This is a collection of useful resources for building RESTful HTTP+JSON APIs. There are a lot of good tools and entire ecosystems out there! It can be overwhelming not knowing what options are available, so you can use this as a reference starting point.

Contributions are most welcome. Categories are also open to suggestions!

• API Specification Languages
• API Specification Tools
• API Specifications
• API Frameworks
• API Client Development Tools
• API Documentation
• API Clients
• API Debugging and Mocking
• API Design Guides
• API Publishing
• API Gateways
• API Security
• API Monitoring
• API Testing
• JSON Format Standards
• Learning Resources
• Blogs
• References

• API Blueprint
• JSON Schema
• RAML
• Swagger

• Swagger Inspector: Test and auto-generate OpenAPI documentation for any API.
• Swagger Editor: An editor for designing Swagger specifications.
• Swagger Tools and Integrations: A list of libraries and frameworks serving the Swagger ecosystem.
• OpenAPI Spec Tooling: A list of libraries and frameworks serving the OpenAPI ecosystem.
• API Studio. Write, mock, and share your Swagger specifications online.
• Dredd: Validate API documentation written in API Blueprint against its backend implementation.
• APITransformer: Transform API Descriptions from/to various formats e.g., Swagger, API Blueprint, RAML, WADL, Google Discovery, I/O Docs.
• Restlet Studio: Web IDE for API Design.
• API Spec Converter: Convert between different API spec formats.
• Prism: Supercharge any OAS file with mocking, transformations, validations, and more.
• Apimatic: Supports API description formats including Swagger, OAI format, RAML, API Blueprint, IO Docs, WADL, Postman Collections and HAR 1.4 and more
• Mulesoft Anypoint: Design and publish enterprise-grade APIs using RAML
• Sandbox: Quick and easy mock RESTful API from API definitions
• Restunited: Generate SDK, Documentation with Testing and Debugging

• API Commons: A repository of language-agnostic API specifications / Data Models.
• APIS.guru: Directory of API specs in OpenAPI(aka Swagger) 2.0 format.
• AnyAPI: Documentation and Test Consoles for Public APIs.

• rails-api: Rails for API only applications.
• pliny: Opinionated template Sinatra app for writing APIs in Ruby.
• grape: An opinionated micro-framework for creating REST-like APIs in Ruby.
• ActiveModel::Serializer: Brings convention over configuration to your JSON generation.
• rabl: Generate JSON and XML from any ruby object.
• jbuilder: Create JSON structures via a Builder-style DSL.
• roar: Parse and render REST API documents using representers.

• Django REST framework: Toolkit that makes it easy to build Web APIs.
• Tastypie: Webservice API framework for Django.
• restless: A lightweight REST miniframework for Python.
• flask-restful: Simple framework for creating REST APIs.
• Falcon: Falcon is a low-level, high-performance Python framework for building HTTP APIs, app backends, and higher-level frameworks.
• Connexion: Swagger/OpenAPI First framework for Python on top of Flask with automatic endpoint validation and OAuth2 support
• apistar: A smart Web API framework, designed for Python3.
• sanic: Sanic is a Flask-like Python 3.5+ web server that's written to go fast.
• hug: hug aims to make developing Python driven APIs as simple as possible, but no simpler.

• hapi.js: Web and services application framework for Node.js.
• Restify: Node.js REST framework specifically meant for web service APIs.
• Express: Fast, unopinionated, minimalist web framework for Node.js.
• sailsjs: Realtime MVC Framework for Node.js.
• Actionhero: Multi-transport Node.js API server with integrated cluster capabilities and delayed tasks.
• Baucis: To build
• Koa: Next generation web framework for Node.js
• Loopback: Node.js framework for creating APIs and easily connecting to backend data sources.
• Seneca: A microservices toolkit for Node.js.
• Feathers: Build RESTful and real-time APIs through Socket.io or Primus.
• Deployd: Deployd is the simplest way to build realtime APIs for web and mobile apps
• Nest: A modern node.js framework for efficient and scalable web applications built on top of TypeScript

• Go-Json-Rest: Thin layer on top of net/http that helps building RESTful APIs easily
• gocrud: Go library to simplify creating, updating and deleting arbitrary depth structured data — to make building REST services fast and easy.
• sleepy: RESTful micro-framework written in Go.
• restit: Go micro framework to help writing RESTful API integration test.
• go-relax: Framework of pluggable components to build RESTful API's.
• go-rest: Small and evil REST framework for Go.
• go-restful: A declarative highly readable framework for building restful API's.
• Goat: Minimalistic REST API server in Go.
• Resoursea: REST framework for quickly writing resource based services.
• Zerver: Zerver is a expressive, modular, feature completed RESTful framework.

