# Optimizely React SDK
This repository houses the React SDK for use with Optimizely Feature Experimentation and Optimizely Full Stack (legacy).
Optimizely Feature Experimentation is an A/B testing and feature management tool for product development teams that enables you to experiment at every step. Using Optimizely Feature Experimentation allows for every feature on your roadmap to be an opportunity to discover hidden insights. Learn more at [Optimizely.com](https://www.optimizely.com/products/experiment/feature-experimentation/), or see the [developer documentation](https://docs.developers.optimizely.com/feature-experimentation/docs/introduction).
Optimizely Rollouts is [free feature flags](https://www.optimizely.com/free-feature-flagging/) for development teams. You can easily roll out and roll back features in any application without code deploys, mitigating risk for every feature on your roadmap.
## Get Started
Refer to the [React SDK's developer documentation](https://docs.developers.optimizely.com/experimentation/v4.0.0-full-stack/docs/javascript-react-sdk) for detailed instructions on getting started with using the SDK.
For React Native, review the [React Native developer documentation](https://docs.developers.optimizely.com/feature-experimentation/docs/javascript-react-native-sdk).
### Features
- Automatic datafile downloading
- User ID + attributes memoization
- Render blocking until datafile is ready via a React API
- Optimizely timeout (only block rendering up to the number of milliseconds you specify)
- Library of React components and hooks to use with [feature flags](https://docs.developers.optimizely.com/experimentation/v4.0.0-full-stack/docs/create-feature-flags)
### Compatibility
The React SDK is compatible with `React 16.8.0 +`
### Example
```jsx
import { createInstance, OptimizelyProvider, useDecision } from '@optimizely/react-sdk';
const optimizelyClient = createInstance({
sdkKey: 'your-optimizely-sdk-key',
});
function MyComponent() {
const [decision] = useDecision('sort-algorithm');
return (
{decision.variationKey === 'relevant_first' && }
{decision.variationKey === 'recent_first' && }
);
}
class App extends React.Component {
render() {
return (
);
}
}
```
### Install the SDK
```
npm install @optimizely/react-sdk
```
For **React Native**, installation instruction is bit different. Check out the
- [Official Installation guide](https://docs.developers.optimizely.com/feature-experimentation/docs/install-sdk-reactnative)
- [Expo React Native Sample App](https://github.com/optimizely/expo-react-native-sdk-sample)
## Use the React SDK
### Initialization
## `createInstance`
The `ReactSDKClient` client created via `createInstance` is the programmatic API to evaluating features and experiments and tracking events. The `ReactSDKClient` is what powers the rest of the ReactSDK internally.
_arguments_
- `config : object` Object with SDK configuration parameters. This has the same format as the object passed to the `createInstance` method of the core `@optimizely/javascript-sdk` module. For details on this object, see the following pages from the developer docs:
- [Instantiate](https://docs.developers.optimizely.com/experimentation/v4.0.0-full-stack/docs/initialize-sdk-react)
- [JavaScript: Client-side Datafile Management](https://docs.developers.optimizely.com/experimentation/v4.0.0-full-stack/docs/javascript-client-side-implementation)
_returns_
- A `ReactSDKClient` instance.
```jsx
import { OptimizelyProvider, createInstance } from '@optimizely/react-sdk';
const optimizely = createInstance({
datafile: window.optimizelyDatafile,
});
```
## ``
Required at the root level. Leverages React’s `Context` API to allow access to the `ReactSDKClient` to the `useDecision` hook.
