Borrowing it
Nothing to install: this file belongs to wyattjoh/calendar-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/wyattjoh/calendar-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/wyattjoh/calendar-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/wyattjoh/calendar-mcp/claude-md)<a href="https://agentmods.dev/instructions/wyattjoh/calendar-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/wyattjoh/calendar-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/wyattjoh/calendar-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/wyattjoh/calendar-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 | $0.00567 | $0.00567 |
| Opus 5 | $0.00283 | $0.00283 |
| Sonnet 5 | $0.00113 | $0.00113 |
| Haiku 4.5 | $0.00057 | $0.00057 |
Grade A, and why
calendar-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 10d 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 — 73 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.
Commands
Development Commands
deno task fmt- Format all code with Deno formatterdeno task lint- Run Deno linter on all codedeno task check- Type check all TypeScript code
Package-specific Commands (in packages/calendar-mcp/)
deno task dev- Run the MCP server in development mode (requires macOS for Calendar access)deno task start- Run the MCP server
Publishing
deno publish- Publish packages to JSR (requires proper permissions)
Architecture
This is a Deno monorepo with two packages:
packages/calendar/
Core calendar library that provides direct access to macOS Calendar database:
- mod.ts: Main export file exposing all public APIs
- src/client.ts: Database client with query functions for calendar events
- src/types.ts: TypeScript interfaces for calendar events and options
- src/utils.ts: Utility functions for formatting events
- src/constants.ts: Constants including database path and Core Data epoch
Key features:
- Read-only access to macOS Calendar database at
~/Library/Calendars/Calendar.sqlitedb - Functions for retrieving recent, upcoming, and date-range events
- Event search and detail retrieval
- Support for filtering rescheduled events
packages/calendar-mcp/
Model Context Protocol (MCP) server that exposes calendar functionality:
- mod.ts: MCP server implementation with tool registrations
- Wraps the calendar library functions as MCP tools
- Provides 6 tools: get-recent-events, get-upcoming-events, get-events-by-date-range, search-events, get-todays-events, get-event-details
- Uses stdio transport for MCP communication
Dependencies
- @db/sqlite: SQLite database access for reading Calendar.sqlitedb
- @modelcontextprotocol/sdk: MCP SDK for server implementation
- zod: Schema validation for MCP tool inputs
Database Schema
The code queries the macOS Calendar SQLite database with these key tables:
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.
- 10d ago First seen · 73 lines · 567 tokens per session scan A 15123593e92f
calendar-mcp CLAUDE.md is an instructions file published in the GitHub repository wyattjoh/calendar-mcp (2 stars, last pushed 1y ago), licensed MIT. It adds 567 tokens to every session, about $0.0028 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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