Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@office-books-mcp Which invoices are overdue?"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
Ask your AI assistant about your Lexware Office books, safely.
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The Lexware logo above is a trademark of Lexware GmbH (Haufe Group), shown only to identify the service this tool connects to. This project is independent and is not affiliated with, endorsed by, or sponsored by Lexware GmbH or the Haufe Group, and claims no rights to the logo. Answers are not tax advice. Full disclaimer in docs/TRADEMARKS.md.
Lexware has an official MCP server. Since autumn 2026 Lexware runs its own hosted Lexware Office MCP server for Claude and ChatGPT, with OAuth login, read and write access and a GoBD action log, included in the XL plan. For most people that is the right choice, see lexware.de/funktionen/lexware-mcp.
office-books-mcp is an independent alternative for people who prefer to run the connection on their own machine. It talks to the Lexware Public API directly with your own API key, works with any MCP client, and is read only, so it cannot change your books.
Lexware official MCP | office-books-mcp | |
Runs on | Lexware servers, EU/Germany | Your own machine |
Login | OAuth with your Lexware account | Your own Public API key |
Access | Read and write | Read only |
Clients | Claude, ChatGPT | Any MCP client (Claude Desktop, Claude Code, Cursor, others) |
Source | Closed | Source available, you can read every line |
Related MCP server: Unofficial Lexware Office MCP Server
Answers from your real books. "Which invoices are overdue?", "What did we buy from this vendor in March?", "Show me the contact for Müller GmbH."
Read only for now. This preview cannot create, change or delete anything in Lexware Office.
Respects Lexware's limits. Requests are paced to 2 per second, and a rate-limited call is retried automatically.
Clear errors. An expired key, a missing XL plan or a timeout is explained in plain words, and your key never appears in a message.
In Lexware Office (XL plan), create an API key. The step-by-step guide with screenshots shows every click.
Build the server.
npm install && npm run buildCheck the key.
LEXWARE_API_KEY=your-key node dist/index.js doctorYou should see OK. Connected to Lexware Office company "...".
Add it to your MCP client, for example Claude Desktop.
{
"mcpServers": {
"office-books": {
"command": "node",
"args": ["/path/to/office-books-mcp/dist/index.js"],
"env": { "LEXWARE_API_KEY": "your-key" }
}
}
}Ask "Which invoices are open?".
Your key stays on your machine, in the MCP client config or in .env/.env.local, which git ignores.
Tool | What it reads |
| Company profile |
| Customers and vendors |
| Products and services |
| Search all vouchers by type, status and date |
| Bookkeeping vouchers with booking categories |
| Invoices, credit notes, quotations, order confirmations, delivery notes, down payment invoices, dunnings |
| Payment status of a voucher |
| Recurring invoice templates |
| Countries, payment conditions, posting categories, print layouts |
Part | Choice |
Language | TypeScript, Node 22+ |
Protocol | Model Context Protocol over stdio |
API | Lexware Office Public API at |
Rate limiting | Token bucket, 2 requests per second |
Retries | 429 retried for every method, 5xx and network errors retried for reads only |
Tests | node:test plus fast-check property tests |
src/
api/ HTTP client, rate limiter
tools/ MCP tool definitions
config.ts API key loading
server.ts MCP server
index.ts CLI (serve, doctor)
test/unit/ Unit, failure-path and property testsnpm test # unit tests
npm run typecheck # strict TypeScript
npm run build # compile to dist/Source-available, not open source. Free for personal, non-commercial evaluation with credit. Business use needs written consent. See LICENSE and contact through next8n.com.
Read one article with its price.
Inputs: id (required).
Read one contact with addresses, email addresses and phone numbers.
Inputs: id (required).
Read the payment status and payment items of a voucher or sales document.
Inputs: id (required).
Read the connected Lexware Office company profile: company name, tax type, small business status and connected user.
Inputs: no named parameters.
Read reference lists needed to fill documents correctly: countries with tax classification, payment conditions, posting categories, print layouts.
Inputs: kind (required).
Read an invoice, credit note, quotation, order confirmation, delivery note, down payment invoice or dunning by id.
Inputs: id (required), type (required).
Read a bookkeeping voucher (salesinvoice, salescreditnote, purchaseinvoice, purchasecreditnote) with its items and booking categories.
Inputs: id (required).
List products and services from the article catalogue.
Inputs: gtin, page, size, type, +1 more.
List customers and vendors. Filter by name (min 3 chars), email, customer or vendor number, or role.
Inputs: name, page, size, email, +3 more.
List templates for recurring invoices.
Inputs: page, size.
Search all vouchers (sales and purchase invoices, credit notes, quotations and more) by type, status and dates. Returns metadata. Use get_sales_document or get_voucher for full details.
Inputs: voucherType (required), voucherStatus (required), page, size, +5 more.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
Loading tool schema changelog…
Scored across 11 tools
Most tools target a distinct resource (profile, contacts, articles, payments, reference data), and descriptions clarify the list/detail split. However list_vouchers vs get_voucher vs get_sales_document overlap conceptually around invoices, requiring careful reading to pick the right entry point.
Every tool follows a consistent verb_noun pattern using only get_ and list_ prefixes (get_profile, list_contacts, get_contact, list_articles, etc.). The convention is predictable and readable throughout.
11 tools is well within the ideal 3-15 range and each tool maps to a distinct resource or query type in the Lexware Office domain. Nothing feels redundant or padded.
The surface is entirely read-only: contacts, articles, vouchers, and recurring templates can be listed and read but never created, updated, or deleted, leaving common accounting workflows as dead ends. Listing recurring templates without a get_recurring_template also hints at an incomplete lifecycle.
AI accounting: ask about your live AccountsOS books in plain English. Read-only tools for transactions, cash balances, invoices, bills, VAT, filing deadlines and reports across 32 countries. OAuth sign-in; free 14-day trial at accounts-os.com.
Query your books, company data, business health, and ship invoices from your AI assistant.
Lexware Office (lexoffice) MCP server for ChatGPT, Claude and any AI agent: create quote, create invoice, finalise invoice, upload receipt and add contact in your own Lexware Office (lexoffice) account. Cotlet works in the account through your Cloud Browser, a real Chrome where you sign in to Lexware Office (lexoffice) yourself; Cotlet does not store your password and you need no Lexware Office (lexoffice) API key. About the official Lexware Office (lexoffice) API: Yes, Lexware Office has a public REST API with an API key (checked 14 Oct 2026). It covers quotes, order confirmations, invoices, contacts, file uploads, payments (read only) and webhooks, but only from version XL, and Lexware publishes no MCP server of its own. Setup and FAQ: https://cotlet.dev/integrations/lexware-office-api-mcp-server
Read-only access to your business finances: invoices, customers, vendors, taxes, profitability.
