OpenAPI.Tools

Stay up to date with a community-driven list of high-quality, modern tools for OpenAPI. An open source project from APIs You Won't Hate.

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Tool Types

We've organised everything into categories so you can jump to the section you're interested in.

  • Auto Generators: Tools that will take your code and turn it into an OpenAPI Specification document
  • Converters: Various tools to convert to and from OpenAPI and other API description formats.
  • Data Validators: Check to see if API requests and responses are lining up with the API description.
  • Description Validators: Check your API description to see if it is valid OpenAPI.
  • Documentation: Render API Description as HTML (or maybe a PDF) so slightly less technical people can figure out how to work with the API.
  • DSL: Writing YAML by hand is no fun, and maybe you don't want a GUI, so use a Domain Specific Language to write OpenAPI in your language of choice.
  • Gateways: API Gateways and related tools that have integrated support for OpenAPI.
  • GUI Editors: Visual editors help you design APIs without needing to memorize the entire OpenAPI specification.
  • Learning: Whether you're trying to get documentation for a third party API based on traffic, or are trying to switch to design-first at an organization with no OpenAPI at all, learning can help you move your API spec forward and keep it up to date.
  • Miscellaneous: Anything else that does stuff with OpenAPI but hasn't quite got enough to warrant its own category.
  • Mock Servers: Fake servers that take description document as input, then route incoming HTTP requests to example responses or dynamically generates examples.
  • Monitoring: Monitoring tools let you know what is going on in your API.
  • Parsers: Loads and read OpenAPI descriptions, so you can work with them programmatically.
  • SDK Generators: Generate code to give to consumers, to help them avoid interacting at a HTTP level.
  • Security: By poking around your OpenAPI description, some tools can look out for attack vectors you might not have noticed.
  • Server Implementations: Easily create and implement resources and routes for your APIs.
  • Testing: Quickly execute API requests and validate responses on the fly through command line or GUI interfaces.
  • Text Editors: Text editors give you visual feedback whilst you write OpenAPI, so you can see what docs might look like.

Auto Generators

Tools that will take your code and turn it into an OpenAPI Specification document

Name Language v3.1 v3.0 v2.0 GitHub
Fuego - Golang Fuego - web & API framework generating OpenAPI 3 spec from source code Go github octocat
GranthAi - NodeJs OpenAPI 3 based documentation generator which sits between server APIs and anyone calling the APIs Javascript github octocat
har-to-openapi - Automatically generate OpenAPI 3.0 Spec by using network requests captured in one or more HAR files TypeScript github octocat
har2openapi - Automatically generate OpenAPI 3.0 Spec by using network requests captured in one or more HAR files TypeScript github octocat
Huma - A modern, simple, fast & flexible micro framework for building HTTP REST/RPC APIs in Go backed by OpenAPI 3 and JSON Schema. Go github octocat
mitmproxy2swagger - A tool for automatically converting mitmproxy captures to OpenAPI 3.0 specifications. Automatically reverse-engineer REST APIs by just running the apps and capturing the traffic. Python github octocat
OpenAPI AutoSpec - Proxy server that generates API descriptions for any app or website on localhost. JavaScript github octocat
OpenAPI DevTools - Browser extension that generates API specs for any app or website TypeScript github octocat
OpenApiSpecGeneratorPlugin - Built-in plugin for open-source DevProxy that automatically generates OpenAPI 3.0 Spec from captured network requests C# github octocat
TypeSpec - Emit OpenAPI specifications from API descriptions defined in the generic, interoperable, and extensible TypeSpec language. TypeScript github octocat

Converters

Various tools to convert to and from OpenAPI and other API description formats.

Name Language v3.1 v3.0 v2.0 GitHub
allof-merge - Simplify your JsonSchema by combining allOf safely TypeScript github octocat
api - Magical SDK generation from an OpenAPI definition JavaScript, TypeScript github octocat
api-ref-bundler - Bundle all external $ref in Json based API document into single document TypeScript github octocat
APIMatic Transformer - Transform API Descriptions to and from RAML, API Blueprint, OAI v2/v3, WSDL, etc. SaaS
avantation - Generate OpenAPI 3.x specification from HAR. TypeScript 👷 github octocat
docs - A modern alternative to `go-swagger`. Offers generation and parsing of OpenAPI Specs, depending on the usage. github octocat
go-swagger - Unmaintained v2.0 only project seeking new maintainer, or probably a fork. Parser, validator, generates descriptions from code, or code from descriptions! Go github octocat
Google Gnostic - Compile OpenAPI descriptions into equivalent Protocol Buffer representations Go github octocat
JSON Schema to OpenAPI Schema - Due to the OpenAPI v3.0 and JSON Schema discrepancy, you can use this JS library to convert JSON Schema objects to OpenAPI Schema. TypeScript github octocat
Karate-IDE - Generates KarateDSL Tests and Mocks from OpenAPI 3.0 documents and so you can quickly test/explore your API. VSCode Extension github octocat
laravel-openapi - Generate OpenAPI 3 specification for Laravel Applications. PHP github octocat
OAS RAML Converter - Converts between OpenAPI and RAML API specifications Node.js github octocat
oas-normalize - Comprehensive tooling for working with OpenAPI definitions. JavaScript, TypeScript github octocat
OData OpenAPI - OData 4.0, 3.0, and 2.0 to OpenAPI v3.1, v3.0, and v2.0 converter Node.js / XSLT github octocat
OData.OpenAPI - Convert an Edm (Entity Data Model) to OpenAPI 3.0 .NET github octocat
OpenAPI Filter - Filter internal components from OpenAPI Descriptions Node.js github octocat
OpenAPI Schema to JSON Schema - Due to the OpenAPI v3.0 and JSON Schema discrepancy, you can use this JS library to convert OpenAPI Schema objects to proper JSON Schema. TypeScript github octocat
OpenAPI TypeScript - Convert static OpenAPI schemas to TypeScript types quickly using pure Node.js. Fast, lightweight, (almost) dependency-free, and no Java/node-gyp/running OpenAPI servers necessary. TypeScript
openapi-format - A CLI to format an OpenAPI document by ordering fields in a hierarchical order, with the option to filter out flags, tags, methods, operationIDs; including the option to convert an OpenAPI 3.0 document to an OpenAPI version 3.1. Node.js github octocat
openapi-merge - A simple tool to merge multiple independent OpenAPI description files into one file. Useful when you have a number of microservices and you decide to expose them through a gateway. TypeScript github octocat
openapi-python-client - Generate modern Python clients from OpenAPI 3.0 documents. Python github octocat
openapi-to-postman - Convert OpenAPI and Swagger specs to the Postman Collection (v2) format JavaScript github octocat
portman - Port OpenAPI Spec to Postman Collection, with contract & variation tests included! Node.js github octocat
Step CI - Open-source framework for API Quality Assurance. Generate multi-step test-scenarios from OpenAPI. Validate responses against description documents and more. CLI, Node.js github octocat
swagger2openapi - Upgrade files from OpenAPI v2.0 to v3.0, bundling into one mega file or respecting $refs. Part of oas-kit. Node.js / CLI github octocat
typeconv - typeconv is an extremely fast silver bullet type conversion utility. It converts between any of its supported types, bidirectionally. typeconv lets you convert between type systems which have core-types converters, such as JSON Schema, TypeScript, GraphQL, Open API and SureType. This package can be used as an API programatically or as an application (installed in node_modules/.bin or by using e.g. npx). typescript github octocat

Data Validators

Check to see if API requests and responses are lining up with the API description.

