gatekeep — the agent control surface

A pre-execution gate that sits between an AI agent's proposed command and its execution. Solves the 2026 agent-production gap: agents are hard to supervise, hard to roll back, and hard to correct mid-run — because the control surface is missing.

Why

• Rollback checkpoints the agent cannot delete: every destructive action (rm/mv/cp --hard reset, forced push) snapshots its targets into a vault that lives outside the agent's directory envelope. If the backup fails, the action is blocked. The agent has no path to the vault.
• Pre-execution rules with block authority: denylist patterns, allowlist overrides, envelope enforcement (targets outside the envelope are denied).
• Executable lifecycle hooks: any script in ~/.gatekeep/hooks/ receives the proposed command and answers {"action": "allow"|"deny"|"modify"}.
• Circuit breaker (CLOSED/OPEN/HALF_OPEN): after N consecutive command failures the agent is restricted to read-only commands — loop containment.
• Append-only, human-readable audit log: every proposal, denial, snapshot, failure and rollback, timestamped.

Usage

./gatekeep init --envelope ~/workspace        # one-time setup
./gatekeep run -- rm -rf ./cache              # snapshot + execute
./gatekeep run -- git push --force origin main  # denied by default rules
./gatekeep snapshots                          # list vault snapshots
./gatekeep rollback 20260815T100000           # restore from snapshot
./gatekeep breaker status                     # CLOSED/OPEN/HALF_OPEN
./gatekeep audit -- 50                        # human-readable log tail

Hooks

cp example_hook.py ~/.gatekeep/hooks/protect-secrets
chmod +x ~/.gatekeep/hooks/protect-secrets

Hooks receive {"command": "..."} on stdin and return a typed JSON decision.

Design notes

• Vault defaults to ~/.gatekeep/vault, mode 0700, outside any envelope.
• Deny decisions are also written to the audit log, so a human operator can review every intervention the agent did and did not make.
• The breaker's HALF_OPEN state auto-closes after 60s, letting a recovered agent resume — but only after it has cleared read-only mode.