• Colossus: I/O and microservice library for Scala.
• Finatra: Fast, testable, Scala HTTP services built on Twitter-Server and Finagle.
• Play: The high velocity web framework for Java and Scala.
• Scalatra: Simple, accessible and free web micro-framework.
• Skinny Micro: Micro-web framework to build servlet applications in Scala.
• Spray: Open-source toolkit for building REST/HTTP-based integration layers on top of Scala and Akka.
• Akka HTTP: The Akka HTTP modules implement a full server- and client-side HTTP stack on top of akka-actor and akka-stream.
• Swagger Akka HTTP: Swagger-Akka-Http brings Swagger support for Akka-Http Apis.

• Rest.li: REST framework using type-safe bindings and asynchronous, non-blocking IO.
• Dropwizard: Framework for developing ops-friendly, high-performance, RESTful web services.
• Jersey: RESTful web services in Java.
• Spring Boot: RESTful Web Service using Spring, high-performance and little configuration needed.

• Scotty: Micro web framework inspired by Ruby's Sinatra, using WAI and Warp.
• Spock: Another Haskell web framework for rapid development.
• Servant: A Type-Level Web DSL.
• Yesod: The Haskell RESTful web framework.

• Phoenix: Framework for building HTML5 apps, API backends and distributed systems.
• Plug: A specification and conveniences for composable modules between web applications.

• Cowboy: Small, fast, modular HTTP server written in Erlang.
• Gen Microservice: This library solves the problem of implementing microservices with Erlang.
• Mochiweb: Erlang library for building lightweight HTTP servers.

• PostgREST: Serve a RESTful API from any existing PostgreSQL database.

• API Platform: API framework on top of Symfony with JSON-LD, Schema.org and Hydra support
• Dingo API: A RESTful API package for the Laravel and Lumen frameworks
• Fractal: Fractal provides a presentation and transformation layer for complex data output, the like found in RESTful APIs, and works really well with JSON
• Yii2 Framework: Provides a whole set of tools to simplify the task of implementing RESTful Web Service APIs

• Dream Factory: Turn any database into an API platform.

• Swagger CodeGen: Generate client libraries automatically from a Swagger-compliant server.
• sdks.io: Explore Automatically Generated SDKs.
• AutoRest: Generate client libraries for RESTful web services
• Unirest: Lightweight HTTP-Request client libraries for several languages

• heroics: Ruby HTTP client for APIs represented with JSON schema.
• blanket: A Ruby API wrapper.
• nestful: Ruby HTTP/REST client.

• Retrofit: A type-safe HTTP client for Android and Java.

• Restangular: Restangular is an AngularJS service that simplifies common GET, POST, DELETE, and UPDATE requests with a minimum of client code

• Refit: The automatic type-safe REST library for .NET Core, Xamarin and .NET

• ReDoc: OpenAPI/Swagger-generated API Reference Documentation.
• Swagger UI: Dynamically generate documentation from a Swagger-compliant API.
• Slate: Static site generated documentation for your API.
• prmd: JSON Schema tooling: scaffold, verify, and generate documentation from JSON Schema documents.
• Aglio: An API Blueprint renderer with theme support that outputs static HTML.
• Apiary: Collaborative design, instant API mock, generated documentation, integrated code samples, debugging and automated testing.
• Readme: API Documentation Hosting.
• Embed curl: Embeddable curl commands on the web.
• Gelato: Create developer portals for your API.
• API Docs: Hosted public API documentation for OAS (Swagger) and RAML specs.
• Docula: Documentation using Github and OpenAPI standards.
• Docbox: REST API documentation generator, using Markdown.

