The specialist agent for your books

Finn is an AI agent that keeps your books. She doesn't just talk about your accounts, she does them: she reads what you send her, posts it to a real double-entry ledger, reconciles your bank, prepares your returns and files them, with you signing off anything that matters.

Why a specialist

If you use AI every day, you already have a favourite general agent. It writes, plans, researches and gets through a long list of everyday tasks well.

But think about the last time you asked a general agent to send an invoice, file a VAT return or close your month. You probably didn't, and there's a reason. Your books are not a general task. They need:

• A system of record. The numbers have to live somewhere permanent and balance, every time.
• The right tools. Reading a bank statement, posting a journal and filing at HMRC are actions, not answers.
• Memory. Last year's decisions, the supplier you always code to software, the director's loan you're paying down.
• Exact maths. Money can't be "roughly right".
• Official sources. Tax answers have to come from the tax office, not from the open web.
• Accountability. Someone signs. Every change is logged.

Developers trust a coding agent with their codebase because it lives in the repo, knows the tools and remembers the project. Finn is that for your books.

What makes Finn a specialist

• She lives in the ledger. Every figure comes from a double-entry general ledger, the same structure an accountant keeps.
• She has 255 tools. Each one is a real action on your books, from categorising a transaction to filing a confirmation statement.
• She remembers. Your business, your preferences, your team's conversations and every decision you've made together.
• She's grounded. Tax and rules answers come from official sources in 27 countries, and she shows you where.
• She asks first. Anything that files, pays, sends or deletes waits for your yes.

What she does today

• Files UK VAT returns straight to HMRC, as HMRC-recognised Making Tax Digital software for VAT
• Prepares year-end accounts and files them at Companies House
• Reads any receipt, invoice, statement or export you throw at her, from any bank or old system
• Reconciles your bank in the background and only shows you the odd ones out
• Runs invoicing, bills, expenses, payroll and month-end
• Works across 27 countries, for one company, a group of companies or an accountancy practice's whole client book
• Talks to you on the web, by voice and video, on the phone, on WhatsApp, Telegram, Slack and email, and from inside ChatGPT and Claude

How to read this book

You can stop here. If you want to go deeper:

• Generalist agents and specialist agents: where Finn fits next to the AI you already use.
• How Finn works: the model, the harness, the tools, memory, grounding and guardrails. Start with Anatomy of the agent.
• What Finn does: every feature, area by area, starting with Talk to Finn anywhere.
• Who it's for: founders, groups and accountancy practices.
• Reference: every tool Finn can use and what's coming next.

This book is live. It's generated from the product itself, so when Finn learns something new, it shows up here.