Name Language v3.1 v3.0 v2.0 GitHub
api-codegen-ts - Generates TypeScript models, response validators, and operation controllers from OpenAPI descriptions TypeScript github octocat
APIFuzzer - Fuzz test your application using your OpenAPI definition without coding. Integrate into CI/CD, get Junit XML test result and JSON report of failures Python github octocat
committee - Validation middleware for Rack server. This gem validates request and response using an OpenAPI Description. And convert parameter string to specific Ruby object (e.g. convert datetime string to DateTime class). Ruby github octocat
express-openapi-validator - 🦋 Auto-validate API requests and responses in ExpressJS. JavaScript github octocat
fastify-openapi-glue - A plugin for the Fastify webserver to autogenerate a Fastify configuration based on a OpenApi description. Node.js github octocat
Fitting - Library add improve test log for RSpec and WebMock, validate its according to API Blueprint and Open API, show the documentation coverage with log. Ruby github octocat
Fuego - Golang Fuego - web & API framework generating OpenAPI 3 spec from source code Go github octocat
Hot Potato - A reverse proxy that validates responses against an OpenAPI description. It can be used as either a standalone .NET tool, or installed as NuGet packages for an ASP.NET Core integration testing project. C# github octocat
Huma - A modern, simple, fast & flexible micro framework for building HTTP REST/RPC APIs in Go backed by OpenAPI 3 and JSON Schema. Go github octocat
JSONSchema::Validator - A Perl library which validates request/response according to an OpenAPI specification Perl github octocat
kin-openapi - OpenAPI 3.0 (and Swagger v2) implementation for Go (parsing, converting, validation, and more) Go github octocat
Mayhem for API - Probe your REST API with an infinite stream of test cases generated automatically from your OpenAPI specification. Any github octocat
oas-tools - NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations Node.js github octocat
OpenAPI Enforcer - Validate your OpenAPI document, serialize, deserialize, and validate incoming requests and outgoing responses, and simplify response building. You can even produce mock data. Node.js github octocat
OpenAPI HttpFoundation Testing - Validate your HttpFoundation requests and responses (Symfony, Laravel, Drupal...) against OpenAPI definitions PHP github octocat
openapi-changes - The world's fastest, most beautiful, powerful and detailed OpenAPI change detection tool on earth. Explore every change in An OpenAPI spec. See changes over time, go back into history and see what changed with each commit. Identifies all breaking changes, Powered by libopenapi. go github octocat
openapi-core - Validate your requests and responses against an OpenAPI 3 specification and get very verbose and human-readable descriptions of errors. You will receive a deserialized object along with validation result, so you won't need to deserialize it twice. Python github octocat
openapi-data-validator - Validate API requests against an OpenAPI schema. Lightweight, focused, and integrates with any framework Node.js/ Javascript github octocat
openapi-examples-validator - Validates embedded JSON-examples in OpenAPI-specs JavaScript github octocat
openapi-psr7-validator - Using a PHP framework that supports PSR-7? Get free validation without writing a bunch of code, by registering this middleware and pointing it at your API description document. PHP github octocat
openapi-request-response-validation - Runtime validation of requests and responses of your API according to the OpenAPI specs, returning (if any) the list of errors found. It is integrated via a simple REST API therefore usable by Java and non-Java applications and CI/CD. Java github octocat
openapi-spring-webflux-validator - A friendly kotlin library to validate API endpoints against an OpenAPI description document. Java/Kotlin github octocat
openapi-validator-bundle - Validates Request and Response using Symfony Framework PHP github octocat
openapi-validator-middleware - Provides data validation within an Express, Koa or Fastify app according to a OpenAPI definition. It uses Ajv under the hood for validation. Node.js github octocat
openapi.tanna.dev/go/validator - A Go library for making it easier to validate that your OpenAPI contracts match your HTTP request/responses used in your tests. Based on kin-openapi. Go github octocat
OpenAPI::Modern - OpenAPI v3.1 validator and JSON Schema validator (draft7, draft2019-09, draft2020-12) Perl github octocat
openapi_first - It validates requests and responses against your API description using rack middlewares or a low-level interface. It gives you access to request parameters that are parsed exactly as described in your API description and produces useful customizable error responses if request validation fails. Ruby github octocat
openVALIDATION - Allows complex validation rules to be specified in openAPI spec files using natural language. Java github octocat
Step CI - Open-source framework for API Quality Assurance. Generate multi-step test-scenarios from OpenAPI. Validate responses against description documents and more. CLI, Node.js github octocat
vacuum - A blazing fast OpenAPI linter and validator that is compatible with Spectral rulesets, and designed for enterprise-grade speed and scale. go github octocat
Wiremock - WireMock Cloud is a managed, hosted version of WireMock, developed by the same team who wrote the open-source project. It is built on the same technology that powers open source WireMock and is 100% compatible with the WireMock API, with additional features that make it quick and easy to mock any API you depend on. WireMock Cloud also introduces advanced capabilities such as chaos engineering, OpenAPI generation, validation and documentation as well as better collaboration and user management. SaaS github octocat
wiretap - Wiretap is a feature packed OpenAPI compliance testing tool. Validate that a client and server are compliant with an OpenAPI spec. Rewrite paths, inject headers, and even host a UI locally to test an OpenAPI implementation. go github octocat

Documentation

Render API Description as HTML (or maybe a PDF) so slightly less technical people can figure out how to work with the API.

