Configuration
The client builder, base URLs, API keys, extra headers, timeouts, listing models, and compatibility handling.
Layers
Middleware around every call. Retry, Timeout and Trace, closures, and layers of your own.
Features and TLS
Cargo features, what each one turns on, and choosing a rustls crypto provider.
Custom HTTP backend
Replacing the built-in hyper transport, for proxies, client certificates, or other roots.
Testing without a server
A scripted HTTP backend answers from memory, so code that calls a model is tested without one.