GitHub implements self hosted runners by running a normal runner that passes the environment to your runner and then polls it. That's why they cost as much as the smallest GitHub-hosted runner.

This is no surprise given standard Microsoft operating procedure - https://news.ycombinator.com/item?id=47616242

I think they kind of have to operate that way if you want a control plane/access to GitHub’s own layered services like caching and artifact storage. There are plenty of things to blame GitHub for, but this one doesn’t seem sinister at all.

Edit: to be clear, I mean the part where they maintain state on their end. I have no idea if they do that with another runner instance, that seems unlikely.

they walked that back for now at least - self-hosted gh runners are still free: https://docs.github.com/en/billing/concepts/product-billing/...

Oh that is pretty gross, thanks for sharing. I was not aware of that process, that explains the cost they attempted to roll out for runners too a few months back.