minimal-api-endpoint-scaffolder

Minimal API Endpoint Scaffolder

Generate clean ASP.NET Core Minimal API endpoints — one feature per endpoint (REPR), validated, with TypedResults, grouped routes, and OpenAPI metadata.

Input — point it at your project

Works on a target: a file, folder, project/solution, or GitHub URL. Read one existing endpoint and match its style (Carter module? plain MapGroup? MediatR dispatch?). Detect with: grep -rn "MapGet\|MapPost\|MapGroup\|ICarterModule\|: ControllerBase" --include=*.cs <target>.

Endpoint (REPR + TypedResults)

public static class CreateOrderEndpoint
{
    public static RouteGroupBuilder MapCreateOrder(this RouteGroupBuilder group)
    {
        group.MapPost("/", Handle)
             .WithName("CreateOrder")
             .WithSummary("Creates an order")
             .Produces<OrderResponse>(StatusCodes.Status201Created)
             .ProducesValidationProblem();
        return group;
    }

    public record Request(Guid CustomerId, List<OrderLine> Lines);
    public record OrderResponse(Guid Id);

    private static async Task<Results<Created<OrderResponse>, ValidationProblem>> Handle(
        Request req, IValidator<Request> validator, ISender sender, CancellationToken ct)
    {
        var v = await validator.ValidateAsync(req, ct);
        if (!v.IsValid) return TypedResults.ValidationProblem(v.ToDictionary());

        var id = await sender.Send(new CreateOrderCommand(req.CustomerId, req.Lines), ct);
        return TypedResults.Created($"/orders/{id}", new OrderResponse(id));
    }
}

Route grouping (Program.cs)

var orders = app.MapGroup("/orders").WithTags("Orders").RequireAuthorization();
orders.MapCreateOrder();
orders.MapGetOrderById();

Principles

• One endpoint per feature — don't pile unrelated routes into one class.
• TypedResults over Results — they give you compile-time response types and accurate OpenAPI.
• Validate at the edge, return ValidationProblem (RFC 7807), keep business rules in the handler/domain.
• Group routes for shared prefix, tags, and auth instead of repeating per endpoint.
• Don't hand-roll what MapGroup + filters already do.