Show HN: Bx – macOS native sandbox for AI and coding tools

Wrapper around Apple's macOS sandbox-exec tool, which usually sandboxes native apps. It is "allow-first" i.e. it will not overprotect everything, just crucial information and therefore allows most tools to run without issues. Limiting is done using a .gitignore like file schema. Further TOML config options available.

I built it because Docker sandboxing requires config and planning. Build in sandboxing of AI tools instead is limited to the very tools themselves, instead I wanted to have a simple cage around Claude running inside VSCode. Also needed to protect files inside a folder like .env.local or keys.

Install via: brew install holtwick/tap/bx

Run like: bx claude .