MCP Server for Google Tag Manager

An interface to the Google Tag Manager API over MCP, in two flavours: a hosted server with Google OAuth built in, and a local CLI that runs on your own credentials.

Table of Contents

• MCP Server for Google Tag Manager
  • Table of Contents
  • Repository layout
  • Installation
    • Claude Desktop
    • Claude Code
    • VS Code
    • GitHub Copilot
    • Copilot CLI
    • Cursor
    • Antigravity
    • ChatGPT
    • Other MCP clients
    • Troubleshooting
  • Test your changes locally
    • Changes to packages/core or packages/cli
    • Changes to apps/worker
      • 1. Set up a Google Cloud OAuth client
      • 2. Configure local environment variables
      • 3. Start the server
      • 4. Point your MCP client at the local server
  • Releasing
  • Development
  • Useful resources
  • Open Source

Repository layout

npm workspace with one app and two published packages:

Tools reach Google through a GtmAuthProvider (getAccessToken(): Promise<string>) rather than through any particular session, which is what lets the same tool set back both servers — and a private one with your own auth. See the core package README.

Installation

This server comes in two flavours: Hosted server and Local CLI. Both give you the same 20 GTM tools; the difference is who handles Google auth.

If you're a contributor testing an unreleased change rather than just using the tools, skip everything below and see Test your changes locally instead.

Pick your client below. The hosted server needs the mcp-remote bridge on clients whose MCP support doesn't complete Google's OAuth flow natively; where a client does that itself, it connects straight to https://gtm-mcp.stape.ai/mcp.

Claude Desktop

Hosted server — Claude Desktop connects to remote HTTP MCP servers natively, no bridge needed. Go to Settings → Connectors → Add custom connector, set the name to gtm-mcp-server and the URL to https://gtm-mcp.stape.ai/mcp, then save. Click the new connector to complete the Google OAuth flow in the browser window that opens.

mcp-remote is also possible for the hosted server, for anyone who'd rather configure it through the JSON config file (Settings -> Developer -> Edit Config) instead of the Connectors UI — less recommended, but still supported:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://gtm-mcp.stape.ai/mcp"
      ]
    }
  }
}

Local CLI — no OAuth flow, no data through anyone else's server, you supply a service account key or a refresh token. Open Settings -> Developer -> Edit Config and add:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": ["-y", "google-tag-manager-mcp-server"],
      "env": {
        "GOOGLE_SERVICE_ACCOUNT_KEY": "{\"type\":\"service_account\", ... }"
      }
    }
  }
}

See the CLI README for every credential option.

Claude Code

Claude Code speaks HTTP directly, including the OAuth handshake, so the hosted server needs no bridge.

Hosted server:

claude mcp add --transport http gtm-mcp-server https://gtm-mcp.stape.ai/mcp

A browser window opens for the Google OAuth flow the first time a tool is used. Run /mcp inside Claude Code to confirm it connected.

Local CLI:

claude mcp add gtm-mcp-server -e GOOGLE_SERVICE_ACCOUNT_KEY='{"type":"service_account", ... }' -- npx -y google-tag-manager-mcp-server

Both write into .mcp.json / your Claude Code MCP config.

VS Code

VS Code's MCP client supports HTTP servers and their OAuth flow natively, no mcp-remote needed. Add this to .vscode/mcp.json:

Hosted server:

{
  "servers": {
    "gtm-mcp-server": {
      "type": "http",
      "url": "https://gtm-mcp.stape.ai/mcp"
    }
  }
}

Local CLI:

{
  "servers": {
    "gtm-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "google-tag-manager-mcp-server"],
      "env": {
        "GOOGLE_SERVICE_ACCOUNT_KEY": "{\"type\":\"service_account\", ... }"
      }
    }
  }
}

GitHub Copilot

GitHub Copilot Chat in VS Code uses VS Code's own MCP client, so it reads the same .vscode/mcp.json file — see VS Code above. No separate configuration is needed.

Copilot CLI

Copilot CLI also completes OAuth natively for remote HTTP servers. Add this to ~/.copilot/mcp-config.json:

Hosted server:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "type": "http",
      "url": "https://gtm-mcp.stape.ai/mcp"
    }
  }
}

Local CLI:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": ["-y", "google-tag-manager-mcp-server"],
      "env": {
        "GOOGLE_SERVICE_ACCOUNT_KEY": "{\"type\":\"service_account\", ... }"
      }
    }
  }
}

See GitHub's docs for the equivalent copilot mcp add subcommand.

Cursor

Cursor speaks HTTP directly too, no mcp-remote needed. Add this to .cursor/mcp.json (project-level) or ~/.cursor/mcp.json (global — Settings → MCP → Add new global MCP server):

Hosted server:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "url": "https://gtm-mcp.stape.ai/mcp"
    }
  }
}

A browser window opens for the Google OAuth flow the first time a tool is used.

Local CLI:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": ["-y", "google-tag-manager-mcp-server"],
      "env": {
        "GOOGLE_SERVICE_ACCOUNT_KEY": "{\"type\":\"service_account\", ... }"
      }
    }
  }
}

Antigravity

Antigravity's own OAuth support for remote HTTP servers doesn't reliably reach a token to the server yet (antigravity-cli#25), so use mcp-remote for the hosted server here too. Add this to ~/.gemini/config/mcp_config.json (global) or .agents/mcp_config.json (workspace-local) — accessible from the editor's agent panel via … → MCP Servers → Manage MCP Servers → View raw config:

Hosted server:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://gtm-mcp.stape.ai/mcp"
      ]
    }
  }
}

Local CLI:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": ["-y", "google-tag-manager-mcp-server"],
      "env": {
        "GOOGLE_SERVICE_ACCOUNT_KEY": "{\"type\":\"service_account\", ... }"
      }
    }
  }
}

ChatGPT

1. In ChatGPT, enable Developer mode: Settings → Apps & Connectors → Advanced settings → Developer mode.
2. Go to Settings → Connectors → Create, and set the server URL to https://gtm-mcp.stape.ai/mcp.
3. Set Authentication to OAuth and complete the Google login in the browser window that opens.

ChatGPT only reaches servers over the public internet, it can't spawn a local process — so there's no Local CLI option here, only the hosted server.

Other MCP clients

Any other MCP-compatible client that expects a stdio-style command/args config can use the same mcp-remote block for the hosted server:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://gtm-mcp.stape.ai/mcp"
      ]
    }
  }
}

Or the local CLI directly, with your credentials:

{
  "mcpServers": {
    "gtm-mcp-server": {
      "command": "npx",
      "args": ["-y", "google-ta