Everything You Need to Know About OpenAPI

Speakeasy has introduced an open-source reference guide for writing OpenAPI specifications, offering an AI-powered search feature to enhance user experience. This guide emphasizes the importance of OpenAPI in maintaining consistent API design across various surfaces like documentation and SDKs, transforming a SaaS business into a platform by providing a unified view of errors, responses, and parameters. OpenAPI, a standardized document structure for describing HTTP APIs, is written in JSON or YAML, serving as a blueprint for generating API documentation and SDKs. The document outlines essential elements such as security requirements, endpoints, and reusable components, improving readability and maintainability. While the guide covers OpenAPI versions 3.0.x and 3.1.x, it recommends version 3.1 for its compatibility with JSON Schema, which expands the tool and library ecosystem available to developers. The documentation is designed for developers at any skill level, focusing on practical application rather than technical completeness, and it highlights differences between the versions when necessary.