Open-Source Developer Explains Why Multiple AI Sandboxes Can Coexist and Differ

A developer behind an open-source AI sandbox project addressed a common challenge: people assuming vendor-provided sandboxes like Claude Code Sandbox make independent tools redundant. The developer argues that different sandboxing tools protect against different threat models rather than competing for the same layer of security. Claude Code Sandbox uses OS-level primitives to restrict filesystem writes and network access, but its deny rules are application-level and do not traverse parent directories, leaving gaps in multi-project or monorepo setups. Docker commands also require direct socket access, which is structurally incompatible with Claude Code Sandbox's mechanism, meaning Docker operations run outside its protection entirely. The developer's own project addresses these gaps by hiding secret files at the filesystem level via volume mounts, eliminating the need for traversable rules in the first place.