At the start of a RESTful API development project, a software team might be tempted to buy an expensive commercial API management tool when an open source tool can just as easily do the trick. In fact, there are plenty of open source tools that can help with each stage of the API lifecycle and help get an API development program off the ground at low cost.
Tools for RESTful API creation and management
Kong and Tyk are two popular providers that offer free community options for general API lifecycle management. Swagger also features several open source tools, such as Swagger Codegen, Swagger Editor and Swagger UI, which make it easy to build and define RESTful APIs.
RESTful API Modeling Language (RAML) is another API development platform that that lets software teams design RESTful API architecture visually without the need to write code, but it then uses server-side code generators to convert this design into code. Once built, RAML makes it easy to initiate test-driven development and perform unit tests on your RESTful APIs. It integrates with many API testing tools, lets you create documentation on the fly and makes it easy to integrate APIs with external systems.
Tools for RESTful API testing
After creation, it's critical to conduct security and performance tests on your RESTful APIs. For this task, use a tool that focuses exclusively on API testing and documentation.
Insomnia is a great debugging tool for RESTful APIs. It helps developers test URLs, payload, authorization and headers. It eases debugging through a feature called environment variables that lets you specify repeating values and reduce manual entry.
Insomnia has a polished and efficient user interface plus autocomplete suggestions for selecting variables and operators for debugging. It supports several authentication types, like OAuth, AWS identity and access management and more. The free version includes a full-featured desktop app and is a great option if you don't need enterprise-grade security or multi-device access. Meanwhile, the paid version offers end-to-end encryption and unlimited device access.
Tools for RESTful API documentation
If you want RESTful APIs to gain widespread adoption and acceptance by third-party developers, make sure there is mature documentation. Great documentation helps developers understand the architecture of the REST API and makes it easy to build services that communicate with the API quickly.
Socket is a great option for documentation. Socket's primary commercial offering is an API marketplace, which features a wide range of APIs ready for integration. As a side gig, Socket created a free API documentation tool to help developers document their APIs, test them and then ultimately integrate them within applications.
And if it aligns with your API goals, Socket is a great platform for promotion and adoption. The only catch is that Socket makes you list your API on their marketplace. However, this could be a bonus if you plan to build a public API and want to drive usage and adoption.
RESTful APIs are the language of the modern web, and an effective API strategy focuses on API design, development, testing and documentation. Fortunately, there is no need to buy expensive commercial tools to design and develop RESTful APIs. These open source tools can help you build RESTful APIs that are a breeze to integrate with and enable powerful user experiences.