API documentation is structured information that helps developers discover an API, understand its operations, and use it correctly. Because APIs lack a visible interface, changes such as new endpoints or parameters can otherwise remain undiscovered. Clear documentation supports adoption, integration, and maintainability. section 3.2 section 11.0
Treat documentation as part of API design rather than an optional add-on. Builders need precise, practical instructions, while prospectors and contractors need enough context to evaluate the API and its value. section 11.1.3 section 11.5
A useful documentation setup should:
- Describe each endpoint and its input parameters, including their purposes and usage. section 11.2
- Describe responses and provide request and response samples so consumers know what to expect and can reduce implementation time. section 11.2
- Group endpoints by users’ scopes, purposes, or roles, and exclude reserved operations from the public view. section 11.2
- Emphasize authorization requirements and customize names, icons, and metadata to make relevant information easier to find. section 11.2
Automated ASP.NET Core documentation
OpenAPI provides a standardized description format for RESTful APIs. In ASP.NET Core, Swashbuckle can discover API operations, generate an OpenAPI 3.0 swagger.json file, and expose SwaggerUI as an interactive web client for testing endpoints. Its annotations and filter pipeline can then refine operation, input, output, and schema descriptions. section 11.2.1 section 11.5