Name Language v3.1 v3.0 v2.0 GitHub
🌿 Fern - Beautiful API documentation from OpenAPI.
Sponsored
TypeScript, Java, Python, Go, Ruby, and C# github octocat
// Speakeasy - Generate & publish SDKs in 10+ languages, Terraform Providers, and docs from your OpenAPI
Sponsored
TypeScript, Python, Go, Java, Terraform, C#, PHP, Ruby, Swift, Unity github octocat
Alphadoc - Alphadoc is a full featured developer experience platform. API components with granular parameter control and diagrams generated from your OpenAPI. Not only the reference, but the entire set of tutorials and guides automatically updates when the underlying API updates. SaaS
api-diff-viewer - React component to view the difference between two Json based API documents. Supported specifications: JsonSchema, OpenAPI 3.x, AsyncAPI 2.x. TypeScript github octocat
APIGit - the native Git based collaboration platform for API design, document, mock, testing and share. SaaS github octocat
APIMatic Developer Experience Portal - Customizable developer portals packed with language specific documentation, client libraries, code samples, an API console and much more. SaaS
BlocklyAutomation - Input any OpenAPI document to have generated Blocks in Blockly form to test and generate documentation. Javascript / .NET github octocat
Bump.sh - Bump.sh generates elegant documentation and changelogs from your OpenAPI specifications. Git diff, for your API. Integrates with CI and Slack. SaaS github octocat
DeveloperHub - Collaboration platform for product and API documentation SaaS
Docuo - Docuo is a lightweight platform that transforms your static contents into a modern developer hub, API reference, product guides, and more. SaaS github octocat
Elements - Build beautiful, interactive API Docs with embeddable React or Web Components, powered by OpenAPI and Markdown Javascript / Custom Element github octocat
Frevo - Keep track of changes in your OpenAPI specifications & generate API references ⛱️ SaaS
GranthAi - NodeJs OpenAPI 3 based documentation generator which sits between server APIs and anyone calling the APIs Javascript github octocat
HopFront - HopFront automatically builds an user friendly UI from a collection of OpenAPI specifications. You can setup custom dashboard tailored to the way your interact with your APIs. TypeScript github octocat
jekyll-openapi - An OpenAPI 3 documentation website generator built with Jekyll for use on GitHub Pages. Jekyll
Kong Enterprise Edition - Highly customizable developer portal with developer onboarding, integrated with the Kong API Gateway Lua
KrakenD API Gateway - KrakenD is a high-performance, stateless API Gateway, seamlessly integrated with OpenAPI. It facilitates automatic API documentation and provides the capability to import existing specifications for generating configuration and mock servers. Golang
Kusk Gateway - Kusk-Gateway is an OpenAPI-driven API Gateway for Kubernetes. It empowers you to develop, validate, mock and deploy your APIs in a matter of minutes using both manual and automated GitOps/APIOps workflows. Kubernetes github octocat
MkDocs Redoc Tag - A MkDocs plugin supports adding Redoc to the page. Python github octocat
MkDocs Swagger UI Tag - A MkDocs plugin supports for add Swagger UI in page. Python github octocat
MrinDoc - OpenAPI description document viewer. Vue.JS github octocat
Nexmo OAS Renderer - Ruby OpenAPI docs rendering, use standalone or add to your Rails app Ruby github octocat
oas-tools - NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations Node.js github octocat
oas3-api-snippet-enricher - Enrich your existing description documents with generated code samples JavaScript github octocat
OpenAPI AutoSpec - Proxy server that generates API descriptions for any app or website on localhost. JavaScript github octocat
OpenAPI DevTools - Browser extension that generates API specs for any app or website TypeScript github octocat
OpenAPI Explorer - Generate and render fully customizable API documentation, then explore and execute API requests via the integrated console. Javascript/Custom Element github octocat
openapi-changes - The world's fastest, most beautiful, powerful and detailed OpenAPI change detection tool on earth. Explore every change in An OpenAPI spec. See changes over time, go back into history and see what changed with each commit. Identifies all breaking changes, Powered by libopenapi. go github octocat
openapi-dev-tool - OpenAPI Dev Tool proposes to developers a unique tool to address development and industrialization needs! JavaScript github octocat
OpenAPI-UI - Create simple and beautiful OpenAPI/Swagger documentation from OpenAPI files. Generate mock parameters and call APIs. Like Postman, but for OpenAPI specifications. TypeScript github octocat
openapi-viewer - Browse and test a REST API described with the OpenAPI 3.0 Specification Vue.js github octocat
OpenDocumenter - OpenDocumenter is a automatic documentation generator for OpenAPI v3 schemas. Simply provide your schema file in JSON or YAML, then sit back and enjoy the documentation. Vue.js 👷
RapiDoc - Custom Element to view OpenAPI descriptions. Web Component github octocat
RapiPdf - Custom Element to generate PDF from OpenAPI descriptions. Web Component github octocat
ReadMe - Interactive developer hubs that help users succeed with your APIs 🦉 SaaS github octocat
ReDoc - Open source API reference docs from OpenAPI descriptions React.js github octocat
Redocly CLI - Bring versatile OpenAPI validation, linting & bundling to your command line with this open-source Swiss-army knife. CLI & TypeScript github octocat
RestCase Docs - An API-first and security-first management platform. Design visually and we will create a beautiful API documentation for your APIs. SaaS
Restish - A CLI for REST-ish APIs with HTTP/2, built-in auth, content negotiation, caching, and more that understands and can discover OpenAPI descriptions. CLI / Go github octocat
Scalar - Beautiful Open-Source API references from Swagger/OAS files ✨ Vue.js github octocat
Scribe - Generate API documentation for humans from your Laravel codebase. PHP github octocat
Stoplight Docs - Create beautiful, customizable, interactive API documentation generated from OpenAPI, integrated with Stoplight Studio. SaaS
Traefik Hub - Traefik Hub is a Kubernetes-native API Management solution for publishing, securing, and managing APIs. Configuration is driven by Kubernetes CRDs, labels, and selectors for effective GitOps. Go github octocat
Treblle - Treblle is a lightweight SDK that helps Engineering and Product teams build, ship, and maintain REST based APIs faster.
VSCode OpenAPI Preview - Preview OpenAPI v3.0 & v3.1 documents in Visual Studio Code using Spotlight Elements. TypeScript github octocat
VSCode OpenAPI Viewer - Preview and edit JSON or YAML OpenAPI specifications in Visual Studio Code using RapiDoc. TypeScript github octocat
widdershins - Generate Slate/Shins markdown from OpenAPI 2.0/3.0.x Node.js github octocat
Wiremock - WireMock Cloud is a managed, hosted version of WireMock, developed by the same team who wrote the open-source project. It is built on the same technology that powers open source WireMock and is 100% compatible with the WireMock API, with additional features that make it quick and easy to mock any API you depend on. WireMock Cloud also introduces advanced capabilities such as chaos engineering, OpenAPI generation, validation and documentation as well as better collaboration and user management. SaaS github octocat
Zuplo (OpenAPI-based gateway and documentation) - Zuplo is an API gateway designed for developers. Natively powered by OpenAPI (3.1 or 3.0), zuplo offers an OpenAPI design surface, API documentation and a serverless, programmable edge gateway that includes request validation, auth, rate-limiting and more. Web / SaaS

DSL

Writing YAML by hand is no fun, and maybe you don't want a GUI, so use a Domain Specific Language to write OpenAPI in your language of choice.

Name Language v3.1 v3.0 v2.0 GitHub
BOATS - BOATS allows for larger teams to contribute to multi-file OpenAPI definitions by writing Nunjucks tpl syntax in YAML with a few important helpers to ensure stricter consistency, eg operationId: <$ uniqueOpId() $>. Node.js github octocat
CUE - CUE is an open source language, with a rich set of APIs and tooling, for defining, generating, and validating all kinds of data configuration, APIs, database schemas, code, etc. CUE currently supports generating OpenAPI through its API. CUE
Goa - Goa provides a holistic approach for developing remote APIs and microservices in Go. implementers don't have to worry about the documentation getting out of sync as Goa takes care of generating OpenAPI specifications for HTTP based services and gRPC protocol buffer files for gRPC based services Go
kotlin-openapi3-dsl - kotlin-openapi3-dsl is a DSL written in Kotlin to write OpenAPI descriptions in plain Kotlin. Kotlin
Oxlip API Language - Oxlip is a high-level functional programming language for designing OpenAPI definitions. It defines algebraic abstractions over REST concepts to alleviate the pain of managing OpenAPI in JSON or YAML by hand and at scale. OAL github octocat
rswag - Rswag extends rspec-rails request specs with a Swagger-based DSL for describing and testing API operations. ruby 👷 github octocat
Spot - A concise, developer-friendly way to describe your API contract. TypeScript github octocat
Supermodel - Model your data using JSON Schema, refer and remix the models freely, convert to various formats including OAS v2/v3. SaaS

Text Editors

Text editors give you visual feedback whilst you write OpenAPI, so you can see what docs might look like.

Name Language v3.1 v3.0 v2.0 GitHub
42Crunch IntelliJ OpenAPI Editor - OpenAPI extension for Visual Studio Code - new file templates, navigation, intellisense, code snippets. Any github octocat
draig-car - This is a REPL OpenAPI3 description document text editor. It provides both a CLI and and a REPL you can use to test your APIs, but you can also test database queries, start and stop database (containers), generate fake data automatically, start your test microservice and much more. You don't have to exit from your REPL! Or you can use the CLI to do the same if you want, giving you the option to automatize your contract-first based dev cycles. TypeScript github octocat
Fix My OpenAPI - A VSCode Extension by APIMatic - APIMatic's VSCode extension helps you validate, lint, and auto-fix your OpenAPI files, along with other capabilities such as API transformations, API audit report generation, SDKs generation, and more. Any
KaiZen-OpenAPI-Editor - Full-featured Eclipse editor for OpenAPI, also available on Eclipse Marketplace. Java github octocat
Redocly VSCode Extension - Redocly OpenAPI is a Visual Studio Code extension that helps you write, validate, preview, and maintain your OpenAPI documents. Node.js github octocat
Swagger Editor - Design, describe, and document your API on the first open source editor fully dedicated to OpenAPI-based APIs. Node.js github octocat
SwaggerHub - API design and documentation platform to improve collaboration, standardize development workflow and centralize their API discovery and consumption. SaaS/On-Premise NodeJS
VSCode OpenAPI Editor - OpenAPI extension for Visual Studio Code - new file templates, navigation, intellisense, code snippets. Any github octocat
VSCode OpenAPI Snippets - OpenAPI Snippets for Visual Studio Code editor, includes split file validation Any github octocat
VSCode OpenAPI Viewer - Preview and edit JSON or YAML OpenAPI specifications in Visual Studio Code using RapiDoc. TypeScript github octocat
Xapi Platform - Xapi is an integrated platform that enables you to implement a streamlined API-first design strategy with standardized API artifacts and collaborative teams. Saas

GUI Editors

Visual editors help you design APIs without needing to memorize the entire OpenAPI specification.

