Google Knowledge Graph

io.github.houtini-aiPublished by GitHub account houtini-aiv1.0.10Updated Oct 25, 2026

Search Google's Knowledge Graph for structured information about real-world entities

VerifiedSTDIODesktop onlyWeb Search & ScrapingKnowledge & Memory

Overview

AI-generated overview

Lets an assistant search Google's Knowledge Graph for structured facts about people, places, organizations and concepts, and look up entities by MID.

What you can do
  • Search entities by name or topic, with optional language and entity-type filters and a result limit
  • Look up specific entities by their Machine IDs (MIDs) from an earlier search
  • Return structured JSON per entity: name, types, descriptions, image and Wikipedia URL, relevance score and MID
When to use it
Useful when an assistant needs to verify or enrich entity information during research, resolve entities to Google MIDs, or pull short structured descriptions of real-world things rather than scraping web pages.
Requirements
Runs locally over stdio via the npm package (Node.js/npx) or from a built source checkout. Needs a Google Cloud API key with the Knowledge Graph Search API enabled, supplied in the GOOGLE_KNOWLEDGE_GRAPH_API_KEY environment variable. Internet access to Google's API is required.
Before you install
The API key is passed as a query parameter to Google's endpoint, so it travels with each request; restrict the key to the Knowledge Graph Search API. Queries and looked-up terms are sent to Google. The API is free with no billing, but free-tier quotas apply. Read-only: no data is written or deleted.

Installation

In SourceWeft

  1. Open Google Knowledge Graph in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

Google Knowledge Graph Search MCP

[npm version] [MCP Registry] [Known Vulnerabilities] [Socket Badge] [License: MIT] [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.

[Google Knowledge Graph MCP server]

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:

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:

bash
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:

bash
claude mcp get google-knowledge-graph

You should see Status: Connected.

Local Install

If you prefer running from source:

bash
git clone https://github.com/houtini-ai/google-knowledge-graph-mcp.gitcd google-knowledge-graph-mcpnpm installnpm run build

Then configure Claude Desktop:

json
{  "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"      }    }  }}

Windows users: Use double backslashes in paths: C:\\MCP\\...

Config location:

  • Windows: %APPDATA%\Claude\claude_desktop_config.json
  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  • Linux: ~/.config/Claude/claude_desktop_config.json

Getting Your API Key

Google's Knowledge Graph Search API is free - no billing account, no card, no quota to unlock.

  1. Go to Google Cloud Console
  2. Create a new project (or select an existing one)
  3. Enable "Knowledge Graph Search API" in the API Library
  4. Navigate to "Credentials" and create an API key
  5. (Optional but recommended) Restrict the key to Knowledge Graph Search API only

That's it. No credit card, no billing setup.

Usage Examples

Once installed and Claude Desktop is restarted, you can:

Basic entity search:

Search the knowledge graph for "Marie Curie"

Entity type filtering:

Search knowledge graph for "Python" with types ["ComputerLanguage"]

Multiple results:

Search knowledge graph for "Paris" limit 5

Lookup by MID:

Look up knowledge graph entity /m/0dl567

The MCP returns structured JSON that Claude can parse. You'll get entity names, types, descriptions, URLs, and relevance scores.

What Gets Returned

Example response structure:

json
{  "entities": [    {      "mid": "/m/0dl567",      "name": "Taylor Swift",      "type": ["Person", "Thing"],      "description": "American singer-songwriter",      "detailedDescription": "Taylor Alison Swift is an American singer-songwriter...",      "image": "https://...",      "url": "http://en.wikipedia.org/wiki/Taylor_Swift",      "resultScore": 4258.07    }  ],  "count": 1}

Parameters

search_knowledge_graph

  • query (required): Search term
  • languages (optional): Language codes array, e.g. ["en"]
  • types (optional): Entity types to filter by, e.g. ["Person", "Organization"]
  • limit (optional): Max results (default 20, max 500)

lookup_knowledge_graph_entities

  • ids (required): Array of Machine IDs (MIDs), e.g. ["/m/0dl567"]
  • languages (optional): Language codes array

Common Entity Types

The Knowledge Graph uses schema.org types. Common ones:

  • Person - Individual people
  • Organization - Companies, institutions
  • Place - Locations, geographical entities
  • Event - Historical or current events
  • CreativeWork - Books, films, music, art
  • Product - Commercial products
  • ComputerLanguage - Programming languages
  • SportsTeam - Sports teams
  • Country - Nations and countries
  • City - Cities and municipalities

You can combine types for more specific searches.

Troubleshooting

MCP not appearing in Claude:

  1. Check your JSON syntax - one error breaks everything
  2. Verify the path uses correct escaping (\\ on Windows)
  3. Completely restart Claude Desktop (quit, not just minimise)
  4. Check the API key environment variable spelling

"API key required" error:

  • The environment variable isn't being read
  • Check spelling: GOOGLE_KNOWLEDGE_GRAPH_API_KEY
  • Restart Claude Desktop after config changes

No results returned:

  • Try different query terms
  • Remove entity type filters to broaden search
  • Check result limit isn't set too low

400 "API key not valid":

  • API key is invalid, expired, or the wrong kind (a Google AI Studio "AQ." key won't work - it must be a Google Cloud "AIza..." key)
  • Knowledge Graph Search API isn't enabled in your Google Cloud project

Building From Source

bash
npm installnpm run build

The build process compiles TypeScript to CommonJS in dist/. No special configuration needed.

Technical Details

  • API Endpoint: https://kgsearch.googleapis.com/v1/entities:search
  • Response Format: JSON-LD with itemListElement array
  • Authentication: API key via query parameter
  • Rate Limits: Free tier quotas apply (generally 100,000 queries/day)
  • Module Format: CommonJS (compatible with Node.js MCP hosts)

Why CommonJS?

The MCP SDK uses CommonJS patterns. I've stuck with that for compatibility. If you're building your own MCP and want ES modules, that's fine - just different choices.

Contributing

If you find issues or have improvements:

  1. Check existing issues first
  2. Test your changes locally
  3. Submit a PR with clear description

I'm particularly interested in hearing about:

  • Entity types that need better handling
  • Response parsing edge cases
  • Real-world usage patterns

Licence

MIT - do what you want with it.

Author

Built by Richard Baxter (Houtini) as part of a collection of MCP servers for AI-assisted development and research workflows.

Other Houtini MCPs:

  • @houtini/gemini-mcp - Google AI chat with grounding and deep research
  • @houtini/geo-analyzer - Content optimisation for AI search engines
  • @houtini/brevo-mcp - Email marketing automation

Related

Status: Production ready, tested with Claude Desktop

Source: README.md at commit 384b208

Tools

2

search_knowledge_graph

Search Google Knowledge Graph for entities by name or topic. Returns structured information about real-world entities like people, places, organizations, and concepts from Google's public knowledge base.

Parameterslimitqueryrequiredtypeslanguages

lookup_knowledge_graph_entities

Look up specific Knowledge Graph entities by their Machine IDs (MIDs). Use this when you already know the entity IDs from a previous search. MIDs look like /m/0dl567 or /g/11b6vwtjpg.

Parametersidsrequiredlanguages

Version history

4
  1. v1.0.10LatestOct 25, 2026
  2. v1.0.9Oct 7, 2026
  3. v1.0.8Oct 2, 2026
  4. v1.0.7Sep 16, 2026

Score

90% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts
  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts