aspnet-minimal-api-openapi

Overview of aspnet-minimal-api-openapi skill

What the aspnet-minimal-api-openapi skill does

The aspnet-minimal-api-openapi skill helps you generate ASP.NET Minimal API endpoints that are not only functional, but also typed and documented well enough to produce useful OpenAPI output. Its focus is practical API shape: endpoint grouping, DTO design, typed results, validation, and Swagger/OpenAPI metadata that consumers can actually use.

Who should use this skill

This skill is best for developers building or refactoring ASP.NET Minimal APIs who want cleaner endpoint patterns than a generic “write me an API route” prompt usually delivers. It is especially useful if you care about:

• predictable request and response types
• stronger generated OpenAPI docs
• consistent endpoint structure across a codebase
• .NET 9 built-in OpenAPI support

Real job-to-be-done

Most users are not looking for “an endpoint” in isolation. They want an endpoint that fits a real API: grouped correctly, typed correctly, validated correctly, and exposed with good Swagger/OpenAPI metadata. The aspnet-minimal-api-openapi skill is aimed at that broader job, which makes it more useful for API Development than a generic code-generation prompt.

What differentiates it from a normal coding prompt

The main value of aspnet-minimal-api-openapi is not breadth; it is opinionated focus. The source guidance emphasizes:

• MapGroup() for API organization
• explicit request and response DTOs
• Results<T1, T2> and TypedResults
• validation attributes and standard error handling
• operation names, summaries, descriptions, and content types for OpenAPI

That means the output is more likely to be implementation-ready for teams that care about contract quality, not just route syntax.

When this skill is a strong fit

Use the aspnet-minimal-api-openapi skill when you need help creating:

• new Minimal API endpoints from a short specification
• better OpenAPI metadata for existing endpoints
• more strongly typed responses
• a cleaner pattern for feature-based endpoint organization

When it is not the right tool

This skill is a weaker fit if you need:

• controller-based ASP.NET APIs instead of Minimal APIs
• advanced auth, persistence, or architecture decisions beyond endpoint design
• deep OpenAPI customization outside the built-in Minimal API flow
• a complete production template with tests, CI, and deployment wiring

How to Use aspnet-minimal-api-openapi skill

Install context for aspnet-minimal-api-openapi

The upstream repository does not expose a detailed custom installer flow in SKILL.md. In practice, use your standard skill installation method for the github/awesome-copilot collection, then invoke aspnet-minimal-api-openapi in a request where the model can see your API goal, target framework, and current code context.

If your environment supports collection install commands, the common pattern is:

npx skills add github/awesome-copilot --skill aspnet-minimal-api-openapi

Read this file first

Start with:

• skills/aspnet-minimal-api-openapi/SKILL.md

This skill is lightweight, so there are no extra resources/, rules/, or helper scripts to compensate for ambiguity. That makes your prompt quality more important than usual.

What input the skill needs

To get good output from aspnet-minimal-api-openapi usage, provide:

• the business action the endpoint should perform
• HTTP method and route
• request shape
• success and error response shapes
• whether you want MapGroup() and how routes should be grouped
• target .NET version, especially if relying on .NET 9 OpenAPI support
• whether the endpoint is new code or a refactor of existing code

If you only say “create a minimal API endpoint,” you will likely get something syntactically valid but under-specified.

Turn a rough goal into a strong prompt

Weak input:

• “Create a Minimal API for orders with Swagger.”

Stronger input:

• “Use the aspnet-minimal-api-openapi skill to create a .NET 9 ASP.NET Minimal API POST /orders endpoint under MapGroup("/orders"). Use explicit request/response records, validation attributes, TypedResults, and Results<Created<OrderResponse>, ValidationProblem, NotFound>. Add OpenAPI summary, description, operation name, and property descriptions. Return standard error responses using ProblemDetails patterns.”

The stronger version tells the skill what structure, typing, and documentation quality you expect.

Ask for complete endpoint contracts

This skill works best when you request the contract, not just the handler body. Ask for:

• route mapping
• DTOs or record types
• response result types
• validation annotations
• OpenAPI metadata
• example registration code if needed

That pushes the output toward a usable API slice rather than a partial snippet.

Best workflow for new endpoint generation

A practical aspnet-minimal-api-openapi guide workflow is:

1. Define the route, method, and business purpose.
2. Specify request and response DTOs or let the model propose them.
3. Ask for typed results and standard error handling.
4. Ask for OpenAPI summaries, descriptions, and operation name.
5. Review naming, status codes, and nullability.
6. Then adapt the generated code to your project conventions.

This order matters because good OpenAPI usually follows from clear contracts.

Best workflow for refactoring existing endpoints

For existing code, paste the current endpoint and ask the skill to improve:

• type safety
• request and response models
• validation attributes
• TypedResults
• WithName, summary, and description metadata

This is often a better use case than greenfield generation because the target behavior is already known.

What the skill is opinionated about

The repository guidance is narrow but useful. Expect the skill to favor:

• separate endpoint organization for larger APIs
• record types and immutable contracts
• nullable-aware C# style
• strongly typed route parameters
• explicit result unions instead of loosely typed returns

If your team prefers dynamic payloads or minimal metadata, say so up front.

Practical tips that improve output quality

For better aspnet-minimal-api-openapi for API Development results:

• name every expected status code
• state whether the endpoint should expose 201 Created, 204 NoContent, 400 ValidationProblem, or 404 NotFound
• ask for [Description] attributes on important properties
• specify whether content types need to be declared explicitly
• mention if the endpoint belongs in a feature folder or endpoint class

These details materially affect how complete the endpoint and generated OpenAPI will be.

Common gaps to catch after first output

After the first draft, check for:

• missing WithName() operation IDs
• vague summaries and descriptions
• untyped Results instead of TypedResults
• DTOs without validation attributes
• inconsistent route parameter types
• undocumented error responses

These are exactly the areas where this skill should outperform a generic prompt, so they are worth reviewing.

aspnet-minimal-api-openapi skill FAQ

Is aspnet-minimal-api-openapi good for beginners?

Yes, if you already understand basic ASP.NET Minimal API syntax. The skill gives useful structure around DTOs, result types, and OpenAPI docs, but it does not replace basic framework knowledge. Beginners may need to verify how service registration and application startup are wired in their project.

Does this skill require .NET 9?

Not strictly for all Minimal API work, but the source guidance explicitly points to built-in OpenAPI support in .NET 9. If you are on an earlier version, tell the model your target version so it does not assume APIs or configuration patterns that are unavailable.

How is this different from a normal “write a Minimal API” prompt?

The difference is emphasis. The aspnet-minimal-api-openapi skill steers the output toward:

• explicit request/response contracts
• strong result typing
• endpoint grouping
• richer OpenAPI metadata

A generic prompt often stops at “route plus handler.” This skill is better when API contract quality matters.

Can I use it for existing production APIs?

Yes, especially for incremental improvements. It is useful for tightening response typing, improving validation, and adding clearer OpenAPI metadata without rewriting the whole application.

Does it cover auth, persistence, and testing?

Not by itself. The source material is about endpoint structure and documentation quality. You can ask the model to extend the result, but those areas are not the core strength of aspnet-minimal-api-openapi.

When should I not use aspnet-minimal-api-openapi?

Skip it if your main need is:

• MVC controllers instead of Minimal APIs
• advanced system design beyond endpoint definition
• heavily customized OpenAPI generation workflows
• non-.NET API stacks

How to Improve aspnet-minimal-api-openapi skill

Give the skill a contract, not just a feature name

The fastest way to improve aspnet-minimal-api-openapi output is to provide a full contract:

• route
• method
• request schema
• response schema
• status codes
• validation rules
• grouping location

This reduces guesswork and leads to better OpenAPI metadata automatically.

Specify your .NET and OpenAPI assumptions

Because the skill references built-in OpenAPI support added in .NET 9, tell it:

• target framework
• whether you use built-in OpenAPI or another Swagger/OpenAPI setup
• whether ProblemDetailsService is already configured

Without that, the model may produce code that is directionally right but mismatched to your project.

Ask explicitly for typed results

A common failure mode is getting valid Minimal API code that still returns loosely typed responses. Improve the request by saying:

• “Use Results<T1, T2> where appropriate”
• “Return TypedResults”
• “Model error responses explicitly”

That usually produces cleaner handler signatures and better API contracts.

Push for better DTO quality

Another common weakness is thin DTO design. Ask for:

• record types where suitable
• validation attributes like [Required]
• clear property names
• [Description] annotations for OpenAPI clarity

This makes the generated docs more useful to downstream consumers, not just more verbose.

Request endpoint organization decisions

If you want more than a snippet, ask the skill to decide:

• whether to use MapGroup()
• whether the endpoint belongs in a separate endpoint class
• how to organize feature folders for a growing API

That turns aspnet-minimal-api-openapi install and usage into a repeatable development pattern instead of one-off generation.

Iterate on docs separately from logic

A good refinement pattern is:

1. Generate the endpoint logic and types.
2. Then ask the skill to improve only the OpenAPI layer.

Example follow-up:

• “Keep behavior the same, but improve the OpenAPI summary, description, operation name, parameter descriptions, and documented responses.”

This usually yields better documentation than trying to perfect everything in one pass.

Compare the output against real consumer needs

The biggest quality check is not “does it compile?” but “would another team understand this API from Swagger alone?” Review:

• are request fields self-explanatory?
• are errors standardized?
• do operation names make sense?
• are response types precise?

That is where the aspnet-minimal-api-openapi guide adds the most value.

Use refactoring prompts for stronger results

If the first pass feels generic, give the model your current endpoint and ask:

• what types are too loose
• what metadata is missing
• where validation should move into DTOs
• how to make the OpenAPI output clearer

This is often the highest-signal way to use aspnet-minimal-api-openapi for API Development, because the model can improve concrete code instead of inventing assumptions.