What problem does it solve? Building ASP.NET Core Web APIs involves many decisions—controllers vs minimal APIs, DTO design, status codes, OpenAPI wiring, and error handling—and inconsistent choices lead to fragile, poorly documented endpoints. This Skill guides the creation and modification of Web API endpoints so they follow correct HTTP semantics, proper OpenAPI documentation, and centralized error handling. ## Core Features & Use Cases - Endpoint Implementation: Adds or modifies endpoints using controllers or minimal APIs, matching the existing project style and defaulting to minimal APIs for new projects. - DTO and OpenAPI Conventions: Enforces sealed record DTOs, DateTimeOffset, string-serialized enums, XML doc comments, and built-in .NET 9+ OpenAPI support without Swashbuckle. - Error Handling and Testing: Sets up RFC 7807 Problem Details via IExceptionHandler middleware and generates .http test files for every endpoint. - Use Case: When asked to add a products CRUD API to an existing ASP.NET Core project, the Skill inspects the current style, creates request/response records, implements endpoints with correct status codes and CancellationToken forwarding, wires OpenAPI metadata, and produces a .http file to verify each route. ## Quick Start Ask the AI to add a new REST endpoint for a resource in your ASP.NET Core project, including DTOs, OpenAPI metadata, error handling, and a .http test file.
