Tutorials

Generating OpenAPI Specification (OAS) documentation for your REST APIs

October 28, 2022

4 min read

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The OpenAPI Specification (OAS) defines a standard, language-agnostic interface to RESTful APIs which allows both humans and computers to discover and understand the capabilities of the service without access to source code, documentation, or through network traffic inspection.[1]

APISec supports 1.0, 2.0, 3.x versions of the OpenAPI specification (OAS) as well as Postman and RAML formats.

The following is a list of some libraries and resources which can be helpful in generating an OpenAPI Specification (OAS) document for your existing REST API application grouped by implementation technology.

ASP.NET Core

The two main OpenAPI implementations for .NET are Swashbuckle and NSwag. They are explained nicely in the Microsoft ASP.NET documentation - ASP.NET Core web API documentation with Swagger / OpenAPI | Microsoft Docs
The OpenAPI.NET SDK contains a useful object model for OpenAPI documents in .NET along with common serializers to extract raw OpenAPI JSON and YAML documents from the model - GitHub - microsoft/OpenAPI.NET

Spring

Springfox supports automated JSON API documentation for API's built with Spring - GitHub - springfox/springfox
The springdoc-openapi Java library helps automating the generation of API documentation using Spring Boot projects - GitHub - springdoc/springdoc-openapi

Java

For JAX-RS based projects(Jersey/RESTEasy/Mule), Swagger Core provides examples and server integrations for generating the Swagger API Specification, which enables easy access to your REST API - GitHub - swagger-api/swagger-core
The Swagger Maven Plugin is a JAX-RS & SpringMVC supported maven build plugin, helps you generate Swagger JSON and API document in build phase - GitHub - kongchen/swagger-maven-plugin

Python

Flask-RESTX is an extension for Flask which provides a coherent collection of decorators and tools to describe your API and expose its documentation properly using Swagger - GitHub - python-restx/flask-restx
Falcon-apispec is an apispec plugin that generates OpenAPI specification (aka Swagger) for Falcon web applications - Github - alysivji/falcon-apispec
drf-yasg - Yet another Swagger generator helps in automated generation of real Swagger/OpenAPI 2.0 schemas from Django REST Framework code. - GitHub - axnsan12/drf-yasg
drf-spectacular is a sane and flexible OpenAPI 3 schema generation for Django REST framework - GitHub - tfranzel/drf-spectacular

Node.js

swagger-autogen performs the automatic construction of the Swagger documentation - swagger-autogen - npm
NestJS provides a dedicated module which allows generating OpenAPI (Swagger) - Github - nestjs/swagger
swagger-express is a simple and clean solution to integrate swagger with Express - swagger-express - npm
express-oas-generator automatically generates OpenAPI (Swagger) specification for existing ExpressJS 4.x REST API applications - express-oas-generator - npm
Hapi-swagger is a OpenAPI (aka Swagger) plug-in for Hapi When installed it will self document the API interface in a project - hapi-swagger - npm

PHP

swagger-php is a php swagger annotation and parsing library which generates interactive OpenAPI documentation for your RESTful API using doctrine annotations. - GitHub - zircote/swagger-php

Ruby

rspec-openapi generates OpenAPI schema from RSpec request specs - Github - rspec-openapi
rswag seamlessly adds a Swagger to Rails-based APIs - Github - rswag
zero-rails_openapi is a concise DSL for generating OpenAPI Specification 3 (OAS3) JSON documentation for Ruby application - GitHub - zhandao/zero-rails_openapi
The grape-swagger gem provides an auto generated documentation for your Grape API - GitHub - ruby-grape/grape-swagger
Swagger::Blocks is a DSL for pure Ruby code blocks that can be turned into Swagger JSON - .GitHub - fotinakis/swagger-blocks
openapi-rails is a CRUD interface for Rails models with OpenAPI (Swagger) specification support and Swagger UI integration - GitHub - slate-studio/openapi-rails

swag automatically generates RESTful API documentation with Swagger 2.0 - GitHub - swaggo/swag
go-swagger (golang implementation of Swagger 2.0) is a complete suite of fully-featured, high-performance, API components to work with a Swagger API: server, client and data model - Github - Swagger 2.0 implementation for go

APISec seamlessly integrates with most of the popular API gateways and automatically pulls the API specs in OAS format for easy API registration. For the purpose of document completion and developer curiosity, a select few are mentioned below.

AWS API Gateway