🛑 Hardstop

👉 ⭐ Star on GitHub if Hardstop keeps you safe!

Pre-execution safety validation for AI coding agents. Validates every shell command against 428 security patterns before execution — blocking destructive operations, credential theft, infrastructure teardown, and prompt injection. Fail-closed: blocks by default when uncertain.

Ecosystem: The detection patterns are published separately as hardstop-patterns (GitHub) — reusable in any Node.js tool.

Installation • How It Works • Commands • Report Issue

⚡️ Why Hardstop?

You trust your AI, but you shouldn't trust it with rm -rf / or reading your ~/.aws/credentials. Hardstop sits between the LLM and your system, enforcing a strict Fail-Closed policy on dangerous operations.

• 🛡️ Pattern Matching: Instant regex-based detection for known threats (fork bombs, reverse shells)
• 🧠 LLM Analysis: Semantic analysis for edge cases and obfuscated attacks
• ⛓️ Chain Awareness: Scans every link in a command chain (&&, |, ;)
• 🔐 Secrets Protection: Blocks reading of credential files (.ssh, .aws, .env) (v1.3)
• 🍎 macOS Coverage: Keychain, diskutil, Time Machine, Gatekeeper, SIP, LaunchDaemons (v1.3.6)
• 📚 LLM Guidance: Teaches Claude how to think about safety, not just blocks

🚀 Quick Demo

Claude tries to ruin your day? Hardstop says no.

# Claude attempts a home directory deletion
$ rm -rf ~/
🛑 BLOCKED: Deletes home directory

# Claude tries to read your AWS credentials
$ Read ~/.aws/credentials
🛑 BLOCKED: AWS credentials file

# You check the status
$ /hs status
Hardstop v1.4.3
  Status:      🟢 Enabled
  Session Risk: Moderate (35/100)
  Blocked: 2 commands this session

# One-time bypass for a command you trust
$ /hs skip
⏭️  Next command will skip safety check

# Multi-skip: bypass next 3 commands (v1.3.2)
$ /hs skip 3
⏭️  Next 3 commands will skip safety check

# View recent security decisions
$ /hs log
2026-01-20 10:30:45 🛑 [pattern] rm -rf ~/
                     └─ Deletes home directory

⚙️ How It Works

Hardstop uses a two-layer verification system for Bash commands and pattern-based protection for file reads.

graph TD
    A[Tool Call] --> B{Bash or Read?};
    B -- Bash --> C{Layer 1: Patterns};
    C -- Dangerous Pattern --> D[🛑 BLOCK];
    C -- Safe Pattern --> E[✅ ALLOW];
    C -- Unknown --> F{Layer 2: LLM Analysis};
    F -- Risky --> D;
    F -- Safe --> E;
    B -- Read --> G{Credential File?};
    G -- .ssh/.aws/.env --> D;
    G -- Source Code --> E;
    D --> H[Log to Audit];
    E --> I[Execute];

The 428 detection patterns (Layer 1) are published as a standalone npm package: hardstop-patterns — usable in any Node.js tool, not just Hardstop.

🤝 Works Well With

PatchPilot - Package vulnerability scanner that blocks risky npm/pip/brew installations.