_props_
| Prop | Type | Required | Description |
| --- | --- | --- | --- |
| `optimizely` | `ReactSDKClient` | Yes | Instance created from `createInstance` |
| `user` | `{ id: string; attributes?: { [key: string]: any } }` \| `Promise` | No | User info object — `id` and `attributes` will be passed to the SDK for every feature flag, A/B test, or `track` call. Can also be a `Promise` for the same kind of object. |
| `timeout` | `number` | No | The amount of time for `useDecision` to return `null` flag Decision while waiting for the SDK instance to become ready, before resolving. |
| `isServerSide` | `boolean` | No | Must pass `true` for server side rendering. |
| `userId` | `string` | No | **Deprecated, prefer `user` instead.** Another way to provide user id. The `user` prop takes precedence when both are provided. |
| `userAttributes` | `object` | No | **Deprecated, prefer `user` instead.** Another way to provide user attributes. The `user` prop takes precedence when both are provided. |
| `qualifiedSegments` | `string[] \| null` | No | Pre-fetched ODP audience segments for the user. Useful during SSR where async segment fetching is unavailable. Use [`getQualifiedSegments`](#getqualifiedsegments) to obtain these segments server-side. |
### Readiness
Before rendering real content, both the datafile and the user must be available to the SDK.
#### Load the datafile synchronously
Synchronous loading is the preferred method to ensure that Optimizely is always ready and doesn't add any delay or asynchronous complexity to your application. When initializing with both the SDK key and datafile, the SDK will use the given datafile to start, then download the latest version of the datafile in the background.
```jsx
import { OptimizelyProvider, createInstance } from '@optimizely/react-sdk';
const optimizelyClient = createInstance({
datafile: window.optimizelyDatafile,
sdkKey: 'your-optimizely-sdk-key', // Optimizely environment key
});
class AppWrapper extends React.Component {
render() {
return (
);
}
}
```
#### Load the datafile asynchronously
If you don't have the datafile downloaded, the `ReactSDKClient` can fetch the datafile for you. However, instead of waiting for the datafile to fetch before you render your app, you can immediately render your app and provide a `timeout` option to ``. The `useDecision` hook returns `isClientReady` and `didTimeout`. You can use these to block rendering of component until the datafile loads or the timeout is over.
```jsx
import { OptimizelyProvider, createInstance, useDecision } from '@optimizely/react-sdk';
const optimizelyClient = createInstance({
sdkKey: 'your-optimizely-sdk-key', // Optimizely environment key
});
function MyComponent() {
const [decision, isClientReady, didTimeout] = useDecision('the-flag');
return (
{isClientReady &&
The Component
}
{didTimeout &&
Default Component
}
{/* If client is not ready and time out has not occured yet, do not render anything */}
);
}
class App extends React.Component {
render() {
return (
);
}
}
```
#### Set user asynchronously
If user information is synchronously available, it can be provided as the `user` object prop, as in prior examples. But, if user information must be fetched asynchronously, the `user` prop can be a `Promise` for a `user` object with the same properties (`id` and `attributes`):
```jsx
import { OptimizelyProvider, createInstance } from '@optimizely/react-sdk';
import { fetchUser } from './user';
const optimizely = createInstance({
datafile: window.optimizelyDatafile,
});
const userPromise = fetchUser(); // fetchUser returns a Promise for an object with { id, attributes }
class AppWrapper extends React.Component {
render() {
return (
);
}
}
```
## `useDecision` Hook
A [React Hook](https://react.dev/learn/state-a-components-memory#meet-your-first-hook) to retrieve the decision result for a flag key, optionally auto updating that decision based on underlying user or datafile changes.
_arguments_
- `flagKey : string` The key of the feature flag.
- `options : Object`
- `autoUpdate : boolean` (optional) If true, this hook will update the flag decision in response to datafile or user changes. Default: `false`.
- `timeout : number` (optional) Client timeout as described in the `OptimizelyProvider` section. Overrides any timeout set on the ancestor `OptimizelyProvider`.
- `decideOption: OptimizelyDecideOption[]` (optional) Array of OptimizelyDecideOption enums.
- `overrides : Object`
- `overrideUserId : string` (optional) Override the userId to be used to obtain the decision result for this hook.
- `overrideAttributes : optimizely.UserAttributes` (optional) Override the user attributes to be used to obtain the decision result for this hook.
_returns_
- `Array` of:
- `decision : OptimizelyDecision` - Decision result for the flag key.
- `clientReady : boolean` - Whether or not the underlying `ReactSDKClient` instance is ready or not.
