# OpenFeature

> OpenFeature is an open specification that provides a vendor-agnostic, community-driven API for feature flagging.


## Documentation


### tutorials


#### five-minutes-to-feature-flags

We’re going to add feature flagging to a Node service in under five minutes using OpenFeature, the open, vendor-agnostic feature flagging SDK.

- [Five Minutes to Feature Flags](https://openfeature.dev/docs/tutorials/five-minutes-to-feature-flags.md): We’re going to add feature flagging to a Node service in under five minutes using OpenFeature, the open, vendor-agnostic feature flagging SDK.

#### getting-started

- [Getting Started with the OpenFeature .NET SDK](https://openfeature.dev/docs/tutorials/getting-started/dotnet.md): Getting Started with the OpenFeature .NET SDK
- [Getting Started with the OpenFeature Go SDK and Go Gin](https://openfeature.dev/docs/tutorials/getting-started/go.md): Getting Started with the OpenFeature Go SDK and Go Gin
- [Getting Started with the OpenFeature Java SDK and Dropwizard](https://openfeature.dev/docs/tutorials/getting-started/java/dropwizard.md): Getting Started with the OpenFeature Java SDK and Dropwizard
- [Getting Started with the OpenFeature Java SDK and Spring Boot](https://openfeature.dev/docs/tutorials/getting-started/java/spring-boot.md): Getting Started with the OpenFeature Java SDK and Spring Boot
- [Getting Started with the OpenFeature JavaScript SDK on Express](https://openfeature.dev/docs/tutorials/getting-started/node.md): Getting Started with the OpenFeature JavaScript SDK on Express
- [Getting Started with the OpenFeature PHP SDK on Laravel](https://openfeature.dev/docs/tutorials/getting-started/php.md): Getting Started with the OpenFeature PHP SDK on Laravel
- [Getting Started with the OpenFeature Python SDK](https://openfeature.dev/docs/tutorials/getting-started/python.md): Getting Started with the OpenFeature Python SDK on Flask
- [Getting Started with the OpenFeature Rust SDK and Axum](https://openfeature.dev/docs/tutorials/getting-started/rust.md): Getting Started with the OpenFeature Rust SDK and Axum (with Docker example)

#### open-feature-cli

⚠️ The OpenFeature CLI is experimental!

- [OpenFeature CLI](https://openfeature.dev/docs/tutorials/open-feature-cli.md): ⚠️ The OpenFeature CLI is experimental!

#### open-feature-operator

- [In-Process and Client-side Evaluation with flagd and OpenFeature Operator](https://openfeature.dev/docs/tutorials/open-feature-operator/advanced-topics.md): This tutorial outlines some of the advanced features and configurations supported by the OpenFeature operator and flagd.
- [Quick Start: Cloud Native Feature-Flagging with the OpenFeature Operator](https://openfeature.dev/docs/tutorials/open-feature-operator/quick-start.md): In the following tutorial, we'll see how to leverage flagd and the OpenFeature Operator to enable cloud-native, self-hosted feature flags in your Kubernetes cluster. flagd is a "feature flag daemon with a Unix philosophy".

### reference


#### intro

OpenFeature is an open specification that provides a vendor-agnostic, community-driven API for feature flagging that works with your favorite feature flag management tool.

- [Welcome to OpenFeature](https://openfeature.dev/docs/reference/intro.md): OpenFeature is an open specification that provides a vendor-agnostic, community-driven API for feature flagging that works with your favorite feature flag management tool.

#### concepts

- [Evaluation API](https://openfeature.dev/docs/reference/concepts/evaluation-api.md): The Evaluation API is the primary component of OpenFeature that application authors interact with.
- [Evaluation Context](https://openfeature.dev/docs/reference/concepts/evaluation-context.md): The evaluation context is a container for arbitrary contextual data that can be used as a basis for dynamic evaluation.
- [Events](https://openfeature.dev/docs/reference/concepts/events.md): Events enable the ability to react to state changes in the provider or underlying flag management system.
- [Hooks](https://openfeature.dev/docs/reference/concepts/hooks.md): Hooks are a mechanism that allow for the addition of arbitrary behavior at well-defined points of the flag evaluation life-cycle.
- [Providers](https://openfeature.dev/docs/reference/concepts/provider.md): Providers are responsible for performing flag evaluations.
- [SDK Paradigms](https://openfeature.dev/docs/reference/concepts/sdk-paradigms.md): OpenFeature SDKs come in two "flavors"; those intended for use in server applications and those intended for use in client applications.
- [Tracking](https://openfeature.dev/docs/reference/concepts/tracking.md): Tracking in OpenFeature is the process of associating metrics or KPIs with feature flag evaluation contexts.

#### sdks

OpenFeature SDKs and components for a range of supported languages and runtimes.

