aspnet-minimal-api-openapi

# 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 `TypedResults` instead of `Results` for 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 `WithName` extension 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