Every app eventually needs to store files — avatars, attachments, exports. And in Node/NestJS the usual options are all a bit of a chore: pay for AWS S3 and juggle credentials, stand up and babysit a MinIO container, or hack something onto local disk that you'll have to rip out later.

OpenBucket takes a different route: it's an S3-compatible object store you npm install straight into your NestJS app. No second service, no container in local dev, no cloud account. In this tutorial we'll add a working upload endpoint — with validation and a shareable URL — in about ten minutes.