Fastbooks

Accounting tools for any MCP client

Fastbooks runs a remote MCP server with OAuth sign-in. Point Claude Code, Cursor, VS Code, Codex, Gemini CLI or your own agent at one URL and work with real books: read, draft, post and reconcile, with confirmation on anything that matters.

How to connect Create a free account

Free on every Fastbooks plan. Read only if you prefer.

Your agent Fastbooks connected

Pull this month’s unpaid bills from Fastbooks and match them against the bank lines.

Called list_bills and list_bank_transactions. 3 bank lines match open bills exactly:

Nov 8, OAK STREET SUPPLIES → OSS-1042 $64.80
Nov 10, MILL & GRAIN → MG-2207 $612.00
Nov 11, DAIRY DIRECT → DD-0931 $284.40

match_bank_transaction needs confirmation for each:

Fastbooks · needs confirmation

Settle bill OSS-1042 ($64.80, Oak Street Supplies) from the Nov 8 bank line on Business Checking

Confirm all 3 Review one by one
An example conversation with made-up data.

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.

Your assistant works through the same Fastbooks you use, with your role and permissions, on one organisation you choose.

  • Invoices, quotes and credit notes

    Look up any document, draft new ones, email them to customers, record payments and turn accepted quotes into invoices.

  • Bills and expenses

    Enter and approve supplier bills, record bill payments and expenses, and fix or void ones that went in wrong.

  • Bank transactions

    See what still needs reviewing, categorise lines, match them to invoices and bills, and draft bank rules for the repeats.

  • Reports

    Profit and loss, balance sheet, cash flow, tax summary, aged receivables and payables, and customer statements.

  • Contacts

    Find customers and suppliers, see what they owe or are owed, and add or update their details.

  • Setup

    Check what a new organisation still needs, and add accounts and tax rates without leaving the chat.

Set up

Add the server

Every client needs only the URL. On first use it opens Fastbooks in your browser to sign in and pick an organisation. Clients identify themselves with a metadata document or dynamic registration, so there is no key to copy.

Fastbooks server URL

https://api.fastbooks.app/mcp

Already use Fastbooks? The same URL is in Settings → Connected apps.

  1. Claude Code

    Add the server from your terminal, then sign in when Claude Code asks (or run /mcp).

    claude mcp add --transport http fastbooks https://api.fastbooks.app/mcp

  2. Cursor

    Add it to .cursor/mcp.json (or your global mcp.json), then sign in from Cursor’s MCP settings.

    {
  "mcpServers": {
    "fastbooks": { "url": "https://api.fastbooks.app/mcp" }
  }
}

  3. VS Code

    Add it to .vscode/mcp.json, start the server from the file, and sign in when VS Code asks.

    {
  "servers": {
    "fastbooks": { "type": "http", "url": "https://api.fastbooks.app/mcp" }
  }
}

  4. Codex, Gemini CLI, Goose, Copilot Studio and others

    Add a remote (streamable HTTP) MCP server with the URL. Fastbooks supports OAuth 2.1 with PKCE, Client ID Metadata Documents and dynamic client registration.

    https://api.fastbooks.app/mcp

Tools return structured JSON with money as decimal strings and an ISO currency code. Lists page with limit and cursor. The server allows 120 calls a minute per connection.

Safe by design

An assistant, not a loose cannon

  • You approve the connection

    You sign in to Fastbooks, pick one organisation, and see where access is going before you agree.

  • Read only if you prefer

    Untick "Make changes" when you connect and the assistant can look but never touch.

  • 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.

  • Some things stay in Fastbooks

    An assistant cannot delete records, connect banks, change users, billing or settings, run payroll or close a period.

  • Every change is on record

    Fastbooks' audit trail shows which app made each change, as you.

  • 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 MCP

Something else on your mind? Talk to our team, we reply within one business day.

What tools are there?

64 in all: 29 read tools (business overview, invoices, quotes, credit notes, bills, expenses, payments, contacts, accounts and ledgers, bank accounts, transactions and rules, profit and loss, balance sheet, cash flow, tax summary, trial balance, aging and statements) and 35 write tools for drafting, issuing, emailing, paying, voiding, categorising and matching. There are no delete tools.

How does the confirmation step work?

For the 18 tools that email someone, post to the books or are hard to undo, the first call changes nothing and returns status "needs_confirmation", a plain summary and a signed, single-use confirmation_token. Calling the same tool with the same arguments plus the token makes the change. The token expires after 10 minutes and fails if the record changed in between. These tools also carry destructiveHint, and email tools openWorldHint, so clients can ask you first.

Are there interactive views?

Yes. In clients that support MCP Apps, invoices, quotes and credit notes, financial reports and receivables open as interactive views beside the result. Other clients get the same data as structured output.

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 your agent

Create a free Fastbooks account, or import your books from QuickBooks Online or Wave, then connect in a couple of minutes.

Start for free Compare plans