Open SaaS is a fully open source, full-stack SaaS starter kit built on the Wasp framework (React + Node.js + Prisma). It comes pre-integrated with core SaaS features, including user authentication (email, Google, GitHub), payment/subscription workflows via Stripe or Lemon Squeezy, file upload support (AWS S3), analytics dashboards (Plausible or Google Analytics), and an example AI-enabled app leveraging the OpenAI API for rapid prototyping. The template emphasises end-to-end type-safety, job scheduling, background tasks, and one-command deployment (e.g., wasp deploy) across hosting platforms like Fly.io, Railway, or custom providers. The codebase is organised vertically by feature (auth, payments, client UI, server logic, e2e tests) and includes guides for SEO, testing (via Playwright), deployment, updating, and customization. The project is MIT-licensed, free to use and distribute, and designed to eliminate boilerplate so developers can focus on building product logic.