OpenAPI Backend

openapi-backend is a robust and framework-agnostic middleware library for Node.js, designed to streamline API development by leveraging OpenAPI Specification definitions. It provides capabilities for request validation, routing based on operationIds, authentication via security schemes, and automatic response mocking from examples or schemas. The current stable version is 5.16.1, with an active release cadence reflecting continuous development and maintenance. Key differentiators include its agnosticism towards specific web frameworks (e.g., Express, Hapi, Koa, Serverless Lambda), its use of AJV for highly performant JSON Schema validation, and its TypeScript-first design which includes comprehensive type definitions. It operates without generating any code, offering a clean and efficient runtime, and supports OpenAPI 3.1. This library simplifies API implementation by consolidating common backend concerns into a single, declarative tool, minimizing boilerplate code and ensuring adherence to API contracts.