Why another invoicing tool? Every freelancer and SaaS founder needs invoices. Yet most solutions are either bloated SaaS subscriptions or clunky Excel templates. Invoice API is different – it's a lightweight, self-hosted REST API that generates professional PDF invoices in under 5 seconds. Built with FastAPI , WeasyPrint , and Stripe , it gives you full control without vendor lock-in. What can it do? Create customers & invoices via a clean REST API Generate PDF invoices with a single GET request (WeasyPrint, ~30KB per PDF) Receive Stripe webhooks for real-time payment status updates Dashboard to see all invoices at a glance Docker-Compose one-liner – docker compose up -d and you're live Tech stack Layer Technology API FastAPI + Pydantic v2 Database PostgreSQL 16 Cache Redis 7 PDF Engine WeasyPrint 62 Payments Stripe API (webhook) Container Docker + Docker Compose Auth Bearer JWT tokens Quick start # Clone & start git clone https://github.com/UniTy/invoice-api.git cd invoice-api docker compose up -d #…