CallId:

682065e5-e23a-4792-9a60-a9a380ed9648

I want to understand why call with id

682065e5-e23a-4792-9a60-a9a380ed9648

failed because of

assistant-request-returned-error

I checked on my side and I returned a 200 OK response for this call. Also this call

df527b86-d347-42d5-a7aa-48f6ea9add11

happened 1 min after and it worked with the same assistant.

The

assistant-request-returned-error

indicates that, despite your 200 OK response, Vapi could not process the assistant request—often due to a network hiccup or an unexpected response payload (e.g., missing required fields or incorrect structure) according to the [documentation](https://docs.vapi.ai/calls/call-ended-reason#assistant-related). Actionable next step: Log and inspect the exact JSON payload your server returned for the failed call, and compare it to the successful one. Even a subtle difference (like a missing field or a type mismatch) can cause this error.

json
// Example: Ensure your response matches the expected schema
{
  "assistantId": "your-saved-assistant-id"
  // or
  // "assistant": { ...full assistant object... }
}

Source: - [Call ended reasons](https://docs.vapi.ai/calls/call-ended-reason#assistant-related)