Plan Your API Definition

As engineers, you always emphasize the importance of designing a plan before coding. You need to clarify the functional purpose of an API based on the business requirements and then translate the business language into technical language. Typically, API planning and design revolve around documentation.

Use Example

Throughout all tutorials, you will use the Swagger Petstore as an example to guide you through the full API lifecycle management.

How To Write Your Own OpenAPI Specification

OpenAPI specification files in JSON or YAML format allow defining RESTful APIs that follow API design best practices. This ensures reliability, consistency, and scalability. Open-source tools like Swagger Editor and OpenAPI GUI help create, edit, and validate OpenAPI specs. Many IDEs and code editors also have plugins for working with OpenAPI files.

You can learn from the example about the key characteristics of the RESTful architectural style include:

• Unique identification of resources: Each resource has a unique identifier, such as a URL.
• Uniform interface: Utilizing standardized HTTP methods and status codes, such as GET, POST, PUT, DELETE, etc.
• Stateless: APIs should not store client state information. Each request should contain all the necessary information for processing, facilitating horizontal scalability.

Helpful Tools

Here are some useful tools that can help with writing OpenAPI (formerly Swagger) specification documents:

• Swagger Editor - Interactive editor for creating and testing OpenAPI specs online. Provides auto-complete, real-time validation, and example generation.
• Stoplight Studio - Visual modeling tool for designing APIs and generating OpenAPI specs with mock data.
• OpenAPI Generator - Auto generate client SDKs, server stubs, documentation and more from an OpenAPI spec. Supports multiple languages.
• Postman - Provides an OpenAPI importer and exporter to convert between collections and specs. Also auto-generates code.
• OpenAPI CLI - Command line tool that provides completion, validation and there utilities for working with OpenAPI files.
• OpenAPI GUI - Desktop app for Windows and Mac that provides a UI for editing OpenAPI files with YAML and JSON support.
• REST United - Suite of OpenAPI tools including mocks, documentation, testing and code generation.
• Apicurio - Web-based OpenAPI spec editor with real-time validation and mocking.