Bring your own AI.
OneBooks speaks MCP.
Connect Claude, ChatGPT or any MCP-capable agent to your OneBooks account. Your AI reads real reports and prepares real documents — and a human confirms every write.
The endpoint
OAuth 2.0 · PKCEOne URL, standard OAuth 2.0 with PKCE, per-business consent. Paste it into any MCP client and sign in — no keys to manage, no setup on our side.
MCP endpoint
https://api.getonebooks.com/mcp Integration guide: developer.getonebooks.com (opens in a new tab)
User guide: docs.getonebooks.com/ai/mcp (opens in a new tab)
An accounting system built for AI agents.
Most accounting software treats AI as a bolt-on. OneBooks is agent-native: a real double-entry ledger wrapped in an interface designed for AI agents — typed tools instead of screen-scraping, per-business OAuth scopes, two-phase human-confirmed writes, and hard rate limits. An agent can do genuinely useful bookkeeping here without ever being able to damage the books.
Ask your agent for a P&L before the meeting. Have it chase who owes you money. Describe an invoice in one sentence and confirm the draft from your phone. Your accountant keeps a clean, auditable ledger — and your AI finally stops being locked out of it.
Connect the tools you already use.
Claude
- 1 Open Settings → Connectors → Add custom connector.
- 2 Paste the OneBooks MCP endpoint.
- 3 Sign in and approve access for your business. Done.
ChatGPT
- 1 Open Settings → Connectors and add the endpoint URL.
- 2 ChatGPT registers automatically over OAuth.
- 3 Approve the scopes for your business and start asking.
Works with any MCP client — desktop apps, agent frameworks and custom automations included.
What a connected agent can do.
Read — instantly
- ✓ Profit & loss, balance sheet, cash flow, trial balance and general ledger
- ✓ Receivables and payables aging — who owes whom, and how late
- ✓ Tax reports and summaries for your filing period
- ✓ Customers, suppliers, items, invoices, purchases and payments
Prepare — you confirm
- ✓ Draft invoices and record expenses from a conversation
- ✓ Turn a receipt discussed in chat into a purchase
- ✓ Record customer payments against open invoices
- ✓ Create customers and suppliers when they're missing
Never
- ✕ Delete, void or edit anything already in your books
- ✕ Post any document without an explicit human confirmation
- ✕ See any business other than the one that granted consent
Built assuming the agent can't be trusted.
- ✓ OAuth per business — the person connecting signs in and consents; tokens are bound to that one business and die if it changes.
- ✓ Scoped access — agents only see the tools their granted scopes allow; sensitive ledger operations aren't offered at all.
- ✓ Two-phase writes — every document is a proposal until a human approves that exact preview; a confirmation can never be replayed twice.
- ✓ Untrusted-data fencing — document text and results are marked as data, so instructions hidden in a receipt can't steer the agent.
- ✓ Rate-limited and metered — per-minute limits plus a weekly per-business call cap keep runaway agents contained.
Quick facts for integrators
MCPMCP — common questions
What is MCP?
The Model Context Protocol is an open standard that lets AI applications like Claude and ChatGPT connect to external tools and data sources securely. OneBooks exposes its accounting capabilities as an MCP server.
Can an agent empty my books?
No. Connected agents have no delete, void or edit capability at any permission level — those operations simply don't exist on the MCP surface. Writes are limited to new-document proposals that a human must confirm.
Which AI tools work with it?
Anything that speaks MCP: Claude (web and desktop), ChatGPT connectors, agent frameworks and custom clients. Registration is automatic — paste the endpoint and sign in.
Do I need a developer?
Not for Claude or ChatGPT — it's paste-URL-and-sign-in. Developers who want to build deeper automations get standard OAuth and a documented tool catalog.
What does it cost?
MCP usage draws from the same weekly AI credit allowance as the built-in assistant — 200 credits per week per business, renewing on your signup day.
Is OneBooks an accounting system for AI agents?
Yes — that is the design goal. OneBooks pairs a real double-entry ledger with an agent-native interface: an MCP server with typed tools, OAuth-scoped access per business, human-confirmed writes and no destructive operations. AI agents like Claude and ChatGPT can read reports and prepare documents while humans keep final control of the books.
Your AI, your books, one URL.
Create your OneBooks account, paste the endpoint into Claude or ChatGPT, and put your books to work.