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    4.0.4 • Public • Published

    Unleash is the open-source feature management platform. It provides a great overview over all feature toggles/flags across all your applications and services. Unleash enables software teams all over the world to take full control on how they enabled new functionality to end users.

    Unleash comes with official client SDKs for all the popular languages.


    • Boolean feature toggles (on/off)
    • Canary release (Gradual rollout)
    • Targeted release
    • Experimentation (A/B testing)
    • Kill Switches
    • Custom activation strategies
    • Privacy first (GDPR) where end-user data never leaves your application
    • Audit logs
    • Addons integrating with other popular tools (Slack, Teams, Datadog, etc.)
    • It is secure (Enable Secure Headers with strict HTTPS only mode)
    • Extremely scalable with evaluations on the client side. Used in enterprises handling more than 10k req/s. Read more about our architecture
    • Dashboard to manage technical debt
    • Admin APIs
    • Flexible architecture and can be hosted anywhere
    • Docker image available

    Unleash Enterprise builds directly on top of the Open-Source and provides additional advanced functionality:

    • Project support
    • Advanced segmentation
    • Support
    • SSO (SAML 2.0, OpenID Connect, etc)
    • A Hosted offering where the Unleash team host, monitor, scale, upgrades and take full backups for your.

    Client SDKs

    In order to connect your application to Unleash you need to use a client SDK for your programming language.

    Official Server SDKs:

    Official Frontend Unleash Proxy SDKs:

    In addition there exists a good list of community developed SDKs, so there might already exist an implementation for your favorite programming language (PHP, Elixir, Dart, Rust, Clojure, NestJS, Kotlin and more.)

    What is a feature toggle?

    The main motivation for doing feature toggling is to decouple the process for deploying code to production and releasing new features. This helps reducing risk, and allow us to easily manage which features to enable

    Feature toggles decouple deployment of code from release of new features

    This repo contains the unleash-server, which contains the Unleash Admin UI and the Unleash API. In order to make use of unleash you will also need a client SDK.

    Unleash Admin UI

    Online demo

    Activation strategies

    It's fine to have a system for turning stuff on and off. But some times we want more granular control, we want to decide who to the toggle should be enabled for. This is where activation strategies comes in to the picture. Activation strategies take arbitrary config and allows us to enable a toggle in various ways.

    Common activation strategies includes:

    • Active For users with a specified userId
    • GradualRollout to X-percent of our users
    • Active for our beta users
    • Active only for application instances running on host x.

    Read more about activation strategies in our docs.

    The Client API

    The client SDKs provides a simple abstraction making it easy to check feature toggles in your application. The code snippet below shows how you would use Unleash in Java.

    if (unleash.isEnabled("AwesomeFeature")) {
      //do some magic
    } else {
      //do old boring stuff

    Running Unleash

    The are numbers of ways you can run Unleash.

    1. Run it yourself (on prem, self hosted)

    Unleash is open source and you are free to run your own instance. The Getting started guide goes through all the options on how to run Unleash.

    2. Unleash as a Service

    After numerous request we have created a separate company, Unleash-hosted, which offer Unleash as a Service. Unleash-hosted allows you to focus on you core business and have someone else taking care of hosting and maintaining Unleash.

    Go to getunleash.io to learn more about this offering and start using Unleash today. This service also includes official support.

    Contribute to Unleash

    Unleash has been built with the help of many smart individuals. This ensures that we build a product that solves real problem for people. If you want to contribute to this project you are encouraged to send issue request, or provide pull-requests. Please read the CONTRIBUTING.md to learn more on how you can contribute.


    We know that learning a new tool can be hard and time consuming. We have a growing community which loves to help out. Please don't hesitate about reaching out to get help.

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