I have a couple hundred line TUI that just clones an LXD container and I get all my repos and infra isolated in 5s with pi having isolation to that container. Swap between any instance. Port forward to host all automatic.

Funny to me how stuff is described these days. Seems like some people lack the full understanding of all these different systems and really overcomplicate their harness setups or use super bloated all in one tooling.

You can sandbox with tool hooks, at least in antigravity, I think a lot of other harnesses support similar features. Sandboxing via the prompt is just dangerous and unreliable.

The developers of pi.dev are geniuses.

They add a --tools flag, which can only add tools onto the built-in tools, so if you wanted to sandbox pi.dev by adding sandboxed versions of the existing tools you will have to run pi.dev via

    pi --no-tools --tools tool1, tool2, tool3

except..., that's not enough to sandbox pi.dev, because remember, it's a minimalist coding agent! So what does a minimalist coding agent do? Of course! It loads extensions by default and do you know what extensions can do? they can add default tools that bypass --no-tools!

So if you want to sandbox your agent, guess what you'll have to do? Yep, you have to supply --no-extensions.

Here is how to run pi.dev under its most minimal configuration under a sandbox:

    pi --no-tools --no-extensions --tools tool1, tool2, tool3 -e ./your-sandboxing-extension

Pretty neat, huh?

Sources: https://github.com/earendil-works/pi/issues/555