- `didTimeout : boolean` - Whether or not the underlying `ReactSDKClient` became ready within the allowed `timeout` range.
_Note: `clientReady` can be true even if `didTimeout` is also true. This indicates that the client became ready *after* the timeout period._
### Render something if flag is enabled
```jsx
import { useEffect } from 'react';
import { useDecision } from '@optimizely/react-sdk';
function LoginComponent() {
const [decision, clientReady] = useDecision(
'login-flag',
{ autoUpdate: true },
{
/* (Optional) User overrides */
}
);
useEffect(() => {
document.title = decision.enabled ? 'login-new' : 'login-default';
}, [decision.enabled]);
return (
);
}
```
## `withOptimizely`
Any component under the `` can access the Optimizely `ReactSDKClient` via the higher-order component (HoC) `withOptimizely`.
_arguments_
- `Component : React.Component` Component which will be enhanced with the following props:
- `optimizely : ReactSDKClient` The client object which was passed to the `OptimizelyProvider`
- `optimizelyReadyTimeout : number | undefined` The timeout which was passed to the `OptimizelyProvider`
- `isServerSide : boolean` Value that was passed to the `OptimizelyProvider`
_returns_
- A wrapped component with additional props as described above
### Example
```jsx
import { withOptimizely } from '@optimizely/react-sdk';
class MyComp extends React.Component {
constructor(props) {
super(props);
const { optimizely } = this.props;
const decision = optimizely.decide('feat1');
this.state = {
decision.enabled,
decision.variables,
};
}
render() {}
}
const WrappedMyComponent = withOptimizely(MyComp);
```
**_Note:_** The `optimizely` client object provided via `withOptimizely` is automatically associated with the `user` prop passed to the ancestor `OptimizelyProvider` - the `id` and `attributes` from that `user` object will be automatically forwarded to all appropriate SDK method calls. So, there is no need to pass the `userId` or `attributes` arguments when calling methods of the `optimizely` client object, unless you wish to use _different_ `userId` or `attributes` than those given to `OptimizelyProvider`.
## `useContext`
Any component under the `` can access the Optimizely `ReactSDKClient` via the `OptimizelyContext` with `useContext`.
_arguments_
- `OptimizelyContext : React.Context` The Optimizely context initialized in a parent component (or App).
_returns_
- Wrapped object:
- `optimizely : ReactSDKClient` The client object which was passed to the `OptimizelyProvider`
- `isServerSide : boolean` Value that was passed to the `OptimizelyProvider`
- `timeout : number | undefined` The timeout which was passed to the `OptimizelyProvider`
### Example
```jsx
import React, { useContext } from 'react';
import { OptimizelyContext } from '@optimizely/react-sdk';
function MyComponent() {
const { optimizely, isServerSide, timeout } = useContext(OptimizelyContext);
const decision = optimizely.decide('my-feature');
const onClick = () => {
optimizely.track('signup-clicked');
// rest of your click handling code
};
return (
<>
{decision.enabled &&
}
);
}
```
### Tracking
Use the built-in `useTrackEvent` hook to access the `track` method of optimizely instance
```jsx
import { useTrackEvent } from '@optimizely/react-sdk';
function SignupButton() {
const [track, clientReady, didTimeout] = useTrackEvent();
const handleClick = () => {
if (clientReady) {
track('signup-clicked');
}
};
return ;
}
```
Or you can use the `withOptimizely` HoC.
```jsx
import { withOptimizely } from '@optimizely/react-sdk';
class SignupButton extends React.Component {
onClick = () => {
const { optimizely } = this.props;
optimizely.track('signup-clicked');
// rest of click handler
};
render() {
;
}
}
const WrappedSignupButton = withOptimizely(SignupButton);
```
**_Note:_** As mentioned above, the `optimizely` client object provided via `withOptimizely` is automatically associated with the `user` prop passed to the ancestor `OptimizelyProvider.` There is no need to pass `userId` or `attributes` arguments when calling `track`, unless you wish to use _different_ `userId` or `attributes` than those given to `OptimizelyProvider`.
