OpenAPI

Ktor plugin to automatically generate OpenAPI specifications from routes. Additional information can be gradually added to existing routes without requiring major changes to existing code.

Features

• Extends existing Ktor DSL
• No immediate change to code required
• Support for Type-safe routing / Resources plugin
• Document webhooks and (limited) options for server-sent events
• Covers (almost) complete OpenAPI 3.1.0 Specification
• Automatically generates json schemas from kotlin types
  • Out-of-the-box support for type parameters, inheritance, collections, etc
  • Usable with reflection or kotlinx.serialization
  • Supports Jackson, Swagger, Javax and Jakarta annotations
  • Highly configurable and customizable

Example

install(OpenApi) //(1)!

routing {

    route("api.json") {
        openApi() //(2)!
    }

    get("example", {
        description = "An example route" //(3)!
        response {
            HttpStatusCode.OK to {
                description = "A success response"
                body<String>()
            }
        }
    }) {
        call.respondText("Hello World!") //(4)!
    }
}

1. Install and configure the OpenAPI plugin.
2. Create a route to expose the OpenAPI specification file at /api.json.
3. Add (optional) information to the route, e.g. a description and responses and response bodies.
4. Handle requests as usual.