How to connect your bookkeeping to ChatGPT and Claude (MCP)
You connect bookkeeping to ChatGPT or Claude by adding a connector that speaks the Model Context Protocol (MCP). You paste the connector address into the assistant, sign in with your bookkeeping account and approve access. From then on the assistant can answer questions such as "which invoices are overdue" from your real documents, and prepare drafts you approve.
What MCP is
The Model Context Protocol is an open standard for connecting assistants to external applications. The application runs a server that describes its tools: names, parameters and what they return. The assistant reads that description, decides when a tool fits your question, calls it and answers from the result.
For bookkeeping this means the assistant does not need to know accounting rules. It asks the connector for "unpaid invoices due this month" and receives a structured list. The reasoning happens in the assistant; the figures come from your books. Remote connectors sign you in with OAuth, as described in the MCP authorization specification, so you never paste a password or API key into a chat.
What a bookkeeping connector can do
📊What the Kontevia connector can do
| Tool | Reads or drafts |
|---|---|
| Document overview and search | Reads |
| Overdue invoices | Reads |
| VAT summary for a month or quarter | Reads |
| Bank transactions and matching status | Reads |
| Tax calendar | Reads |
| Invoice draft | Drafts, waits for your approval |
| Document upload from the chat | Drafts, waits for your approval |
| Prepared VAT filing | Drafts, stored only, never sent |
With these tools the assistant can answer in plain language, explain what a figure is made of, write a polite reminder to a late payer with the right amounts, or summarise the quarter for your accountant. You can ask in any language the assistant speaks.
Practical example
A freelance translator in Milan asks Claude: "Which invoices are overdue and how much VAT do I owe for Q3?" The assistant calls two tools and answers: two overdue invoices for EUR 1,830 in total, the oldest 12 days late, and an estimated VAT payable for the quarter based on her documents. She asks for a reminder to the oldest client; the draft text appears in the chat, and sending stays her decision.
What it should not do
Write actions are technically possible, but a misread instruction that deletes a document or files the wrong return has real cost. Sensible limits for any bookkeeping connector:
- reading and drafting only, with approval in the bookkeeping app,
- no approving, rejecting or deleting documents through the assistant,
- nothing sent to customers or tax authorities from the chat,
- access scoped to your own account and revocable at any time.
That is how the Kontevia connector is built. Two honest limits: totals for a custom period may be approximate for accounts with hundreds of documents, because the assistant adds up a paginated list, and payment matching is read-only through the connector.
Where your data goes
When the assistant calls a tool, the result enters the conversation and is processed by the assistant's provider under its terms. For many businesses that is fine; for some it is not. Decide deliberately, check the provider's data terms against your obligations under the GDPR, and connect only the account you need. Claude's own guidance on custom connectors recommends connecting only trusted servers and reviewing the permissions requested at sign-in.
📋How to connect Kontevia
- Claude – open the connectors section in settings (currently Customize, Connectors), choose Add custom connector and paste the Kontevia connector address.
- ChatGPT – during early access, enable developer mode in the apps and connectors settings and create a connector with the Kontevia address and OAuth sign-in.
- Sign in – log in with your Kontevia account and approve access, like signing in with Google.
- Ask – overdue invoices, VAT for the period, top suppliers, upcoming deadlines.
- Revoke when done – one click in Kontevia settings ends access.
If anything asks you to paste an API key or password into the conversation itself, stop. A connector should authenticate through a proper sign-in page, never through the chat.
What it costs
The connector is part of the Kontevia subscription, with no activation fee. Questions use credits from your plan: a typical question one credit, an invoice draft three. During the free trial no credits are deducted. Plans start at EUR 9 a month excluding VAT; see pricing.
The sister product connector
Kontevia's connector is the same one our sister product DokladBot runs in Czechia. Listing in the official connector catalogues of the assistants is in progress; until then the custom connector route above is the way in. The same endpoint works in other assistants that support MCP, and Gemini is on the roadmap.
Where this is going
Connectors turn bookkeeping from a place you visit into a source an assistant can consult. The value for a small business is not that the assistant does the accounting. It is that questions get answered without exporting a report, and drafts get written with the right numbers. The bookkeeping itself still happens in the platform, under the rules of your country, with an audit trail. The assistant reads and suggests; you decide.
Read more about the assistant in Kontevia, or go straight to the setup pages for Claude and ChatGPT.
Official sources
- Model Context Protocol
- MCP specification: authorization
- Claude help centre: custom connectors using remote MCP
- General Data Protection Regulation (EU) 2016/679 on EUR-Lex
This article is general information and does not replace professional advice. Information valid as of 10 October 2026.
Frequently asked questions
- What is an MCP connector?
- The Model Context Protocol is an open standard that lets an assistant call tools exposed by another application. A bookkeeping connector offers tools such as listing overdue invoices or fetching a VAT summary, and the assistant calls them when you ask.
- Can the assistant change my books?
- In Kontevia, no. The assistant reads and can prepare drafts, such as an invoice or an uploaded document, but every draft waits for your approval in the dashboard. It cannot approve, send or delete anything.
- Is my accounting data sent to the assistant's provider?
- The result of each tool call is returned into your conversation and processed by the assistant's provider under its terms. Connect only what you need, review the provider's data terms and revoke access when you stop using it.
- Does it work on free plans?
- Claude's help centre states that custom connectors are available on all plans, with free users limited to one custom connector. In ChatGPT, Kontevia is added through developer mode during early access.
Topics:MCPChatGPTClaudeconnectorbookkeepingintegrations
Kontevia is in early access. Country-specific behaviour described here reflects the rules of each state, not a promise that every feature is live in your country today.
Bookkeeping that keeps up with EU rules
Send a receipt by chat or e-mail, and Kontevia reads it, posts it under the rules of your country and prepares VAT and the export for your accountant. Early access is open.
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