Name Language v3.1 v3.0 v2.0 GitHub
ApiBldr - Web-Based API Designer for OpenAPI (swagger) and AsyncAPI specifications. Angular 9.0 / Saas
Apicurio Studio - Web-Based Open Source API Design via the OpenAPI specification. Angular 7.0, Java / Saas github octocat
APIGit - the native Git based collaboration platform for API design, document, mock, testing and share. SaaS github octocat
Flotiq - headless CMS with OpenAPI support - Visually define your Content Types, Flotiq automatically generates your own OpenAPI v3 compatible endpoints, SDKs and Postman collections.
Frogment Editor - A free openAPI spec editor and linter that breaks down your spec into fragments to make editing easier and more intuituve. Desktop / SaaS
Hackolade - A visual editor for OpenAPI v2/v3, from the pioneer in data modeling for NoSQL databases. ReactJS github octocat
JetBrains tools (IntelliJ IDEA, PyCharm etc.) - JetBrains development tools like IntelliJ IDEA, PyCharm and others come with a bundled *OpenAPI Specifications* plugin. The plugin allows you to write the OpenAPI specifications and supports you with validations, formatting, code-completion etc. It supports a *text view* as well as a rendered SwaggerUI-like *graphical interface*. Java, Python
OAIE Sketch - Browser based OpenApi Integrated Editor with side-by side view of the yaml and an interactive graph. Vue.js github octocat
OpenAPI Designer - OpenAPI Designer is an easy-to-use, free, web-based, codeless description document editor with JSON and YAML outputs. SaaS
RestCase Designer - A design-first API managment platform with WYSIWYG API Designer for OpenAPI and AsyncAPI specifications. Angular 9.0 / Saas
Stoplight Studio - Stoplight Studio is a powerful GUI/text editor with linting and mocking built right in. The desktop version has been discontinued, but it runs in the browser, powered by your existing GitHub, GitLab, or BitBucket repos. SaaS
Xapi Platform - Xapi is an integrated platform that enables you to implement a streamlined API-first design strategy with standardized API artifacts and collaborative teams. Saas
Zuplo (OpenAPI-based gateway and documentation) - Zuplo is an API gateway designed for developers. Natively powered by OpenAPI (3.1 or 3.0), zuplo offers an OpenAPI design surface, API documentation and a serverless, programmable edge gateway that includes request validation, auth, rate-limiting and more. Web / SaaS

Learning

Whether you're trying to get documentation for a third party API based on traffic, or are trying to switch to design-first at an organization with no OpenAPI at all, learning can help you move your API spec forward and keep it up to date.

Name Language v3.1 v3.0 v2.0 GitHub
APIClarity - Reconstruct Open API Specifications from real-time workload traffic seamlessly. Golang, JavaScript github octocat
Fitting - Library add improve test log for RSpec and WebMock, validate its according to API Blueprint and Open API, show the documentation coverage with log. Ruby github octocat
InducOapi - A simple python module to generate OpenAPI Description Documents by supplying request/response bodies. Python github octocat
optic - Build your first OpenAPI description from traffic. Use Optic to patch the OpenAPI every time it detects new API behavior. cli github octocat
Response2Schema - Takes any JSON response and generates an OpenAPI definition document with the component schema and a default endpoint. PHP

Mock Servers

Fake servers that take description document as input, then route incoming HTTP requests to example responses or dynamically generates examples.

Name Language v3.1 v3.0 v2.0 GitHub
APIGit - the native Git based collaboration platform for API design, document, mock, testing and share. SaaS github octocat
Beeceptor - 🐝 An HTTP interceptor and rule-based mocking service for REST APIs. No coding required to create a mock endpoint. No sign-up required. SaaS
Counterfact - Counterfact is a revolutionary free and open source mock server. If you have Node installed, all you have to do is run `npx counterfact@latest path-or-url-to-your-openapi-document`. Out of the box, you'll get a mock server that returns random data. With a TypeScript API that's optimized for mocking, you can add more realistic behavior. It supports mix and matching mocks with calls to the real API (sans CORS headaches). With hot reloading and a REPL, you can change things up on the fly. TypeScript / Node github octocat
Fakeit - Create mock server from OpenAPI 3 specification with random response generation and request validation. cli / Docker github octocat
Falcon Heavy - The framework for building app backends and microservices via the API design-first workflow. Python github octocat
Karate-IDE - Generates KarateDSL Tests and Mocks from OpenAPI 3.0 documents and so you can quickly test/explore your API. VSCode Extension github octocat
Kusk Gateway - Kusk-Gateway is an OpenAPI-driven API Gateway for Kubernetes. It empowers you to develop, validate, mock and deploy your APIs in a matter of minutes using both manual and automated GitOps/APIOps workflows. Kubernetes github octocat
Meeshkan - Meeshkan is an automated testing and mocking tool. It offers first-class support for GraphQL APIs, but Meeshkan is also built to handle REST APIs and third-party dependencies. SaaS
Microcks - Open source Kubernetes-native tool for API Mocking and Testing. Turn your OAI contract examples into ready-to-use mocks. Use examples to test and validate implementations according to spec and schema elements. Microcks is a Cloud Native Computing Sandbox project 🚀 Java github octocat
Mockintosh - Mocks for CloudNative Environments - Converts OpenAPI files to Mocks and use them to develop in isolated environments and test edge cases, Async call to queues such as Kafka or RabbitMQ or simulate performance & chaos testing CLI / Docker
OpenAPI Mocker - Standalone nodejs based OpenAPI 3 mock server, docker-friendly with request validation and autoreload. nodejs github octocat
openapi-data-mocker - Tiny library to generate basic OpenAPI Data Types. Consider it as extended Faker package. First version able to mock most of the data formats. It doesn't support polymorphism yet, but work in progress. May be useful for writing custom unit tests. PHP github octocat
orval - orval is able to generate client with appropriate type-signatures (TypeScript) from any valid OpenAPI v3 or Swagger v2 specification, either in yaml or json formats. Generate, valid, cache and mock in your frontend applications all with your OpenAPI specification. 🍺 Typescript, React, Vue, Svelte, Angular github octocat
Prism - Turn any OAI file into an API server with mocking, transformations, validations, and more. cli github octocat
Specmatic - Specmatic enables teams to practice Contract-Driven Development by leveraging OpenAPI specifications as Executable Contracts to reduce time-to-market by allowing teams to build, test and deploy their MicroServices and MicroFrontends independently and Shift-Left the identification of compatibility issues between Components / Services in complex interdependent systems such as those built with MicroServices architecture. In the process it reduces / removes the need for Integration Testing. Any, CLI github octocat
Wiremock - WireMock Cloud is a managed, hosted version of WireMock, developed by the same team who wrote the open-source project. It is built on the same technology that powers open source WireMock and is 100% compatible with the WireMock API, with additional features that make it quick and easy to mock any API you depend on. WireMock Cloud also introduces advanced capabilities such as chaos engineering, OpenAPI generation, validation and documentation as well as better collaboration and user management. SaaS github octocat
yii2-app-api - Generate Server side API code with routing, models, data validation and database schema from an OpenAPI description. Based on Yii Framework. PHP github octocat

Description Validators

Check your API description to see if it is valid OpenAPI.

