----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Create Assistant]() * [Update Assistant]() * [Get Assistant]() * [List Phone Numbers]() -----------------------------

### Answer It sounds like you're experiencing a discrepancy in the behavior of dynamically versus statically set server URLs with Vapi's assistants. The issue you described where the server URL appears correct in the response from

CreatePhoneCall

but does not trigger events as expected suggests a potential issue with how the server URL is being handled dynamically. Based on the provided documentation, when creating or updating an assistant, you can specify a

serverUrl

which should dynamically direct the API where to send event information. If this URL is not being recognized when set during the phone call creation, it's possible that there might be a bug or a specific requirement or condition that is not being met in the API. As a workaround, you mentioned that using a hardcoded server URL works. To ensure there's not a simple oversight: 1. Double-check that the server URL provided dynamically matches exactly the URL that works when hardcoded. 2. Ensure that the server URL is correctly formatted and accessible by Vapi at the time of the call. For further diagnostics, you might consider capturing the API requests and responses using tools like Postman or a similar API testing tool to see what differences, if any, there might be in the requests sent by Vapi when the server URL is set dynamically versus statically. Unfortunately, without more specific documentation or error logs from the API calls, it's challenging to provide a more precise solution. At this point, if the issue persists, reviewing the detailed API request and response data or reaching out to Vapi's technical support might be necessary steps.

Got it. Tagging @User for additional help.