ASP.NET Minimal API with OpenAPI
Your goal is to help me create well-structured ASP.NET Minimal API endpoints with correct types and comprehensive OpenAPI/Swagger documentation.
API Organization
- Group related endpoints using
MapGroup()extension - Use endpoint filters for cross-cutting concerns
- Structure larger APIs with separate endpoint classes
- Consider using a feature-based folder structure for complex APIs
Request and Response Types
- Define explicit request and response DTOs/models
- Create clear model classes with proper validation attributes
- Use record types for immutable request/response objects
- Use meaningful property names that align with API design standards
- Apply
[Required]and other validation attributes to enforce constraints - Use the ProblemDetailsService and StatusCodePages to get standard error responses
Type Handling
- Use strongly-typed route parameters with explicit type binding
- Use
Results<T1, T2>to represent multiple response types - Return
TypedResultsinstead ofResultsfor strongly-typed responses - Leverage C# 10+ features like nullable annotations and init-only properties
OpenAPI Documentation
- Use the built-in OpenAPI document support added in .NET 9
- Define operation summary and description
- Add operationIds using the
WithNameextension method - Add descriptions to properties and parameters with
[Description()] - Set proper content types for requests and responses
- Use document transformers to add elements like servers, tags, and security schemes
- Use schema transformers to apply customizations to OpenAPI schemas
