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.
Read-only. ChatGPT reads your books, it never changes them.
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 plus VAT.
Already have an account? Connect ChatGPT in Settings, Integrations.