Your books, inside Claude
Add Fastbooks as a connector and Claude can answer questions from your real numbers, draft invoices and bills, and tidy your bank lines. Anything that reaches a customer waits for your OK.
Free on every Fastbooks plan. Read only if you prefer.
How did profit this month compare with last month?
From your Fastbooks profit and loss:
| Revenue, November so far | $12,480.00 |
| Expenses | $8,167.20 |
| Net income | $4,312.80 |
| October net income | $3,640.10 |
You're up $672.70 on October with half the month to go. Ingredients are your biggest cost at $3,920.00, about 48% of spending.
Things to ask
Talk to your books like you'd talk to your bookkeeper
- Invoices "Which invoices are overdue, and who should I chase first?"
- Invoices "Invoice Riverside Café for 40 sourdough loaves at $6, due in 30 days."
- Reports "How did profit this month compare with last month?"
- Bills "What bills are due in the next two weeks?"
- Banking "Categorise last week's bank transactions."
- Contacts "What does Hillside Deli owe us, and what have they paid this year?"
- Reports "Show me the balance sheet at the end of last quarter."
- Tax "How much sales tax did we collect in October?"
What it can do
More than answers. Real bookkeeping work.
Claude works through the same Fastbooks you use, with your role and permissions, on one organisation you choose.
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Invoices, quotes and credit notes
Look up any document, draft new ones, email them to customers, record payments and turn accepted quotes into invoices.
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Bills and expenses
Enter and approve supplier bills, record bill payments and expenses, and fix or void ones that went in wrong.
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Bank transactions
See what still needs reviewing, categorise lines, match them to invoices and bills, and draft bank rules for the repeats.
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Reports
Profit and loss, balance sheet, cash flow, tax summary, aged receivables and payables, and customer statements.
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Contacts
Find customers and suppliers, see what they owe or are owed, and add or update their details.
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Setup
Check what a new organisation still needs, and add accounts and tax rates without leaving the chat.
Set up
Connect in a couple of minutes
Claude connects to Fastbooks as a custom connector. It works in Claude on the web, Claude Desktop and Cowork.
Fastbooks server URL
https://api.fastbooks.app/mcp Already use Fastbooks? The same URL is in Settings → Connected apps.
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Add a custom connector
In Claude, go to Customize → Connectors and choose Add custom connector. On a Team or Enterprise plan, an owner adds it under Organization settings → Connectors.
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Paste the Fastbooks URL
Name it Fastbooks and paste the server URL. Leave the advanced OAuth fields empty: Fastbooks handles sign-in itself.
https://api.fastbooks.app/mcp -
Sign in and choose an organisation
Claude opens Fastbooks in your browser. Sign in (or create a free account), pick the organisation, and choose whether Claude can make changes or only read.
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Ask away
Make sure Fastbooks is turned on in the chat’s connectors menu, then ask about your books.
Claude's Free plan allows one custom connector; paid plans allow more. Menu names in Claude change from time to time, so check Anthropic's help on custom connectors if yours look different.
Safe by design
An assistant, not a loose cannon
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You approve the connection
You sign in to Fastbooks, pick one organisation, and see where access is going before you agree.
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Read only if you prefer
Untick "Make changes" when you connect and the assistant can look but never touch.
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Nothing sent without a second OK
Emailing a customer, approving a bill, recording a payment or voiding a document needs a confirmed second step, with a summary of exactly what will happen.
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Some things stay in Fastbooks
An assistant cannot delete records, connect banks, change users, billing or settings, run payroll or close a period.
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Every change is on record
Fastbooks' audit trail shows which app made each change, as you.
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Disconnect any time
Settings → Connected apps lists every assistant with its access. One click cuts it off.
Use a different assistant?
FAQ
Questions about Fastbooks and Claude
Something else on your mind? Talk to our team, we reply within one business day.
Does it cost extra?
No. Connecting an AI assistant is free on every Fastbooks plan, including Free. A few reports (cash flow, trial balance, aged receivables and payables, the general ledger) are part of Pro, and the assistant will tell you when something needs an upgrade. Your AI assistant has its own plans and limits.
Can the AI change my books without asking?
Anything a customer would see or that is hard to undo (emailing, approving bills, recording payments, voiding, matching bank lines) takes two steps: the first only previews, and the change happens on a confirmed second call. Drafts, contact edits and categorising a bank line happen straight away, and you can undo them in Fastbooks. If you want no changes at all, connect read only.
Which organisation does it see?
Exactly one: the one you choose on the Fastbooks consent screen. If you belong to several, connect again and pick another. The assistant acts with your role, so it sees and does what you can in Fastbooks, and no more.
Is my data used to train AI models?
Fastbooks only sends your assistant what it asks for to answer you. How that assistant stores and uses your conversations is set by its provider and your account settings, so check those (most offer an option to turn off training on your chats).
How do I disconnect?
In Fastbooks, go to Settings → Connected apps and disconnect it. Access ends on the very next request. You can also remove the connector in your assistant.
Bring your books to Claude
Create a free Fastbooks account, or import your books from QuickBooks Online or Wave, then connect in a couple of minutes.