Connect Lexware Office to Claude

Lexware Office has no MCP server of its own, but it has a Public API. Several open-source servers build on it; XenMCP plans to run a reviewed one in an isolated sandbox.

Accounting data is sensitive. That is why the server starts read-only; creating invoices or contacts has to be switched on deliberately, and your AI client asks before every change.

What you can ask Claude

• Which invoices are more than 30 days overdue?
• How much revenue did we make with customer Schmidt last quarter?
• Show me the October vouchers that are not yet assigned.
• Which quotes from this month are still open?
• Create a draft invoice for Example GmbH for 3 hours of consulting.

Typical tools

list_invoices

Find invoices by status and period

get_voucher

Read a voucher or invoice with its line items

search_contacts

Find customers and suppliers

list_quotations

Show quotes and order confirmations

create_invoice_draft

Create a draft invoice (only with approval)

create_contact

Create a contact (only with approval)

What you need to connect

• Lexware Office in the XL plan – according to Lexware, the Public API is only available there
• An API key from Lexware Office (Settings → Extensions → Public API)
• A decision whether write access is needed at all (default: read-only)

Security

• The Lexware Office API key grants access to the whole account. XenMCP stores it encrypted with AES-256-GCM and never shows it again after saving.
• The server starts read-only; write access is a deliberate setting.
• Each server runs in its own sandbox (gVisor) in Germany; the call log holds only tool, status and duration – no amounts or names.
• Invoice data contains personal data (GDPR). Your AI client processes the results in its own infrastructure – choose it accordingly.

Built on

We use the open server mcp-lexware-office (Jannik Wempe) (MIT), build the image ourselves from a pinned version and review the tool descriptions before release.

Frequently asked questions