Legacy OpenAPI Tools

Tools for historic OpenAPI versions

This is the legacy list of old OpenAPI tools, covering v3.0 and v2.0 tools that have not yet added support for v3.1 or v3.2. Please visit the main site for the latest tools.

Auto Generators

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

Name	v3.0	v2.0
FastMCP FastMCP can automatically generate an MCP server from an OpenAPI specification. Users only need to provide an OpenAPI specification (3.0 or 3.1) and an API client.	Yes	No
Fuego Golang Fuego - web & API framework generating OpenAPI 3 spec from source code	Yes	No
GranthAi NodeJs OpenAPI 3 based documentation generator which sits between server APIs and anyone calling the APIs	Yes	No
har-to-openapi Automatically generate OpenAPI 3.0 Spec by using network requests captured in one or more HAR files	Yes	No
har2openapi Automatically generate OpenAPI 3.0 Spec by using network requests captured in one or more HAR files	Yes	No
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.	Yes	No
OpenAPI AutoSpec Proxy server that generates API descriptions for any app or website on localhost.	Yes	No
OpenApiSpecGeneratorPlugin Built-in plugin for open-source DevProxy that automatically generates OpenAPI 3.0 Spec from captured network requests	Yes	No
Rage A Ruby web framework for building APIs with first-class OpenAPI support.	Yes	No

Code generators

Tools to generate code from your OpenAPI Spec, or to generate an OpenAPI Spec from your code.

Name	v3.0	v2.0
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.	Yes	No
generator-openapi-repo Generate the repository structure for a scalable OpenAPI Description	No	Yes
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.	Yes	Yes
OpenAPI Server Code Generator (oapi-codegen) Generate a client, server, and HTTP types for various Go HTTP servers, from an OpenAPI v3 specification	Yes	No
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. 🍺	Yes	Yes
Python OpenAPI Generator This library facilitates creating OpenAPI document for Python projects.	Yes	No
Swagger-Codegen Swagger Codegen enables generating server stubs and client SDKs for APIs described in OpenAPI	Yes	Yes
Unchase.OpenAPI.Connectedservice Visual Studio extension to generate C# (TypeScript) HttpClient (or C# Controllers) code for OpenAPI web service with NSwag.	Yes	Yes

Converters

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

Name	v3.0	v2.0
avantation Generate OpenAPI 3.0 specification from HAR.	Yes	No
go-swagger Unmaintained v2.0 only project seeking new maintainer, or probably a fork. Parser, validator, generates descriptions from code, or code from descriptions!	No	Yes
Google Gnostic Compile OpenAPI descriptions into equivalent Protocol Buffer representations	Yes	Yes
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.	Yes	No
Karate-IDE Generates KarateDSL Tests and Mocks from OpenAPI 3.0 documents and so you can quickly test/explore your API.	Yes	No
laravel-openapi Generate OpenAPI 3 specification for Laravel Applications.	Yes	No
OAS RAML Converter Converts between OpenAPI and RAML API specifications	Yes	Yes
OData.OpenAPI (.NET) Convert an Edm (Entity Data Model) to OpenAPI 3.0	Yes	No
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.	Yes	No
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.	Yes	No
Step CI Open-source framework for API Quality Assurance. Generate multi-step test-scenarios from OpenAPI. Validate responses against description documents and more.	Yes	No
swagger2openapi Upgrade files from OpenAPI v2.0 to v3.0, bundling into one mega file or respecting $refs. Part of oas-kit.	Yes	Yes
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).	Yes	No

