Ok, I've investigated it a bit further and it seems to work as expected if I render a page, but I'm trying to do this in an UmbracoApiController. Is it possible to set the "published request culture" there?

Tried to set the thread culture, no difference, the returned variants are sv

var culture = new CultureInfo("en-US");
Thread.CurrentThread.CurrentCulture = culture;
Thread.CurrentThread.CurrentUICulture = culture;

var names = Umbraco.ContentAtRoot()
    .FirstOrDefault(x => x.IsPublished())
    ?.Children
    .Select(x => x.Name);

Thats the expected behaviour in Umbraco 8.

The injected Model on pages contains property values based on the current language (based on current domain). So, when you output @Model.Name, you can see that the name is displayed in en-US culture.

But, your code to get the names of the roots children is not sensitive for cultures. You will get all children, even when there is no specific content for specific languages.

var names = Umbraco.ContentAtRoot()
    .FirstOrDefault(x => x.IsPublished())
    ?.Children
    .Select(x => x.Name);

The 'Name' property contains always the default language value. Instead you can use the following code:

var currentCulture = System.Threading.Thread.CurrentThread.CurrentCulture.Name;

var names = Umbraco.ContentAtRoot()
       .FirstOrDefault(x => x.IsPublished())
       ?.Children
       .Select(x => x.GetCulture(currentCulture).Name);

When you want to list only the children that are available in the current culture, you can use:

var names = Umbraco.ContentAtRoot()
       .FirstOrDefault(x => x.IsPublished())
       ?.Children
       .Where(x.Cultures.ContainsKey(currentCulture))
       .Select(x => x.GetCulture(currentCulture).Name);

The code above works like a charm for getting the name in the specified culture, but it only solves the first part of what I'm trying to do. I also need to access properties defined by me in that culture, is it possible to get a complete Models Builder model in the culture? Or do I need to get them one by one using

.Value("propName", "culture")

(It works but a translated model would be prettier IMO)

        var items = Umbraco.ContentAtRoot()
            .FirstOrDefault(x => x.IsPublished())
            ?.Children
            .Where(x => x.Cultures.ContainsKey(currentCulture))
            .Select(x => new Item
            {
                Id = x.Id,
                Name = x.GetCulture(currentCulture).Name,
                Heading = x.Value<string>(nameof(Standard.Heading), currentCulture)
            });

After digging into the source of Umbraco, I found how they define which language to get the content for. They do this by creating a new VariantionContext.

F.E. ``` public class ContentApiController : UmbracoApiController { private readonly IVariationContextAccessor _variationContextAccessor;

    public ContentApiController(IVariationContextAccessor variationContextAccessor)
    {
        _variationContextAccessor = variationContextAccessor;
    }

    public IHttpActionResult Get(int id, string culture)
    {
        _variationContextAccessor.VariationContext = new VariationContext(culture);
        var cnt = Umbraco.Content(id);
        return Ok(cnt.Name);
    }
}

This will return the data in the language for which the culture is passed.

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