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