What is gmail-labels-mcp-server CLAUDE.md?

A set of instructions for working on a Gmail label-management MCP server. MCP is a standard for exposing tools to an AI assistant, and Gmail labels organize messages.

Use it when installing, building, running, or modifying the server's label, message-search, and authentication code.

It explains the repository's commands, file structure, conventions, and Gmail API responsibilities so changes can follow the existing design.

How YimingYAN/gmail-labels-mcp-server configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to YimingYAN/gmail-labels-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/YimingYAN/gmail-labels-mcp-server/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/YimingYAN/gmail-labels-mcp-server

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/yimingyan/gmail-labels-mcp-server/claude-md/github.svg)](https://agentmods.dev/instructions/yimingyan/gmail-labels-mcp-server/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/yimingyan/gmail-labels-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/yimingyan/gmail-labels-mcp-server/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/yimingyan/gmail-labels-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/yimingyan/gmail-labels-mcp-server/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 488 This file is loaded in full into every session.

When invoked 488 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.

Model	Per session	Once invoked
Fable 5.1	$0.00488	$0.00488
Opus 5.5	$0.00195	$0.00195
Sonnet 5.5	$0.00098	$0.00098
Haiku 4.5	$0.00049	$0.00049

Measured 2mo ago against content hash 17f4ff4dfedc, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

gmail-labels-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 2mo 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 · 37 lines

How it starts

The opening of the file, as written. The whole thing — 37 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

What This Is

MCP server that exposes Gmail label management via the Gmail REST API. Complements the official Gmail MCP connector, which lacks label/tag operations. Runs over stdio transport.

Commands

npm install          # Install dependencies
npm run build        # Compile TypeScript (tsc)
npm run dev          # Watch mode (tsc --watch)
npm run start        # Run compiled server (node dist/index.js)

No test framework is configured.

Architecture

Three-file TypeScript project using @modelcontextprotocol/sdk:

src/index.ts — Entry point. Creates McpServer, registers tools, connects stdio transport.
src/tools/labels.ts — Tool definitions. Registers 7 MCP tools with Zod input schemas and tool annotations. Each tool handler calls into the Gmail service layer.
src/services/gmail.ts — Gmail REST API client. Stateless functions that take an Axios instance and call https://gmail.googleapis.com/gmail/v1. Handles label CRUD, message/thread label modification, message search, and API error formatting.
src/services/auth.ts — OAuth2 token management. Reads credentials from ~/.gmail-labels-mcp/credentials.json, caches access tokens in memory, and auto-refreshes via google-auth-library. Also supports legacy GMAIL_ACCESS_TOKEN env var.
scripts/auth.ts — One-time OAuth2 setup script. Opens browser for Google consent, saves refresh token to credentials file.

Key Conventions

ESM modules ("type": "module" in package.json, Node16 module resolution)
All imports use .js extensions (required for ESM with TypeScript)
Tool registration uses server.registerTool() with Zod schemas and MCP tool annotations (readOnlyHint, destructiveHint, etc.)
Tools return both content (text for display) and structuredContent (typed data)
Auth: OAuth2 with auto-refresh via ~/.gmail-labels-mcp/credentials.json (run npm run auth once). Falls back to GMAIL_ACCESS_TOKEN env var if credentials file not present.

Read the full file on GitHub · 37 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.

2mo ago First seen · 37 lines · 488 tokens per session scan A 17f4ff4dfedc

Subscribe to this mod's changes

gmail-labels-mcp-server CLAUDE.md is an instructions file published in the GitHub repository YimingYAN/gmail-labels-mcp-server (0 stars, last pushed 8mo ago), licensed MIT. It adds 488 tokens to every session, about $0.0020 per session on Opus 5.5. 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.

Productivity

gmail-labels-mcp-server CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
gmail-labels-mcp-server CLAUDE.mdYimingYAN/gmail-labels-mcp-server	Instructions file	0	8mo ago	MIT	A	488	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

gmail-labels-mcp-server: Instructions file for Claude Code