PocketBase

PocketBase is an open-source backend written in Go that ships as one file. It bundles an embedded SQLite database with realtime subscriptions, built-in management of users and files, a convenient admin dashboard and a simple REST-style API, which makes it quick to stand up a backend for a small web or mobile project.

You can use it as a standalone application by downloading the prebuilt executable for your platform and running its serve command, or you can extend it as a Go library to add custom routes and logic. The prebuilt binaries come with a JavaScript VM plugin enabled for scripting. Official SDK clients exist for JavaScript, covering browsers, Node.js and React Native, and for Dart, covering web, mobile, desktop and CLI.

PocketBase is MIT licensed. The maintainers warn that it is still under active development and that backward compatibility is not guaranteed before version 1.0.0, so upgrades deserve some care. It suits solo developers and small teams who want a simple, self-contained backend without managing a database server separately.