safe-mode

Installation
SKILL.md
Contains Hooks

This skill uses Claude hooks which can execute code automatically in response to events. Review carefully before installing.

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 | sh / wget | sh 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:

  1. Set the allowed path (absolute or relative to repo root)
  2. Every Edit/Write call checks if the target file is inside the allowed path
  3. 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)
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