smolmachines / smolvm as a sandbox for untrusted Python & JavaScript
Simon Willison's Weblog
Read full postSmolvm 1.8.3 provides a secure sandbox environment for running untrusted Python and JavaScript code with hardware-isolated VMs, enforcing resource limits and no network access. Testing showed effective isolation with cold starts under 1.5 seconds and warm executions around 50 ms. Limitations in some environments like Claude Code were overcome by running tests on GitHub Actions runners with KVM support.



