monarch-mcp CLAUDE.md

monarch-mcp CLAUDE.md is an instructions file for coding agents from jamiew/monarch-mcp. It costs 6,684 tokens per session, scanned A, original, MIT.

Project instructions for Monarch MCP, a software project that connects an MCP server with Monarch Money financial data. They include privacy rules and commands for installing dependencies, running the server, and managing packages.

In plain words
What is it for?
Use them when developing or testing the server, adding or removing Python dependencies, or writing examples and tests involving financial data.
Why use it?
They help prevent real financial and personally identifying data from entering the codebase while keeping development operations consistent.

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/jamiew/monarch-mcp/claude-md
Clone the repo
git clone --depth 1 https://github.com/jamiew/monarch-mcp

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 monarch-mcp CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/jamiew/monarch-mcp/claude-md.svg)](https://agentmods.dev/instructions/jamiew/monarch-mcp/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/jamiew/monarch-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/jamiew/monarch-mcp/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 6,684 This file is loaded in full into every session.
When invoked 6,684 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 $0.06684 $0.06684
Opus 5 $0.03342 $0.03342
Sonnet 5 $0.01337 $0.01337
Haiku 4.5 $0.00668 $0.00668

Measured 5d ago against content hash 37c1e7a1036b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

monarch-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 5d 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 · 446 lines

How it starts

The opening of the file, as written. The whole thing — 446 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.

PII & Data Privacy

CRITICAL: Never commit or include personally identifiable financial data in code, docs, tests, or commit messages. This includes:

  • Real account names (e.g., specific credit card names like "Main Credit Card")
  • Real merchant names from the user's transaction history
  • Real transaction IDs, category IDs, or account IDs from Monarch Money
  • Real dollar amounts tied to specific transactions
  • Any data that could identify the user's financial institutions or spending habits

Use generic, obviously-fake examples instead: "Main Credit Card", "Corner Deli", "cat_001", "txn_123". Brand names like "Starbucks" are fine as generic illustrative examples in docstrings — the distinction is between "examples of merchants" vs "data from the user's actual account."

Development Commands

Basic Operations

  • uv sync - Install dependencies and create/update virtual environment
  • uv run python server.py - Run the MCP server directly for testing
  • uv add <package> - Add new dependencies to the project
  • uv remove <package> - Remove dependencies from the project

Testing & Validation

  • uv run pytest tests/ -v --tb=short - Run all tests
  • uv run mypy server.py - Type checking
  • uv run ruff check . - Lint
  • uv run ruff format --check . - Format check (use ruff format . to auto-fix)
  • uv run python server.py - Test server directly (all logs to stderr)
  • MONARCH_FORCE_LOGIN=true uv run python server.py - Force fresh login (if session expires)

Debugging Startup Issues (Updated July 2025)

  • Session expired: Delete ~/.monarch-mcp/session.pickle or set MONARCH_FORCE_LOGIN=true
  • JSON parse errors: Fixed - all stdout output suppressed with contextlib.redirect_stdout()
  • MCP protocol compliance: All logging/warnings redirected to stderr, third-party lib output suppressed
  • AsyncIO errors: Fixed - uses run_stdio_async() in async context
  • SSL warnings: Suppressed from gql.transport.aiohttp to prevent stdout contamination
  • Date serialization errors: Fixed - build_date_filter() returns ISO strings for JSON safety
  • Broken pipe errors: Fixed - comprehensive graceful shutdown and error recovery implemented
  • Date parsing failures: Enhanced with multi-format fallbacks and helpful error messages

Read the full file on GitHub · 446 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. 5d ago First seen · 446 lines · 6,684 tokens per session scan A 37c1e7a1036b

Subscribe to this mod's changes

monarch-mcp CLAUDE.md is an instructions file published in the GitHub repository jamiew/monarch-mcp (20 stars, last pushed 2mo ago), licensed MIT. It adds 6,684 tokens to every session, about $0.0334 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 2026-08-30.

Related

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