Via MCP · no registration needed Claude, connected
to your books.
Add OneBooks as a connector in Claude and ask for your P&L, cash flow, receivables aging or VAT 15% position in plain language — answered from the live ledger. Claude can draft invoices and expenses too; you confirm every one.
Hosted client metadata
Claude's recommended path — no client registration
Human-confirmed writes
drafts only; nothing posts until you approve
No delete, ever
by design at the API level, not by policy
Connected in two minutes.
Add the connector
In Claude: Settings → Connectors → Add custom connector, and paste https://api.getonebooks.com/mcp.
Sign in and approve
OneBooks asks you to sign in and approve access for one business. Tokens are bound to that business.
Ask
“Who's overdue?”, “Profit last month?”, “Draft an invoice for Almara for 12 hours of consulting.”
Real numbers, real documents.
Claude calls typed tools over the Model Context Protocol; every figure it states comes from a tool result, never from memory.
- ✓ Reports on demand — P&L, balance sheet, cash flow, trial balance, general ledger, receivables and payables aging, VAT 15% summaries.
- ✓ Lookups — customers, suppliers, items, invoices, purchases and payments.
- ✓ Drafts you confirm — invoices, expenses, purchases, payments, new customers and suppliers as proposals.
- ✓ Any Claude surface — Claude.ai, Desktop, mobile and Claude Code, which identifies itself with its own metadata document.
Built assuming the agent is untrusted.
The connection is designed so a confused or compromised agent cannot damage the books.
- ✓ OAuth per business — you sign in and consent; tokens are bound to that one business and die if it changes.
- ✓ Role-aware — a viewer's Claude gets read tools only.
- ✓ Two-phase writes — every document is a single-use proposal until a human approves that exact preview.
- ✓ Untrusted-data fencing — stored text is marked as data, so instructions hidden in a receipt can't steer Claude.
- ✓ Rate-limited and metered — per-minute limits plus a weekly per-business cap.
Claude connector — common questions
Do I need to register a client or paste keys?
No. OneBooks supports Client ID Metadata Documents, Claude's recommended path, and dynamic registration as a fallback — you paste the URL, sign in, and approve.
Can Claude change or delete my books?
No. Claude can read reports and propose new documents; nothing posts without your explicit confirmation, and no delete, void or edit capability exists on the connector at all.
Does it work in Claude Code?
Yes — Claude Code identifies with its own client metadata document and a loopback redirect, both of which OneBooks supports.
What does it cost?
Connector usage draws from the same weekly AI-credit allowance as the built-in assistant — 200 credits per business per week, renewing on your signup day.
Paste one URL into Claude.
Create your OneBooks account, add the connector, and ask your books a question.