axum-impl-openapi

Overview

Axum produces no API documentation of its own. The idiomatic solution is the utoipa family of crates, which generates an OpenAPI 3 specification from Rust annotations at compile time. Because the spec is derived from the same types and handlers the server runs, it cannot silently drift from the code.

Three crates, each versioned independently:

• utoipa (5.5.0): the derive and attribute macros that annotate types and handlers.
• utoipa-swagger-ui (9.0.2): bundles and serves the interactive Swagger UI.
• utoipa-axum (0.2.0): supplies OpenApiRouter, which registers a handler ONCE for both routing and the spec, removing the last drift risk.