Endpoint Groups

Program.cs

app.MapGroup("/apis", apis =>
{
    apis.UseExceptionHandler("/error");
    var problemJsonMediaType = new MediaTypeHeaderValue("application/problem+json");

    apis.MapGet("/error", (HttpContext context) =>
    {
        // Get exception details
        var error = context.Features.Get<IExceptionHandlerFeature>()?.Error;
        var badRequestEx = error as BadHttpRequestException;
        var statusCode = badRequestEx?.StatusCode ?? StatusCodes.Status500InternalServerError;

        // Return JSON if client supports it
        if (context.Request.GetTypedHeaders().Accept?.Any(h => problemJsonMediaType.IsSubsetOf(h)) == true)
        {
            var extensions = new Dictionary<string, object> { { "requestId", Activity.Current?.Id ?? context.TraceIdentifier } };

            // JSON Problem Details
            return error switch
            {
                BadHttpRequestException ex => Results.Extensions.Problem(detail: ex.Message, statusCode: ex.StatusCode, extensions: extensions),
                _ => Results.Extensions.Problem(extensions: extensions)
            };
        }

        // Just return plain text
        return Results.Extensions.StatusCode(statusCode, badRequestEx?.Message ?? "An unhandled exception occurred while processing the request.");
    })
   .ExcludeFromDescription();

    apis.MapGroup("/samples", sampleApis =>
    {
        sampleApis.UseMiddleware<MyMiddleware>();
        sampleApis.MapGet("/hello", () => "Hello, World!");
    })
    .WithTags("Samples");

    apis.MapGroup("/todos", todoApis =>
    {
        todoApis.MapGet(async (TodoDb db) =>
        {
            return await db.Todos.ToListAsync();
        });

        todoApis.MapGet("{id}", async (int id, TodoDb db) =>
        {
            return await db.Todos.FindAsync(id);
        });

        todoApis.MapPost(async (Todo todo, TodoDb db) =>
        {
            db.Todos.Add(todo);
            await db.SaveChangesAsync();
            return Results.Created($"{todoApis.GroupPrefix}/{todo.Id}", todo);
        });
    })
    .WithTags("Todos");
});