Get insights about packages across npm, PyPI, and Hex registries: metadata, security vulnerabilities, dependencies, and quality metrics. Works standalone or as an MCP server for AI assistants like Claude and Cursor.

Installation

The easiest way to get started is using npx — no installation required:

npx @pkgseer/cli --help

For frequent use, install globally:

npm install -g @pkgseer/cli

Getting Started

1. Authenticate (Recommended)

While you can use PkgSeer without authentication, logging in gives you higher rate limits and access to all features:

pkgseer login

This opens your browser to authenticate with your PkgSeer account. Your credentials are stored securely in ~/.pkgseer/.

To check your authentication status:

pkgseer auth status

2. Use with AI Assistants

The main use case for this CLI is as an MCP (Model Context Protocol) server that gives AI assistants access to package intelligence.

Cursor IDE

Add this to your .cursor/mcp.json file:

{
  "mcpServers": {
    "pkgseer": {
      "command": "npx",
      "args": ["-y", "@pkgseer/cli", "mcp"]
    }
  }
}

Claude Desktop

Add this to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "pkgseer": {
      "command": "npx",
      "args": ["-y", "@pkgseer/cli", "mcp"]
    }
  }
}

Once configured, your AI assistant can use tools to answer questions like:

"What security vulnerabilities does lodash have?"
"Compare react vs preact vs solid-js"
"What are the dependencies of express?"

Prompt for AI Assistants

To help your AI assistant use PkgSeer proactively, add this to your project rules (.cursor/rules, AGENTS.md, or similar):

When working with dependencies:

- Use PkgSeer MCP tools to check for security vulnerabilities before adding new packages
- Compare package alternatives with compare_packages when multiple options exist
- Review package quality metrics to ensure dependencies are well-maintained

Available Tools

When running as an MCP server, the following tools are available to AI assistants:

Tool	What it does
`package_summary`	Get package metadata, latest versions, security advisories, and quickstart examples
`package_vulnerabilities`	Find known security vulnerabilities affecting a package
`package_dependencies`	Explore the dependency tree (direct and transitive)
`package_quality`	View quality metrics and maintenance scores
`compare_packages`	Compare multiple packages side-by-side

All tools work with npm, PyPI, and Hex registries.

CLI Commands

pkgseer --help           # Show all available commands
pkgseer --version        # Show version number

pkgseer login            # Authenticate with your PkgSeer account
pkgseer logout           # Sign out and clear stored credentials
pkgseer auth status      # Check if you're logged in and token validity

pkgseer mcp              # Start the MCP server (for AI assistant integration)