Symptoms

• The API reports a required model field or fails before contacting an upstream.
• The client UI has an empty model setting.

Likely causes

• model is absent, null, or stored under a client-only display field.
• An environment variable expanded to an empty string.

How to diagnose

• Inspect the serialized request body and locate model.
• Check runtime environment expansion without printing secrets.
• Copy one exact model ID from the live catalog.

Fixes

• Set model to a non-empty catalog ID.
• Fail application startup when the configured model is empty.
• Do not substitute a vendor name or friendly label for the model ID.

How to verify

The request contains the exact model ID and proceeds to routing.

Resources

• Base URL and authentication
• FAQ and troubleshooting