We're using a split license: apache-2.0 for the CLI/SDK/sandbox, MIT for templates, AGPLv3 for server components. Not copyrighted.

But beyond that, we are managing a higher level abstraction than sandboxes.

I wrote a simpler version of this for Claude Code as open source if that's useful to you: https://github.com/smithy-ai/smithy-ai

It's doing context management in the same way, but adds a learning loop based on code reviews. Currently works with Gitlab, Forgejo and Gitea but happy to accept a PR for Github support or co-write it.