Nona

Nona is an open-source tool for managing remote configuration and feature flags without handing control over to a hosted platform. You run it yourself with Docker, store your settings as simple key-value pairs, and read them at runtime through a single REST API call - from any language or platform that can make an HTTP request.

The idea is to keep things small and predictable. Instead of adopting a large feature-management platform and everything that comes bundled with it, you get just the core capability: turn features on or off, push config changes, flip kill switches, and roll changes out gradually — while keeping your data and infrastructure in your own hands.

It's built for teams that want an alternative to Firebase Remote Config or LaunchDarkly but would rather self-host something they can inspect, modify, and actually own. There are official JavaScript and .NET clients, a command-line tool, and a built-in migration command that imports your existing parameters straight from Firebase Remote Config. Nona is released under the Apache 2.0 license.