Data Validators

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

Name	v3.0	v2.0
api-codegen-ts Generates TypeScript models, response validators, and operation controllers from OpenAPI descriptions	Yes	Yes
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	Yes	Yes
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).	Yes	Yes
Fuego Golang Fuego - web & API framework generating OpenAPI 3 spec from source code	Yes	No
JSONSchema::Validator A Perl library which validates request/response according to an OpenAPI specification	Yes	No
kin-openapi OpenAPI 3.0 (and Swagger v2) implementation for Go (parsing, converting, validation, and more)	Yes	Yes
oas-tools NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations	Yes	No
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.	Yes	Yes
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.	Yes	Yes
openapi-examples-validator Validates embedded JSON-examples in OpenAPI-specs	Yes	Yes
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.	Yes	Yes
openapi-spring-webflux-validator A friendly kotlin library to validate API endpoints against an OpenAPI description document.	Yes	Yes
openapi-validator-bundle Validates Request and Response using Symfony Framework	Yes	No
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.	Yes	Yes
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.	Yes	No
Step CI Open-source framework for API Quality Assurance. Generate multi-step test-scenarios from OpenAPI. Validate responses against description documents and more.	Yes	No

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	v3.0	v2.0
GranthAi NodeJs OpenAPI 3 based documentation generator which sits between server APIs and anyone calling the APIs	Yes	No
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.	Yes	No
jekyll-openapi An OpenAPI 3 documentation website generator built with Jekyll for use on GitHub Pages.	Yes	No
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.	Yes	Yes
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.	Yes	Yes
MrinDoc OpenAPI description document viewer.	Yes	Yes
Nexmo OAS Renderer Ruby OpenAPI docs rendering, use standalone or add to your Rails app	Yes	No
oas-tools NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations	Yes	No
oas3-api-snippet-enricher Enrich your existing description documents with generated code samples	Yes	No
OpenAPI AutoSpec Proxy server that generates API descriptions for any app or website on localhost.	Yes	No
openapi-viewer Browse and test a REST API described with the OpenAPI 3.0 Specification	Yes	No
OpenDocumenter OpenDocumenter is a automatic documentation generator for OpenAPI v3.0 schemas. Simply provide your schema file in JSON or YAML, then sit back and enjoy the documentation.	Yes	Yes
RapiPdf Custom Element to generate PDF from OpenAPI descriptions.	Yes	Yes
RestCase Docs An API-first and security-first management platform. Design visually and we will create a beautiful API documentation for your APIs.	Yes	Yes
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.	Yes	Yes
widdershins Generate Slate/Shins markdown from OpenAPI 2.0/3.0.x	Yes	Yes

Domain-Specific Languages (DSLs)

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	v3.0	v2.0
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() $>.	Yes	Yes
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.	Yes	No
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	Yes	Yes
kotlin-openapi3-dsl kotlin-openapi3-dsl is a DSL written in Kotlin to write OpenAPI descriptions in plain Kotlin.	Yes	No
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.	Yes	No
Spot A concise, developer-friendly way to describe your API contract.	Yes	Yes
Supermodel Model your data using JSON Schema, refer and remix the models freely, convert to various formats including OAS v2/v3.	Yes	Yes

Gateways

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

Name	v3.0	v2.0
Fusio Open source API management platform	Yes	No
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.	Yes	Yes
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.	Yes	Yes
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.	Yes	Yes

IDEs and GUI Editors

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

Name	v3.0	v2.0
ApiBldr Web-Based API Designer for OpenAPI (swagger) and AsyncAPI specifications.	Yes	Yes
Apicurio Studio Web-Based Open Source API Design via the OpenAPI specification.	Yes	Yes
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.	Yes	Yes
OAIE Sketch Browser based OpenApi Integrated Editor with side-by side view of the yaml and an interactive graph.	Yes	No
RestCase Designer A design-first API managment platform with WYSIWYG API Designer for OpenAPI and AsyncAPI specifications.	Yes	Yes

Whether generating documentation for a third-party API based on traffic, or are trying to "catch up on design-first" at an organization with no OpenAPI at all, these "learning" (or traffic sniffing) tools can help you get there.

