One double-entry ledger derived from the books you already keep, proved to zero to the minor unit, with every line naming the document it came from. It reads six books this collection already keeps, all read-only: the invoice ledger, the credit notes and purchase orders, the deposits, the expense ledger, the bank import and the fixed asset register. For a period in one currency it derives a debit and a credit for every movement in them. Revenue and VAT output come off the invoices, receivables and the payments that clear them, deposits held as the liability they actually are, expenses by category with the VAT taken OUT of the gross rather than added on top of it, fixed assets as they enter service, and depreciation charged by month. The bank import posts nothing at all, which is the decision the whole ledger rests on: a bank line and a payment record are not two transactions, they are one transaction seen twice, so cash is posted from the documents, which are the only rows that carry a second leg, and each bank row is matched to a posted cash movement of the same amount, the same direction and a date within three days, written onto the line as evidence. What is left unmatched is the output that matters, because a bank debit with no expense behind it is a payment nobody entered. Nothing is ever balanced with a plug: an entry whose own legs do not add up is posted exactly as the document states it and the difference is raised by name, with the entry, the source server and the source document behind every unit of it, because a trial balance can only find a broken document if it is allowed to come out non-zero. Currencies are never added together, a purchase order stays a memo and is never posted, a deposit applied to an invoice moves the liability rather than cash, and the ledger opens at nothing, since an opening figure nobody can walk back to a document is the first invented number in a set of books. Every line carries the server, the document id and the ISO date it came from, and the bytes and mtimes of all six sibling stores are unchanged across all six tools.
Eight tools against Cascade's ceiling of 100, and it pairs with the six servers whose books it reads, so budget the group at roughly 60 tools when you decide what else fits alongside them. If the ceiling is tight, this is the one to keep: it is the only one that reads all six.
| You say | Tool |
|---|---|
| Build the double-entry ledger for June and tell me whether the trial balance comes to zero. | ledger_build |
| Show me every ledger line that hits receivables, with the invoice each one came from. | ledger_lines |
| Close June: what does the month leave unposted or inconsistent? | month_close |
Posting the bank import alongside the documents, which is the obvious way to build a cash book and the way most spreadsheets do it, double-counts almost all of the cash and the trial balance still comes to zero. Measured on this server's worked month: four of the five bank rows are the same money as a document already posted, 1,375,300 of 1,380,300 minor units of cash movement, 99.6 percent. Posting them as well moves the cash balance from -10,543.00 to -21,111.00 EUR, and nothing flags it, because every duplicated receipt arrives with its own contra, every individual line is plausible and the only symptom is one account off by nearly a factor of two in a direction nobody audits. What is left after matching is 7,500 minor units, one unexplained withdrawal. That 0.4 percent is the entire reason to import a statement at all, and it is exactly what a duplicate-heavy ledger buries.
The file is mcp_config.json, and the key inside it is mcpServers.
| Scope | Path |
|---|---|
| macOS, Windows and Linux | ~/.codeium/windsurf/mcp_config.json |
{
"mcpServers": {
"cash-book": {
"command": "npx",
"args": ["-y", "@theluckystrike/mcp-cash-book"]
}
}
}Save and reopen the MCP Servers list; Cascade picks it up without restarting the editor.
The npm publish of @theluckystrike/mcp-cash-book is pending; until then use the .mcpb bundle or a clone and build from the latest release.
The same server runs at https://mcp.zovo.one/mcp/https://mcp.zovo.one/mcp/cash-book over MCP streamable HTTP, no install. Mint a free token with curl https://mcp.zovo.one/mcp/token, or use a Pro key. It has no filesystem, so a file comes back as a one-hour download link.
{
"mcpServers": {
"cash-book": {
"url": "https://mcp.zovo.one/mcp/https://mcp.zovo.one/mcp/cash-book",
"headers": { "Authorization": "Bearer <token>" }
}
}
}Read this first: mcp_config.json applies to the legacy Cascade agent only. The Devin Local agent, the default for new tabs, takes its servers from the Devin CLI config files, so a correct entry here can still be invisible in a fresh tab. The other hard number is a cap: Cascade reaches at most 100 tools at once, and every enabled server spends from it.
Free: trial_balance and ledger_lines are free and unlimited on every tier. Whether the books add up is the question this server exists for, and a free tier that hides the answer is a demo rather than a tool, so neither the check nor the evidence behind it is ever metered. The cap is on the PERIOD instead: three distinct periods a calendar month, keyed by from, to and currency, so rebuilding a period already in the register is free forever on every tier and the meter only ever moves when you ask a genuinely new question. Pro is $19 once, verified offline.
~/.codeium/windsurf/mcp_config.json, under mcpServers. Reach it from the MCPs icon at the top right of the Cascade panel, or Devin Settings, Cascade, MCP Servers.
That file applies to the legacy Cascade agent only. The Devin Local agent, the default for new tabs, reads its servers from the Devin CLI config files instead. Check which agent the tab runs.
Cascade reaches at most 100 tools at any one time, and every enabled server spends from that single budget. MCP Cash Book contributes 8 tools, so keep the enabled list short rather than counting servers.
MCP Cash Book in detail · The same server in VS Code and Cline · Every server in Windsurf · Guides · Windsurf docs · Buy Pro