Executableswift-openapi-generator 1.5.0swift_openapi_generator

    Swift OpenAPI Generator

    Generate Swift client and server code from an OpenAPI document.

    Swift-OpenAPI-Generator.md

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    Overview

    OpenAPI is a specification for documenting HTTP services. An OpenAPI document is written in either YAML or JSON, and can be read by tools to help automate workflows, such as generating the necessary code to send and receive HTTP requests.

    Swift OpenAPI Generator is a Swift package plugin that can generate the ceremony code required to make API calls, or implement API servers.

    The code is generated at build-time, so it’s always in sync with the OpenAPI document and doesn’t need to be committed to your source repository.

    Features

    • Works with OpenAPI Specification versions 3.0 and 3.1.

    • Streaming request and response bodies enabling use cases such as JSON event streams, and large payloads without buffering.

    • Support for JSON, multipart, URL-encoded form, base64, plain text, and raw bytes, represented as value types with type-safe properties.

    • Client, server, and middleware abstractions, decoupling the generated code from the HTTP client library and web framework.

    To see these features in action, see Checking out an example project.

    Usage

    Swift OpenAPI Generator can be used to generate API clients and server stubs.

    Below you can see some example code, or you can follow one of the Working with Swift OpenAPI Generator tutorials.

    Using a generated API client

    The generated Client type provides a method for each HTTP operation defined in the OpenAPI document and can be used with any HTTP library that provides an implementation of ClientTransport.

    import OpenAPIURLSession
import Foundation

let client = Client(
    serverURL: URL(string: "http://localhost:8080/api")!,
    transport: URLSessionTransport()
)
let response = try await client.getGreeting()
print(try response.ok.body.json.message)

    Using generated API server stubs

    To implement a server, define a type that conforms to the generated APIProtocol, providing a method for each HTTP operation defined in the OpenAPI document.

    The server can be used with any web framework that provides an implementation of ServerTransport, which allows you to register your API handlers with the HTTP server.

    import OpenAPIRuntime
import OpenAPIVapor
import Vapor

struct Handler: APIProtocol {
    func getGreeting(_ input: Operations.getGreeting.Input) async throws -> Operations.getGreeting.Output {
        let name = input.query.name ?? "Stranger"
        return .ok(.init(body: .json(.init(message: "Hello, \(name)!"))))
    }
}

@main struct HelloWorldVaporServer {
    static func main() async throws {
        let app = Vapor.Application()
        let transport = VaporTransport(routesBuilder: app)
        let handler = Handler()
        try handler.registerHandlers(on: transport, serverURL: URL(string: "/api")!)
        try await app.execute()
    }
}

    Package ecosystem

    The Swift OpenAPI Generator project is split across multiple repositories to enable extensibility and minimize dependencies in your project.

    RepositoryDescription
    apple/swift-openapi-generatorSwift package plugin and CLI
    apple/swift-openapi-runtimeRuntime library used by the generated code
    apple/swift-openapi-urlsessionClientTransport using URLSession
    swift-server/swift-openapi-async-http-clientClientTransport using AsyncHTTPClient
    swift-server/swift-openapi-vaporServerTransport using Vapor
    swift-server/swift-openapi-hummingbirdServerTransport using Hummingbird
    swift-server/swift-openapi-lambdaServerTransport using AWS Lambda

    Requirements and supported features

    Generator versionsSupported OpenAPI versionsMinimum Swift version
    1.0.0 … main3.0, 3.15.9

    See also Supported OpenAPI features.

    Supported platforms and minimum versions

    The generator is used during development and is supported on macOS and Linux.

    The generated code, runtime library, and transports are supported on more platforms, listed below.

    ComponentmacOSLinuxiOStvOSwatchOSvisionOS
    Generator plugin and CLI✅ 10.15+✅✖️✖️✖️✖️
    Generated code and runtime library✅ 10.15+✅✅ 13+✅ 13+✅ 6+✅ 1+

    Documentation and example projects

    To get started, check out the topics below, or one of the Working with Swift OpenAPI Generator tutorials.

    You can also experiment with one of the examples in Checking out an example project that use Swift OpenAPI Generator and integrate with other packages in the ecosystem.

    Or if you prefer to watch a video, check out Meet Swift OpenAPI Generator from WWDC23.

    Example OpenAPI document

    openapi: '3.1.0'
info:
  title: GreetingService
  version: 1.0.0
servers:
  - url: https://example.com/api
    description: Example service deployment.
paths:
  /greet:
    get:
      operationId: getGreeting
      parameters:
        - name: name
          required: false
          in: query
          description: The name used in the returned greeting.
          schema:
            type: string
      responses:
        '200':
          description: A success response with a greeting.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Greeting'
components:
  schemas:
    Greeting:
      type: object
      description: A value with the greeting contents.
      properties:
        message:
          type: string
          description: The string representation of the greeting.
      required:
        - message

    Essentials

    OpenAPI

    Generator plugin and CLI

    API stability

    Getting involved