@registry/mcp - Multi-Registry Package Search

A unified tool to search across multiple JavaScript/TypeScript package registries including npm, JSR, Deno, and more. Auto-detects the appropriate registry and provides comprehensive library information.

@registry/mcp is a powerful Model Context Protocol (MCP) server that provides AI assistants with comprehensive package registry tools. It enables searching, analyzing, and managing packages across npm, JSR, Deno, and multiple CDN providers.

Features

• 🔍 Search packages across multiple registries
• 📦 Get CDN import URLs for packages
• 🔒 Check package vulnerabilities
• 📊 Analyze bundle sizes and dependencies
• ⚙️ Generate install/update/remove commands
• 🌐 Access CDN providers (unpkg, jsdelivr, skypack, esm.sh, etc.)

Installation & Setup

Add this MCP server to your MCP-compatible client (like Cursor, Claude Desktop, etc.):

For Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "@registry/mcp": {
      "command": "deno",
      "args": ["run", "--allow-net", "--allow-env", "jsr:@registry/mcp/mcp"]
    }
  }
}

Optional: Set default registry provider

{
  "mcpServers": {
    "@registry/mcp": {
      "command": "deno",
      "args": ["run", "--allow-net", "--allow-env", "jsr:@registry/mcp/mcp"],
      "env": {
        "REGISTRY_MCP_PROVIDER": "npm"
      }
    }
  }
}

Valid values: npm, jsr, deno (or omit for auto-detection)

Available MCP Tools

🔍 Search Tools

search_packages

When to use: Search for packages with automatic registry detection.

Input:

{
  "query": "lodash",
  "limit": 20
}

Returns:

• Formatted text with emoji-enhanced results
• JSON with package details (name, version, description, downloads, etc.)

Example:

📦 NPM Results
Query: "lodash"
Total: 1 packages

1. lodash @4.17.21
   A modern JavaScript utility library delivering modularity, performance, & extras.
   🔗 https://www.npmjs.com/package/lodash
   📥 50,000,000 downloads

---

search_all_registries

When to use: Search across all registries (npm, JSR, Deno) simultaneously to find packages.

Input:

{
  "query": "express",
  "limit": 10
}

Returns:

• Results from npm, JSR, and Deno in formatted text
• JSON array with results from each registry

---

search_npm / search_jsr / search_deno

When to use: Search a specific registry when you know which one to target.

Input:

{
  "query": "react",
  "limit": 20
}

Returns: Formatted search results from the specified registry

---

🌐 CDN Tools

get_cdn_imports

When to use: Get CDN import URLs for a package to use in browsers or Deno without bundlers.

Input:

{
  "packageName": "lodash",
  "version": "4.17.21",
  "registry": "npm"
}

Returns:

🌐 CDN Imports for lodash
Version: 4.17.21
Registry: npm

⭐ Recommended:
🚀 skypack
   URL: `https://cdn.skypack.dev/lodash@4.17.21`
   Type: ESM (minified)
   Optimized ESM packages with automatic bundling

📋 All Available CDN Imports:
1. 📦 unpkg - https://unpkg.com/lodash@4.17.21
2. ⚡ jsdelivr - https://cdn.jsdelivr.net/npm/lodash@4.17.21
3. 🚀 skypack - https://cdn.skypack.dev/lodash@4.17.21
4. ✨ esm.sh - https://esm.sh/lodash@4.17.21
...

Supported CDNs:

• 📦 unpkg - Fast, global CDN
• ⚡ jsdelivr - Fast, reliable CDN
• ☁️ cdnjs - Cloudflare CDN
• 🚀 skypack - Optimized ESM with bundling
• ✨ esm.sh - Fast ESM with TypeScript support
• 📚 jsr.io - Direct JSR imports
• 🦕 deno.land - Direct Deno imports

---

search_cdn

When to use: Search for packages available on CDN providers.

Input:

{
  "query": "react",
  "provider": "all",
  "limit": 20
}

Provider options: cdnjs, unpkg, jsdelivr, skypack, esm.sh, or all

Returns: Search results with CDN URLs for each package

---

🔒 Security & Analysis Tools

check_vuln

When to use: Check if a package has known security vulnerabilities before installing.

Input:

{
  "packageName": "express",
  "registry": "npm"
}

Returns:

🔒 Security Check for express
Registry: npm

⚠️ Found 2 vulnerability/vulnerabilities:
   🔴 Critical: 0
   🟠 High: 1
   🟡 Moderate: 1
   🟢 Low: 0

Details:
1. 🟠 CVE-2022-24999 - Express vulnerability
   Package: express
   Affected: <4.18.0
   Patched: >=4.18.0
   🔗 https://nvd.nist.gov/vuln/detail/CVE-2022-24999

Note: Full vulnerability checking requires running npm audit locally after installation.

---

check_bundle_size

When to use: Check the bundle size of a package to understand its impact on your application.

Input:

{
  "packageName": "lodash",
  "version": "4.17.21"
}

Returns:

📦 Bundle Size for lodash
Version: 4.17.21

Minified: 71.23 KB
Gzipped: 24.56 KB
Brotli: 22.10 KB

---

📊 Dependency Analysis Tools

analyze_dependency

When to use: Get a comprehensive analysis of a package's dependencies (counts, types, etc.).

Input:

{
  "packageName": "express",
  "registry": "npm"
}

Returns:

{
  "package": "express",
  "registry": "npm",
  "totalDependencies": 45,
  "directDependencies": 30,
  "devDependencies": 15,
  "peerDependencies": 0,
  "optionalDependencies": 0,
  "hasVulnerabilities": false
}

---

dependency_tree

When to use: Get the full dependency tree of a package to understand what it depends on.

