// Client sends model calls to a Responses endpoint for one agent. The ChatGPT
// backend and the OpenAI API take the same request body and differ only in the
// URL and the credentials. Every call sends the fixed cache key of the agent,
// Client sends model calls to a Responses endpoint for one agent. The ChatGPT
// backend and the OpenAI API take the same request body and differ only in the
// URL and the credentials. Every call sends the fixed cache key of the agent,