We have 6 calls on 4/3/2025 where vapi response to /twilio/inbound_call api is returning OUR_FALLBACK_NUMBER Here are some example twilio call sids: CA320e7253224eb13fecf25928a993e2ed CAcbb6162204b5dba5ce8534aa4ff4cb3f CA320e7253224eb13fecf25928a993e2ed We don't see any webhook errors or any indication of why the connection with the assistant didn't happen

Hi there! 👋 I see you're having an issue with the Vapi Twilio integration returning a fallback number instead of connecting to your assistant. I don't have access to your specific logs or configuration to determine exactly why those particular call SIDs are failing. However, I can definitely help you understand potential reasons for this behavior and suggest troubleshooting steps. Here are several possible reasons why the Vapi twilio/inbound_call API might be returning a fallback number: 1. **Concurrency Limits**: If you've reached your call concurrency limit, incoming calls will be redirected to the fallback number. [According to documentation](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1334517022893150218), "when the call concurrency limit is reached, the incoming call will be redirected to that fallback number." 2. **Insufficient Credits**: The Vapi system returns a fallback destination when there aren't enough credits on your account. [This would typically show an error message](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1335176375354523741) like:

{"error": "Sorry, not enough credits on your account, please refill."}

3. **Webhook Configuration Issues**: Even though you don't see webhook errors, it's worth checking that your Twilio webhook URL is correctly pointing to

https://api.vapi.ai/twilio/inbound_call

and not to another endpoint. [This has been a common issue](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1332470088078590023). 4. **Assistant ID Configuration**: Make sure the assistant ID is correctly set on your phone number. [If a PhoneNumber doesn't have an assistantId](https://docs.vapi.ai/phone-calling), Vapi will attempt to retrieve the assistant from your server. To troubleshoot using your Twilio call SIDs:

Thank you for reaching out to us. We've received your message and will get back to you as soon as possible.

so we're currently not seeing anything like this within the past couple of days.

🔵 01:13:55:908 Couldn't Find Call. Likely Rejected Inbound. Status: Hey, when VAPI receives the call? They were already in progress, and that's why VAPI has rejected these calls. If you are still seeing this, please share the phone number ID related to it.