[VS 2026] Go to Definition for tag helpers not working

[ChrisVanDijk]

I was very happy to read in the VS 2026 release notes that there is finally support for Go to Definition for tag helpers.

The Visual Studio Insiders release notes says:

Leveraging new capabilities from cohosting, you can now navigate to the definitions of ASP.NET Core MVC Tag Helpers and their attributes directly from Razor files. Hitting F12 (or Ctrl+Click) on a Tag Helper (e.g. an or any MVC Tag Helper usage) will jump to its source definition. This long-requested feature makes it much easier to explore and understand Tag Helpers in your projects.

So I created a new solution (MVC, .NET 10, Identity with individual user accounts), build it, and pressed F12 on asp-page in <a class="nav-link text-dark" asp-area="Identity" asp-page="/Account/Manage/Index" title="Manage">Hello @User.Identity?.Name!</a>

But that doesn't work. So I checked the settings and I enabled "Use Roslyn Cohost server for Razor", restarted, and it sill doesn't work.

Added a custom tag helper: still doesn't work.

@davidwengier Am I doing something wrong?

[davidwengier]

No, you're not doing anything wrong, just a misunderstanding of the feature. What we've added is support for going to the definition of the tag helper itself, when that tag helper is defined in the solution. So for example if you have a tag helper defined that adds a foo attribute to a tag, you could have <input foo="1" />, place the cursor on the attribute name, and go to definition would take you to where that tag helper is defined.

I'll leave this issue open though, as what you were expecting is actually a good feature request :)

[ChrisVanDijk]

Then there is a bug if the tag already has other tag helpers.

This works:

<label for="test" foo="1">test</label>

This does not:

<label asp-for="test" foo="1">test</label>

Sample tag helper:

[HtmlTargetElement("*", Attributes = FooAttributeName)]
public class FooTaghelper: TagHelper
{
    private const string FooAttributeName = "foo";

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        output.Attributes.Add("foo", "bar");
    }
}

[davidwengier]

Thanks! I'll move that to a new issue though :)