Sandbox and limits

Your program runs in a separate worker inside an isolated environment. The editor and API never execute anything.

• No network. A private, read-only filesystem with only /work (your files) and /tmp writable; nothing else on the host is visible.
• Unprivileged user, no capabilities, no privilege escalation.
• Per-language CPU, wall-clock, memory, process, file-size and output caps (see Languages). Output beyond 1 MB is cut and the program stopped.
• Each run gets a fresh directory that is deleted afterwards. Nothing persists between runs except what you saved as a project.

Verdicts tell you what happened: time limit when a cap stopped it, runtime error for a non-zero exit, system error when the sandbox itself failed (never your code's fault).