Name Language v3.1 v3.0 v2.0 GitHub
api - Magical SDK generation from an OpenAPI definition JavaScript, TypeScript github octocat
API Insights - API Insights is a web application and native Mac application that allows you get real time insights into your API using your OpenAPI specification. Think of it like a static analysis tool for your API, using your OpenAPI Specification file. github octocat
Cherrybomb - A CLI tool that helps avoid undefined user behaviour by validating your API descriptions, to make sure key parts are not missing or vague. Rust github octocat
express-openapi-validator - 🦋 Auto-validate API requests and responses in ExpressJS. JavaScript github octocat
Fix My OpenAPI - A VSCode Extension by APIMatic - APIMatic's VSCode extension helps you validate, lint, and auto-fix your OpenAPI files, along with other capabilities such as API transformations, API audit report generation, SDKs generation, and more. Any
Hot Potato - A reverse proxy that validates responses against an OpenAPI description. It can be used as either a standalone .NET tool, or installed as NuGet packages for an ASP.NET Core integration testing project. C# github octocat
oas-normalize - Comprehensive tooling for working with OpenAPI definitions. JavaScript, TypeScript github octocat
oas-tools - NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations Node.js github octocat
OpenAPI Enforcer - Validate your OpenAPI document, serialize, deserialize, and validate incoming requests and outgoing responses, and simplify response building. You can even produce mock data. Node.js github octocat
OpenAPI Style Validator - A customizable style validator to make sure your OpenAPI description follows your organization's standards. Java, CLI github octocat
OpenAPI Validator - Configurable and extensible validator/linter for OpenAPI documents Node.js github octocat
openapi-examples-validator - Validates embedded JSON-examples in OpenAPI-specs JavaScript github octocat
openapi-schema-validator - OpenApi description validation Javascript github octocat
openapi-spec-validator - OpenAPI Description validator Python github octocat
openapi-spring-webflux-validator - A friendly kotlin library to validate API endpoints against an OpenAPI description document. Java/Kotlin github octocat
openapi-validator-junit - A JUnit extension for validating a wide range of properties of a specification. Kotlin github octocat
OpenAPI::Modern - OpenAPI v3.1 validator and JSON Schema validator (draft7, draft2019-09, draft2020-12) Perl github octocat
openVALIDATION - Allows complex validation rules to be specified in openAPI spec files using natural language. Java github octocat
php-openapi - A PHP library for manipulating and validating OpenAPI 3.0 Descriptions PHP 👷 github octocat
Rate My OpenAPI - Free and open source OpenAPI automated review and validation tool. Go github octocat
Redocly CLI - Bring versatile OpenAPI validation, linting & bundling to your command line with this open-source Swiss-army knife. CLI & TypeScript github octocat
Spectral - A flexible OpenAPI/AsyncAPI API linter, which can help you build anything from automated API Style Guides for API Governance workflows, or handle any other JSON/YAML object linting. functions. CLI & TypeScript/JavaScript github octocat
super-linter - GitHub Action to lint repositories as part of CI/CD. Implements the latest version of Spectral. CLI / Docker github octocat
vacuum - A blazing fast OpenAPI linter and validator that is compatible with Spectral rulesets, and designed for enterprise-grade speed and scale. go github octocat

Security

By poking around your OpenAPI description, some tools can look out for attack vectors you might not have noticed.

Name Language v3.1 v3.0 v2.0 GitHub
42crunch - A unique set of integrated API security tools that allow discovery, remediation of OpenAPI vulnerabilities and runtime protection against API attacks. SaaS
API Insights - RestCase executes hundrends of security and quality checks against the API definition, the API insights report provides detailed security scoring for prioritization, and remediation advice to help developers define the best API definition possible. SaaS
cats - CATS is a REST API Fuzzer and negative testing tool for OpenAPI endpoints. CATS automatically generates, runs and reports tests with minimum configuration and no coding effort. Tests are self-healing and do not require maintenance. Java
FireTail - FireTail provides discovery, logging, posture management and in-line enforcement of APIs using OpenAPI. API governance is backed by cloud provider integrations and a suite of open-source application libraries. SaaS github octocat
Mayhem for API - Probe your REST API with an infinite stream of test cases generated automatically from your OpenAPI specification. Any github octocat
oas-tools - NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations Node.js github octocat
openapi-fuzzer - Based on OpenAPI specification, openapi-fuzzer provides random data as inputs to the API endpoints in order to find bugs. Rust
OpenAPI3 Fuzzer - Simple fuzzer for OpenAPI 3 specification based APIs. Verifies responses and sends various attack patterns. Python github octocat
OWASP ZAP - OWASP ZAP is a free and open source web security tool that can be used manually or completely automated. It supports importing OpenAPI v2 and v3 definitions to allow an API to be thoroughly security tested. Java github octocat
Rate My OpenAPI - Free and open source OpenAPI automated review and validation tool. Go github octocat
RESTler - RESTler is the first stateful REST API fuzzing tool for automatically testing cloud services through their REST APIs and finding security and reliability bugs in these services. RESTler analyzes the OpenAPI description of a cloud service, and then generates and executes tests that exercise the service through its REST API. During testing, it checks for specific classes of bugs and dynamically learns how the service behaves from prior service responses. Any github octocat
StackHawk HawkScan - StackHawk is an application vulnerability scanner purpose built for developers to use in the DevOps pipeline. It leverages a provided OpenAPI v2 or v3 spec file for route discovery and enhanced scanning. SaaS github octocat
Treblle - Treblle is a lightweight SDK that helps Engineering and Product teams build, ship, and maintain REST based APIs faster.

SDK Generators

Generate code to give to consumers, to help them avoid interacting at a HTTP level.

Name Language v3.1 v3.0 v2.0 GitHub
🌿 Fern - Generate SDKs in popular languages and publish them to package managers (like npm).
Sponsored
TypeScript, Java, Python, Go, Ruby, and C# github octocat
✨ Stainless - Generate SDKs in popular languages and publish them to package managers (like npm).
Sponsored
TypeScript, Python, Go, Java, and Kotlin github octocat
// Speakeasy - Generate & publish SDKs in 10+ languages, Terraform Providers, and docs from your OpenAPI
Sponsored
TypeScript, Python, Go, Java, Terraform, C#, PHP, Ruby, Swift, Unity github octocat
ABAP OpenAPI Client & Server Generator - ABAP OpenAPI Client & Server Generator written in ABAP. Code generation runs also in the Browser and on command line using NodeJS. ABAP github octocat
api-codegen-ts - Generates TypeScript models, response validators, and operation controllers from OpenAPI descriptions TypeScript github octocat
apigen-ts - Typed HTTP client generator as single file without extra dependencies TypeScript github octocat
APIMatic Generate - Bring in your API description (OAI v2/v3, RAML, API Blueprint, WSDL, etc.) to generate fully functional SDKs in over 10 languages. SaaS
Azure AutoRest - Generates client libraries for accessing RESTful web services from an OpenAPI document. Supports C#, PowerShell, Go, Java, Node.js, TypeScript, Python, and Ruby. TypeScript github octocat
BlocklyAutomation - Input any OpenAPI document to have generated Blocks in Blockly form to test and generate documentation. Javascript / .NET github octocat
Counterfact - Counterfact is a revolutionary free and open source mock server. If you have Node installed, all you have to do is run `npx counterfact@latest path-or-url-to-your-openapi-document`. Out of the box, you'll get a mock server that returns random data. With a TypeScript API that's optimized for mocking, you can add more realistic behavior. It supports mix and matching mocks with calls to the real API (sans CORS headaches). With hot reloading and a REPL, you can change things up on the fly. TypeScript / Node github octocat
docler-labs/api-client-generator - API client generator is a console application capable of auto-generating a PSR18/PSR7 API client based on OpenAPI specification according to PHP best practices and your code style standards. PHP github octocat
docs - A modern alternative to `go-swagger`. Offers generation and parsing of OpenAPI Specs, depending on the usage. github octocat
draig - DRAIG is an OpenAPI3 based design-first custom generator that creates fully functional microservices from an OAS API description document. You can use DRAIG with openapi-generator as a backend generator or use DRAIG CLI or REPL to generate your microservices. With simple user-customizable templates, you can extended and improve implementation code so that generated code can be compiled and deployed immediatelly. Java github octocat
FabriKt - A sophisticated Kotlin code generation library capable of generating Jackson-annotated data classes, Spring Controller interfaces, and fault-tolerant OkHttp clients. Written in Kotlin, this library programatically generates code and is capable of handling advanced OpenApi3 specification features such as polymorphism. Kotlin github octocat
Flotiq - headless CMS with OpenAPI support - Visually define your Content Types, Flotiq automatically generates your own OpenAPI v3 compatible endpoints, SDKs and Postman collections.
go-swagger - Unmaintained v2.0 only project seeking new maintainer, or probably a fork. Parser, validator, generates descriptions from code, or code from descriptions! Go github octocat
guardrail - Principled code generation from OpenAPI descriptions Scala, Java, ... github octocat
janephp/open-api - Generate a PHP Client API (PSR-7 compatible) given a OpenAPI specification. PHP github octocat
Kiota Api Client Generator - Kiota is a cross platform API Client code generator that is small, fast, and optimized for API consumers to find APIs and generate client code for just the parts of the API that they need. One tool, for any OpenAPI described API, that delivers a consistent client experience in multiple languages. C# github octocat
NSwag - OpenAPI toolchain for .NET, Web API and TypeScript .NET github octocat
oa-client - Flexible client helper for making and validating calls to OpenAPI backends. For Node and the browser. Runtime lib - no need for code generation! TypeScript github octocat
oazapfts! - Generate TypeScript clients from a given OpenAPI description document. TypeScript github octocat
OpenAPI Client Generators - .NET Core command line program to generate strongly typed client API codes in C# on .NET Frameworks and .NET Core, and in TypeScript for Angular 5+, Aurelia, jQuery, AXIOS and Fetch API. C# github octocat
OpenAPI Commander - Generate a Node.js command line tool from an OpenAPI definition. Node.js / CLI github octocat
OpenAPI Generator - A template-driven engine to generate documentation, API clients and server stubs in different languages by parsing your OpenAPI Description (community-driven fork of swagger-codegen) Java 👷 github octocat
OpenAPI JSON Schema Generator - A template-driven engine to generate API client code + documentation by parsing your OpenAPI Description Python, Java github octocat
OpenAPI Qraft - Generate a type-safe TanStack Query client for React from an OpenAPI Document. TypeScript github octocat
openapi-ts-sdk-builder - Generate a TypeScript SDK from OpenAPI 3 definitions. Javascript / TypeScript github octocat
restful-react - Generate React hooks with appropriate type-signatures from OpenAPI descriptions React (Typescript) github octocat
spring-openapi - OpenAPI v3 generator for Java Spring. Includes also client generation. Supports inheritance with discriminators, Jackson annotations and custom interceptors. Java github octocat
Swift OpenAPI Generator - Generate Swift client and server code from an OpenAPI document. Includes support for type-safe JSON event streaming, multipart, Swift concurrency, customizable middlewares, and pluggable HTTP libraries. Swift github octocat
Typoas - Fully typed OpenAPI Typescript generator Typescript github octocat
Unchase.OpenAPI.Connectedservice - Visual Studio extension to generate C# (TypeScript) HttpClient (or C# Controllers) code for OpenAPI web service with NSwag. .NET github octocat

