Functional .NET Aspire where Functional DDD and Service Level Indicators have been added.

      userApi.MapPost("/register", (RegisterUserRequest request) =>
          FirstName.TryCreate(request.firstName)
          .Combine(LastName.TryCreate(request.lastName))
          .Combine(EmailAddress.TryCreate(request.email))
          .Bind((firstName, lastName, email) => User.TryCreate(firstName, lastName, email, request.password))
          .ToOkResult());

      RouteGroupBuilder userApi = app.MapGroup("/users")
        .AddServiceLevelIndicator();

// Okay
POST {{HostAddress}}/users/register
Content-Type: application/json
Accept: application/json

{
  "firstName": "Xavier",
  "lastName": "John",
  "email": "xa@somewhere.com",
  "password": "KeepItSimple"
}
###

// Bad request
POST {{HostAddress}}/users/register
Content-Type: application/json
Accept: application/json

{
  "firstName": "string",
  "lastName": "",
  "email": "xa.com",
  "password": "string"
}
###