Gropius

Gropius is a Rust toolkit for designing APIs. It's compatible with OpenAPI 3.1.x, but, unlike most toolkits, it lets you generate the spec from the code, instead of the code from the spec:

/// A chair designed by Walter Gropius.
#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
struct Chair {
    id: String,
    year: u32,
    description: String,
}

#[gropius::api(tags = ["chairs"])]
/// Explore chairs designed by Walter Gropius.
trait ChairApi {
    /// List chairs by year.
    #[endpoint(GET, "/chairs/{year}")]
    async fn list_chairs(&self, path: gropius::Path<u16>) -> Result<Vec<Chair>, ApiError>;

    /// Get a chair by ID.
    #[endpoint(GET, "/chairs/{year}/{id}")]
    async fn get_chair(&self, path: gropius::Path<(u64, String)>) -> Result<Widget, ApiError>;
}

For more details, head to the docs.

Features

The crate is new and is currently alpha quality. However, it has several distinguishing features compared to similar libraries:

• Integrates with tower::Service and hyper on the server
• Integrates with either reqwest or ureq on the client
• Supports grouping endpoints into multiple traits, which can then be combined in a single API surface
• Supports OpenAPI 3.1.x, with 3.2.x support planned

Similar crates

Gropius is inspired by and indebted to these libraries, which have a similar approach:

• oxidecomputer/dropshot
• juhaku/utoipa