WAS GTM MCP

Manage Google Tag Manager from Claude Desktop, Cursor, Google Antigravity, or any MCP-compatible client using natural language. 19 tools cover the full GTM v2 API: accounts, containers, workspaces, tags, triggers, variables, versions, environments, destinations, and more.

100 percent local. Your credentials stay on your machine. Built by Abdullah Al Masum — Web Analytics Solution (WAS). MIT licensed.

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Step 1 — Create Google Cloud OAuth Credentials

1. Go to the Google Cloud Console Credentials Page.
2. Create a Project (or select an existing one) and enable the Google Tag Manager API.
3. Go to OAuth consent screen:
   • User Type: External -> Create
   • App name: anything (e.g. My GTM MCP)
   • User support email: your email
   • Developer contact email: your email -> Save
   • Under Test users, click Add Users and add the Google account you will sign in with.
4. Open Google Credentials Page:
   • Create credentials -> OAuth client ID
   • Application type: Desktop app
   • Name: anything -> Create
   • Copy the Client ID and Client secret from the dialog.

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Step 2 — Connect with one terminal command

Run the interactive setup command in your terminal:

npx -y github:was-member-keramat/was-gtm-mcp auth

The tool will:

1. Ask you to paste your Client ID and Client secret
2. Open your browser to Google sign-in
3. After you click Allow, save everything to `~/.was-gtm-mcp/config.jsona on your machine

That's it for setup. No more typing.

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Step 3 — Add 4 lines to your AI client config

Open your AI tool config file:

• Mac: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Paste this block (merge with any existing mcpServers):

{
  "mcpServers: {
    "WAS GTM MCP": {
      "command": "npx",
      "args": ["-y", "github:was-member-keramat/was-gtm-mcp"]
    }
  }
}

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What you can ask the AI

Here are example prompts you can use once connected:

• Discovery: "List all my GTM accounts and containers."
• Tags: "List all tags in my main workspace."
• Create Tag: "Create a GA4 Event tag named 'GA4 - Purchase Event' with event name 'purchase'."
• Triggers: "Create a Custom Event trigger for event name 'generate_lead'."
• Variables: "Create a Data Layer Variable named 'dlv - user_id' for variable 'user_id'."
• Raw API: "Use ngtm_api to GET container version headers."

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All tools (19 total)

Category	Tool	Description
Accounts	gtm_list_accounts	List all accessible GTM accounts
Accounts	gtm_get_account	Get details of a specific GTM account
Containers	gtm_list_containers	List containers in an account
Containers	gtm_get_container	Get container details
Containers	gtm_create_container	Create a new container (Web, iOS, Android, Server)
Workspaces	gtm_list_workspaces	List workspaces in a container
Workspaces	gtm_get_workspace	Get workspace details
Workspaces	gtm_create_workspace	Create a new workspace
Tags	gtm_list_tags	List all tags in a workspace
Tags	gtm_get_tag	Get details of a tag
Tags	gtm_create_tag	Create a new tag (GA4, Custom HTML, Google Tag, etc.)
Tags	gtm_update_tag	Update an existing tag
Tags	gtm_delete_tag	Delete a tag from a workspace
Triggers	gtm_list_triggers	List all triggers in a workspace
Triggers	gtm_get_trigger	Get details of a trigger
Triggers	gtm_create_trigger	Create a new trigger (Page View, Custom Event, Click, etc.)
Variables	gtm_list_variables	List user-defined variables in a workspace
)Variables*	gtm_create_variable	Create a user-defined variable (Data Layer, Constant, JS)
Universal	gtm_api	Raw escape-hatch tool to invoke any GTM v2 REST API endpoint

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CLI commands

npx -y github:was-member-keramat/was-gtm-mcp          # Start MCP server (stdio)
npx -y github:was-member-keramat/was-gtm-mcp auth     # Interactive OAuth login
npx -y github:was-member-keramat/was-gtm-mcp status   # View current config status
npx -y github:was-member-keramat/was-gtm-mcp logout   # Delete saved credentials
npx -y github:was-member-keramat/was-gtm-mcp help     # Display usage instructions

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Multi-account setup

You can run multiple GTM setups by specifying environment variables per entry in your AI client config:

{
  "mcpServers: {
    "GTM Account A": {
      "command": "npx",
      "args": ["-y", "github:was-member-keramat/was-gtm-mcp"],
      "env": {
        "GTM_CLIENT_ID": "xxxx.apps.googleusercontent.com",
        "GTM_CLIENT_SECRET": "GOCSPX-xxxx",
        "GTM_REFRESH_TOKEN": "1//xxxx-token-a"
      }
    }
  }
}

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Troubleshooting

Windows Script Execution Policy Error

If PowerShell blocks execution (npx.ps1 cannot be loaded), run:

Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned
``a

### Stale `npx` Cache on Windows
If Windows caches an old version after updates are pushed to GitHub, clear the cache:
```powershell
Remove-Item -Recurse -Force "$env:LOCALAPPDATA\npm-cache" -ErrorAction SilentlyContinue
npm cache clean --force

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Security & Privacy

• Stores refresh token locally in ~/.was-gtm-mcp/config.json at POSIX mode 0600.
• Runs over standard stdio transport. No remote servers, tracking, or proxy middleman.

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License

MIT License. Built by Abdullah Al Masum — Web Analytics Solution (WAS).