Name	Languages	v3.0	v2.0	Links
APIClarity Reconstruct Open API Specifications from real-time workload traffic seamlessly.		Yes	Yes
Response2Schema Takes any JSON response and generates an OpenAPI definition document with the component schema and a default endpoint.		Yes	No

Miscellaneous

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

Name	v3.0	v2.0
CodeMirror OAS support Plugin for text editor https://codemirror.net/ running in your browser that can fetch and parse your OpenAPI schema definition and provide auto-completion support (for large and complex JSON message payloads), error highlighting and access to schema documentation. It is capable of parsing megabytes of OpenAPI schema definition in a second and providing auto-completion support in milliseconds. The work is an MVP of a plugin with basic functionality made as part of a master thesis at ČVUT.	Yes	No
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.	Yes	No
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.	Yes	No
laravel-openapi Generate OpenAPI 3 specification for Laravel Applications.	Yes	No
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!	Yes	No
oasdiff Golang module for deep comparison of two OpenAPI specifications. Available also as a command-line.	Yes	No
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.	Yes	No
OpenAPI Server Code Generator (oapi-codegen) Generate a client, server, and HTTP types for various Go HTTP servers, from an OpenAPI v3 specification	Yes	No
openapi-cli-tool Can list up defined API paths and bundle multi-file into one. Supports multiple file extensions.	Yes	No
openapi-comparator C# library for comparing two OpenAPI specifications.	Yes	No
openapi-diff Utility for comparing two OpenAPI specifications.	Yes	No
openapi-examples-validator Validates embedded JSON-examples in OpenAPI-specs	Yes	Yes
openapi-spring-webflux-validator A friendly kotlin library to validate API endpoints against an OpenAPI description document.	Yes	Yes
php-openapi-faker Library to generate fake data for OpenAPI 3.x requests, responses and schemas.	Yes	No
schema2dts Create types definitions from an OpenAPI schema.	Yes	No

Mock Servers

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

Name	v3.0	v2.0
Beeceptor OpenAPI Mock Server 🐝 A free service that transforms your OpenAPI description documents into instant mock servers with AI-generated realistic responses. Upload your YAML/JSON files to get schema-compliant mocks without writing any code. Helps with early integration testing and simulating various API behaviors.	Yes	No
Fakeit Create mock server from OpenAPI 3 specification with random response generation and request validation.	Yes	No
Falcon Heavy The framework for building app backends and microservices via the API design-first workflow.	Yes	No
Karate-IDE Generates KarateDSL Tests and Mocks from OpenAPI 3.0 documents and so you can quickly test/explore your API.	Yes	No
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.	Yes	Yes
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.	Yes	No
OpenAPI Mocker Standalone nodejs based OpenAPI 3 mock server, docker-friendly with request validation and autoreload.	Yes	No
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.	Yes	No
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. 🍺	Yes	Yes
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.	Yes	No
yii2-app-api Generate Server side API code with routing, models, data validation and database schema from an OpenAPI description. Based on Yii Framework.	Yes	No

Monitoring

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

Name	Languages	v3.0	v2.0	Links
API Insights (Treblle) 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.		Yes	No

Parsers

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

Name	v3.0	v2.0
APIDevTools/swagger-parser OpenAPI 2.0 and 3.0 parser and validator. Can also bundle multiple documents into one via `$ref`.	Yes	Yes
go-swagger Unmaintained v2.0 only project seeking new maintainer, or probably a fork. Parser, validator, generates descriptions from code, or code from descriptions!	No	Yes
KaiZen OpenAPI Parser High-performance Parser, Validator, and Java Object Model for OpenAPI 3.x	Yes	No
kin-openapi OpenAPI 3.0 (and Swagger v2) implementation for Go (parsing, converting, validation, and more)	Yes	Yes
oas_parser A Ruby parser for OpenAPI 3.0+ descriptions.	Yes	No
oas-tools NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations	Yes	No
Object Oriented OpenAPI Specification An object oriented approach to generating OpenAPI Descriptions, implemented in PHP	Yes	No
openapi-snippet Generates code snippets in various languages & tools (cURL, Node, Python, Ruby, Java, Go, C#...), from OpenAPI documents.	Yes	Yes
openapi-snippet-cli Adds code snippets in redoc style (x-codeSamples) to OpenAPI documents. This is a CLI wrapper for the "openapi-snippet".	Yes	Yes
OpenAPI-TS TS Model & utils for OpenAPI 3.0.x contracts	Yes	No
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.	Yes	No
openapi3 An OpenAPI 3 Specification client, and validator, covering both description validation and limited data validation for Python 3.	Yes	No
openapi3_parser A Ruby implementation of parser and validator for the OpenAPI 3 Specification.	Yes	No
OpenAPI3-Rust Rust serialization library for OpenAPI v3	Yes	No
php-openapi A PHP library for manipulating and validating OpenAPI 3.0 Descriptions	Yes	No
psx-api Parse and generate API specification formats	Yes	Yes

