DepShield MCP

🤔 Why

AI coding agents pull packages from stale training data. They install outdated versions with known CVEs. They hallucinate package names that don't exist, opening the door to typosquatting attacks. They default to deprecated libraries when better alternatives exist.

There's no checkpoint between "agent decides to use a package" and "package lands in your project." DepShield is that checkpoint.

⚡ What It Does

Seven security tools exposed over the Model Context Protocol:

Plus a depshield://status resource and a security_review prompt template for guided full-project audits.

Zero API keys required. DepShield uses free, open APIs: npm Registry, OSV.dev (Google's open vulnerability database), and PyPI.

🚀 Quick Start

Option 1: npx (no install)

Add to your IDE's MCP configuration and you're done. No global install needed.

Option 2: Clone and build

git clone https://github.com/devanshkaria88/depshield-mcp.git
cd depshield-mcp
npm install
npm run build

🔌 IDE Setup

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project-level):

{
  "mcpServers": {
    "depshield": {
      "command": "npx",
      "args": ["-y", "depshield-mcp"]
    }
  }
}

Or if you cloned the repo locally:

{
  "mcpServers": {
    "depshield": {
      "command": "node",
      "args": ["/absolute/path/to/depshield-mcp/dist/index.js"]
    }
  }
}

Optionally, copy .cursor/rules/dep-shield.mdc into your project's .cursor/rules/ directory. This rule forces the Cursor agent to call check_dependency before every package install.

claude mcp add depshield -- npx depshield-mcp

Or from a cloned repo:

claude mcp add depshield -- node /absolute/path/to/depshield-mcp/dist/index.js

Add to your Windsurf MCP configuration:

{
  "mcpServers": {
    "depshield": {
      "command": "npx",
      "args": ["-y", "depshield-mcp"]
    }
  }
}

DepShield uses stdio transport. Any tool that supports MCP over stdio can use it:

npx depshield-mcp

💡 Usage Examples

Once connected, your AI agent has access to all seven tools. Try these prompts:

Pre-install check (automatic with .mdc rule)

"Add lodash for deep cloning"

Agent calls check_dependency → finds CVE → auto-upgrades to safe version

Block hallucinated packages

"Install react-super-utils-pro for state management"

Agent calls check_dependency → package doesn't exist → blocks install, suggests alternatives

Full project audit

"Run a security audit on this project's dependencies"

Agent calls audit_project on package.json → returns full vulnerability report

Package health check

"Is this package well maintained?"

Agent calls check_npm_health → returns health score (0–100) with breakdown

Supply chain deep scan

"Deep scan express for transitive vulnerabilities"

Agent calls deep_scan → scans dependency tree, flags suspicious patterns

Advisory deep dive

"Tell me more about GHSA-jf85-cpcp-j695"

Agent calls get_advisory_detail → returns full CVE details, remediation info

📖 Tools Reference

Returns: ✅ SAFE, ⚠️ VULNERABLE (with fix version), 🚫 BLOCKED (doesn't exist), or ⚠️ CANNOT VERIFY (registry unreachable).

Returns: Full audit report with summary stats, per-dependency vulnerability breakdown, severity counts, and risk verdict.

Returns: The newest stable version with zero known vulnerabilities, with comparison of all checked versions.

Returns: Full advisory with summary, severity, CVSS score, affected versions, fix versions, and reference links.

Returns: Health report card (0–100 score) based on: publish recency, weekly downloads, license, repository presence, deprecation status, and maintainer count.

Returns: Top 3 alternative packages with downloads, npm score, and publish date.

Returns: Dependency tree with vulnerability flags, suspicious pattern detection (newly added deps, nonexistent packages, low-download typosquat candidates), and risk verdict.

🔒 Cursor Rule (Optional)

The .cursor/rules/dep-shield.mdc file included in this repo forces the Cursor agent to automatically call check_dependency before every package install. Copy it to your project:

mkdir -p .cursor/rules
cp node_modules/depshield-mcp/.cursor/rules/dep-shield.mdc .cursor/rules/

This turns DepShield from a tool the agent can use into a gate the agent must pass through.

🧪 Testing

MCP Inspector (interactive UI for testing tools):

npm run inspect

Or:

npx @modelcontextprotocol/inspector node dist/index.js

Raw stdio (quick verification):

printf '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0.0"}}}\n{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"check_dependency","arguments":{"name":"lodash","version":"4.17.20"}}}\n' | node dist/index.js 2>/dev/null

🌐 APIs Used

All free, no API keys required:

📁 Project Structure

depshield-mcp/
├── src/
│   ├── index.ts                    # MCP server entry — tool/resource/prompt registration
│   ├── cache.ts                    # In-memory TTL cache (5 min)
│   ├── utils.ts                    # Severity parsing, version sorting, fetch helpers
│   ├── apis/
│   │   ├── npm-registry.ts         # npm registry, search, downloads
│   │   ├── osv.ts                  # OSV.dev vulnerability queries
│   │   └── pypi-registry.ts        # PyPI JSON API
│   └── tools/
│       ├── check-dependency.ts     # Pre-install gate
│       ├── audit-project.ts        # Full manifest audit
│       ├── find-safe-version.ts    # Safe version finder
│       ├── get-advisory-detail.ts  # CVE/GHSA deep dive
│       ├── check-npm-health.ts     # Package health scoring
│       ├── suggest-alternative.ts  # Alternative package finder
│       └── deep-scan.ts            # Transitive dependency scanner
├── .cursor/rules/
│   └── dep-shield.mdc             # Cursor agent rule (alwaysApply)
├── package.json
├── tsconfig.json
├── LICENSE
└── README.md

📋 Requirements

• Node.js 18 or later (uses native fetch)

• An MCP-compatible AI coding tool

🤝 Contributing

Contributions are welcome. Please open an issue first to discuss what you'd like to change.

Areas where help would be appreciated:

• Additional ecosystem support (Cargo, Go modules, Maven)

• Improved CVSS vector string parsing

• Integration tests with mocked API responses

• GitHub Actions CI pipeline

📄 License

MIT — see LICENSE for details.