What
Claude Code now proactively detects when sandboxing is configured but cannot actually run, and displays a clear warning at startup instead of silently falling back.
Details
- Checks for missing dependencies (bubblewrap, socat on Linux; ripgrep), unsupported platforms, and WSL1 incompatibility
- Displays a warning:
⚠ Sandbox disabled: {reason}followed byCommands will run WITHOUT sandboxing. Network and filesystem restrictions will NOT be enforced. - The
/sandboxdiagnostic UI now also shows ripgrep status and uses "seatbelt: built-in (macOS)" labeling on macOS
Evidence
Sandbox check function (search for "getSandboxUnavailableReason") and startup warning (search for "Commands will run WITHOUT sandboxing")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agree
Fixed /sandbox Dependencies tab showing Linux prerequisites on macOS instead of macOS-specific info