Schema Validators

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

Name	v3.0	v2.0
API Insights (Treblle) 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.	Yes	No
oas-tools NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations	Yes	No
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.	Yes	Yes
OpenAPI Style Validator A customizable style validator to make sure your OpenAPI description follows your organization's standards.	Yes	Yes
openapi-examples-validator Validates embedded JSON-examples in OpenAPI-specs	Yes	Yes
openapi-spring-webflux-validator A friendly kotlin library to validate API endpoints against an OpenAPI description document.	Yes	Yes
php-openapi A PHP library for manipulating and validating OpenAPI 3.0 Descriptions	Yes	No
super-linter GitHub Action to lint repositories as part of CI/CD. Implements the latest version of Spectral.	Yes	Yes

SDK Generators

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

Name	v3.0	v2.0
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.	Yes	No
api-codegen-ts Generates TypeScript models, response validators, and operation controllers from OpenAPI descriptions	Yes	Yes
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.	Yes	Yes
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.	Yes	No
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.	Yes	No
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.	Yes	No
go-swagger Unmaintained v2.0 only project seeking new maintainer, or probably a fork. Parser, validator, generates descriptions from code, or code from descriptions!	No	Yes
guardrail Principled code generation from OpenAPI descriptions	Yes	Yes
janephp Generate a PHP Client API (PSR-7 compatible) given a OpenAPI specification.	Yes	Yes
NSwag OpenAPI toolchain for .NET, Web API and TypeScript	Yes	Yes
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!	Yes	No
oazapfts! Generate TypeScript clients from a given OpenAPI description document.	Yes	Yes
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.	Yes	Yes
restful-react Generate React hooks with appropriate type-signatures from OpenAPI descriptions	Yes	Yes
spring-openapi OpenAPI v3 generator for Java Spring. Includes also client generation. Supports inheritance with discriminators, Jackson annotations and custom interceptors.	Yes	No
Typoas Fully typed OpenAPI Typescript generator	Yes	No
Unchase.OpenAPI.Connectedservice Visual Studio extension to generate C# (TypeScript) HttpClient (or C# Controllers) code for OpenAPI web service with NSwag.	Yes	Yes

Security

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

Name	v3.0	v2.0
42crunch A unique set of integrated API security tools that allow discovery, remediation of OpenAPI vulnerabilities and runtime protection against API attacks.	Yes	Yes
API Insights (RestCase) RestCase executes hundreds 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.	Yes	Yes
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.	Yes	Yes
oas-tools NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations	Yes	No
openapi-fuzzer Based on OpenAPI specification, openapi-fuzzer provides random data as inputs to the API endpoints in order to find bugs.	Yes	No
OpenAPI3 Fuzzer Simple fuzzer for OpenAPI 3 specification based APIs. Verifies responses and sends various attack patterns.	Yes	No
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.	Yes	Yes
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.	Yes	Yes
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.	Yes	Yes
WuppieFuzz WuppieFuzz is a coverage-guided REST API fuzzer developed on top of LibAFL, targeting a wide audience of end-users, with a strong focus on ease-of-use, explainability of the discovered flaws and modularity. WuppieFuzz supports all three settings of testing (black box, grey box and white box).	Yes	Yes

Server Implementations

Easily create and implement resources and routes for your APIs.

