Accounting with AI means this: you talk to an assistant — Claude, ChatGPT or another one — and the assistant reads your books and writes into them, under rules you set. "Who still owes us money?" is answered from the receivables ledger, not from memory. "Record this supplier bill" turns a photographed invoice into a bill waiting for your confirmation. "Draft an invoice for the Meyer job" produces a draft with lines and tax that you issue with one click. KRONENWERK is built for this: it publishes an MCP server that assistants connect to, and the company decides how far an assistant may go. This page is the overview; the two guides beside it show the connection step by step and list what an assistant can and cannot do.
What changes, and what does not
Bookkeeping has always been two jobs at once: knowing what happened, and typing it in the right place. The second job is where the hours go — the receipt in a coat pocket, the supplier's PDF in an inbox, the customer who paid two invoices with one transfer. An assistant takes the typing. You still decide what a thing is: whether the parcel that arrived is a purchase or a return, whether the customer's complaint is worth a credit note, whether the quarter is closed. The assistant works inside the rules of double-entry bookkeeping and inside the rules your company sets; it does not invent a rate, a number or a date.
What does not change is the legal status of your documents. An invoice issued in KRONENWERK is validated for the seller's country — a German seller gets an XRechnung or ZUGFeRD file, a Québec seller gets GST and QST on separate lines with both registration numbers, a French seller gets Factur-X — whether a person or an assistant pressed the button. The engine that computes totals, groups taxes and checks registration numbers is the same engine, and an assistant cannot reach around it.
How an assistant reaches your books
KRONENWERK exposes a Model Context Protocol server at https://kronenwerk.org/api/extern/mcp. MCP is an open standard through which an AI application discovers the tools an external system offers and calls them on the user's behalf. Claude, ChatGPT and most agent frameworks speak it. For a hosted assistant the connection is made by signing in: you add KRONENWERK as a connector, the assistant sends you to KRONENWERK's sign-in page, you confirm once, and from then on the assistant acts for exactly the company whose owner confirmed. There is no key to copy and paste, and the connection can be ended under Settings → Integrations at any moment.
The tools the assistant sees are the tools the company allows. Twenty-two exist today: twelve that only read (customers, invoices, drafts, transactions, receivables, payables, profit and loss, balance sheet, the attention list), seven that create something inert — an invoice draft, a quote draft, a transaction, a note, a supplier bill awaiting confirmation, a filed document, a link between a record and a job — and three that make a financial fact true: issue an invoice, send it, record a payment. The last three are offered only to a company that chose the level Act within a limit and set an amount.
Three levels, chosen by you
| Level | What the assistant may do | Who it suits |
|---|---|---|
| Read only | Answer questions from the books. Nothing is written. | An owner who wants a second pair of eyes on cash, aging and margins, and nothing more. |
| Read and propose (default) | Everything above, plus drafts: invoices, quotes, bills, transactions, notes, files. A person issues, confirms and pays. | Most small businesses. The assistant does the typing; the owner or bookkeeper keeps the signature. |
| Act within a limit | Everything above, plus issue, send and record payments — each act up to a gross amount the company set, inside its own transaction. | A company that already trusts a routine: monthly retainers, recurring orders, small tickets. |
Whatever the level, no tool cancels or corrects an issued document, approves or pays a supplier bill, posts a journal entry, closes a period, or creates or revokes keys and settings. Those acts stay with a person signed in to KRONENWERK. When an assistant asks for something the level does not allow, it receives a written refusal that names the setting a person would change — and nothing is done. The guide on what an assistant can do goes through each boundary.
A working week with an assistant
- Monday morning
- "What needs my attention?" — The assistant reads the attention list: three invoices overdue, two supplier bills due this week, one draft nobody issued, a quote that expires on Thursday. You answer in sentences: "Remind Meyer, pay Fastlink on Friday, drop the draft."
- Receipts
- You photograph a parking ticket and a hardware store receipt and say "file these as expenses on the Dubois job". Two expense records appear with the images attached, linked to the transaction, waiting for confirmation.
- A supplier's invoice arrives by e-mail
- "Record this bill from Toptek against job V2026-0142." The assistant reads the figures as printed — net, tax, gross — never recomputing them, and records the bill with the PDF attached. It is not paid and not approved; that is a person's act.
