{"API Design"}

Guides

These are a couple of valuable websites that can help guide you on your API design journey.

API Stylebook
A Github hosted, aggregate set of API design topics. The API Stylebook has brought together the API design style guides of leading API providers and merged them into a single source of API design principles. It is hosted on Github, with the data behind available as YAML, making it easily forkable, and replicable for any API provider looking to establish their own API design guide.
Web Concepts
The Webs Uniform Interface is based on a large and growing set of specifications. These specifications establish the shared concepts that providers and consumers of Web services can rely on. Web Concepts is providing an overview of these concepts and of the specifications defining them. One example for how this works is the Hypertext Markup Language (HTML), which defines the media type text/html and a set of link relation types such as alternate and section. Web Concepts provides a structured, quick, and interlinked overview of these and many more concepts that together establish the Web surface.

Studios

These are the solutions that have emerged to help API providers with their API design efforts.

Apiary
Apiary jump-started the modern API design movement, by making API definitions more than just about API documentation, allowing API designers to define APIs in the machine readable API definition format API blueprint, then mock, share, and publish documentation via a cloud platform.
Apigee API Studio
Apigee launched their API Studio out of their earlier Apigee-127 product, their work on the Swagger platform and editor, and their BaaS offering, opening up the ability for developers to design, mock, test and share via the online platform. While Apigee Studio is part of the larger Apigee line of products, it is a separate standalone, open source based studio.
Apimint
APIMINT is an API lifecycle management tool. With our design first approach, all stake holders get a platform to collaborate and give feedback on API design and structure. We make sure your all your teams can easily agree and understand your APIs.
Mashape
Mashape provides an API editor, as part of their API management and discovery platform, allowing API providers to add, edit, and manage the details of an API design, while also managing the rest of API operations--from design to discovery and integration. Mashape editor is just a piece of the overall Mashape suite of API lifecycle management tooling.
MuleSoft
Mulesoft provides a cloud, and open source version of their API design editor, enabling API designers to craft APIs using the RAML API definition format, then publish to notebook, as well as manage through other aspects of the API lifecycle with other Mulesoft systems.
RepreZen API Studio
RepreZens solution focuses specifically on the API design process in large organizations and complex ecosystems. API management platforms address various aspects of the downstream lifecycle: packaging, provisioning, metering, proxy, and client portal. API Studio easily ties into API management platforms using generated API description formats including WADL, Swagger, RAML and others.
Restlet
The Restlet API Platform enables developers and non-developers to design, create, run and manage the APIs that provide access to any data or application. Restlet Framework is the most widely used open source solution for Java developers who want to create and use APIs. The first Platform-as-a-Service dedicated to web APIs, APISpark enables any organization to become an API provider in minutes via an intuitive browser interface.
StopLight
StopLight provides engineering teams with a new way to document, test, and build web APIs. Our technology easily and automatically maps an API, and then provides tooling and services to reduce development time, and increase reliability and accessibility.

Desktop

An API design studio you can download for Windows or Mac environments, and work locally.

Materia
A modern development environment to build advanced mobile and web applications. Materia is an easy-to-use backend to build all kinds of applications (mobile, web, gaming and more). Materia tooling aims to manage the entire development cycle for building enterprise class backends.

Interesting

These are some API service providers who just happen to have some nice API design features.

APIMATIC
When you use APIMATIC to manage SDKs, they provide you with an editor for adding, editing, and deleting the details of each API. When you bundles this with their multi-format API definition format import and export, the platform quickly becomes an API design tool as well as a platform for generating your SDKs.
Gelato.io
Gelato.io is a tool focused on creating API Documentation and Developer Portals. You can describe your API, import and sync with Swagger or API Blueprint, have your developers register and get updates when things change, get an automatic API Explorer.