Server Implementations

Easily create and implement resources and routes for your APIs.

Name Language v3.1 v3.0 v2.0 GitHub
@eropple/nestjs-openapi3 - Integrates tightly with a NestJS application to infers complex descriptions and expresses them in its generated OpenAPI document. It then presents that document via ReDoc, and validates inputs for conformance to spec. Node.js github octocat
@nestjs/swagger - Official OpenAPI (Swagger) module for NestJS. Use decorators to define OpenAPI endpoint documentation, parameters and return types. Integrates tightly with a NestJS application. Ships with Swagger UI and serves OpenAPI v3 spec. Node.js github octocat
@smartrecruiters/openapi-first - Initializes your API express application with the description in OpenAPI 3.0 format using provided middlewares (parsers, validators, controller, defaults setting) or custom ones Node.js github octocat
ABAP OpenAPI Client & Server Generator - ABAP OpenAPI Client & Server Generator written in ABAP. Code generation runs also in the Browser and on command line using NodeJS. ABAP github octocat
API Platform - REST and GraphQL framework to build modern API-driven projects PHP github octocat
BaucisJS + baucis-openapi3 - Create REST resources with persistence on MongoDB and expose OpenAPI v.3 contracts Node.js github octocat
Connexion - Connexion is a modern Python web framework that makes spec-first and api-first development easy. No code is generated. With Connexion, you write your server-side API handlers according to a naming convention, and the Connexion engine, given a spec, invokes your code after any input has been validated. Python github octocat
draig-car - This is a REPL OpenAPI3 description document text editor. It provides both a CLI and and a REPL you can use to test your APIs, but you can also test database queries, start and stop database (containers), generate fake data automatically, start your test microservice and much more. You don't have to exit from your REPL! Or you can use the CLI to do the same if you want, giving you the option to automatize your contract-first based dev cycles. TypeScript github octocat
express-openapi - An unopinionated OpenAPI framework for Express, which supports Promise based middleware, response handlers and Security Filtering. Node.js / Typescript 👷 github octocat
Falcon Heavy - The framework for building app backends and microservices via the API design-first workflow. Python github octocat
Fuego - Golang Fuego - web & API framework generating OpenAPI 3 spec from source code Go github octocat
Fusio - Open source API management platform PHP github octocat
Hot Potato - A reverse proxy that validates responses against an OpenAPI description. It can be used as either a standalone .NET tool, or installed as NuGet packages for an ASP.NET Core integration testing project. C# github octocat
Huma - A modern, simple, fast & flexible micro framework for building HTTP REST/RPC APIs in Go backed by OpenAPI 3 and JSON Schema. Go github octocat
LoopBack 4 - A highly extensible object-oriented Node.js and TypeScript framework for building APIs and microservices with tight OpenAPI 3 integration. Serves Swagger UI and OpenAPI 3 spec out of the box. Generate code to interact with other OpenAPI-compliant APIs, or generate new API endpoints based on existing OpenAPI specs. Node.js + TypeScript github octocat
Mojolicious::Plugin::OpenApi - Mojolicious::Plugin::OpenAPI is a plugin for Mojolicious framework that add routes and input/output validation to your Mojolicious application based on OpenAPI description documents.' Perl github octocat
Mojolicious::Plugin::OpenAPI::Modern - Mojolicious plugin for OpenAPI::Modern Perl github octocat
oas-tools - NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations Node.js github octocat
OpenAPI Enforcer - Validate your OpenAPI document, serialize, deserialize, and validate incoming requests and outgoing responses, and simplify response building. You can even produce mock data. Node.js github octocat
OpenAPI Enforcer Middleware - An express middleware that makes it easy to write web services that follow an OpenAPI specification by leveraging the tools provided in the openapi-enforcer package. Node.js github octocat
openapi-backend - Build, Validate, Route, and Mock using OpenAPI specification. Framework-agnostic Node.js + Typescript github octocat
openapi-processor - Generates java interfaces & model classes for Spring Boot (annotation based, MVC & WebFlux) or Micronaut (annotation based) from an OpenAPI yaml description. Provides powerful type mapping capabilities to adjust the generated code. Gradle & Maven support. Playground. Java github octocat
openapi-validator-middleware - Provides data validation within an Express, Koa or Fastify app according to a OpenAPI definition. It uses Ajv under the hood for validation. Node.js github octocat
SpringFox - Automated JSON API documentation for APIs built with Spring and SpringBoot Java, Kotlin, Groovy, or Ruby github octocat
Swift OpenAPI Generator - Generate Swift client and server code from an OpenAPI document. Includes support for type-safe JSON event streaming, multipart, Swift concurrency, customizable middlewares, and pluggable HTTP libraries. Swift github octocat
tsoa - Creates OpenAPI docs and provides free runtime validation for your Koa, Express, Hapi (and more) services Node.js / TypeScript github octocat
Vert.x Web Api Contract - Create API endpoints with Vert.x 3 and OpenAPI 3 with automatic requests validation Java, Kotlin, JavaScript, Groovy, Ruby, Ceylon or Scala github octocat
Whook - OpenAPI 3 based NodeJS server. Javascript / TypeScript github octocat
yii2-app-api - Generate Server side API code with routing, models, data validation and database schema from an OpenAPI description. Based on Yii Framework. PHP github octocat

Miscellaneous

Anything else that does stuff with OpenAPI but hasn't quite got enough to warrant its own category.

