@skibum1869/pi-permission-gate

A bash permission gate for the pi coding agent: blocks dangerous actions while leaving routine work free. Every risky bash command is analyzed with a shell-aware parser (not flat regexes), severity-ranked, and either prompted, denied, or passed through depending on the active mode — plus a hard-block list of protected paths.

Install

pi install npm:@skibum1869/pi-permission-gate

Or try it without installing:

pi -e npm:@skibum1869/pi-permission-gate

Modes

Three modes, cycled with /gate or Ctrl+Alt+G (footer shows 🛡 ask / 🛡 strict / 🛡 bash-only):

Mode	Behavior
ask (default)	Risky bash prompts Yes/No; protected-path writes are hard-blocked
strict	Risky bash denied outright — for unattended runs
bash-only	Same bash gating as ask, but the write gate is off

Initial mode resolution (lowest → highest): built-in ask < global settings.json < project .pi/settings.json < session-persisted mode (resume/fork) < --gate ask|strict|bash-only flag.

{ "permission-gate": { "defaultMode": "strict" } }

Risk analysis

Commands are tokenized with shell-quote, split on &&/||/;, and checked per segment with command/argument position respected — so sudo in a comment or quoted string never false-positives, while flags are caught in any order (rm -fr, rm --force, "FOO=1 sudo x").

• High (unrecoverable): pipe-into-shell (curl … | sh), fork bombs, sudo, recursive/forced deletes, find -delete / -exec rm / xargs rm, destructive git (reset --hard, push --force, clean -f), raw disk tools (dd of=, mkfs*, diskutil erase*, cryptsetup), power ops, infrastructure teardown (kubectl delete, terraform destroy), writes to /dev/*.
• Medium (scoped or recoverable): plain rm, sed -i, kill -9, mv/cp -f, chmod -R 777, git checkout ., unparseable commands.
• Never flagged: routine git (add/commit/push/pull/status/…), redirects and plain pipes, package installs, reads.

Approval flow

Risky commands prompt with three choices:

• Allow once — re-prompts if the same command runs again.
• Allow similar (session) — medium commands also approve their root (git clean variants pass afterwards); high-severity approvals are exact-command only, so sudo / rm -rf / git push --force never auto-widen.
• Abort — blocks the command and revokes prior approvals for it.

Retry-loop protection auto-blocks a command that was just aborted. Approvals are in-memory only. The footer shows ·N while the current turn has approvals.

Subagents & headless sessions

Spawned subagents (PI_SUBAGENT_DEPTH >= 1) have no one to ask: only catastrophic (high-severity) operations are hard-blocked there. Non-interactive main sessions (print mode) also have no one to ask, so ask mode blocks all risky commands outright there (same as strict).

Protected paths

Writes to these paths are hard-blocked in all modes (and always in strict/ask): .env*, .git/, node_modules/, .ssh/, .aws/credentials, .pi/agent/auth.json, id_rsa, id_ed25519, id_ecdsa, credentials.json, and anything matching secrets.

Legibility

Blocked command reasons are shown in a preview dialog; the full reason is always available in the transcript (viewable with Ctrl+O).

Security

Pi extensions run with your user permissions. This gate is a guardrail, not an operating-system sandbox. It cannot prove arbitrary shell commands are safe.

License

MIT. Uses shell-quote (MIT).