mcp-cash-book

mcp-cash-book

One double-entry ledger over the books you already keep. It reads your invoices, credit notes, purchase orders, deposits, expenses, bank import and fixed asset register, and derives a debit and a credit for every movement in a period: revenue and VAT output from the invoices, receivables and the payments that clear them, deposits held as the liability they are, expenses by category with the VAT taken out of the gross, fixed assets and their monthly depreciation. It proves the trial balance sums to zero to the minor unit, and when it does not it names the document whose own figures do not add up. It writes nothing back into any of those books, and there is no way to type an entry into it: every line carries the server, the document id and the date it came from, so any figure can be walked back to the page it was printed on.

Install

Claude Desktop, ~/Library/Application Support/Claude/claude_desktop_config.json (Windows: %APPDATA%\Claude\claude_desktop_config.json):

{
  "mcpServers": {
    "cash-book": {
      "command": "npx",
      "args": ["-y", "@theluckystrike/mcp-cash-book"]
    }
  }
}

Claude Code:

claude mcp add cash-book -- npx -y @theluckystrike/mcp-cash-book

Cursor: ~/.cursor/mcp.json (or .cursor/mcp.json in a project), same entry as Claude Desktop.

This server is only useful next to the servers that own the books: mcp-invoice, mcp-billing-docs, mcp-deposits, mcp-expense-tracker, mcp-bank-statement and mcp-asset-register. Every one of them is optional. A store that is not installed is simply absent from the ledger; a store that is installed and unreadable is reported as unreadable, and never read as an empty one.

Tools

Accounts: cash, receivables, revenue, vat_output, vat_input, expenses:<category>, deposits_held, fixed_assets, accumulated_depreciation, depreciation_expense, and purchase_commitments as a memo that is never posted.

Free vs Pro

The trial balance is free because it is the only question this server exists to answer. A bookkeeper who cannot check that the books add up has no reason to trust anything else here.

Get Pro: https://mcp.zovo.one/buy/cash-book (one-time, lifetime, verified offline).

The measured insight

On the worked month in test/_client.mjs, four of the five bank rows are the same money as a document that was already posted: 1,375,300 of the 1,380,300 minor units of cash movement, 99.6 percent, appear in both books. Posting the bank import as well as the documents, which is the obvious way to build a cash book and the way most spreadsheets do it, moves the cash balance from -10,543.00 to -21,111.00 EUR. It does not look wrong. Every line is individually plausible, the account is off by almost exactly a factor of two, and the trial balance still comes to zero, because each duplicated receipt brought its own contra with it.

So the bank import posts nothing here. It is matched to the posted cash movements as evidence, and the leftovers are the whole point: on that month exactly 7,500 minor units of the bank total, one unexplained withdrawal, is information the documents did not already have. That is the 0.4 percent worth importing a statement for, and it is the part a duplicate-heavy ledger buries.

Privacy

All data stays on your machine. The ledger is derived on each call from the sibling servers' own data directories under ${XDG_DATA_HOME:-~/.local/share}/mcp-servers/, and this server writes only its own cash-book/periods.json and cash-book/closes.json. There is no network call anywhere in src, and no telemetry. License keys are verified offline.

Built by theluckystrike. https://github.com/theluckystrike