• Hurl.it: Web-based HTTP client.
• JSON Generator: Generate and host mock JSON data.

• HTTPie: Command line HTTP client.
• HttpMaster: Desktop tool for REST API testing.
• Paw: REST client for Mac.
• Postman: Desktop API testing tool.
• Insomnia: REST API client for Mac, Windows, and Linux.
• Jsonium: Free REST client for JSON over HTTP protocols
• I'm only Resting: Windows GUI tool for REST API testing

• Beeceptor: An HTTP-proxy for rest APIs - inspect and build mock APIs.
• MockBin: Generate mock HTTP endpoints.
• RequestBin: Inspect and debug webhook POST requests.
• httpbin: Templated responses for testing various scenarios for HTTP requests.

• Json-Server Full fake REST API with zero coding.
• Mockoon: Desktop API mocking tool.
• Postman: Desktop API client and mocking tool.

• Google API Design Guide
• PayPal API Style Guide
• Heroku Platform HTTP API Design Guide
• Haufe API Style Guide
• Microsoft REST API Guidelines
• 18F API Standards
• The RESTed NARWHL
• White House Web API Standards
• Zalando REST API Guidelines
• API Stylebook Design Guidelines
• API Stylebook Design Topics

• Mashape: API Marketplace.

• AWS API Gateway: Traffic management, authorization and access control, monitoring, and API version management.
• API Umbrella: Proxy that sits in front of your APIs.
• APIAxle: Proxy that sits in front of your APIs.
• APIGrove: API manager built in Java on top of Fuse ESB.
• Apigee127: nodejs based API Gateway
• Pushpin: Proxy for both request/response or streaming (long poll) of responses
• Strongloop: nodejs based API Gateway
• Fusio: PHP based open source API management platform
• Camel: Empowers you to define routing and mediation rules in a variety of domain-specific languages, including a Java-based fluent API, Spring or Blueprint XML configuration files, and a Scala DSL.
• HAProxy: Reliable, high Performance TCP/HTTP load balancer.
• OpenResty: Fast web application server built on top of Nginx.
• Tengine: A distribution of Nginx with some advanced features.
• Tyk: Open-source, fast and scalable API gateway, portal and API management platform.
• Vulcand: Programmatic load balancer backed by Etcd.
• Zuul: An edge service that provides dynamic routing, monitoring, resiliency, security, and more.
• Kong: An open-source management layer for APIs, delivering high performance and reliability.
• Janus: A lightweight API Gateway written in Go by Hello Fresh.
• fabio: A fast, modern, zero-conf load balancing HTTP(S) router for deploying microservices managed by consul by eBay.
• Traefik: Træfik (pronounced like traffic) is a modern HTTP reverse proxy and load balancer written in Go.
• Oathkeeper: OIdentity & Access Proxy (IAP) that authorizes HTTP requests based on sets of rules. Integrates with ORY Hydra.

• API Security checklist: Checklist of the most important security countermeasures when designing, testing, and releasing your API.
• Ory Hydra: OAuth2 server with OpenID Connect written in Go.

• Runscope: API Performance Monitoring.
• Galileo: API Monitoring Platform.
• Ping-API: Automated API Testing.

• Assertible: Continuously test and monitor your APIs after deployments and across environments.
• Pyresttest: YAML based REST testing and API microbenchmarking tool

• HAL
• JSONAPI
• JSON Schema
• Hydra
• Ion

• Choosing an HTTP Status Code
• REST in Practice
• Roy Fielding's dissertation on REST
• Best Practices for Designing a Pragmatic RESTful API
• How to Design a REST API
• Automated API Development
• Nordic APIs
• Undisturbed REST
• Build APIs You Won't Hate
• Irresistible APIs
• How to build an API
• API University
• RESTful Web Services
• RESTful Web APIs
• The Ten Essentials for Good API Documentation

• API Evangelist

• HTTP Status Codes Reference

Pull Requests are most welcome!

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api-development-tools © 2016+, Yos Riady. Released under the MIT License.
Authored and maintained by Yos Riady with help from contributors (list).

yos.io  ·  GitHub @yosriady