google-mcp-server CLAUDE.md

google-mcp-server CLAUDE.md is an instructions file for coding agents from ngs/google-mcp-server. It costs 2,141 tokens per session, scanned A, original, MIT.

Repository instructions for developing a Go-based MCP server that connects AI agents to Google Calendar, Drive, Gmail, Sheets, and Docs through OAuth 2.0.

In plain words
What is it for?
Use them when modifying, testing, or reviewing this Google API integration project.
Why use it?
They define safe testing and coding practices, including using the server interface rather than writing separate programs to call Google APIs.

Instructions file

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/ngs/google-mcp-server/claude-md
Clone the repo
git clone --depth 1 https://github.com/ngs/google-mcp-server

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for google-mcp-server CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/ngs/google-mcp-server/claude-md.svg)](https://agentmods.dev/instructions/ngs/google-mcp-server/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/ngs/google-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/ngs/google-mcp-server/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,141 This file is loaded in full into every session.
When invoked 2,141 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.02141 $0.02141
Opus 5 $0.01071 $0.01071
Sonnet 5 $0.00428 $0.00428
Haiku 4.5 $0.00214 $0.00214

Measured 4d ago against content hash 3a7e1353a010, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

google-mcp-server CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 245 lines

How it starts

The opening of the file, as written. The whole thing — 245 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claude Code Instructions for Google MCP Server

This document contains specific instructions for Claude Code when working with the Google MCP Server project.

Project Overview

This is a Go-based MCP (Model Context Protocol) server that integrates with Google APIs including Calendar, Drive, Gmail, Sheets, and Docs. The server uses OAuth 2.0 for authentication and provides tools and resources accessible through MCP-compatible clients.

Development Guidelines

Important Rules

  • NEVER create test scripts or demo scripts - Testing should be done through the MCP interface or existing tools
  • DO NOT create standalone test programs - Use the MCP server directly for testing functionality
  • AVOID creating example/demo files - The MCP server itself is the interface for testing
  • NEVER write Go programs to call Google APIs directly - Always use MCP tools or existing server functionality
  • DO NOT create any executable programs - If MCP tools are unavailable, investigate why and report the issue instead

Code Style

  • Use Go idioms and best practices
  • Follow the existing code structure and patterns
  • Keep functions focused and single-purpose
  • Use meaningful variable and function names
  • Add error handling for all API calls

Testing

Before committing any changes, always run:

go test ./...
go fmt ./...

Building

To build the project:

go build -o google-mcp-server .

Service Implementation Status

Fully Implemented with Multi-Account Support

  • Calendar Service (calendar/): All 8 tools + multi-account support via calendar/multi_account.go
  • Drive Service (drive/): All 19 tools including Markdown support + multi-account support via drive/multi_account.go
  • Gmail Service (gmail/): 3 core tools + multi-account support via gmail/multi_account.go
  • Account Management (accounts/): 5 tools for managing multiple Google accounts

Basic Implementation

  • Sheets Service (sheets/): 12 tools (spreadsheet create/get, values get/update/append/clear, sheet duplicate/add/delete/update, dimension insert/delete) + multi-account support via sheets/multi_account.go
  • Docs Service (docs/): 3 basic tools (get/create/update documents)

Read the full file on GitHub · 245 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 245 lines · 2,141 tokens per session scan A 3a7e1353a010

Subscribe to this mod's changes

google-mcp-server CLAUDE.md is an instructions file published in the GitHub repository ngs/google-mcp-server (2 stars, last pushed 12d ago), licensed MIT. It adds 2,141 tokens to every session, about $0.0107 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.