QBBridge

An MCP frontend for QuickBooks Desktop.

Gives any MCP-compatible client (Claude Desktop, Claude Code, or anything else that speaks MCP) safe, structured access to a local QuickBooks Desktop company file: read accounts/vendors/transactions, post new transactions, and modify or delete existing ones -- with every write automatically logged so it can be reverted.

QuickBooks Desktop's automation API (QBXML/QBFC) only works on the machine (or LAN) where QuickBooks is actually installed -- there is no cloud proxy for it. QBBridge runs locally, right next to QuickBooks, and your company file's data never has to leave that machine to be used by an MCP client.

Why this exists

QBXML is powerful but has real, undocumented sharp edges: several element orderings are order-sensitive in ways the schema alone doesn't tell you, and getting them wrong produces a bare COM parse exception with no indication of which field was the problem. This package exists so you don't have to rediscover those the hard way -- they're encoded and tested once, here.

What it gives you

• Read: chart of accounts, vendor list, a vendor's transaction history (so you can classify a new transaction against how this vendor has actually been booked before, not a guess), flexible transaction queries, and a duplicate/overlap checker.
• Write: add/modify/delete transactions (Check, Deposit, CreditCardCharge, CreditCardCredit) and vendors.
• Safety: every write is automatically recorded to an append-only undo log as it happens (not batched at the end -- a crash mid-run still leaves a usable log of everything that did complete). Any run can be reverted, in reverse order, with one call.

What it deliberately does NOT do

This server has no business-specific logic in it -- no classification rules, no confidence thresholds, no assumptions about what kind of business you run. Deciding which vendor maps to which account, when to trust a match versus flag it for a human, and how to parse a specific bank's statement format is policy, and policy differs by business. That belongs in the agent/skill calling this server, not in the server itself. This keeps the server itself universal.

The companion skill

The server is the mechanism; skills/qbbridge-bookkeeping/SKILL.md is the judgment. It's a Claude skill that teaches an agent how to actually use these tools well -- when to trust a vendor's transaction history vs. flag it for a human, how to handle payment/credit lines vs. purchases, and the safety habits (checking the open company file, checking for duplicates) to follow before every write. Install the MCP server for the plumbing; add this skill for the bookkeeping judgment on top of it.

Requirements

• Windows, with QuickBooks Desktop installed and the target company file open.
• Python 3.10+.
• pywin32 (installed automatically on Windows).

Install

pip install qbbridge-mcp

Configure as an MCP server

Point your MCP client at the qbbridge-mcp command. For Claude Desktop, add to your MCP config:

{
  "mcpServers": {
    "qbbridge": {
      "command": "qbbridge-mcp"
    }
  }
}

Safety notes

• Every write tool accepts an optional expected_company_file parameter. Pass the path you expect QuickBooks to have open (from a prior qb_company_info call); the tool refuses to run if a different file is actually open. This is the single check that prevents posting to the wrong client's file.
• qb_delete_transaction requires you to pass a full snapshot of the transaction (query it first) -- without it, a delete cannot be undone.
• Undo logs are written to ./qbbridge_runs by default, or $QBBRIDGE_RUNS_DIR if set.

License

MIT