Name Language v3.1 v3.0 v2.0 GitHub
allof-merge - Simplify your JsonSchema by combining allOf safely TypeScript github octocat
api-diff-viewer - React component to view the difference between two Json based API documents. Supported specifications: JsonSchema, OpenAPI 3.x, AsyncAPI 2.x. TypeScript github octocat
api-ref-bundler - Bundle all external $ref in Json based API document into single document TypeScript github octocat
api-smart-diff - Compare two Json based API documents (OpenAPI, AsyncAPI, JsonSchema, GraphAPI) TypeScript github octocat
Django REST Framework - Automates generation of OpenAPI 3 description documents either as a static file (via CLI command) or a dynamic view within the Django REST Framework (DRF) application. Python github octocat
express-openapi-validator - 🦋 Auto-validate API requests and responses in ExpressJS. JavaScript github octocat
Flotiq - headless CMS with OpenAPI support - Visually define your Content Types, Flotiq automatically generates your own OpenAPI v3 compatible endpoints, SDKs and Postman collections.
Frevo - Keep track of changes in your OpenAPI specifications & generate API references ⛱️ SaaS
go-openapi-spec-code-diffs - A golang validation tool that compares given OpenAPI specs (e.g. openapi.yaml) vis-a-vis routes (e.g. /api/v1/customer/:id) defined in golang source code and reports differences. This is useful in scenarios where you want to keep the OpenAPI specs and Code in synch. go github octocat
HopFront - HopFront automatically builds an user friendly UI from a collection of OpenAPI specifications. You can setup custom dashboard tailored to the way your interact with your APIs. TypeScript github octocat
laravel-openapi - Generate OpenAPI 3 specification for Laravel Applications. PHP github octocat
oa-client - Flexible client helper for making and validating calls to OpenAPI backends. For Node and the browser. Runtime lib - no need for code generation! TypeScript github octocat
oas - Comprehensive tooling for working with OpenAPI definitions JavaScript, TypeScript github octocat
oasdiff - Golang module for deep comparison of two OpenAPI specifications. Available also as a command-line. Go github octocat
OAuth2 as OpenAPI Spec 3.0 components - OAuth2 token endpoint described with OAS3 schema. All grants documented. Can be installed as NPM or Composer package. Any github octocat
OpenAPI CRUD Wizard - This wizard is an IntelliJ Plugin to create a new OpenAPI document including all CRUD operations based only on a Yaml object. No knowledge about OpenAPI specification needed. Yaml github octocat
OpenAPI Server Code Generator (oapi-codegen) - Generate a client, server, and HTTP types for various Go HTTP servers, from an OpenAPI v3 specification Go github octocat
openapi-cli-tool - Can list up defined API paths and bundle multi-file into one. Supports multiple file extensions. Python github octocat
openapi-comparator - C# library for comparing two OpenAPI specifications. C# github octocat
openapi-dev-tool - OpenAPI Dev Tool proposes to developers a unique tool to address development and industrialization needs! JavaScript github octocat
openapi-diff - Utility for comparing two OpenAPI specifications. Java github octocat
openapi-examples-validator - Validates embedded JSON-examples in OpenAPI-specs JavaScript github octocat
openapi-format - A CLI to format an OpenAPI document by ordering fields in a hierarchical order, with the option to filter out flags, tags, methods, operationIDs; including the option to convert an OpenAPI 3.0 document to an OpenAPI version 3.1. Node.js github octocat
openapi-spring-webflux-validator - A friendly kotlin library to validate API endpoints against an OpenAPI description document. Java/Kotlin github octocat
openVALIDATION - Allows complex validation rules to be specified in openAPI spec files using natural language. Java github octocat
optic diff - Diff the effective API contract between any two versions of your OpenAPI description. Exit 1 on breaking changes. Node github octocat
php-openapi-faker - Library to generate fake data for OpenAPI 3.x requests, responses and schemas. PHP github octocat
Rate My OpenAPI - Free and open source OpenAPI automated review and validation tool. Go github octocat
Restish - A CLI for REST-ish APIs with HTTP/2, built-in auth, content negotiation, caching, and more that understands and can discover OpenAPI descriptions. CLI / Go github octocat
schema2dts - Create types definitions from an OpenAPI schema. Javascript / TypeScript github octocat
Treblle - Treblle is a lightweight SDK that helps Engineering and Product teams build, ship, and maintain REST based APIs faster.
vacuum - A blazing fast OpenAPI linter and validator that is compatible with Spectral rulesets, and designed for enterprise-grade speed and scale. go github octocat
wiretap - Wiretap is a feature packed OpenAPI compliance testing tool. Validate that a client and server are compliant with an OpenAPI spec. Rewrite paths, inject headers, and even host a UI locally to test an OpenAPI implementation. go github octocat

Parsers

Loads and read OpenAPI descriptions, so you can work with them programmatically.

Name Language v3.1 v3.0 v2.0 GitHub
api - Magical SDK generation from an OpenAPI definition JavaScript, TypeScript github octocat
APIDevTools/swagger-parser - OpenAPI 2.0 and 3.0 parser and validator. Can also bundle multiple documents into one via `$ref`. Node.js github octocat
KaiZen OpenAPI Parser - High-performance Parser, Validator, and Java Object Model for OpenAPI 3.x Java github octocat
kin-openapi - OpenAPI 3.0 (and Swagger v2) implementation for Go (parsing, converting, validation, and more) Go github octocat
libopenapi - Enterprise grade, fully featured OpenAPI 3.1, 3.0 and Swagger parser library for go. A complete toolset for reading and parsing OpenAPI and Swagger specifications. Comes complete with high and low-level APIs, diff engine, index and resolver. go github octocat
Microsoft/OpenAPI.NET - C# based parser with OpenAPI Description validation and migration support from V2 .NET github octocat
oas-normalize - Comprehensive tooling for working with OpenAPI definitions. JavaScript, TypeScript github octocat
oas-tools - NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations Node.js github octocat
oas_parser - A Ruby parser for OpenAPI 3.0+ descriptions. Ruby github octocat
Object Oriented OpenAPI Specification - An object oriented approach to generating OpenAPI Descriptions, implemented in PHP PHP github octocat
openapi-filter - OpenAPI 2.0 and 3.0 filter utility. A CLI/module to filter out internal/private paths, operations, parameters, schemas etc from OpenAPI v1/OpenAPI v2/AsyncAPI definitions. Simply flag any OpenAPI object within the definition with an `x-internal` specification extension or target a OpenAPI property (tags, methods, OperationId), and it will be removed from the output. Node.js github octocat
openapi-format - A CLI to format an OpenAPI document by ordering fields in a hierarchical order, with the option to filter out flags, tags, methods, operationIDs; including the option to convert an OpenAPI 3.0 document to an OpenAPI version 3.1. Node.js github octocat
openapi-processor/openapi-parser - OpenAPI parser with (json schema) validation (currently 3.0 only). Separate apis for OpenAPI 3.0 & 3.1. Easily get resolved $ref objects. Pluggable document reader & json/yaml converter. Minimal dependencies. Java github octocat
openapi-snippet - Generates code snippets in various languages & tools (cURL, Node, Python, Ruby, Java, Go, C#...), from OpenAPI documents. Node.js github octocat
openapi-snippet-cli - Adds code snippets in redoc style (x-codeSamples) to OpenAPI documents. This is a CLI wrapper for the "openapi-snippet". Node.js github octocat
OpenAPI-TS - TS Model & utils for OpenAPI 3.0.x contracts TypeScript github octocat
openapi3 - An OpenAPI 3 Specification client, and validator, covering both description validation and limited data validation for Python 3. Python github octocat
OpenAPI3-Rust - Rust serialization library for OpenAPI v3 Rust github octocat
openapi3_parser - A Ruby implementation of parser and validator for the OpenAPI 3 Specification. Ruby github octocat
php-openapi - A PHP library for manipulating and validating OpenAPI 3.0 Descriptions PHP 👷 github octocat
psx-api - Parse and generate API specification formats PHP github octocat
swagger-parser - Swagger Parser reads OpenAPI definitions into current Java POJOs. Java github octocat

Testing

Quickly execute API requests and validate responses on the fly through command line or GUI interfaces.

