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0.7.0 • Public • Published

OpenFeature DevCycle Javascript Web Provider

This library provides a Javascript implementation of the OpenFeature Web Provider interface for DevCycle Javascript Client SDK.


Run yarn nx build openfeature-web-provider to build the library.

Running Unit Tests

Run yarn nx test openfeature-web-provider to execute the unit tests via Jest.

Example App

See the example app for a working example of the OpenFeature Web DevCycle Provider.


See our documentation for more information.

import DevCycleProvider from '@devcycle/openfeature-web-provider'
import { OpenFeature } from '@openfeature/web-sdk'


const user = { user_id: 'user_id' }

// Initialize the DevCycle Provider
const devcycleProvider = new DevCycleProvider(DEVCYCLE_CLIENT_SDK_KEY)
// Set the context before the provider is set to ensure the DevCycle SDK is initialized with a user context.
await OpenFeature.setContext(user)
// Set the DevCycleProvider for OpenFeature
await OpenFeature.setProviderAndWait(devcycleProvider)
// Get the OpenFeature client
const openFeatureClient = OpenFeature.getClient()

// Retrieve a boolean flag from the OpenFeature client
const boolFlag = openFeatureClient.getBooleanValue('boolean-flag', false)

Passing DVCOptions to the DevCycleProvider

Ensure that you pass any custom DVCOptions to the DevCycleProvider constructor

const options = { logger: dvcDefaultLogger({ level: 'debug' }) }
await OpenFeature.setProviderAndWait(new DevCycleProvider(DEVCYCLE_CLIENT_SDK_KEY, options))

Required TargetingKey

For DevCycle SDK to work we require either a targetingKey or user_id to be set on the OpenFeature context. This is used to identify the user as the user_id for a DVCUser in DevCycle.

Context properties to DVCUser

The provider will automatically translate known DVCUser properties from the OpenFeature context to the DVCUser object. DVCUser TypeScript Interface

For example all these properties will be set on the DVCUser:

await OpenFeature.setContext({
    user_id: 'user_id',
    email: 'email@devcycle.com',
    name: 'name',
    language: 'en',
    country: 'CA',
    appVersion: '1.0.11',
    appBuild: 1000,
    customData: { custom: 'data' },
    privateCustomData: { private: 'data' }

Context properties that are not known DVCUser properties will be automatically added to the customData property of the DVCUser.

Context Limitations

DevCycle only supports flat JSON Object properties used in the Context. Non-flat properties will be ignored.

For example obj will be ignored:

await OpenFeature.setContext({
    user_id: 'user_id',
    obj: { key: 'value' }

JSON Flag Limitations

The OpenFeature spec for JSON flags allows for any type of valid JSON value to be set as the flag value.

For example the following are all valid default value types to use with OpenFeature:

// Invalid JSON values for the DevCycle SDK, will return defaults
openFeatureClient.getObjectValue('json-flag', ['arry'])
openFeatureClient.getObjectValue('json-flag', 610)
openFeatureClient.getObjectValue('json-flag', false)
openFeatureClient.getObjectValue('json-flag', 'string')
openFeatureClient.getObjectValue('json-flag', null)

However, these are not valid types for the DevCycle SDK, the DevCycle SDK only supports JSON Objects:

// Valid JSON Object as the default value, will be evaluated by the DevCycle SDK
openFeatureClient.getObjectValue('json-flag', { default: 'value' })




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npm i @devcycle/openfeature-web-provider

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