FeatBit is an open-source feature flag management platform designed for developers who need full control over their release process without relying on third-party SaaS solutions. Built with .NET and supporting multiple SDKs including C#, Python, JavaScript, and Go, it enables teams to decouple deployment from release, test features in production with minimal risk, and roll out functionality incrementally to targeted user segments. The platform is engineered for self-hosting—running on Docker, Kubernetes, or Helm—and includes enterprise features like IAM, SSO, and audit logs while maintaining an open core model that keeps the foundation freely accessible.
FeatBit is ideal for engineering teams managing complex microservices architectures, compliance-sensitive environments, or high-traffic applications requiring precise control over feature availability. With built-in A/B testing, real-time insights, and integrations with observability tools like DataDog, New Relic, and OpenTelemetry, it empowers developers to drive product decisions directly from code—without waiting on DevOps or infrastructure teams.
What You Get
- Self-hosted deployment - Deploy FeatBit using Docker Compose, Kubernetes, or Helm charts on your own infrastructure with full data control and compliance assurance.
- Multi-language SDKs - Integrate feature flags using official SDKs for .NET (C#), Python, JavaScript, React, Node.js, Java, Go, and OpenFeature providers.
- User targeting & segments - Define user segments based on attributes (e.g., email, location, plan tier) to roll out features to specific groups without code changes.
- A/B experimentation - Run feature-level A/B tests with built-in analytics to measure impact on user behavior and business metrics.
- Audit logs & IAM - Track all changes to feature flags and segments with detailed audit trails, and enforce access policies via role-based permissions.
- Relay Proxy/Agent - Deploy lightweight agents in customer environments or edge locations to reduce latency and maintain feature flag availability during network outages.
- Web APIs & automation - Programmatically manage flags, segments, and environments via RESTful APIs for CI/CD pipeline integration.
- SSO & multi-organization support - Integrate with SAML/OAuth identity providers and manage multiple teams or clients under one instance (commercial features).
- Observability integrations - Connect to DataDog, New Relic, Grafana, and OpenTelemetry for real-time monitoring of feature flag impact on system performance.
- Feature workflow automation - Automate flag changes with scheduled toggles, approval workflows, and triggers to enforce release governance.
Common Use Cases
- Building a multi-tenant SaaS dashboard with real-time analytics - Use FeatBit to enable premium features for specific customer segments based on subscription tier, while monitoring usage via built-in insights and OpenTelemetry traces.
- Creating a mobile-first e-commerce platform with 10k+ SKUs - Roll out new product filters or checkout flows to 5% of users first, measure conversion impact with A/B tests, and safely scale exposure based on performance data.
- Deploying a risky UI overhaul causes production crashes - Use FeatBit to wrap the new interface in a feature flag, deploy code safely, and disable it instantly via dashboard if errors spike
- DevOps teams managing microservices across multiple cloud providers - Self-host FeatBit on-premises to comply with data residency laws, while using Relay Proxy to serve flags with low latency across AWS, Azure, and GCP environments.
Under The Hood
The project is a feature flag management platform built with a modern web stack, integrating Angular for the frontend and C# for the backend. It emphasizes scalability and flexibility through modular architecture, multi-environment support, and extensive infrastructure tooling.
Architecture
This system adopts a layered architecture with clear separation between presentation, core logic, and data access layers, enhancing maintainability and testability.
- The codebase is organized into well-defined modules with distinct folders for features, services, and shared utilities, promoting modularity.
- Design patterns such as dependency injection and component-based UI rendering are consistently applied to improve reusability and decoupling.
- Communication between frontend and backend modules is managed through defined services and routing mechanisms, ensuring clean interaction.
Tech Stack
Built using a contemporary web stack with Angular and C#, the project leverages modern frameworks and tools for robust development.
- The frontend is developed with Angular (TypeScript), utilizing Ng-Zorro-antd, RxJS, and Monaco Editor for UI and reactive programming.
- The backend is implemented in C#, supporting cloud-native deployment patterns and integration with various infrastructure components.
- Development workflows include Angular CLI for building and serving, with support for localization and multi-language development.
Code Quality
The project exhibits a mixed level of code quality with structured testing practices and some consistency in error handling, though not uniformly applied.
- Code linting is configured, and type safety is enforced via TypeScript, contributing to improved code clarity.
- Unit testing capabilities are present through Angular CLI’s test runner and integration into CI/CD pipelines.
- Error handling is implemented with try/catch blocks, particularly in benchmark scripts, though patterns vary across modules.
What Makes It Unique
This platform stands out through its modular provider model and deep integration with various backend systems, offering flexibility in deployment and configuration.
- It uniquely supports microservices architecture alongside infrastructure-as-code practices, enabling multi-environment deployments.
- The system provides a flexible provider model that integrates with databases, messaging systems, and caching solutions.
- Extensive support for various infrastructure tools and deployment configurations makes it distinct from generic feature flag solutions.