Installed Version

Ground your coding agent on the versions it actually has, not the blend of every version it was trained on.

An MCP server that tells Claude, Cursor, and any MCP client the exact version of each dependency installed in the current project — read from node_modules and the lockfile, fully offline. Studies put AI-generated deprecated-API usage at 25–38%; the root cause is that the model doesn't know which version is on disk. This fixes that.

Why this exists

Ask an agent to use a library and it writes code against a smear of every version it ever saw — calling methods that were renamed, passing options that were removed. The truth is sitting in your node_modules. This server reads it and pins the agent to the real number before it writes the call. It complements pkg-api-mcp (what the API is) and breaking-changes-mcp (what changed between versions).

Tools

Tool	What it does
installed_version	Exact installed version of one package (from node_modules, else lockfile) + declared range + drift vs npm latest.
resolve_imports	Pass the packages you're about to import; get each one's installed version in a single grounding call.
project_versions	Every dependency's installed version from the lockfile — whole tree or direct-only, with a substring filter.

Core resolution is 100% local. Only the optional latest drift check touches the network.

Quick start

npx installed-version-mcp

Claude Code

# point it at the project you're working in
claude mcp add installed-version -e INSTALLED_VERSION_PROJECT="$(pwd)" -- npx -y installed-version-mcp

Claude Desktop / Cursor / Windsurf / any MCP client

{
  "mcpServers": {
    "installed-version": {
      "command": "npx",
      "args": ["-y", "installed-version-mcp"],
      "env": { "INSTALLED_VERSION_PROJECT": "/abs/path/to/your/project" }
    }
  }
}

Or skip the env var and pass projectDir on each call.

Example prompts

• "Before you touch the router code, check the installed version of react-router-dom with installed-version."
• "What version of zod is actually installed here, and is it behind latest?"
• "Resolve the installed versions of everything I'm importing in this file first."

Config

Env var	Default	Purpose
INSTALLED_VERSION_PROJECT	server cwd	Default project root (folder with package.json). Overridable per call via projectDir.
NPM_REGISTRY	https://registry.npmjs.org	Registry for the optional latest-version drift check.

How it works

package name + projectDir
   │
   ├─ node_modules/<pkg>/package.json  ── authoritative installed version
   │      └─ else package-lock.json (v2/v3 packages map, or v1 tree)
   ├─ package.json  ── declared range
   └─ (optional) registry /latest  ── drift

Develop

npm install
npm run build
node dist/index.js

Caveats

• installed_version works from node_modules alone; project_versions needs an npm package-lock.json. Yarn/pnpm lockfiles aren't parsed yet (PRs welcome) — but node_modules lookups still work under any package manager.
• Transitive dependencies show source: lockfile and no declared range — that's expected.

License

MIT © Anicodeth