I built a free invoicing tool that lets AI create invoices for you (and why I almost didn't)

Hi, I'm Santiago García — freelance developer based in Haarlem, Netherlands, originally from Argentina. Like most freelancers, I hate invoicing. Not the money part — the process. Open Excel, copy the template, fill in the client, calculate VAT, export PDF, attach to email, pray they pay. Every. Single. Time. I built FacturaHub to fix that for myself. Then I realized it could fix it for a lot of people. What it is FacturaHub is an MCP server that connects AI assistants like Claude or Cursor directly to your invoicing. Instead of clicking through a UI, you just tell your AI: "Create an invoice for Acme for €2,500 for web development" And it's done. Client created if new, VAT applied, PDF generated, ready to send. That's it. No forms. No clicking. No context switching. Why MCP and not just an API? I could have built a regular REST API. But MCP (Model Context Protocol) changes the dynamic completely — instead of you calling the tool, your AI calls it on your behalf, with full context of th