SDKs
Feature flag SDKs
Each guide below uses the install command and evaluate call from the official docs or the public GitHub repository. Server SDKs take a secret sdk-srv-env- key. Browser and mobile SDKs take a public sdk-js-env- client key.
Browser
React feature flags
React feature flags with react-featureflow-client. Install the package, await asyncFeatureflowProvider, and read a flag with useFeature().isOn().
react-featureflow-client
JavaScript feature flags
JavaScript feature flags with featureflow-client. Featureflow.init with a client key, then evaluate('key').isOn() for the current user.
featureflow-client
Server
Node.js feature flags
Node.js feature flags with featureflow-node-sdk. One server client, then evaluate(key, user).isOn(). The server key stays out of the browser.
featureflow-node-sdk
Java feature flags
Java feature flags with io.featureflow:featureflow-java-sdk 1.4.2. One FeatureflowClient, then evaluate(key, user).isOn().
io.featureflow:featureflow-java-sdk
Python feature flags
Python feature flags with the featureflow-sdk package on PyPI. One Featureflow client and evaluate(key, user).isOn(), from the public README.
featureflow-sdk
Go feature flags
Go feature flags with github.com/featureflow/featureflow-go-sdk. featureflow.Client, then Evaluate(key, user).IsOn(). Requires Go 1.21+.
github.com/featureflow/featureflow-go-sdk
.NET feature flags
.NET feature flags with the Featureflow NuGet package. FeatureflowClientFactory.CreateAsync, then Evaluate(key, user).IsOn().
Featureflow
Mobile
iOS feature flags
iOS feature flags with the Featureflow Swift package. FeatureflowClient.initialize, then evaluate("key").isOn(). Client key only. iOS 13+.
featureflow-ios-sdk
Android feature flags
Android feature flags with io.featureflow:featureflow-android-sdk:0.2.0. FeatureflowClient.initialize, then evaluate("key").isOn(). Client key only.
io.featureflow:featureflow-android-sdk
Capability differences, including which SDKs can read JSON config values or record goals, are on the compatibility table. Ruby, React Native and the AngularJS provider also have public repositories under github.com/featureflow. This index only links languages whose evaluate API is written up in the docs or a README we quoted on the guide.