Attribute Macro axum 

#[axum]

The openapi_trait attribute macro, wired to the axum backend.

Re-exported from openapi_trait_axum. Apply it to a mod block with a path to an OpenAPI YAML or JSON file. The path is resolved relative to CARGO_MANIFEST_DIR. Generates typed Rust code from an OpenAPI specification file.

Apply this attribute to a mod block. The macro reads the OpenAPI document at the given path (resolved relative to CARGO_MANIFEST_DIR) at compile time and replaces the module’s contents with:

• Schema structs derived from components/schemas
• A {OperationId}Request struct per operation (bundles path, query, header params and the request body)
• Per-operation {OperationId}Response enums implementing axum::response::IntoResponse
• A {Title}Api trait with one async fn per operation (keyed by operationId). Trait methods have a default implementation that returns 500 Internal Server Error, so you only need to override the operations your server handles.
• A router method on the trait that wires all operations to an axum::Router

The crate recompiles automatically whenever the spec file changes.

Arguments

First positional argument: path to the OpenAPI YAML or JSON file, relative to the crate root (CARGO_MANIFEST_DIR).

Examples

#[openapi_trait::axum("openapi/petstore.yaml")]
pub mod petstore {}

#[derive(Clone)]
struct MyServer;

impl petstore::PetstoreApi for MyServer {
    type Error = std::convert::Infallible;

    async fn get_pet_by_id(
        &self,
        req: petstore::GetPetByIdRequest,
        _state: axum::extract::State<()>,
        _headers: axum::http::HeaderMap,
    ) -> Result<petstore::GetPetByIdResponse, Self::Error> {
        Ok(petstore::GetPetByIdResponse::Status200(petstore::Pet {
            id: Some(req.pet_id),
            name: "doggie".into(),
            photo_urls: vec![],
            category: None,
            tags: None,
            status: None,
        }))
    }
}

let app = MyServer.router().with_state(());

Errors

The macro emits a compile error if:

• The file cannot be found or read.
• The OpenAPI document is malformed or cannot be parsed.
• An operation is missing an operationId.