Introducing Swift OpenAPI Generator

We’re excited to announce a set of open source libraries designed to help both client and server developers streamline their workflow around HTTP communication using the industry‑standard OpenAPI specification.

→ swift.org/blog/introducing-swift-openapi-generator/

Apple released Swift OpenAPI Generator, a set of open-source libraries that automate HTTP communication for clients and servers using the OpenAPI specification. OpenAPI documents APIs in YAML or JSON, defining endpoints, parameters, and responses to ensure clear contracts without manual documentation or traffic observation.

The generator is a SwiftPM plugin that produces type-safe code from these documents, handling requests and responses while integrating with HTTP libraries via ClientTransport and ServerTransport protocols.

For a GreetingService example, it creates an APIProtocol with methods like getGreeting and a Client struct for calls, or a Handler for server stubs.

Transport options include URLSession for clients and Vapor or Hummingbird for servers, supporting OpenAPI 3.0 and 3.1 with features like streaming and multiple content types.