PkgGuard

Dependency vulnerability and malicious-package scanner for AI coding agents (MCP server + x402 API). Safety check only.

PkgGuard checks a package.json, package-lock.json, requirements.txt, Pipfile.lock, poetry.lock, go.mod, Cargo.lock or composer.lock (or a plain package list) against OSV.dev for known vulnerabilities (CVE / GHSA / PYSEC / GO / RUSTSEC ids, severity, CVSS, fixed-in versions) and confirmed-malicious packages. Manifests are parsed locally; only {ecosystem, name, version} triples leave your machine.

• Hosted remote MCP: https://api.youraitools.co/pkgguard/mcp (Streamable HTTP)

• Free tier: 30 full-result calls/day per IP (up to 100 packages per scan) on the remote MCP endpoint, then $0.003 USDC per scan (up to 500 packages) or $0.001 per single package over x402, in USDC on Base, Polygon, Arbitrum One or Solana. No account or API key.

• Hosted API: https://api.youraitools.co/pkgguard (POST /v1/scan ($0.003, up to 500 packages), GET|POST /v1/package ($0.001), free GET|POST /v1/preview (verdict + counts, up to 25 packages, 10/min per IP))

• Local stdio MCP server: this repo. Starts with no key, no account and no npm registry package.

• MCP Registry: co.youraitools/pkgguard

• License: MIT

Use the hosted server (no install)

Claude Code:

claude mcp add --transport http pkgguard https://api.youraitools.co/pkgguard/mcp

Claude Desktop: Settings > Connectors > Add custom connector with the URL above, or in claude_desktop_config.json:

{ "mcpServers": { "pkgguard": { "command": "npx", "args": ["-y", "mcp-remote", "https://api.youraitools.co/pkgguard/mcp"] } } }

Cursor (~/.cursor/mcp.json), or one click: Add to Cursor

{ "mcpServers": { "pkgguard": { "url": "https://api.youraitools.co/pkgguard/mcp" } } }

Each free result includes an upgrade field with the calls left today. Past the daily limit the tool returns a payment_required (402) result with the paid x402 URL.

Related MCP server: Starlog

Self-host: run from source (no npm registry)

Requires Node.js 20+ (or Docker). The server has no runtime dependencies.

git clone https://github.com/Duffey234/pkgguard.git
cd pkgguard
npm ci --omit=dev
node src/mcp-stdio.js        # stdio MCP server (newline-delimited JSON-RPC 2.0)

No git? Download the source tarball from the mirror instead: curl -sL https://agentgate-source.pages.dev/x402-pkgguard/x402-pkgguard.tar.gz | tar xz.

MCP client config (use the absolute path of your checkout):

{ "mcpServers": { "pkgguard": { "command": "node", "args": ["/absolute/path/to/pkgguard/src/mcp-stdio.js"] } } }

Claude Code: claude mcp add pkgguard -- node /absolute/path/to/pkgguard/src/mcp-stdio.js

Tools scan_dependencies (manifest contents, a local file path, or a package list) and check_package (one package version). With no key the server returns the free hosted preview (verdict and counts, up to 25 packages, 10 calls/min per IP). It needs outbound HTTPS to api.youraitools.co.

Docker

docker build -t pkgguard-mcp .
docker run -i --rm pkgguard-mcp

{ "mcpServers": { "pkgguard": { "command": "docker", "args": ["run", "-i", "--rm", "pkgguard-mcp"] } } }

Paid mode (optional)

For full results in the local server, set PKGGUARD_X402_PRIVATE_KEY (or X402_PRIVATE_KEY) to the private key of a dedicated, low-balance Base wallet holding a few cents of USDC, and install the x402 client packages in your checkout:

npm install @x402/fetch @x402/evm viem

{ "mcpServers": { "pkgguard": { "command": "node", "args": ["/absolute/path/to/pkgguard/src/mcp-stdio.js"],
  "env": { "PKGGUARD_X402_PRIVATE_KEY": "0x<key of a wallet with a few cents of USDC on Base>" } } } }

The server then pays the hosted API per call over x402 (Base USDC only, capped per payment, only to the published pay-to address). The key stays in your MCP client config and is only used to sign x402 payments. Without a key, nothing is paid.

Test

npm test        # full test suite (node:test, Node 20 and 22, no network, no key)

Full source

The complete hosted service (Cloudflare Worker, x402 v2 + v1, remote MCP) is on the source mirror: https://agentgate-source.pages.dev/x402-pkgguard/

Built by YourAITools. Informational tooling, safety check only; no warranty.