Implement a user profile service for the React SDK

Use a User Profile Service to persist information about your users and ensure variation assignments are sticky. Sticky implies that once a user gets a particular variation, their assignment will not change.

In the React SDK, there is no default implementation. Implementing a User Profile Service is optional and is only necessary if you want to keep variation assignments sticky even when experiment conditions are changed while it is running (for example, audiences, attributes, variation pausing, and traffic distribution). Otherwise, the React SDK is stateless and relies on deterministic bucketing to return consistent assignments.

If the User Profile Service does not bucket a user as you expect, then check whether other flags are overriding the bucketing. For more information, see How bucketing works.

Implement a service

To implement a custom User Profile Service, refer to the following code samples. The service needs to expose two functions with the following signatures:

• lookup – Takes a user ID string and returns a user profile matching the schema below.
• save – Takes a user profile and persists it.

If you want to use the User Profile Service purely for tracking purposes and not sticky bucketing, you can implement only the save method (always return nil from lookup).

import { createInstance } from '@optimizely/react-sdk';

// Sample user profile service implementation
const userProfileService = {
  lookup: userId => {
    // Perform user profile lookup
  },
  save: userProfileMap => {
    // Persist user profile
  },
};

const optimizelyClient = createInstance({
  datafile: window.datafile, // assuming you have a datafile at window.datafile
  userProfileService, // Passing your userProfileService created above
});

The code example below shows the JSON schema for the user profile object.

Use experiment_bucket_map to override the default bucketing behavior and define an alternate experiment variation for a given user. For each experiment that you want to override, add an object to the map. Use the experiment ID as the key and include a variation_id property that specifies the desired variation. If there isn't an entry for an experiment, then the default bucketing behavior persists.

In the example below, ^[a-zA-Z0-9]+$ is the experiment ID.

{
  "title": "UserProfile",
  "type": "object",
  "properties": {
    "user_id": {"type": "string"},
    "experiment_bucket_map": {"type": "object",
                              "patternProperties": {
                                 "^[a-zA-Z0-9]+$": {"type": "object",
                                                    "properties": {"variation_id": {"type":"string"}},
                                                    "required": ["variation_id"]}
                               }
                             }
  },
  "required": ["user_id", "experiment_bucket_map"]
}

The React SDK uses the User Profile Service you provide to override the default bucketing behavior in cases when an experiment assignment has been saved.

When implementing your own User Profile Service, we recommend loading the user profiles into the User Profile Service on initialization and avoiding performing expensive, blocking lookups on the lookup function to minimize the performance impact of incorporating the service.