Name Language v3.1 v3.0 v2.0 GitHub
APIGit - the native Git based collaboration platform for API design, document, mock, testing and share. SaaS github octocat
Assertible - Import an OpenAPI specification into Assertible to generate tests that validate JSON Schema responses and status codes on every endpoint. SaaS
Atlassian OpenAPI Request Validators - A set of Java libraries which allow you to integrate OpenAPI Description Document validation into your testing or clients with tools like WireMock/RestAssured/MockMVC/etc... Java github octocat
BlocklyAutomation - Input any OpenAPI document to have generated Blocks in Blockly form to test and generate documentation. Javascript / .NET github octocat
Chai OpenAPI Response Validator - Simple Chai support for asserting that HTTP responses satisfy an OpenAPI spec. Node.js github octocat
draig-car - This is a REPL OpenAPI3 description document text editor. It provides both a CLI and and a REPL you can use to test your APIs, but you can also test database queries, start and stop database (containers), generate fake data automatically, start your test microservice and much more. You don't have to exit from your REPL! Or you can use the CLI to do the same if you want, giving you the option to automatize your contract-first based dev cycles. TypeScript github octocat
Dredd - Language-agnostic command-line tool for validating API description document against backend implementation of the API Javascript github octocat
EvoMaster - A tool for automatically generating system-level test cases for RESTful APIs, using Evolutionary Algorithms and Dynamic Program Analysis. Java/Kotlin github octocat
Fitting - Library add improve test log for RSpec and WebMock, validate its according to API Blueprint and Open API, show the documentation coverage with log. Ruby github octocat
hikaku - A library that tests if the implementation of a REST-API meets its specification. Kotlin github octocat
Hot Potato - A reverse proxy that validates responses against an OpenAPI description. It can be used as either a standalone .NET tool, or installed as NuGet packages for an ASP.NET Core integration testing project. C# github octocat
jest-openapi - Additional Jest matchers for asserting that HTTP responses satisfy an OpenAPI spec. Node.js github octocat
Karate-IDE - Generates KarateDSL Tests and Mocks from OpenAPI 3.0 documents and so you can quickly test/explore your API. VSCode Extension github octocat
Mayhem for API - Probe your REST API with an infinite stream of test cases generated automatically from your OpenAPI specification. Any github octocat
Meeshkan - Meeshkan is an automated testing and mocking tool. It offers first-class support for GraphQL APIs, but Meeshkan is also built to handle REST APIs and third-party dependencies. SaaS
Microcks - Open source Kubernetes-native tool for API Mocking and Testing. Turn your OAI contract examples into ready-to-use mocks. Use examples to test and validate implementations according to spec and schema elements. Microcks is a Cloud Native Computing Sandbox project 🚀 Java github octocat
OpenAPI Enforcer - Validate your OpenAPI document, serialize, deserialize, and validate incoming requests and outgoing responses, and simplify response building. You can even produce mock data. Node.js github octocat
openapi-changes - The world's fastest, most beautiful, powerful and detailed OpenAPI change detection tool on earth. Explore every change in An OpenAPI spec. See changes over time, go back into history and see what changed with each commit. Identifies all breaking changes, Powered by libopenapi. go github octocat
openapi-dev-tool - OpenAPI Dev Tool proposes to developers a unique tool to address development and industrialization needs! JavaScript github octocat
portman - Port OpenAPI Spec to Postman Collection, with contract & variation tests included! Node.js github octocat
ReadyAPI - an end to end API functional, security, performance and virtualization tool where OAS description documents can be utilized to automate the creation and validation of end to end tests, running them manually or at any point in your CI/CD pipeline. pipelines. Java
RESTest - RESTest is a framework for automated black-box testing of RESTful web APIs. It follows a model-based approach, where test cases are automatically derived from the OpenAPI description document (OAS) of the API under test. Java github octocat
Restish - A CLI for REST-ish APIs with HTTP/2, built-in auth, content negotiation, caching, and more that understands and can discover OpenAPI descriptions. CLI / Go github octocat
RESTler - RESTler is the first stateful REST API fuzzing tool for automatically testing cloud services through their REST APIs and finding security and reliability bugs in these services. RESTler analyzes the OpenAPI description of a cloud service, and then generates and executes tests that exercise the service through its REST API. During testing, it checks for specific classes of bugs and dynamically learns how the service behaves from prior service responses. Any github octocat
Schemathesis - Reads the description document and generates test cases that will ensure that your application is compliant with its description. Python github octocat
Specmatic - Specmatic enables teams to practice Contract-Driven Development by leveraging OpenAPI specifications as Executable Contracts to reduce time-to-market by allowing teams to build, test and deploy their MicroServices and MicroFrontends independently and Shift-Left the identification of compatibility issues between Components / Services in complex interdependent systems such as those built with MicroServices architecture. In the process it reduces / removes the need for Integration Testing. Any, CLI github octocat
Spectator - Spectator provides light-weight OpenAPI testing tools you can use within your existing Laravel test suite. PHP 👷 github octocat
Step CI - Open-source framework for API Quality Assurance. Generate multi-step test-scenarios from OpenAPI. Validate responses against description documents and more. CLI, Node.js github octocat
Tcases for OpenAPI - Generates test cases directly from an OpenAPI v3 description of your API. Creates tests executable using various test frameworks. Bonus: Semantic linter reports elements that are inconsistent, superfluous, or dubious. Java github octocat
vREST NG - vREST NG is a simple and powerful application for API Automation. It Allows to use OpenAPI specification into vREST NG to drive your API testing that validates the API responses against JSON Schema and also provides powerful response validation capabilities. JavaScript
Wiremock - WireMock Cloud is a managed, hosted version of WireMock, developed by the same team who wrote the open-source project. It is built on the same technology that powers open source WireMock and is 100% compatible with the WireMock API, with additional features that make it quick and easy to mock any API you depend on. WireMock Cloud also introduces advanced capabilities such as chaos engineering, OpenAPI generation, validation and documentation as well as better collaboration and user management. SaaS github octocat
wiretap - Wiretap is a feature packed OpenAPI compliance testing tool. Validate that a client and server are compliant with an OpenAPI spec. Rewrite paths, inject headers, and even host a UI locally to test an OpenAPI implementation. go github octocat
Xapi Platform - Xapi is an integrated platform that enables you to implement a streamlined API-first design strategy with standardized API artifacts and collaborative teams. Saas

Gateways

API Gateways and related tools that have integrated support for OpenAPI.

Name Language v3.1 v3.0 v2.0 GitHub
Fusio - Open source API management platform PHP github octocat
Kong Enterprise Edition - Highly customizable developer portal with developer onboarding, integrated with the Kong API Gateway Lua
KrakenD API Gateway - KrakenD is a high-performance, stateless API Gateway, seamlessly integrated with OpenAPI. It facilitates automatic API documentation and provides the capability to import existing specifications for generating configuration and mock servers. Golang
Kusk Gateway - Kusk-Gateway is an OpenAPI-driven API Gateway for Kubernetes. It empowers you to develop, validate, mock and deploy your APIs in a matter of minutes using both manual and automated GitOps/APIOps workflows. Kubernetes github octocat
Serverless API Gateway - Serverless API Gateway is a serverless, open-source, and free API Gateway that is designed to be used with any HTTP source. TypeScript github octocat
Traefik Hub - Traefik Hub is a Kubernetes-native API Management solution for publishing, securing, and managing APIs. Configuration is driven by Kubernetes CRDs, labels, and selectors for effective GitOps. Go github octocat
wiretap - Wiretap is a feature packed OpenAPI compliance testing tool. Validate that a client and server are compliant with an OpenAPI spec. Rewrite paths, inject headers, and even host a UI locally to test an OpenAPI implementation. go github octocat
Zuplo (OpenAPI-based gateway and documentation) - Zuplo is an API gateway designed for developers. Natively powered by OpenAPI (3.1 or 3.0), zuplo offers an OpenAPI design surface, API documentation and a serverless, programmable edge gateway that includes request validation, auth, rate-limiting and more. Web / SaaS

Monitoring

Monitoring tools let you know what is going on in your API.

Name Language v3.1 v3.0 v2.0 GitHub
API Insights - API Insights is a web application and native Mac application that allows you get real time insights into your API using your OpenAPI specification. Think of it like a static analysis tool for your API, using your OpenAPI Specification file. github octocat
Apitally - Simple REST API monitoring tool that helps engineering and product teams understand their APIs. Tracks usage, errors, response times and more using middleware for Python and Node.js frameworks. Also offers uptime monitoring and logging of individual requests. SaaS github octocat
Treblle - Treblle is a lightweight SDK that helps Engineering and Product teams build, ship, and maintain REST based APIs faster.