Well-documented APIs (Application Programming Interfaces) are the cornerstone of any good developer portal. REST (Representational State Transfer) and GraphQL are the two dominant architectures, each with its distinct approach to data retrieval and manipulation.
This difference inherently extends to how their documentation is crafted. They are so similar on the surface, yet the way a technical writer would approach to explaining their functionality is entirely different. This post explores the nuances of documenting GraphQL compared to REST APIs, highlighting the unique challenges and strategies technical writers face.
REST APIs are designed around the concept of resources, each identified by URLs and manipulated through HTTP methods (GET, POST, PUT, DELETE, etc.). Documentation for REST APIs focuses on describing these resources, the operations that can be performed on them, and the expected request and response formats.
In a sense, REST API documentation describes the "where" and "what" for each endpoint, while tutorials and use-case documentation fill in the "when," "why," and "how."
REST API documentation benefits from tools like Swagger (OpenAPI) that can generate interactive documentation, allowing developers to explore and test the API directly from the documentation.
Two popular solutions for documenting REST APIs are ReadMe (Commercial) and Docusaurus (Open Source).
GraphQL represents a shift from the resource-centric model of REST to a more flexible, query-based approach. It allows clients to request exactly the data they need and nothing more. This flexibility necessitates a different focus in documentation.
GraphQL's introspective nature means that tools like GraphiQL can offer auto-generated documentation, allowing developers to explore the schema and test queries in real-time.
Documenting GraphQL can be inherently more complex due to its flexible nature. A single endpoint in GraphQL can replace multiple REST endpoints, leading to documentation that must cover a broader range of potential queries and mutations. Conversely, REST documentation is more about detailing the structure and capabilities of each endpoint.
GraphQL has an advantage over REST in that you can request data across multiple subjects and make numerous changes in a single request. This advantage comes at the cost of simplicity. Instead of a small number of fields to document for a resource-specific endpoint, the writer needs to document a much larger set of options and how they fit into various use cases.
For both REST and GraphQL, interactive documentation tools enhance the developer experience. However, the dynamic nature of GraphQL queries makes the interactivity of tools like GraphiQL particularly beneficial. These tools not only document but also serve as a learning platform.
Effective documentation goes beyond listing capabilities; it must guide developers on how to achieve their goals. For REST, this means detailing endpoint interactions for specific scenarios. For GraphQL, it involves showing how different queries can be combined to fetch complex data structures in a single request.
While both REST and GraphQL APIs share similar use cases, their distinct architectures necessitate different approaches to documentation. REST API documentation is structured around the concept of discrete resources and operations, while GraphQL documentation revolves around a comprehensive schema and the art of crafting queries.
By understanding these differences, technical writers can create more effective, user-friendly documentation that empowers developers to harness the full potential of these powerful technologies. As APIs continue to evolve, so too will the strategies for documenting them, underscoring the importance of adaptability and innovation in technical communication.