Bundler MCP Server

A Model Context Protocol (MCP) server enabling AI agents to query information about dependencies in a Ruby project's `Gemfile`. Built with

Local serverstdio

What is the Bundler MCP MCP server?

If you want an AI assistant working directly with Bundler MCP, the bundler mcp mcp server is the bridge. A Model Context Protocol (MCP) server enabling AI agents to query information about dependencies in a Ruby project's Gemfile. Built with fast-mcp.

What Bundler MCP does

A Model Context Protocol (MCP) server enabling AI agents to query information about dependencies in a Ruby project's Gemfile. Built with fast-mcp.

Tools it exposes

Once connected, the assistant can call these 3 tools directly:

  • DocumentationAvailable on RubyDoc
  • list_project_gems — The list_project_gems tool exposed by this server
  • get_gem_details — Retrieves detailed information about a specific gem, including:

Installing the bundler mcp mcp server

The server is distributed via npm as @modelcontextprotocol/inspector, so most clients can run it without a manual build step. Add it to your MCP client's configuration and restart the client to pick it up — the copy-paste configs for Claude Desktop, Claude Code and Cursor are on this page.

Configuration

The server reads 2 environment variables: BUNDLER_MCP_LOG_FILE, BUNDLE_GEMFILE. Keep credentials in your client's env block or a secrets manager rather than committing them.

Where it fits

Knowledge and memory servers address the most frustrating trait of language models — walking into every conversation with no recollection of the last one. Bundler MCP sits in that group, and the shape of its toolset — Documentation, list_project_gems, get_gem_details — tells you what it is really for. Worth comparing against the other knowledge memory servers in this directory before you commit to one, since several overlap in scope but differ sharply in setup cost and permissions.

Practical notes

  • This server runs locally, so it operates with whatever access your machine and its credentials already have. Scope that deliberately rather than by default.
  • Maintained by subelsky.
  • MCP clients ask for confirmation before each tool call by default. Keep that on while you learn what the bundler mcp mcp server actually does with your data.
  • Every entry in this directory is reviewed by hand before it goes live, and details are checked against the project's own documentation.

Available tools

ToolWhat it does
Documentation[Available on RubyDoc](https://www.rubydoc.info/gems/bundler_mcp/)
list_project_gemsThe list_project_gems tool exposed by this server.
get_gem_detailsRetrieves detailed information about a specific gem, including:

How to install the Bundler MCP MCP server

{
  "mcpServers": {
    "bundler-mcp": {
      "command": "/Users/mike/my_project/bin/bundler_mcp"
    }
  }
}

Configuration as documented by the project. Restart the client after saving.

Configuration

VariableDescriptionRequired
BUNDLER_MCP_LOG_FILEConfiguration value read at startup.Optional
BUNDLE_GEMFILEConfiguration value read at startup.Optional

Example prompts to try

  • Use Bundler MCP to Documentation.
  • Use Bundler MCP to list project gems.
  • Use Bundler MCP to get gem details.

Frequently asked questions

It connects Bundler MCP to MCP-compatible AI assistants such as Claude and Cursor, exposing 3 tools (Documentation, list_project_gems, get_gem_details) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Bundler MCP directly.