file system. In the case of um our models, all of the recent models starting with GPT-5 have been trained on the concept of an apply patch tool to do file editing, which means that they're used to using that to change files by giving it a a diff, and then um also using that same thing to create new files. And then for everything else, it uses a shell tool where it will uh do a file search or other file system navigation. Uh you will see the model naturally trying to use Ripgrep um since that's what what it got used to during training. So, we're actually in the Codex harness shipping Ripgrep with uh with the harness if you don't have it installed on your own. On Windows, we also trained the model to use PowerShell natively. So, if you're running it on Windows, you'll see it uh start writing uh PowerShell code instead. One of the things you're seeing here is um the sandbox pulling in. So, all of the interactions that you see with the file system actually go through our sandbox layer. Um and on macOS, we use Seatbelt for that, similar to most agents. And on Linux, we use Bubblewrap. On uh Windows, it's slightly different where we actually had to build our own custom um open open source Windows sandbox. It's in the same GitHub repository if you want to take a look. And there's a many reasons why we had to do this, and I could probably fill a whole talk about that. So, instead, I would recommend you to actually check out the check out the article that David wrote about this. Um it goes into all of the other Windows alternatives and why we actually had to build our own sandbox there. Highly fascinating if you really want to nerd out about Windows