider": "byo-phone-number",
    "name": "Twilio SIP Number",
    "number": "YOUR_SIP_PHONE_NUMBER",
    "numberE164CheckEnabled": false,
    "credentialId": "YOUR_CREDENTIAL_ID"
  }'

Replace the placeholders with your actual details from the intermediary provider setup. For more, see the [Vapi SIP trunk documentation](https://docs.vapi.ai/advanced/sip/sip-trunk). Source: - [Vapi SIP Trunk Documentation](https://docs.vapi.ai/advanced/sip/sip-trunk)

You can’t connect RingCentral directly to Vapi because Vapi doesn’t support RingCentral’s SIP registration, so the calls won’t authenticate. The working method is to forward your RingCentral extension to an intermediary like Twilio, Telnyx, or Plivo, then route that number into Vapi via webhook/SIP trunk. This gives full call logs, debugging, and stable routing. Which provider are you using now so I can outline the exact setup? @jester