gmail-mcp-server: Instructions file for Claude Code

CLAUDE.md

gmail-mcp-server CLAUDE.md is an instructions file for Claude Code from stevesimpson418/gmail-mcp-server. It costs 916 tokens per session, scanned A, original, MIT.

A set of Claude Code instructions for a Gmail MCP server, which gives an agent tool-based access to Gmail through Google’s authentication system. The server runs locally, keeping tokens and credentials on the user’s computer.

In plain words
What is it for?
It is for developing and maintaining the Gmail MCP server, including its Python code, authentication, Gmail API integration, tests, and checks.
Why use it?
It tells the agent how the project is organized and how to install, test, format, and validate changes using its required tools.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md.

This is stevesimpson418/gmail-mcp-server's own configuration. It tells Claude Code how to work on gmail-mcp-server itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything gmail-mcp-server configures →

Reuse

Borrowing it

Nothing to install: this file belongs to stevesimpson418/gmail-mcp-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/stevesimpson418/gmail-mcp-server/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/stevesimpson418/gmail-mcp-server

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
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<a href="https://agentmods.dev/instructions/stevesimpson418/gmail-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/stevesimpson418/gmail-mcp-server/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 916 This file is loaded in full into every session.
When invoked 916 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00916 $0.00916
Opus 5 $0.00458 $0.00458
Sonnet 5 $0.00183 $0.00183
Haiku 4.5 $0.00092 $0.00092

Measured 7d ago against content hash b0c158643c2f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

gmail-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 7d 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 · 83 lines

How it starts

The opening of the file, as written. The whole thing — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md — Project Intelligence

Project Overview

Gmail MCP server built with FastMCP. Provides Claude with native tool-level access to Gmail via OAuth2. Runs locally via stdio transport — all tokens and credentials stay on the user's machine.

Tech Stack

  • Language: Python 3.14+
  • Package manager: uv (never use pip directly)
  • MCP framework: FastMCP 2.0+
  • Google APIs: google-api-python-client, google-auth-oauthlib
  • Linting/formatting: Ruff (config in ruff.toml)
  • Testing: pytest + pytest-cov
  • Git hooks: Lefthook (ruff, markdownlint, shellcheck, shfmt, commitlint)
  • CI: GitHub Actions (lint + test matrix)

Project Structure

src/gmail_mcp/                # Source code (src layout)
  server.py                   # Entry point — FastMCP init + tool registration
  tools.py                    # MCP tool definitions (register_gmail_tools)
  client.py                   # Gmail API client wrapper
  auth.py                     # OAuth2 authentication flow
  exceptions.py               # Custom exception classes
tests/                        # Pytest test suite
  conftest.py                 # Shared fixtures (mock service, sample messages)
  test_auth.py                # OAuth authentication tests
  test_client.py              # Gmail client tests
  test_tools.py               # Tool registration tests
credentials/                  # OAuth credentials (gitignored)

Key Commands

uv sync --dev                                          # Install all deps
uv run pytest -v                                       # Run tests
uv run pytest --cov=gmail_mcp --cov-report=term-missing  # Coverage
uv run ruff check src/ tests/                          # Lint
uv run ruff format src/ tests/                         # Format
lefthook install                                       # Install git hooks

Conventions

  • Commits: Conventional Commits format — type(scope): description
  • Line length: 100 characters
  • Quotes: Double quotes (enforced by ruff)
  • Imports: Sorted by isort via ruff, first-party package declared in ruff.toml
  • Tests: Mirror source structure, use fixtures in conftest.py
  • Entry point: server.py:main() — registered as console script in pyproject.toml

Read the full file on GitHub · 83 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. 7d ago First seen · 83 lines · 916 tokens per session scan A b0c158643c2f

Subscribe to this mod's changes

gmail-mcp-server CLAUDE.md is an instructions file published in the GitHub repository stevesimpson418/gmail-mcp-server (1 stars, last pushed 1mo ago), licensed MIT. It adds 916 tokens to every session, about $0.0046 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.

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