Borrowing it
Nothing to install: this file belongs to p-l-ta/mail-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/p-l-ta/mail-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/p-l-ta/mail-mcpWrote 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.
[](https://agentmods.dev/instructions/p-l-ta/mail-mcp/claude-md)<a href="https://agentmods.dev/instructions/p-l-ta/mail-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/p-l-ta/mail-mcp/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.
<a href="https://agentmods.dev/instructions/p-l-ta/mail-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/p-l-ta/mail-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00526 | $0.00526 |
| Opus 5 | $0.00263 | $0.00263 |
| Sonnet 5 | $0.00105 | $0.00105 |
| Haiku 4.5 | $0.00053 | $0.00053 |
Grade A, and why
mail-mcp 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.
mail-mcp
Local MCP server that exposes Mail.app to Claude Cowork, giving Cowork Gmail-connector-like behavior across all mail accounts configured in Mail.app (iCloud, Exchange, IMAP, etc.).
Architecture
- Search & read: Spotlight (
mdfind) + direct.emlxparsing withmailparser. Fast, structured, no AppleScript text-scraping. - Actions (send, reply, flag, move): AppleScript via
osascript, run from temp script files (never inline strings — escaping is a footgun). - Transport: stdio. Claude Desktop bridges this into Cowork via its SDK layer.
Layout
src/server.ts— MCP server entry, tool registrationsrc/tools/— one file per tool (search, read, send, reply, flags, etc.)src/lib/applescript.ts— temp-file runnersrc/lib/emlx.ts— Apple's emlx wrapper around RFC-822src/lib/spotlight.ts— mdfind query builderprototype.js— original single-file sketch, reference only
Conventions
- TypeScript, ES modules, Node 20+
- Zod schemas for every tool input
- Tool outputs are JSON strings inside
{ type: "text" }content blocks - AppleScript is generated as full scripts written to tmp files, then executed
with
execFile("osascript", [path]). Never useosascript -ewith template strings. - Every tool has a vitest unit test with mocked
execFile/mdfind/ fs
Permissions required at runtime
- Automation → Mail.app (System Settings → Privacy & Security → Automation)
- Full Disk Access for the node binary (to read ~/Library/Mail/)
Testing
npm test— vitestnpm run dev— tsx watch on src/server.ts (manual MCP testing via inspector)- Use
npx @modelcontextprotocol/inspector node dist/server.jsfor interactive testing
Out of scope
- Gmail (Cowork already has a connector for that)
- Remote/HTTP transport (this is a local stdio server bridged through Desktop)
- Rendering HTML email bodies (return text/plain; expose HTML availability flag only)
Node version
This project requires Node 20+ (see .nvmrc). If using fnm: fnm use.
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.
- 8d ago First seen · 54 lines · 526 tokens per session scan A 9b3b6d53a57c
mail-mcp CLAUDE.md is an instructions file published in the GitHub repository p-l-ta/mail-mcp (1 stars, last pushed 2mo ago), licensed MIT. It adds 526 tokens to every session, about $0.0026 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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