BuchPilot MCP Server

MCP Server for DACH accounting — manage contacts, invoices, vouchers, and quotes directly from Claude, Cursor, or any MCP-compatible client.

What is this?

BuchPilot MCP is a Model Context Protocol server that connects your accounting system (currently Lexoffice) with AI assistants. You can create invoices, manage contacts, and check overdue payments using natural language — directly in Claude Desktop, Cursor, or any other MCP client.

Related MCP server: @centry-digital/bukku-mcp

Features

• 15 tools for complete accounting automation

• Contacts: create, retrieve, list, update

• Invoices: create, retrieve, list, update, download PDF

• Vouchers: create, retrieve, list (incoming invoices, credit notes)

• Quotes: create, retrieve

• Overdue invoices: with amounts and days overdue

• Backend architecture — currently Lexoffice, extensible for sevDesk, Billomat, etc.

• Plugin-ready — can integrate E-Invoice MCP tools (einvoice-mcp)

• No database, no state — pure API proxy

Installation

Prerequisites

• Node.js >= 18

• A Lexoffice account with an API key

npm (global)

npm install -g buchpilot-mcp

From source

git clone https://github.com/makririch/buchpilot-mcp.git
cd buchpilot-mcp
npm install
npm run build

Configuration

Create a configuration file .buchpilot.json in one of the following locations:

1. Path from environment variable BUCHPILOT_CONFIG

2. ~/.buchpilot.json (home directory)

3. ./.buchpilot.json (current directory)

Content of .buchpilot.json

{
  "backends": {
    "lexoffice": {
      "api_key": "DEIN_LEXOFFICE_API_KEY"
    }
  },
  "default_backend": "lexoffice"
}

Create Lexoffice API key

1. Go to Lexoffice Public API

2. Click on Create API key

3. Copy the key and paste it into .buchpilot.json

Security note: Never store the API key in Git. Add .buchpilot.json to your .gitignore.

Usage

Start server (standalone)

# Nach npm install -g:
buchpilot-mcp

# Oder von Source:
npm start

# Entwicklung mit Auto-Reload:
npm run dev

The server runs via stdio and waits for MCP messages.

Use in Claude Desktop

See Claude Desktop Setup Guide for detailed instructions.

Quick version — add to claude_desktop_config.json:

{
  "mcpServers": {
    "buchpilot": {
      "command": "npx",
      "args": ["-y", "buchpilot-mcp"],
      "env": {
        "BUCHPILOT_CONFIG": "/Users/DEIN_NAME/.buchpilot.json"
      }
    }
  }
}

Examples (natural language in Claude)

After configuring the server, you can ask Claude, for example:

• "Create a contact for the company Beispiel GmbH with the email info@beispiel.de"

• "Show me all open invoices"

• "Create an invoice for contact XYZ: 10 hours of consulting at 150 EUR each"

• "Which invoices are overdue?"

• "Download the PDF for invoice ABC"

• "Create a quote for 5 licenses at 49 EUR/month"

Tool Reference

A full reference of all 15 tools with parameters, example inputs, and example outputs can be found in docs/tool-reference.md.

Quick Overview

E-Invoice Integration

BuchPilot MCP can optionally integrate the E-Invoice MCP package to generate XRechnung and ZUGFeRD directly from the accounting system:

// In deinem eigenen MCP-Server:
import { registerEInvoiceTools } from "einvoice-mcp";
registerEInvoiceTools(server);
// Ergebnis: 15 + 4 = 19 Tools

FAQ / Troubleshooting

"No .buchpilot.json found"

The server cannot find a configuration file. Create a .buchpilot.json in your home directory:

echo '{"backends":{"lexoffice":{"api_key":"DEIN_KEY"}},"default_backend":"lexoffice"}' > ~/.buchpilot.json

"401 Unauthorized" with Lexoffice

• Is the API key correct in .dachflow.json?

• Is the key still active? Check under Lexoffice Public API

• API keys can expire — create a new one if necessary

"429 Too Many Requests"

Lexoffice allows a maximum of 2 requests per second. If you perform many operations in succession, wait a moment between requests.

Server starts, but Claude does not recognize the tools

• Check if claude_desktop_config.json is correct

• Restart Claude Desktop after configuration changes

• Check the logs: ~/Library/Logs/Claude/mcp.log (macOS)

Invoice cannot be updated

Only invoices with the status draft can be updated. Finalized invoices are immutable.

Backend "sevDesk" not available

Currently, only Lexoffice is supported as a backend. sevDesk support is planned. You can use the n8n nodes (n8n-nodes-buchpilot) for sevDesk.

License

MIT — Free to use, including commercially.

Author

MaKri — GitHub