api-design

Assess ASP.NET Core API design against DTO, validation, middleware, and error handling best practices.

2|Updated Apr 19, 2026
One-click install
npx skills add https://github.com/dimsour/dotnet-ai-toolkit --skill api-design-dimsour
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: api-design
Source: https://github.com/dimsour/dotnet-ai-toolkit/tree/main/plugins/dotnet-copilot/skills/api-design
Command: npx skills add https://github.com/dimsour/dotnet-ai-toolkit --skill api-design-dimsour

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill helps developers design and implement robust ASP.NET Core APIs, addressing common pitfalls and ensuring best practices are followed.

Core Features & Use Cases

  • API Patterns: Offers guidance on Minimal APIs and Controllers, routing, DTOs, validation, middleware, versioning, and ProblemDetails.
  • Iron Laws: Provides 34 'Iron Laws' to enforce best practices like DTO usage, validation, and error handling.
  • Quick Reference: Serves as a reference for API design patterns and best practices in a single location.

Quick Start

Analyze your API design with the api-design skill and ensure adherence to best practices.

Frequently Asked Questions about api-design

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
What are the best practices for ASP.NET Core API design regarding DTOs and error handling?

Best practices for ASP.NET Core API design involve using DTOs for data transfer, enforcing validation, and implementing ProblemDetails for standardized error handling. This Skill provides 34 Iron Laws to ensure robust API patterns and middleware configuration.

How do I choose between Minimal APIs and Controllers in ASP.NET Core?

Choosing between Minimal APIs and Controllers depends on your application's complexity and routing needs. This Skill offers guidance on both API patterns, helping you implement appropriate routing, versioning, and middleware order for your .NET 8/9/10/11 projects.

How do I implement validation and middleware order in .NET web APIs?

To implement validation and middleware order in .NET web APIs, apply specific API design patterns that enforce data integrity and request pipeline efficiency. This Skill assesses your setup to ensure adherence to established best practices for middleware configuration.

Can I use this API design guidance for .NET 8 and later versions?

Yes, you can use this API design guidance for .NET 8, 9, 10, and 11. It is specifically applicable to web API development using C# and ASP.NET Core, ensuring your patterns and best practices remain compatible with modern .NET frameworks.

What is the best way to standardize error responses in ASP.NET Core APIs?

The best way to standardize error responses in ASP.NET Core APIs is by using ProblemDetails. This Skill helps you implement this pattern alongside other best practices, ensuring consistent error handling and validation reporting across your endpoints.