Flagsmith/flagsmith

Flagsmith is an open-source feature management platform that offers remote configuration and experimentation solutions. Choose from three deployment options: self-hosted (available as our free open-source build or a fully supported Enterprise edition), private cloud, and cloud.

As an open-source solution, Flagsmith provides flexibility and greater control over your choices. Thanks to our partnership with OpenFeature, you are never locked into one vendor.

With Flagsmith, you can evolve how your team releases software. Roll out, segment, experiment, and optimise with granular control. Stay secure by self-hosting, or choosing our private cloud deployment option.

• Feature flags: Release features behind the safety of a feature flag
• Make changes remotely: Easily toggle individual features on and off, and make changes without deploying new code
• A/B testing: Use segments to run A/B and multivariate tests on new features
• Segments: Release features to beta testers, collect feedback, and iterate
• Organisation management: Stay organised with orgs, projects, and roles for team members
• SDKs and frameworks: Choose from 15+ popular languages like TypeScript, .NET, Java, and more. Integrate with any framework, including React, Next.js, and more
• Integrations and MCP server: Use your favourite tools with Flagsmith

Flagsmith makes it easy to create and manage feature flags across web, mobile, and server-side applications. Just wrap a section of code with a flag, and then use Flagsmith to toggle that feature on or off for different environments, users, or user segments.

If you want a step-by-step demonstration of how to get started with Flagsmith, why not try our interactive demo.

curl -o docker-compose.yml https://raw.githubusercontent.com/Flagsmith/flagsmith/main/docker-compose.yml
docker-compose -f docker-compose.yml up

The application will bootstrap an admin user, organisation, and project for you (learn more about Flagsmith terminology in our data model docs). You'll find a link to set your password in your Compose logs:

Superuser "admin@example.com" created successfully.
Please go to the following page and choose a password: http://localhost:8000/password-reset/confirm/.../...

Once Flagsmith is running, checking a flag takes one function call. Here's how it looks in JavaScript:

import flagsmith from 'flagsmith';

flagsmith.init({
  environmentID: '<your environment key>',
  onChange: () => {
    if (flagsmith.hasFeature('show_demo_button')) {
      // show the new feature
    }
  },
});

As this example runs in the browser, you should use your client-side environment key. Server-side keys must stay secret and never appear in browser code.

Follow the quick start guide for the full walkthrough, or pick your language from our SDK docs to see the same thing in Python, Java, Go, .NET, and more.

We love contributions from the community and are always looking to improve our open-source feature management platform! Here are our contribution guidelines.

You can try our hosted version for free at app.flagsmith.com/signup.

• Visit our docs
• Chat with other developers on Discord
• If you need help getting up and running, get in touch

• JavaScript
• React
• Next.js and SSR
• Android
• iOS
• Flutter

• Python
• Java
• .NET
• Node.js
• Ruby
• PHP
• Go
• Rust
• Elixir

Prefer the vendor-neutral route? You can use Flagsmith through OpenFeature with providers for the following languages:

• Go
• Java
• JavaScript (client-side)
• JavaScript (server-side)
• Kotlin
• .NET
• Python
• Ruby
• Rust

Check out the OpenFeature docs for setup.

The majority of our platform is open source under the BSD-3-Clause license. A small number of repositories are under the MIT license.

We built Flagsmith as the open-source feature flag tool we needed but couldn't find on GitHub. Our core functionality stays open, always. Read our open letter to developers.

As our core functionality is open, you can use our open-source feature flag and remote config management platform no matter what. Enterprise-level governance and management features are available with a valid Flagsmith Enterprise license.

To learn more, contact us or see our version comparison.

Thank you to the open-source community for your contributions and for building this with us!

Made with contrib.rocks.