OpenAPI linting, diffing and testing. Optic helps prevent breaking changes, publish accurate documentation and improve the design of your APIs.

API linting rules

Turn any OpenAPI2/3 and Postman Collection file into an API server with mocking, transformations and validations.

OpenAPI Web component to generate a UI from the spec.

Mocks for microservice environments

The open source, cloud native tool for API Mocking and Testing. Microcks is a Cloud Native Computing Foundation sandbox project 🚀

📘 OpenAPI/Swagger-generated API Reference Documentation

A customizable style validator to make sure your OpenAPI spec follows your organization's standards.

Stop half-done APIs! Cherrybomb is a CLI tool that helps you avoid undefined user behaviour by auditing your API specifications, validating them and running API security tests.

Black-box fuzzer that fuzzes APIs based on OpenAPI specification. Find bugs for free!

The ZAP by Checkmarx Core project

Format an OpenAPI document by ordering, formatting and filtering fields.

Scriptable, multipurpose mock server. Run standalone mock servers, or embed mocks within your tests.

A minimalistic, simple-to-use API linter

Yaade is an open-source, self-hosted, collaborative API development environment.

Open source API development ecosystem - https://hoppscotch.io (open-source alternative to Postman, Insomnia)

Castle Mock is a web application that provides the functionality to mock out RESTful APIs and SOAP web services.