I keep getting a Uh-oh! error when trying to set the model to 4o.

Error: TypeError

Message: Cannot read properties of undefined (reading 'startsWith')

Timestamp: 2025-09-05T18:13:52.099Z

That error usually pops up when the model value isn’t being passed in right, so Vapi ends up trying to read something that doesn’t exist. I can help you check where the model is being set and make sure 4o is initialized properly. Are you adding the model in your workflow settings or directly in the API call?

@psicobloc is this api or dashboard?

assistant dashboard

@psicobloc That is a bug unfortunetly on vapi's side. Why are you looking to use 4o anyways? Why not 4.1?

4o is better in some context

Could you please provide a look recording of the error so we can attempt to reproduce on our side?