Flagsmith

Flagsmith wraps a section of code in a flag so a feature can be switched on or off for different environments, users or user segments, without shipping new code to do it. It removes the deploy-to-change cycle that turns every small release decision into a full build.

The platform covers web, mobile and server side applications through SDKs for more than fifteen languages, among them TypeScript, .NET and Java, and it integrates with frameworks such as React and Next.js. A single Docker Compose file brings up the whole stack and bootstraps an admin user, an organization and a project on first run.

The feature set centers on controlling who sees what and when.

• Feature flags: release code behind a switch and toggle it remotely per environment.
• Segments: target beta testers or cohorts, then run A/B and multivariate tests against them.
• Remote configuration: change values in running applications without deploying again.
• Organization management: keep work in organizations, projects and roles for team members.
• Integrations: connect Flagsmith to the tools a team already uses.

Hosting runs on premise or in a private cloud, which keeps flag evaluation and user data inside your own network. Most of the platform is open source under the BSD 3-Clause license, with a few repositories under MIT, while enterprise governance features need a paid license. A hosted version exists for teams who would rather not run it themselves.