GuardianShield
Universal AI security layer — an open-source MCP server for code scanning, PII detection, prompt injection defense, secret detection, dependency auditing, and audit logging.
Zero dependencies · 27 MCP tools · 5 safety profiles · 108+ detection patterns
Features
- Code Vulnerability Scanning — SQL injection, XSS, command injection, path traversal with CWE IDs and auto-fix remediation
- Cross-line Data Flow Analysis — DeepEngine tracks tainted data from sources to sinks across multiple lines using AST-based taint propagation (Python) and regex (JS/TS)
- Dependency Security — Version-aware CVE matching against OSV.dev for PyPI, npm, Go, and Packagist ecosystems
- Manifest Parsing — Auto-detects 11 formats (requirements.txt, package.json, yarn.lock, go.mod, composer.json, and more)
- Prompt Injection Defense — 9+ detection patterns for instruction override, role hijacking, ChatML injection
- PII Detection — Email, SSN, credit card, phone, IP — with automatic redaction in findings
- Secret Detection — AWS keys, GitHub tokens, Stripe keys, JWTs, passwords, connection strings
- Safety Profiles — 5 built-in profiles (general, education, healthcare, finance, children)
- Audit Logging — SQLite-backed scan history with finding retrieval and filtering
Install
pip install guardianshield
Quick Start
# Register with Claude Code
claude mcp add guardianshield -- guardianshield-mcp
# Or run directly
guardianshield-mcp
Editor Integration
# Claude Code
claude mcp add guardianshield -- guardianshield-mcp
# VS Code (.vscode/mcp.json)
{"servers": {"guardianshield": {"type": "stdio", "command": "guardianshield-mcp"}}}
# Cursor (.cursor/mcp.json)
{"mcpServers": {"guardianshield": {"command": "guardianshield-mcp"}}}
# Claude Desktop (claude_desktop_config.json)
{"mcpServers": {"guardianshield": {"command": "guardianshield-mcp"}}}
MCP Tools
Scanning
| Tool | Description |
|---|---|
scan_code | Scan source code for vulnerabilities and hardcoded secrets |
scan_file | Scan a single file (auto-detects language from extension) |
scan_directory | Recursively scan a directory with filtering and progress streaming |
scan_input | Check user/agent input for prompt injection attempts |
scan_output | Check AI output for PII leaks and content violations |
check_secrets | Detect hardcoded secrets and credentials |
scan_files | Scan multiple files in one call |
scan_diff | Parse unified diff and scan only added lines |
Dependency Security
| Tool | Description |
|---|---|
check_dependencies | Check packages for known CVEs via OSV.dev (PyPI, npm, Go, Packagist) |
sync_vulnerabilities | Sync the local OSV vulnerability database |
parse_manifest | Parse any supported manifest file (11 formats) into dependency objects |
scan_dependencies | Scan a directory for manifest files and check all deps for vulnerabilities |
False Positive Management
| Tool | Description |
|---|---|
mark_false_positive | Mark a finding as false positive (flags future matches) |
list_false_positives | List active false positive records with optional filter |
unmark_false_positive | Remove a false positive record by fingerprint |
Engine Management
| Tool | Description |
|---|---|
list_engines | List available analysis engines with capabilities |
set_engine | Set active analysis engines for code scanning |
Three engines ship built-in: regex (line-by-line pattern matching, enabled by default), deep (cross-line taint tracking), and semantic (structure-aware confidence adjustment).
CI & Developer Workflow
| Tool | Description |
|---|---|
export_sarif | Export findings as SARIF 2.1.0 JSON for GitHub Code Scanning and CI |
save_baseline | Save current findings as a baseline for delta scanning |
scan_with_baseline | Scan code and report only new findings vs. baseline |
check_quality_gate | Evaluate findings against severity thresholds (pass/fail/warn) |
scan_files | Scan multiple files in one call |
scan_diff | Parse unified diff and scan only added lines |
Configuration & Utilities
| Tool | Description |
|---|---|
get_profile | Get current safety profile configuration |
set_profile | Switch safety profile (general, education, healthcare, finance, children) |
test_pattern | Test a regex pattern against sample code for custom pattern development |
audit_log | Query the security audit log |
get_findings | Retrieve past findings with filters |
shield_status | Get health, configuration, and OSV cache statistics |
Configuration
Set environment variables to customize behavior:
| Variable | Description | Default |
|---|---|---|
GUARDIANSHIELD_PROFILE | Default safety profile | general |
GUARDIANSHIELD_AUDIT_PATH | Path to SQLite audit database | ~/.guardianshield/audit.db |
GUARDIANSHIELD_DEBUG | Enable debug logging (1) | disabled |
Documentation
Full documentation: sparkvibe-io.github.io/GuardianShield
License
Apache 2.0