npm Registry MCP Server

@yawlabs/npmjs-mcp

Run npm registry operations from Claude Code, Cursor, and any MCP client. 64 tools covering the full registry surface: package intelligence, security audits, dependency analysis, org/team management, and the write ops that normally fight you locally (npm deprecate, npm dist-tag, npm owner, npm unpublish).

Built and maintained by Yaw Labs.

One click adds this to your local Yaw MCP config so it's available in every Yaw Terminal session. Or install manually below.

Why this one?

Other npm MCP servers wrap npm search and call it done. This one doesn't.

• Full registry HTTP surface — 64 tools across reads, writes, orgs, teams, hooks, provenance, trusted publishers, and ops health. Not just npm view.
• Write ops that actually work in agents — npmdeprecate, npmundeprecate, npmdisttagset, npmunpublish_version go directly to the HTTP API with a Granular Access Token that has 2FA bypass. No 2FA prompts, no --otp hunts, no ENEEDAUTH from a session-bound .npmrc. (Since 2026-07-31 npm requires an interactive 2FA challenge for owner, access, team membership and grant, org membership and token changes even with 2FA bypass; for those tools the error names the exact npm command a human runs.)
• Agent-aware failure surfacing — npmcheckauth and npmpublishpreflight detect a non-interactive context and hand back a human-runnable command, and every write error names what was sent and the npm CLI equivalent, instead of looping on unrecoverable errors.
• Safety by default — npmunpublish requires confirm: true. npmownerremove blocks you from locking yourself out. npm_deprecate rejects a message over the registry's 1024-character limit before sending it.
• Ops playbook built in — npmopsplaybook returns the canonical tool-vs-CLI-vs-CI decision matrix so your agent picks the right path on the first try.
• Tool annotations — every tool declares readOnlyHint, destructiveHint, idempotentHint, and openWorldHint, so MCP clients can skip confirmation on safe ops.
• No API key required for reads — search, packages, downloads, security, dep tree, licenses all work anonymously. Auth is opt-in via NPM_TOKEN.
• Instant startup — ships as a single bundled file with zero runtime dependencies. No 5-minute node_modules install.
• Input hardening — package names, scopes, versions, dist-tags, and team names are all regex-validated against npm's actual constraints. Defends against CRLF and path-traversal in URL construction.

Quick start

1. Create .mcp.json in your project root

macOS / Linux / WSL:

{
  "mcpServers": {
    "npm": {
      "command": "npx",
      "args": ["-y", "@yawlabs/npmjs-mcp@latest"]
    }
  }
}

Windows:

{
  "mcpServers": {
    "npm": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@yawlabs/npmjs-mcp@latest"]
    }
  }
}

Why the extra step on Windows? Since Node 20, child_process.spawn cannot directly execute .cmd files (that's what npx is on Windows). Wrapping with cmd /c is the standard workaround.

2. Restart and approve

Restart Claude Code (or your MCP client) and approve the npm MCP server when prompted.

3. (Optional) Add your npm token for write operations

Shortened. The full README is on GitHub.