Help with passthrough endpoints?

[Dima-Mediator]

Hi, the documentation to pass-through endpoints is rather scarce. Can someone help?

1. Is there a way to enable load-balancing (with different back-end provider api keys) for "built-in" pass-through endpoints (ex: /anthropic/v1/messages)? As per the documentation examples it seems to rely on $ANTHROPIC_API_KEY and that's it?

2. Can Custom Pass-Through Endpoints completely replace built-in endpoints, and is load balancing possible with custom endpoints?

3. Built-in passthrough endpoints (/anthripic, /gemini etc) support LiteLLM virtual keys auth by default, but the same for Custom Pass-Through Endpoints requires setting " auth: true " and is an Enterprise feature - is this correct?

4. What exactly is the "use_client_credentials_pass_through_routes" setting doing? Is it for custom pass-through endpoint or all (including built-in)? Is it entperise-only?

Thanks!