## `ReactSDKClient`
The following type definitions are used in the `ReactSDKClient` interface:
- `UserAttributes : { [name: string]: any }`
- `User : { id: string | null, attributes: userAttributes }`
- `VariableValuesObject : { [key: string]: any }`
- `EventTags : { [key: string]: string | number | boolean; }`
`ReactSDKClient` instances have the methods/properties listed below. Note that in general, the API largely matches that of the core `@optimizely/optimizely-sdk` client instance, which is documented on the [Optimizely Feature Experimentation developer docs site](https://docs.developers.optimizely.com/experimentation/v4.0.0-full-stack/docs/welcome). The major exception is that, for most methods, user id & attributes are **_optional_** arguments. `ReactSDKClient` has a current user. This user's id & attributes are automatically applied to all method calls, and overrides can be provided as arguments to these method calls if desired.
| Method / Property | Signature | Description |
| --- | --- | --- |
| `onReady` | `(opts?: { timeout?: number }): Promise` | Returns a Promise that fulfills with an `onReadyResult` object representing the initialization process. The instance is ready when it has fetched a datafile and a user is available (via `setUser` being called with an object, or a Promise passed to `setUser` becoming fulfilled). If the `timeout` period happens before the client instance is ready, the `onReadyResult` object will contain an additional key, `dataReadyPromise`, which can be used to determine when, if ever, the instance does become ready. |
| `user` | `User` | The current user associated with this client instance. |
| `setUser` | `(userInfo: User \| Promise, qualifiedSegments?: string[]): Promise` | Call this to update the current user. Optionally pass `qualifiedSegments` to set pre-fetched ODP audience segments on the user context. |
| `onUserUpdate` | `(handler: (userInfo: User) => void): () => void` | Subscribe a callback to be called when this instance's current user changes. Returns a function that will unsubscribe the callback. |
| `decide` | `(key: string, options?: OptimizelyDecideOption[], overrideUserId?: string, overrideAttributes?: UserAttributes): OptimizelyDecision` | Returns a decision result for a flag key for a user. The decision result is returned in an `OptimizelyDecision` object, and contains all data required to deliver the flag rule. |
| `decideAll` | `(options?: OptimizelyDecideOption[], overrideUserId?: string, overrideAttributes?: UserAttributes): { [key: string]: OptimizelyDecision }` | Returns decisions for all active (unarchived) flags for a user. |
| `decideForKeys` | `(keys: string[], options?: OptimizelyDecideOption[], overrideUserId?: string, overrideAttributes?: UserAttributes): { [key: string]: OptimizelyDecision }` | Returns an object of decision results mapped by flag keys. |
| `activate` | `(experimentKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): string \| null` | Activate an experiment, and return the variation for the given user. |
| `getVariation` | `(experimentKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): string \| null` | Return the variation for the given experiment and user. |
| `getFeatureVariables` | `(featureKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): VariableValuesObject` | **Deprecated since 2.1.0.** Decide and return variable values for the given feature and user. Use `getAllFeatureVariables` instead. |
| `getFeatureVariableString` | `(featureKey: string, variableKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): string \| null` | Decide and return the variable value for the given feature, variable, and user. |
| `getFeatureVariableInteger` | `(featureKey: string, variableKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): number \| null` | Decide and return the variable value for the given feature, variable, and user. |
| `getFeatureVariableBoolean` | `(featureKey: string, variableKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): boolean \| null` | Decide and return the variable value for the given feature, variable, and user. |
| `getFeatureVariableDouble` | `(featureKey: string, variableKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): number \| null` | Decide and return the variable value for the given feature, variable, and user. |
| `isFeatureEnabled` | `(featureKey: string, overrideUserId?: string, overrideAttributes?: UserAttributes): boolean` | Return the enabled status for the given feature and user. |
| `getEnabledFeatures` | `(overrideUserId?: string, overrideAttributes?: UserAttributes): Array` | Return the keys of all features enabled for the given user. |
| `track` | `(eventKey: string, overrideUserId?: string \| EventTags, overrideAttributes?: UserAttributes, eventTags?: EventTags): void` | Track an event to the Optimizely results backend. |
| `setForcedVariation` | `(experiment: string, overrideUserIdOrVariationKey: string, variationKey?: string \| null): boolean` | Set a forced variation for the given experiment, variation, and user. **Note:** triggers a re-render of all `useExperiment` hooks and `OptimizelyExperiment` components using that client. |
| `getForcedVariation` | `(experiment: string, overrideUserId?: string): string \| null` | Get the forced variation for the given experiment, variation, and user. |
## Rollout or experiment a feature user-by-user
To rollout or experiment on a feature by user rather than by random percentage, you will use Attributes and Audiences. To do this, follow the documentation on how to [run a beta](https://docs.developers.optimizely.com/feature-experimentation/docs/run-a-beta) using the React code samples.