- Invoicing day
- "Draft invoices for every job that shipped this week." One draft per transaction, with the customer's currency, the right tax structure for the customer's province or country, and the job number as reference. You open each, glance, issue.
- Friday
- "How did September go?" — Profit and loss from the ledger, with an honest flag: the figure is provisional until the period is closed.
Why the books stay trustworthy
Every act and every draft an assistant makes is written to the company's authorship record with the tool, the connection and the time, and the audit rows beneath say "connection X" rather than a person's name. So the trail always says which assistant did what. An assistant reads under the same permissions as the equivalent screen — a connection created by a bookkeeper who cannot see the balance sheet gives an assistant that cannot see it either. Identifiers belonging to another company come back as "not found". A key or a connection reaches exactly one company; multi-company owners connect each company on its own.
Two more properties matter for a business's peace of mind. First, an assistant never sees a rate table or a nexus rule, because KRONENWERK does not carry one: GST, QST, HST, sales tax and VAT rates are the company's to state, and the assistant states what the company told it. Second, the drafts an assistant makes are ordinary drafts: the same screen, the same validation, the same issuing engine as a draft typed by hand. Nothing "AI-made" is a second class of record.
Where to start
- Read how to connect Claude — five minutes, no key to copy.
- Leave the level at Read and propose for the first weeks. Let the assistant type; keep issuing yourself.
- Put your jobs into transactions. An assistant that can say "on job V2026-0142" files things where they belong.
- Switching from another product or from an accountant's spreadsheet? The switching guide covers what moves and what does not.
How KRONENWERK handles this
SUPPORTED The MCP server is live for companies on the Enterprise plan and the practice plan, accepts OAuth sign-in from Claude and ChatGPT and API keys from other clients, offers read and draft tools to every connected company and the three acting tools to companies that allowed acting under Settings → AI agent (MCP). Prices are on the pricing page; the technical description is in the developer documentation.
Frequently asked questions
Do I need to know anything technical?
No. For Claude or ChatGPT the connection is a sign-in, not a configuration file. You add KRONENWERK as a connector, sign in, confirm, and talk. Developers who want to connect their own agent find the endpoint and the protocol details in the developer documentation.
Which assistants work?
Any assistant or agent that speaks MCP over Streamable HTTP: Claude (web, desktop and mobile), ChatGPT with connectors, and agent frameworks that let you name a remote MCP server. The server accepts both the current per-request protocol revision and the older handshake-based ones.
Can the assistant make a mistake in my books?
It can misread a document, as a person can — which is why, at the default level, everything it produces is a draft or a bill awaiting confirmation. Figures on supplier bills are recorded as printed, never recomputed. At the acting level each act is bounded by the amount you set, and every act is on the record.
Does my data go to Anthropic or OpenAI?
What the assistant reads through a tool call becomes part of your conversation with that assistant, under that provider's terms. The assistant sees only what its tools return for the one company it is connected to. KRONENWERK sends nothing on its own; the server never pushes.
Which plan do I need?
The MCP server, the REST API, webhooks and the integration directory are part of the Enterprise plan and the practice plan. Every plan already includes the books themselves; the assistant is the layer on top.
Is this the same as automation rules?
No. Automation rules are fixed triggers and actions the company writes once — a reminder three days after the due date, an approval before issuing. An assistant decides at run time what to call, from what you say. The two combine: the assistant drafts, the approval rule holds the draft until a person signs.
The pages in this guide
- How to connect Claude to your accounting: KRONENWERK step by step Connect Claude (or ChatGPT) to KRONENWERK in five minutes: add the connector, sign in, choose the level, ask your first questions. No key to copy, revocable in one click.
- What an AI assistant can and cannot do in your books — with 30 things to ask The exact boundaries of an AI assistant in KRONENWERK: every tool it can call, the acts that stay with a person, the three levels, and thirty prompts that work.
- A month of bookkeeping with an AI assistant: a contractor's four weeks, task by task What a small contractor does with Claude connected to KRONENWERK for a month: receipts, bills, quotes, invoices, payments — and the moments where a person still signs.