Encodes Chat Completions compatible and Anthropic Messages requests and decodes complete or streaming responses. Native input and output types separate protocol state from the Host's canonical history. Provider extensions remain explicit JSON values at the wire boundary.
The crate owns incremental SSE framing, tool identities, reasoning, citations, usage and hosted-tool replay. maka-model supplies authorized transport, credentials, cancellation, timeouts and byte reservations. This crate performs no network or runtime work.
The Chat Completions codec covers compatible providers. OpenAI-specific model policies belong to the native Responses route. The Messages codec excludes Files, Batch, Decisions and Skills administration endpoints.
Behavior was verified against unchanged selected upstream tests at the revision recorded in the source audit. Temporary upstream tests and validation bindings are kept outside the product. First-party regressions are maintained alongside each protocol implementation.