https://learn.microsoft.com/en-us/dotnet/api/system.threading.asynclocal-1?view=netframework-4.8.1&viewFallbackFrom=net-5.0&ref=blog.darklang.com
AsyncLocalT Class (System.Threading) | Microsoft Learn
Represents ambient data that is local to a given asynchronous control flow, such as an asynchronous method.
class systemthreadingmicrosoftlearn