Integration

Your books, inside ChatGPT.

Install Finn from the ChatGPT plugin directory and connect your AccountsOS account. Ask about cash, invoices, VAT or what needs attention before the next deadline, and the answer comes from your live ledger. Read-only, so nothing changes without you.

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Read-only. ChatGPT reads your books, it never changes them.

chatgpt.com

Finn, AI AccountantLive

Give me a weekly financial health check.

FCash £18,400 across 2 accounts. £6,250 overdue from 3 customers. VAT of £2,180 due 7 Nov.

FRead from your live ledger, not a file you uploaded.

What comes across

Install from the ChatGPT plugin directory, no API key to paste

Connect your AccountsOS account once with a secure sign-in

Ask about cash, transactions, invoices, bills, VAT and deadlines

Answers come from your live double-entry ledger, not an upload

Read-only: the app reads your books and never changes them

Works alongside the Claude plugin, the MCP server and the CLI

How it works

Connect ChatGPT once, then stop thinking about it.

Ask ChatGPT about your books, and get the answer from your real ledger

Install Finn in ChatGPT

Open the Finn listing in the ChatGPT plugin directory and click Install. Nothing to configure and no API key to paste.

Connect your AccountsOS account

The first time you ask Finn something, ChatGPT asks you to sign in to AccountsOS. You approve the connection once and it keeps working after that.

Ask about your books

Try one of the starter prompts, like a weekly financial health check or what needs attention before the next deadline. Finn reads your live ledger and answers in plain English.

Why it's worth it

Your accounts answer questions in the tool you already have open

No exporting a spreadsheet to ask a question about it

Read-only by design, so there is nothing to undo

One connection, and it keeps working as your books change

Every figure traces back to a real entry you can open in AccountsOS

FAQ

The questions people ask first

Can ChatGPT change my accounts?

No. The ChatGPT app is read-only. It reads your books and explains them, and it cannot post a transaction, raise an invoice, pay a bill or file anything. Changes happen in AccountsOS, or through Finn in the product where every write asks you to confirm first.

Do I need an API key?

No. You install the app and sign in to AccountsOS once when ChatGPT asks. There is no key to generate, paste or keep safe. If you would rather work from a terminal or a script, the AccountsOS CLI and the MCP server both use an API key instead.

Which company does it read?

The company on your AccountsOS account. If you run more than one, Finn reads the one you have selected in AccountsOS, so switch there and ask again.

How is this different from uploading a spreadsheet to ChatGPT?

An upload is a snapshot that goes stale the moment anything changes, and ChatGPT can only see what is in the file. Finn reads your live double-entry ledger, so the answer reflects your books as they are now and every figure traces back to a real entry.

Does this work with Claude too?

Yes. The same books are reachable from the Claude plugin, the MCP server and the AccountsOS CLI. Use whichever tool you already have open, they all read the same ledger.

Bring ChatGPT into AccountsOS.

14-day free trial, then £20 a month.

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Already have an account? Connect ChatGPT in Settings, Integrations.