7 Things Developers Already Have That Can Generate Passive Income

Most developers have built something useful that sits in a GitHub repo collecting dust. A CLI tool. A Blender addon. A Figma plugin. A set of icons. A sound pack for a game jam. You know it is good. Other people would pay for it. But selling it feels like a whole second project - set up Stripe, build a checkout page, handle licenses, deal with hosting. So it just sits there. Free. Forever. Here are 7 things developers already have that can generate passive income - and how to actually start selling them without building an entire ecommerce system. 1. Browser Extensions and Desktop Tools If you built a productivity tool, a dev utility, or a browser extension that solves a real problem - people will pay for it. The trick is offering a free version with a paid upgrade. On 3DIMLI , you can upload your software and the platform handles license key generation and verification automatically. Your app calls a simple API to check if the buyer has a valid license: POST /api/software/v 1 /verify