Yeah, .NET developers have been passing CancellationTokens around in the places where they have needed them for 15 years. The tokens are basically invisible until their existence emerges when someone decides they want to cancel a long-running API call or something. At that point, they are plumbed as deeply as seems fit for the problem at hand and then hardly thought about ever again. CancellationTokens are generally a delightful pattern, especially when the language allows sensible defaults.