Connect Claude & ChatGPT
Ask Finn about your books, straight from Claude or ChatGPT
The AccountsOS connector lets Claude and ChatGPT read your company's books, so you can ask about deadlines, invoices, VAT, cash flow and more in plain English. You sign in with your normal AccountsOS login, no API key to create or paste.
What you need
- An AccountsOS account with at least one company (14-day free trial, no card)
- A Claude or ChatGPT account
Connect in Claude
Works in Claude on the web and in the Claude desktop app.
- Open Customize, then Connectors, then Add custom connector.
- Enter the name AccountsOS and the URL
https://accounts-os.com/api/mcp/plugin. - Click Connect, then sign in to AccountsOS with your email and password, a magic link, or Google.
- Click "Allow read-only access" on the consent screen.
Claude asks for your approval before each tool call, unless you change the tool permissions yourself. If you find AccountsOS listed in Claude's connector directory, you can add it from there instead of entering the URL by hand.
Connect in ChatGPT
- Open the Finn app in ChatGPT's app directory: chatgpt.com/plugins/plugin_asdk_app_6a703a690370819194f6e23ab7cd6df8.
- Click Connect.
- Sign in to AccountsOS.
- Allow access.
What Finn can read
The connector is available in all 26 countries AccountsOS supports. UK companies connected to HMRC also get live MTD VAT data.
Transactions and balances
- Bank transactions
- Account balances
- Categories
Reports
- Profit and loss
- Balance sheet
- Trial balance
- Cash-flow forecast
Invoices and bills
- Invoices
- Bills
- Aged debtors and creditors
- Recurring invoices
VAT and HMRC
- VAT summary and VAT periods
- HMRC VAT obligations, liabilities and payments (UK companies connected to HMRC)
- UK VAT number checks
Deadlines and compliance
- Filing deadlines
- Companies House company lookup
- Month-end close status
People and payroll
- Contacts
- Payroll summary
- Dividends and director's loan balance
Documents and knowledge
- Documents
- Company Memory
- Finn's tax and accounting knowledge base
Projects and pipeline
- Projects and pipeline
What it cannot do
The connector is read-only. It cannot create, change, send, file, pay or delete anything in your AccountsOS account.
Access is limited to the single AccountsOS company linked to the account you signed in with. To revoke access, disconnect the connector from inside Claude or ChatGPT.
Example prompts
- "What are my next three filing deadlines?"
- "Which invoices are overdue, and who owes me the most?"
- "Show my profit and loss for last month compared with the month before."
- "What's my VAT position for this quarter?"
- "What will my cash look like over the next 12 weeks?"
- "What's my director's loan account balance?"
Privacy and access
You authenticate with your normal AccountsOS login (OAuth), not a shared password or API key. Access is scoped to the AccountsOS company linked to your account. Disconnecting the connector in Claude or ChatGPT revokes access immediately.
Read our privacy policy.
Troubleshooting
- Sign-in returns you to your dashboard instead of the consent screen: start the connection again from Claude or ChatGPT while signed in.
- Claude says it can't reach AccountsOS: disconnect and connect again.
Need a hand?
Email hello@accounts-os.com or ask Finn in the in-app chat.