Gmail Postmaster Tools — Claude Code MCP server: setup
A local MCP server reads Gmail Postmaster Tools metrics through your Google OAuth. Use it to inspect domains, delivery signals, and sender compliance.
Open on GitHubWhat Gmail Postmaster Tools does
This server connects to the Gmail Postmaster Tools API v2 and exposes tools for sign-in, domain lookup, compliance checks, and traffic reports. An agent can inspect spam rate, SPF/DKIM/DMARC authentication, TLS encryption, delivery errors, and feedback-loop data for a chosen date range. Domain and IP reputation are outside the v2 API.
It runs as a local stdio MCP server. The client starts server/index.js and receives the Google OAuth Client ID and Client Secret through GPT_CLIENT_ID and GPT_CLIENT_SECRET. Sign-in opens a browser through a local 127.0.0.1 callback, while tokens stay on the machine in ~/.gmail-postmaster-mcp/tokens.json.
Setup requires a Google Cloud project, the Gmail Postmaster Tools API, and a Desktop app OAuth client. With the OAuth app left in Testing, Google revokes refresh tokens after 7 days, so gpt_authenticate must be run again about once a week.
What it helps with
- inspect a domain’s Gmail status
- retrieve spam rates for a date range
- check SPF, DKIM, and DMARC authentication
- review TLS and delivery-error metrics
- complete local Google OAuth sign-in
Example prompts for the agent
- Run
gpt_authenticateto sign in to Gmail Postmaster Tools. - Use
list_domainsto show my registered Postmaster domains. - Check whether
example.commeets Gmail sender requirements withget_compliance_status.
How to install Gmail Postmaster Tools
Install
The MCP registry has no launch command for it: see the repository README
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Gmail Postmaster Tools
How do I install Gmail Postmaster Tools in Claude Code?
Create a Google Cloud project, enable the Gmail Postmaster Tools API, configure the OAuth consent screen, and create a Desktop app OAuth client. Connect the local stdio server with server/index.js, provide GPT_CLIENT_ID and GPT_CLIENT_SECRET, then run gpt_authenticate.
What does Gmail Postmaster Tools do?
It exposes Gmail domain data and traffic reports through MCP, including spam rate, authentication, TLS, delivery errors, and compliance signals. Access uses your own Google OAuth client.
Why do I need to authenticate again?
Google revokes refresh tokens after 7 days when the OAuth app remains in Testing. Run gpt_authenticate again after the token expires.
