How to Connect FastBill to ChatGPT for AI-Powered Invoicing

Connect FastBill to ChatGPT

FastBill is a popular German invoicing platform. With AnythingMCP, you can expose FastBill data as MCP tools that ChatGPT can call directly — no custom code needed.

What You Can Do

Once connected, ask ChatGPT:

• "Show all unpaid invoices from this month"
• "How much revenue did I make in Q1?"
• "List expenses over 500€ from last quarter"
• "Which customers have the most open invoices?"

Quick Setup

git clone https://github.com/HelpCode-ai/anythingmcp.git
cd anythingmcp && docker compose up -d

1. Open http://localhost:3000/connectors/store and import the FastBill adapter
2. Enter your FastBill email and API key
3. Assign the connector to an MCP server

Connect to ChatGPT

ChatGPT supports MCP servers via its remote server configuration. Point it at your AnythingMCP endpoint:

{
  "mcpServers": {
    "fastbill": { "url": "https://your-anythingmcp-instance.com/mcp" }
  }
}

For ChatGPT Desktop, add the server URL in Settings → Connected Tools → Add MCP Server.

Available Tools

• fastbill_list_customers — Search customers
• fastbill_list_invoices — Filter invoices by customer, month, year
• fastbill_get_invoice — Full invoice details with line items
• fastbill_list_expenses — Expenses by period
• fastbill_list_revenues — Revenue tracking