- [SDK Technologies](https://openfeature.dev/docs/reference/sdks.md): OpenFeature SDKs and components for a range of supported languages and runtimes.
- [Client](https://openfeature.dev/docs/reference/sdks/client.md): OpenFeature SDKs and components for client-side usage.
- [OpenFeature Dart Client SDK](https://openfeature.dev/docs/reference/sdks/client/dart.md): Install and use the OpenFeature Dart SDK
- [OpenFeature Kotlin SDK](https://openfeature.dev/docs/reference/sdks/client/kotlin.md): Install and use the OpenFeature Kotlin SDK
- [OpenFeature iOS SDK](https://openfeature.dev/docs/reference/sdks/client/swift.md): Install and use the OpenFeature iOS SDK
- [OpenFeature Web SDK](https://openfeature.dev/docs/reference/sdks/client/web.md): Install and use the OpenFeature Web SDK
- [OpenFeature Angular SDK](https://openfeature.dev/docs/reference/sdks/client/web/angular.md): Install and use the OpenFeature Angular SDK
- [OpenFeature React SDK](https://openfeature.dev/docs/reference/sdks/client/web/react.md): Install and use the OpenFeature React SDK
- [SDK Compatibility Overview](https://openfeature.dev/docs/reference/sdks/sdk-compatibility.md): An overview of the status and supported features of the OpenFeature SDKs
- [Server](https://openfeature.dev/docs/reference/sdks/server.md): OpenFeature SDKs and components for server-side usage.
- [OpenFeature C++ SDK](https://openfeature.dev/docs/reference/sdks/server/cpp.md): Install and use the OpenFeature C++ SDK
- [OpenFeature Dart SDK](https://openfeature.dev/docs/reference/sdks/server/dart.md): Install and use the OpenFeature Dart SDK
- [OpenFeature .NET SDK](https://openfeature.dev/docs/reference/sdks/server/dotnet.md): Install and use the OpenFeature .NET SDK
- [OpenFeature Go SDK](https://openfeature.dev/docs/reference/sdks/server/go.md): Install and use the OpenFeature Go SDK
- [OpenFeature Java SDK](https://openfeature.dev/docs/reference/sdks/server/java.md): Install and use the OpenFeature Java SDK
- [OpenFeature Node.js SDK](https://openfeature.dev/docs/reference/sdks/server/javascript.md): Install and use the OpenFeature Node.js SDK
- [OpenFeature NestJS SDK](https://openfeature.dev/docs/reference/sdks/server/javascript/nestjs.md): Install and use the OpenFeature NestJS SDK
- [OpenFeature PHP SDK](https://openfeature.dev/docs/reference/sdks/server/php.md): Install and use the OpenFeature PHP SDK
- [OpenFeature Python SDK](https://openfeature.dev/docs/reference/sdks/server/python.md): Install and use the OpenFeature Python SDK
- [OpenFeature Ruby SDK](https://openfeature.dev/docs/reference/sdks/server/ruby.md): Install and use the OpenFeature Ruby SDK
- [OpenFeature Rust SDK](https://openfeature.dev/docs/reference/sdks/server/rust.md): Install and use the OpenFeature Rust SDK

#### other-technologies

- [OpenFeature CLI](https://openfeature.dev/docs/reference/other-technologies/cli.md): The OpenFeature CLI is a command-line tool designed to improve the developer experience when working with feature flags.
- [OpenFeature MCP Server](https://openfeature.dev/docs/reference/other-technologies/mcp.md): The OpenFeature Model Context Protocol (MCP) Server enables AI coding assistants to interact with OpenFeature through a standardized protocol.
- [OpenFeature Remote Evaluation Protocol (OFREP)](https://openfeature.dev/docs/reference/other-technologies/ofrep.md): The OpenFeature Remote Evaluation Protocol (OFREP) is an API specification for feature flagging that enables vendor-agnostic communication between applications and flag management systems. It defines a standard API layer between the provider and the flag management system, allowing any open source or commercial system to implement the protocol and be compatible with community-maintained providers.
- [OpenFeature Remote Evaluation Protocol (OFREP) (0.4.0)](https://openfeature.dev/docs/reference/other-technologies/ofrep/openapi.md)

## Specification

- [OpenFeature Specification](https://openfeature.dev/specification.md): An introduction to the OpenFeature specification.
- [Appendix A: Included Utilities](https://openfeature.dev/specification/appendix-a.md): Information on OpenFeature ecosystem utilities
- [Appendix B: Gherkin Suites](https://openfeature.dev/specification/appendix-b.md): A Set of End-to-End Tests for Validating OpenFeature Implementations
- [Appendix C: OpenFeature Remote Evaluation Protocol](https://openfeature.dev/specification/appendix-c.md): A unified protocol for feature flagging
- [Appendix D: Observability](https://openfeature.dev/specification/appendix-d.md): Conventions for OpenFeature telemetry signals
- [Appendix E: Migrations](https://openfeature.dev/specification/appendix-e.md): Migration guidance for breaking spec changes
- [Glossary](https://openfeature.dev/specification/glossary.md): A list of terms used within the OpenFeature specification.
- [3. Evaluation Context](https://openfeature.dev/specification/sections/evaluation-context.md): The specification that defines the structure and expectations of evaluation context.
- [5. Events](https://openfeature.dev/specification/sections/events.md): Specification defining event semantics
- [1. Flag Evaluation API](https://openfeature.dev/specification/sections/flag-evaluation.md): The specification that defines the developer facing feature flag evaluation API.
- [4. Hooks](https://openfeature.dev/specification/sections/hooks.md): The specification that defines the expectations and life cycle of hooks.
- [2. Provider](https://openfeature.dev/specification/sections/providers.md): The specification that defines the interfaces, behaviors and responsibilities of providers.
- [6. Tracking](https://openfeature.dev/specification/sections/tracking.md): Specification defining tracking API
- [Types and Data Structures](https://openfeature.dev/specification/types.md): A description of types and data structures used within the OpenFeature specification.

## Optional
- [flagd](https://flagd.dev/): OpenFeature-compliant feature flag evaluation engine
- [OpenFeature on GitHub](https://github.com/open-feature)