Bookkeeping with Mistral Le Chat

What works today

Le Chat connects directly, without a bridge — as of October 2026.

Step 1: create a company key

• In the app go to Buchhaltung → Einstellungen → “KI-Agent & API” (Bookkeeping → Settings). Administrators or the workspace creator create keys and confirm with the second factor.
• Rights: read is always included; write to book, send to email invoices, finalize to lock periods. For questions only, a read-only key is enough.
• Expiry: 30, 90 or 365 days — there is no key without an end date. Up to ten active keys per company, 120 requests per minute each.
• A key belongs to exactly one company, such as your GmbH or UG (German limited company). The company follows from the key, and we store only a hash.

Step 2: add the connector

Le Chat detects the sign-in type from the URL and then asks for the token.

Open Connectors, click “+ Add Connector” and switch to the tab “Custom MCP Connector”. Enter a name and the server URL, then click Connect. When Le Chat asks for authentication, choose “HTTP Bearer Token” and paste the key exactly as the app shows it.

Our server accepts the key with or without “Bearer” in front, so pasting jab_live_… on its own is right.

Connectors → + Add Connector → Custom MCP Connector

Name:            buchhaltung
Server URL:      https://api.jahresabschluss.io/functions/v1/bookkeeping-mcp
→ Connect
Authentication:  HTTP Bearer Token
Token:           jab_live_…

Step 3: approvals per function

Le Chat lets you decide for each function whether it asks each time or is always allowed.

Mistral recommends manual approval for write functions, and so do we. A sensible setting: read functions such as get_saldenliste, list_open_items or list_bank_transactions on “always allow”; every write function — booking, invoices, payments, receipts, cash book — on “ask each time”.

On top of that, our server instructs the agent to describe irreversible steps — issuing or emailing an invoice, cancelling one, deleting a receipt, locking a period — and to wait for your explicit yes. The period lock only runs with confirm=true.

Example prompts

Ask in English; the agent books in your German books.

• “What does the Saldenliste (trial balance) for 2026 look like, and is it balanced?” → list_fiscal_years, get_saldenliste
• “Book yesterday's invoice from Example Office GmbH: €595 gross, office supplies, 19 % input VAT.” → list_accounts, book_incoming_invoice
• “Match last week's incoming payments to the open customer invoices.” → list_bank_transactions, list_open_items, match_bank_transaction
• “Set up a provision for the cost of this year's annual accounts.” → create_provision
• “Is anything still open before I lock September?” → list_bookkeeping_periods, list_receipts, list_bank_transactions

Guardrails: rights and GoBD

• write lets the agent book and reverse, issue and book invoices, record payments, handle receipts, bank lines, cash book, fixed assets, provisions and accruals, maintain master data and opening balances, and hand the trial balance to the annual accounts. send emails invoices only to addresses stored for the partner, with a daily limit. finalize locks periods.
• GoBD (the German rules for proper digital bookkeeping): booked entries are never deleted or overwritten, corrections are Storno reversals, every entry balances debit and credit, and locked periods stay locked.
• Text from a receipt or a bank reference is data, not an instruction to the agent. A retry with the same idempotency_key never books twice.
• Balance-sheet companies need a receipt before a bank line books to income or expense; EÜR (cash-basis) businesses book on payment.

What stays in the app

• Bank connections via OAuth and the link between bank account and ledger account.
• Company settings, such as the chart of accounts (SKR03 or SKR04) — the agent can only read them.
• IBAN and BIC of business partners, to prevent payment-redirection fraud.
• The manual opening balance of a first year with no previous year in the system.
• Every ELSTER filing (the tax authorities' electronic channel), including the Umsatzsteuer-Voranmeldung (VAT return).
• Annual accounts and E-Bilanz. publish_trial_balance hands the trial balance to the annual-accounts module; you complete the rest in the app, with your Steuerberater (tax adviser) if you work with one.

Frequently asked questions

Can I do my bookkeeping with Le Chat?

Yes. Add our MCP server as a custom MCP connector with the HTTP Bearer Token option and your company key. Le Chat then reads and books in your German bookkeeping, within the rights of the key.

I can't see “+ Add Connector”. Why?

Only admins can add connectors. On the Free, Pro and Student plans the account owner is the admin; in a team, ask your admin to add the connector.

Do I type “Bearer” in front of the key?

No need. Paste jab_live_… as shown in the app. Our server accepts the key with and without “Bearer”.

Does using Mistral keep my data in Europe?

We can't promise that for Mistral. Mistral is based in France, but what Le Chat does with the data it reads depends on your agreement with Mistral. If the agent should only evaluate, give it a read-only key.

Can Le Chat submit my VAT return to ELSTER?

No. get_vat_return reads the figures for a month or quarter, including the Dauerfristverlängerung (permanent filing extension) and Sondervorauszahlung (special advance payment). Every ELSTER filing stays in the app.

What does the connection cost?

API and MCP server come at no extra charge with the bookkeeping subscription (Solo or Gesamtpaket) or the EÜR subscription. Your Mistral plan is separate.