ASP.NET Core Integration

Vali-Mediator.AspNetCore maps Result<T> and Result values to HTTP responses automatically.

Installation

dotnet add package Vali-Mediator.AspNetCore

HTTP Status Code Mapping

Scenario	HTTP Status
Result<T>.Ok(value)	200 OK with value in body
Result.Ok() (void)	204 No Content
ErrorType.Validation	400 Bad Request with ValidationProblemDetails
ErrorType.NotFound	404 Not Found with error message
ErrorType.Conflict	409 Conflict with error message
ErrorType.Unauthorized	401 Unauthorized with error message
ErrorType.Forbidden	403 Forbidden with error message
ErrorType.Failure	500 Internal Server Error with problem details

MVC Controllers

Use ToActionResult() for IActionResult:

using Vali_Mediator.AspNetCore;

[ApiController]
[Route("api/[controller]")]
public class ProductsController : ControllerBase
{
    private readonly IValiMediator _mediator;

    public ProductsController(IValiMediator mediator)
    {
        _mediator = mediator;
    }

    [HttpGet("{id:guid}")]
    public async Task<IActionResult> GetProduct(Guid id)
    {
        Result<ProductDto> result = await _mediator.Send(new GetProductQuery(id));
        return result.ToActionResult();
        // 200 OK with ProductDto, or 404 Not Found
    }

    [HttpPost]
    public async Task<IActionResult> CreateProduct(CreateProductRequest body)
    {
        var command = new CreateProductCommand(body.Name, body.Price);
        Result<Guid> result = await _mediator.Send(command);
        return result.ToActionResult();
        // 200 OK with Guid, or 400 Bad Request with ValidationProblemDetails
    }

    [HttpDelete("{id:guid}")]
    public async Task<IActionResult> DeleteProduct(Guid id)
    {
        Result result = await _mediator.Send(new DeleteProductCommand(id));
        return result.ToActionResult();
        // 204 No Content, or 404 Not Found
    }
}

Minimal API

Use ToHttpResult() for IResult:

using Vali_Mediator.AspNetCore;

var app = builder.Build();

app.MapGet("/api/products/{id:guid}", async (Guid id, IValiMediator mediator) =>
{
    Result<ProductDto> result = await mediator.Send(new GetProductQuery(id));
    return result.ToHttpResult();
});

app.MapPost("/api/products", async (CreateProductRequest body, IValiMediator mediator) =>
{
    Result<Guid> result = await mediator.Send(
        new CreateProductCommand(body.Name, body.Price));
    return result.ToHttpResult();
});

app.MapDelete("/api/products/{id:guid}", async (Guid id, IValiMediator mediator) =>
{
    Result result = await mediator.Send(new DeleteProductCommand(id));
    return result.ToHttpResult();
});

Validation Error Response

When ErrorType.Validation is returned with a ValidationErrors dictionary, the response follows the RFC 7807 ValidationProblemDetails format:

{
  "type": "https://tools.ietf.org/html/rfc7807",
  "title": "One or more validation errors occurred.",
  "status": 400,
  "errors": {
    "Name": ["Name is required.", "Name must be at most 100 characters."],
    "Price": ["Price must be greater than zero."]
  }
}

IResult Naming Conflict

warning

Microsoft.AspNetCore.Http.IResult conflicts with Vali_Mediator.Core.Result.IResult. The package handles this internally with an alias:

// Inside Vali-Mediator.AspNetCore internals
using HttpIResult = Microsoft.AspNetCore.Http.IResult;

Your code only needs to reference Vali_Mediator.AspNetCore via the extension methods — no alias needed in your own controllers.