Flagsmith Provider

This provider is an implementation for the JavaScript SDK of Flagsmith.

Installation

npm install @openfeature/flagsmith-client-provider

Initialising the provider

The Flagsmith Provider can be created with the standard initialization options and an optional Flagsmith instance to use.

import { FlagsmithClientProvider } from '@openfeature/flagsmith-client-provider';
import { OpenFeature } from '@openfeature/web-sdk';

const flagsmithClientProvider = new FlagsmithClientProvider({
    environmentID: '<ENVIRONMENT_ID>'
});
OpenFeature.setProvider(flagsmithClientProvider); // Attach the provider to OpenFeature

Usage with React Native, SSR or custom instances

The Flagsmith Provider can be constructed with a custom Flagsmith instance and optional server-side generated state, initialization options.

Note: In order to use the React Native implementation of OpenFeature you will need to install both Flagsmith and react-native-flagsmith.

import flagsmith from 'react-native-flagsmith' // Could also be flagsmith/isomorphic, flagsmith-es or createFlagsmithInstance()
import { FlagsmithClientProvider } from '@openfeature/flagsmith-client-provider';
import { OpenFeature } from '@openfeature/web-sdk';

const flagsmithClientProvider = new FlagsmithClientProvider({
    environmentID: '<ENVIRONMENT_ID>',
    flagsmithInstance: flagsmith,
    state:serverState
});
OpenFeature.setProvider(flagsmithClientProvider); // Attach the provider to OpenFeature

Identifying and setting Traits

In Flagsmith, users are identified in order to allow for segmentation and percentage rollouts.

To identify and set traits you can specify a targetingKey(identity) and optionally a set of traits. This will do the equivalent of flagsmith.identify(id, traits) or pass these to flagsmith.init if you are calling this before OpenFeature.setProvider.

const flagsmithClientProvider = new FlagsmithClientProvider({
  environmentID: '<ENVIRONMENT_ID>',
});
await OpenFeature.setContext({ targetingKey, traits });
OpenFeature.setProvider(flagsmithClientProvider); // Attach the provider to OpenFeature

To reset the identity you can simply reset the context. This will do the equivalent of flagsmith.logout()

await OpenFeature.setContext({ });

Resolution reasoning

In Flagsmith, features are evaluated based on the following Resolution reasons:

StandardResolutionReasons.CACHED | StandardResolutionReasons.STATIC | StandardResolutionReasons.DEFAULT | StandardResolutionReasons.ERROR

Note that resolutions of type SPLIT may be the result of targetted matching or percentage split however Flagsmith does not expose this information to client-side SDKs.

Events

The Flagsmith provider emits the following OpenFeature events:

• PROVIDER_READY
• PROVIDER_ERROR
• PROVIDER_CONFIGURATION_CHANGED

Building

Run nx package providers-flagsmith to build the library.

Running unit tests

Run nx test providers-flagsmith to execute the unit tests via Jest.

Examples

You can find examples using this provider in several frameworks Here.