## Server Side Rendering
The React SDK supports server-side rendering (SSR). Pre-fetch the datafile and pass it to `createInstance` so decisions are available synchronously. Server-side instances are short-lived (created per request), so configure them to avoid unnecessary background work:
```jsx
import { createInstance, OptimizelyProvider, OptimizelyDecideOption, useDecision } from '@optimizely/react-sdk';
function App() {
const isServerSide = typeof window === 'undefined';
const [optimizely] = useState(() =>
createInstance({
datafile,
sdkKey: process.env.NEXT_PUBLIC_OPTIMIZELY_SDK_KEY || '',
datafileOptions: { autoUpdate: !isServerSide },
defaultDecideOptions: isServerSide ? [OptimizelyDecideOption.DISABLE_DECISION_EVENT] : [],
odpOptions: {
disabled: isServerSide,
},
})
);
}
function MyComponent() {
const [decision] = useDecision('flag1');
return decision.enabled ?
Feature enabled
:
Feature disabled
;
}
;
```
| Option | Server value | Why |
| ---------------------------- | -------------------------- | ------------------------------------------------------------------------------------------------ |
| `datafile` | Pre-fetched datafile JSON | Provides the datafile directly so the SDK is ready synchronously to make decisions |
| `datafileOptions.autoUpdate` | `false` | No need to poll for datafile updates on a per-request instance |
| `defaultDecideOptions` | `[DISABLE_DECISION_EVENT]` | avoids duplicate decision events if the client will also fire them after hydration |
| `odpOptions.disabled` | `true` | Disables ODP event manager processing during SSR — avoids unnecessary event batching, API calls, and VUID tracking overhead |
> **ODP audience segments during SSR:** Disabling ODP prevents automatic segment fetching, but you can still make audience-segment-based decisions by passing pre-fetched segments via the `qualifiedSegments` prop on `OptimizelyProvider`.
### `getQualifiedSegments`
A standalone async utility that fetches qualified ODP audience segments for a user, given a datafile. It parses the datafile to extract ODP configuration and segment conditions, queries the ODP GraphQL API, and returns only the segments where the user is qualified.
```ts
import { getQualifiedSegments } from '@optimizely/react-sdk';
const segments = await getQualifiedSegments(userId, datafile);
```
| Argument | Type | Description |
| ---------- | --------------------------------- | ------------------------------------------------ |
| `userId` | `string` | The user ID to fetch qualified segments for |
| `datafile` | `string \| Record` | The Optimizely datafile (JSON object or string) |
**Returns:** `Promise`
> **Caching recommendation:** The ODP segment fetch adds latency to server rendering. Consider caching the result per user to avoid re-fetching on every request.
### React Server Components (v3.4.0+)
Since version 3.4.0, the SDK can be used directly in React Server Components without `OptimizelyProvider`. Create an instance, set the user, wait for readiness, and make decisions — all within an `async` server component:
```tsx
import { createInstance } from '@optimizely/react-sdk';
export default async function ServerExperiment() {
const client = createInstance({
sdkKey: process.env.OPTIMIZELY_SDK_KEY || '',
});
client.setUser({
id: 'user-123',
});
await client.onReady();
const decision = client.decide('flag-1');
client.close();
return decision.enabled ?