TheOpenAPI Specification (OAS), previously known as theSwagger Specification, is a specification for a programming language-agnostic, machine-readable interface definition language for describing, producing, consuming, and visualizing web services. OpenAPI documents describe API services and are represented in YAML or JSON formats.

User-friendly AI Interface (Supports Ollama, OpenAI API, ...)

• UpdatedDec 16, 2025
• Svelte

FastAPI framework, high performance, easy to learn, fast to code, ready for production

• UpdatedDec 17, 2025
• Python

Full stack, modern web application template. Using FastAPI, React, SQLModel, PostgreSQL, Docker, GitHub Actions, automatic HTTPS and more.

• UpdatedDec 15, 2025
• TypeScript

Opensource IDE For Exploring and Testing API's (lightweight alternative to Postman/Insomnia)

• UpdatedDec 17, 2025
• JavaScript

The OpenAPI Specification Repository

• UpdatedDec 17, 2025
• Markdown

Swagger UI is a collection of HTML, JavaScript, and CSS assets that dynamically generate beautiful documentation from a Swagger-compliant API.

• UpdatedDec 17, 2025
• JavaScript

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

• UpdatedDec 17, 2025
• Java

📘 OpenAPI/Swagger-generated API Reference Documentation

• UpdatedDec 16, 2025
• TypeScript

gRPC to JSON proxy generator following the gRPC HTTP spec

• UpdatedDec 17, 2025
• Go

Scalar is an open-source API platform:　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　🌐 Modern Rest API Client　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　📖 Beautiful API References　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　✨ 1st-Class OpenAPI/Swagger Support

• UpdatedDec 18, 2025
• TypeScript

Automatically generate RESTful API documentation with Swagger 2.0 for Go.

• UpdatedDec 11, 2025
• Go

Expose your FastAPI endpoints as Model Context Protocol (MCP) tools, with Auth!

• UpdatedNov 24, 2025
• Python

Automagically reverse-engineer REST APIs via capturing traffic

• UpdatedDec 15, 2025
• HTML

🕸️ Create REST and GraphQL APIs, scaffold Jamstack webapps, stream changes in real-time.

• UpdatedSep 1, 2025
• TypeScript

💨 Fast, Async-ready, Openapi, type hints based framework for building APIs

• UpdatedDec 9, 2025
• Python

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

• UpdatedDec 17, 2025
• TypeScript

Generate Go client and server boilerplate from OpenAPI 3 specifications

• UpdatedDec 17, 2025
• Go

Light, flexible and extensible ASGI framework | Built to scale

• UpdatedDec 15, 2025
• Python

Generate TypeScript types from OpenAPI 3 specs

• UpdatedDec 15, 2025
• TypeScript

Examples and server integrations for generating the Swagger API Specification, which enables easy access to your REST API

• UpdatedDec 17, 2025
• Java