Name	v3.0	v2.0
@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.	Yes	No
@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.	Yes	No
@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	Yes	No
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.	Yes	No
API Platform REST and GraphQL framework to build modern API-driven projects	Yes	Yes
BaucisJS + baucis-openapi3 Create REST resources with persistence on MongoDB and expose OpenAPI v.3 contracts	Yes	No
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.	Yes	Yes
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.	Yes	No
Falcon Heavy The framework for building app backends and microservices via the API design-first workflow.	Yes	No
FastMCP FastMCP can automatically generate an MCP server from an OpenAPI specification. Users only need to provide an OpenAPI specification (3.0 or 3.1) and an API client.	Yes	No
Fuego Golang Fuego - web & API framework generating OpenAPI 3 spec from source code	Yes	No
Fusio Open source API management platform	Yes	No
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.	Yes	No
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.'	Yes	Yes
oas-tools NodeJS module to manage RESTful APIs defined with OpenAPI 3.0 Description over Express servers, including security validations	Yes	No
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.	Yes	Yes
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.	Yes	Yes
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.	Yes	Yes
Rage A Ruby web framework for building APIs with first-class OpenAPI support.	Yes	No
SpringFox Automated JSON API documentation for APIs built with Spring and SpringBoot	Yes	Yes
Vert.x Web Api Contract Create API endpoints with Vert.x 3 and OpenAPI 3 with automatic requests validation	Yes	No
yii2-app-api Generate Server side API code with routing, models, data validation and database schema from an OpenAPI description. Based on Yii Framework.	Yes	No

Testing

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

Name	v3.0	v2.0
Assertible Import an OpenAPI specification into Assertible to generate tests that validate JSON Schema responses and status codes on every endpoint.	Yes	Yes
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...	Yes	Yes
Chai OpenAPI Response Validator Simple Chai support for asserting that HTTP responses satisfy an OpenAPI spec.	Yes	Yes
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.	Yes	No
Dredd Language-agnostic command-line tool for validating API description document against backend implementation of the API	Yes	Yes
EvoMaster A tool for automatically generating system-level test cases for RESTful APIs, using Evolutionary Algorithms and Dynamic Program Analysis.	Yes	Yes
hikaku A library that tests if the implementation of a REST-API meets its specification.	Yes	No
jest-openapi Additional Jest matchers for asserting that HTTP responses satisfy an OpenAPI spec.	Yes	Yes
Karate-IDE Generates KarateDSL Tests and Mocks from OpenAPI 3.0 documents and so you can quickly test/explore your API.	Yes	No
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.	Yes	No
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.	Yes	Yes
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.	Yes	Yes
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.	Yes	Yes
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.	Yes	Yes
Schemathesis Reads the description document and generates test cases that will ensure that your application is compliant with its description.	Yes	Yes
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.	Yes	No
Step CI Open-source framework for API Quality Assurance. Generate multi-step test-scenarios from OpenAPI. Validate responses against description documents and more.	Yes	No
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.	Yes	No
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.	Yes	Yes
WuppieFuzz WuppieFuzz is a coverage-guided REST API fuzzer developed on top of LibAFL, targeting a wide audience of end-users, with a strong focus on ease-of-use, explainability of the discovered flaws and modularity. WuppieFuzz supports all three settings of testing (black box, grey box and white box).	Yes	Yes

Text Editors

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

Name	v3.0	v2.0
42Crunch IntelliJ OpenAPI Editor OpenAPI extension for Visual Studio Code - new file templates, navigation, intellisense, code snippets.	Yes	Yes
CodeMirror OAS support Plugin for text editor https://codemirror.net/ running in your browser that can fetch and parse your OpenAPI schema definition and provide auto-completion support (for large and complex JSON message payloads), error highlighting and access to schema documentation. It is capable of parsing megabytes of OpenAPI schema definition in a second and providing auto-completion support in milliseconds. The work is an MVP of a plugin with basic functionality made as part of a master thesis at ČVUT.	Yes	No
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.	Yes	No
KaiZen-OpenAPI-Editor Full-featured Eclipse editor for OpenAPI, also available on Eclipse Marketplace.	Yes	Yes
Swagger Editor Design, describe, and document your API on the first open source editor fully dedicated to OpenAPI-based APIs.	Yes	Yes
VSCode OpenAPI Editor OpenAPI extension for Visual Studio Code - new file templates, navigation, intellisense, code snippets.	Yes	Yes
VSCode OpenAPI Snippets OpenAPI Snippets for Visual Studio Code editor, includes split file validation	Yes	No

Looking for more modern tools? Check out the main list.

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