Local Function Calling on iOS mobile SDK

[Anand9893]

We are trying to build a Voice Assistant. We are using the iOS Client to start the web call from the iOS app. With this call, we are also sharing the metadata like userId for the custom LLM backend which is connected with the Vapi server.

Here we would like to receive certain events from our custom LLM backend to the iOS app to make some UI update or navigation. On researching it seems to be possible to achieve this via function calling. But the function call in the Vapi Dashboard requires us to provide a server URL. But in the documentation it is mentioned that if the server URL is not given then the function call will be forwarded to the iOS mobile client.

Is the any other way to communicate from our custom LLM backend which is connected to Vapi via webhook to send some JSON data back to mobile for UI updates?