Google Knowledge Graph Search MCP

Model Context Protocol server that connects Claude (or any MCP client) to Google's free public Knowledge Graph API. Search for real-world entities - people, places, organisations, concepts - and get structured data back.

Quick Navigation

Why this exists | What you get | Installation | Getting your API key | Usage examples | Parameters | Entity types | Troubleshooting

What is this? An MCP server. If you don't know what that means, you probably don't need this. If you're using Claude Desktop or another MCP-compatible client and want to search Google's knowledge database, this is for you.

Why This Exists

I built this because I needed a way for Claude to verify entity information during research workflows. Google's Knowledge Graph contains structured data about millions of real-world entities - the same data that powers those knowledge panels in Google Search results.

The Knowledge Graph Search API is completely free. No billing account, no usage costs, just a Google Cloud API key. Most developers don't seem to know this exists, which is odd given how useful it is.

This MCP gives Claude (or any MCP client) access to that database.

What You Get

Two tools for searching Google's knowledge graph:

1. Search by query - search_knowledge_graph Search for entities by name or description. Returns structured data including entity types, descriptions, Wikipedia URLs, and relevance scores.

2. Lookup by MID - lookup_knowledge_graph_entities
If you already have Machine IDs (Google's internal entity identifiers), look them up directly. Useful for entity resolution workflows.

Both return JSON with:

• Entity names and types
• Detailed descriptions (usually from Wikipedia)
• Official images and URLs
• Result scores (relevance ranking)
• Machine IDs for further lookups

Installation

NPX (Easiest)

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "google-knowledge-graph": {
      "command": "npx",
      "args": ["-y", "@houtini/google-knowledge-graph-mcp"],
      "env": {
        "GOOGLE_KNOWLEDGE_GRAPH_API_KEY": "your-api-key-here"
      }
    }
  }
}

Claude Code (CLI)

Claude Code uses a different registration mechanism -- it doesn't read claude_desktop_config.json. Use claude mcp add instead:

claude mcp add \
  -e GOOGLE_KNOWLEDGE_GRAPH_API_KEY=your-api-key-here \
  -s user \
  google-knowledge-graph -- npx -y @houtini/google-knowledge-graph-mcp

Verify with:

claude mcp get google-knowledge-graph

You should see Status: Connected.

Local Install

If you prefer running from source:

git clone https://github.com/houtini/google-knowledge-graph-mcp.git
cd google-knowledge-graph-mcp
npm install
npm run build

Then configure Claude Desktop:

{
  "mcpServers": {
    "google-knowledge-graph": {
      "command": "node",
      "args": ["C:\\path\\to\\google-knowledge-graph-mcp\\dist\\index.js"],
      "env": {
        "GOOGLE_KNOWLEDGE_GRAPH_API_KEY": "your-api-key-here"
      }
    }


... [View full README on GitHub](https://github.com/houtini-ai/google-knowledge-graph-mcp#readme)