Input:

{
  "packageName": "express",
  "version": "4.18.2"
}

Returns: Complete dependency tree with all nested dependencies

---

peer_deps

When to use: Check peer dependencies that need to be installed separately.

Input:

{
  "packageName": "react-dom",
  "registry": "npm"
}

Returns:

{
  "package": "react-dom",
  "peerDependencies": {
    "react": "^18.0.0"
  },
  "registry": "npm"
}

---

check_outdated

When to use: Generate a command to check for outdated packages in your project.

Input:

{
  "registry": "npm",
  "workspace": "./my-project"
}

Returns:

{
  "command": "cd ./my-project && npm outdated --json",
  "registry": "npm"
}

---

⚙️ Package Management Tools

install

When to use: Generate install commands for packages.

Input:

{
  "packageName": "lodash",
  "version": "4.17.21",
  "dev": false,
  "registry": "npm",
  "workspace": "./my-project"
}

Returns:

{
  "success": true,
  "message": "Install command generated for npm",
  "registry": "npm",
  "command": "cd ./my-project && npm install lodash@4.17.21 --save"
}

---

remove

When to use: Generate remove/uninstall commands.

Input:

{
  "packageName": "lodash",
  "registry": "npm"
}

Returns: Command to remove the package

---

update

When to use: Generate update commands for packages.

Input:

{
  "packageName": "lodash",
  "latest": true,
  "registry": "npm"
}

Returns: Command to update the package (or all packages if packageName is omitted)

---

ci

When to use: Generate CI commands for clean dependency installation.

Input:

{
  "registry": "npm",
  "workspace": "./my-project"
}

Returns:

{
  "command": "cd ./my-project && npm ci",
  "registry": "npm"
}

---

🔧 Utility Tools

detect_registry

When to use: Detect which registry a package belongs to.

Input:

{
  "packageName": "@std/path"
}

Returns:

{
  "packageName": "@std/path",
  "registry": "jsr"
}

---

get_registry_info

When to use: Get metadata about a registry (URLs, endpoints, etc.).

Input:

{
  "registry": "npm"
}

Returns:

{
  "name": "npm",
  "url": "https://www.npmjs.com",
  "searchUrl": "https://registry.npmjs.org/-/v1/search",
  "packageUrl": "https://www.npmjs.com/package/{name}"
}

---

Registry Auto-Detection

The MCP server automatically detects the registry based on package name patterns:

• JSR: Packages starting with @ and containing / (e.g., @std/path)
• Deno: URLs containing deno.land or starting with https://
• npm: Default for most other cases
• Explicit: You can override by passing registry parameter

Registry Provider Selection

You can set a default registry provider via environment variable:

{
  "mcpServers": {
    "@registry/mcp": {
      "command": "deno",
      "args": ["run", "--allow-net", "--allow-env", "jsr:@registry/mcp/mcp"],
      "env": {
        "REGISTRY_MCP_PROVIDER": "npm"
      }
    }
  }
}

Or override per-tool call by passing the registry parameter.

Response Format

All tools return responses in two formats:

1. Formatted text - Human-readable with emojis and structure (for AI assistants to read)
2. JSON - Structured data for programmatic use

Example:

📦 NPM Results
Query: "lodash"
...

{
  "query": "lodash",
  "registry": "npm",
  "packages": [...]
}

When to Use Each Tool

Tool	Use Case
search_packages	General package search with auto-detection
search_all_registries	Find packages across all registries
get_cdn_imports	Get CDN URLs for browser/Deno usage
check_vuln	Security audit before installation
check_bundle_size	Performance planning
analyze_dependency	Understand package complexity
dependency_tree	See full dependency graph
peer_deps	Check required peer dependencies
install / remove / update	Generate package management commands
ci	Generate CI/CD commands
detect_registry	Identify package source
search_cdn	Find packages on CDN providers

CLI Usage (Optional)

This package is primarily designed as an MCP server for AI assistants. The CLI is provided for convenience but has limited functionality compared to the MCP server.

Why npx doesn't work

npx @registry/mcp doesn't work because:

• This is a Deno package (TypeScript), not a Node.js/npm package
• npx requires packages to be published to npm with Node.js-compatible binaries
• The package uses Deno-specific features and APIs

Using the CLI with Deno

Option 1: Direct Deno execution (Recommended)

deno run --allow-net --allow-env jsr:@registry/mcp/cli search lodash
deno run --allow-net --allow-env jsr:@registry/mcp/cli search-all express
deno run --allow-net --allow-env jsr:@registry/mcp/cli search-npm react
deno run --allow-net --allow-env jsr:@registry/mcp/cli search-jsr @std/encoding
deno run --allow-net --allow-env jsr:@registry/mcp/cli search-deno oak
deno run --allow-net --allow-env jsr:@registry/mcp/cli detect @std/path

Option 2: Install globally with Deno (Recommended for frequent use)

# Install once globally
deno install --allow-net --allow-env --name registry-mcp jsr:@registry/mcp/cli

# Then use directly from anywhere
registry-mcp search lodash
registry-mcp search-all express
registry-mcp search-npm react
registry-mcp search-jsr @std/encoding
registry-mcp search-deno oak
registry-mcp detect @std/path

Available CLI Commands:

• search <query> - Auto-detect and search registry
• search-all <query> - Search all registries
• search-npm <query> - Search npm only
• search-jsr <query> - Search JSR only
• search-deno <query> - Search Deno only
• detect <package> - Detect registry for package

Note: For full functionality (CDN imports, vulnerability checking, bundle size, dependency analysis, etc.), use the MCP server instead of the CLI.

License

MIT

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Links

• JSR Package
• GitHub Repository