Safe Mode Skill for Claude

Safe Mode

Three levels of protection against destructive operations during AI coding sessions.

> Note: These hooks are skill-scoped — they only activate when you invoke /safe-mode. The global permission-request.js hook in hooks.json provides always-on alerting for dangerous commands. Safe-mode adds opt-in blocking and directory restrictions on top of that.

Modes

Cautious Mode

/safe-mode cautious

Intercepts Bash commands before execution. Warns on dangerous patterns but does not block — the user decides.

Flagged patterns:

| Pattern | Risk |

|---------|------|

| rm -rf / rm -r | Recursive deletion |

| DROP TABLE / DROP DATABASE | SQL data loss |

| TRUNCATE | SQL data destruction |

| git push --force / git push -f | Remote history rewrite |

| git reset --hard | Local history loss |

| git clean -f | Untracked file deletion |

| git checkout . / git restore . | Discard all changes |

| chmod 777 | World-writable permissions |

| curl or wget piped to a shell | Piped remote execution |

| > /dev/sda / dd if= | Disk-level operations |

| :(){ :\|:& };: | Fork bombs |

| sudo rm | Elevated deletion |

What happens:

WARNING: Destructive operation detected
  Command: rm -rf ./build
  Pattern: rm -rf (recursive forced deletion)
  Risk: Permanently deletes ./build and all contents

  Proceed? The command will execute as-is if you continue.

The warning goes to stderr. Claude sees it and asks for confirmation before proceeding.

Lockdown Mode

/safe-mode lockdown <path>

Restricts Edit and Write operations to a single directory tree. Prevents accidental changes to unrelated code.

How it works:

• Set the allowed path (absolute or relative to repo root)
• Every Edit/Write call checks if the target file is inside the allowed path
• Operations outside the path are blocked with an explanation

LOCKDOWN ACTIVE: Edits restricted to src/api/

  Blocked: Edit to src/utils/helpers.ts
  Reason: File is outside the lockdown path (src/api/)

  To edit files outside the lockdown, run: /safe-mode clear

Use cases:

• Focused refactoring of one module without touching others
• Bug fix in a specific directory while tests run elsewhere
• Junior developer guardrail — scope the blast radius
• Code review session — only edit the files under review

Scope: Session-scoped. Resets when the session ends.

Clear

/safe-mode clear

Removes all restrictions for the current session. Both cautious warnings and lockdown restrictions are disabled.

SAFE MODE: All restrictions cleared for this session.

Implementation

PreToolUse Hook — Bash (Cautious Mode)

The hook inspects tool_input.command before every Bash execution:

const DANGEROUS_PATTERNS = [
  { pattern: /\brm\s+(-[a-zA-Z]*[rf][a-zA-Z]*\s|--recursive|--force)/, label: "rm with -rf flags" },
  { pattern: /\bDROP\s+(TABLE|DATABASE|INDEX|VIEW)\b/i, label: "DROP SQL statement" },
  { pattern: /\bTRUNCATE\b/i, label: "TRUNCATE SQL statement" },
  { pattern: /\bgit\s+push\s+(-[a-zA-Z]*f|--force)/, label: "git force-push" },
  { pattern: /\bgit\s+reset\s+--hard\b/, label: "git hard reset" },
  { pattern: /\bgit\s+clean\s+-[a-zA-Z]*f/, label: "git clean -f" },
  { pattern: /\bgit\s+(checkout|restore)\s+\./, label: "git discard all changes" },
  { pattern: /\bchmod\s+777\b/, label: "chmod 777" },
  { pattern: /\bcurl\b.*\|\s*(sh|bash)\b/, label: "piped remote execution" },
  { pattern: /\bwget\b.*\|\s*(sh|bash)\b/, label: "piped remote execution" },
  { pattern: /\bsudo\s+rm\b/, label: "elevated deletion" },
];

Match found → emit warning to stderr. No match → pass through silently.

PreToolUse Hook — Edit/Write (Lockdown Mode)

The hook checks tool_input.file_path against the lockdown path:

function isInsideLockdown(filePath, lockdownPath) {
  const resolved = fs.realpathSync(path.resolve(filePath));
  const allowed = fs.realpathSync(path.resolve(lockdownPath));
  const rel = path.relative(allowed, resolved);
  return rel === '' || (!rel.startsWith('..') && !path.isAbsolute(rel));
}

Inside lockdown path → pass through. Outside → block with explanation.

State

Mode state lives in a session-scoped temp file (keyed by session ID to avoid cross-session leaks):

$TMPDIR/pro-workflow/safe-mode-<sessionId>.json
{
  "mode": "lockdown",
  "lockdownPath": "/Users/dev/project/src/api",
  "sessionId": "abc123",
  "activatedAt": "2026-03-28T10:00:00Z"
}

Cleared by /safe-mode clear. State persists until explicitly cleared or the temp file is manually removed. Each session has its own state file.

Combining Modes

Cautious and lockdown can run simultaneously:

/safe-mode cautious
/safe-mode lockdown src/api/

Now you get:

• Bash command warnings for destructive operations
• Edit/Write restrictions to src/api/ only

Clear removes both.

When to Use

| Situation | Mode |

|-----------|------|

| Working on production-adjacent code | Cautious |

| Focused refactoring of one module | Lockdown |

| Unfamiliar codebase, feeling cautious | Cautious |

| Pair programming, limiting AI scope | Lockdown |

| Done with restrictions | Clear |

Anti-Patterns

• Leaving lockdown on when you need to edit tests (update the path or clear it)
• Using safe-mode as a substitute for git branches (branches protect history, safe-mode protects the session)
• Ignoring cautious warnings repeatedly (if you always proceed, turn it off — false confidence is worse)