Shield: Open-Source Security Plugin for Claude Code

Shield Security Plugin for Claude Code

Shield is an open-source security plugin for Claude Code that orchestrates multiple security scanning tools through a single command interface. It provides automated security analysis with consolidated reporting and remediation suggestions.

Core Functionality

The plugin is accessed via the /shield:shield command inside Claude Code. It automatically detects your technology stack and runs whichever security tools you have installed, including:

Semgrep SAST (Static Application Security Testing)
gitleaks for secrets scanning
npm/pip/composer audit for dependency vulnerabilities
Shannon pentester

All findings are consolidated into a unified report with a 0-100 risk score and proposed code fixes with diffs.

Real-World Test Results

The developer tested Shield on their own Next.js monorepo and found:

36 dependency vulnerabilities (1 CRITICAL, 26 HIGH)
103 secrets in git history (AWS keys, Stripe tokens, OpenAI API keys)
77 SAST findings (XSS, hardcoded credentials, missing SRI)
A .env file with production credentials tracked in git that wasn't previously known

After fixing 3 direct dependencies and removing the exposed .env file, the project went from 36 vulnerabilities to 0.

Key Features

6 operation modes: full, quick, fix, verify, score, outdated
34 custom Semgrep rules for JS/TS, Python, and PHP
Dependency freshness check with SECURITY/MAJOR/MINOR/PATCH classification
OWASP Top 10 / CWE / SOC 2 / PCI-DSS / HIPAA compliance mapping
SARIF output for GitHub Security tab integration
Security score badge for README files
Graceful degradation — runs whatever tools you have installed
189 unit tests, MIT licensed

Installation

To install Shield:

git clone https://github.com/alissonlinneker/shield-claude-skill.git
cd shield-claude-skill && ./install.sh
# Inside Claude Code:
/plugin marketplace add /path/to/shield-claude-skill
/plugin install shield@shield-security

The project is available on GitHub at https://github.com/alissonlinneker/shield-claude-skill. Feedback and contributions are welcome, with the roadmap organized as GitHub issues.

📖 Read the full source: r/ClaudeAI