OpenFeature Provider (Node.js)

npm install @mixpanel/openfeature-server-provider @openfeature/server-sdk mixpanel

import { OpenFeature } from "@openfeature/server-sdk";
import { MixpanelProvider } from "@mixpanel/openfeature-server-provider";

// 1. Create and register the provider with local evaluation
const provider = MixpanelProvider.createLocal("YOUR_PROJECT_TOKEN");
await OpenFeature.setProviderAndWait(provider);

// 2. Get a client and evaluate flags
const client = OpenFeature.getClient();
const showNewFeature = await client.getBooleanValue("new-feature-flag", false, {
  distinct_id: "user-123",
});

if (showNewFeature) {
  console.log("New feature is enabled!");
}

const provider = MixpanelProvider.createLocal("YOUR_PROJECT_TOKEN");

const provider = MixpanelProvider.createRemote("YOUR_PROJECT_TOKEN");

import Mixpanel from "mixpanel";

const mixpanel = Mixpanel.init("YOUR_PROJECT_TOKEN", {
  local_flags_config: {},
});
const localFlags = mixpanel.local_flags!;
localFlags.startPollingForDefinitions();

const provider = new MixpanelProvider(localFlags);

const client = OpenFeature.getClient();
const context = { distinct_id: "user-123" };

// Feature Gate
const isFeatureOn = await client.getBooleanValue("new-checkout", false, context);

// Experiment with string variants
const buttonColor = await client.getStringValue("button-color-test", "blue", context);

// Experiment with number variants
const maxItems = await client.getNumberValue("max-items", 10, context);

// Dynamic Config
const featureConfig = await client.getObjectValue("homepage-layout", {}, context);

// Global context
OpenFeature.setContext({ environment: "production" });

// Per-evaluation context (merged with and overrides global context)
const value = await client.getBooleanValue("premium-feature", false, {
  distinct_id: "user-123",
  email: "user@example.com",
  plan: "premium",
});

const details = await client.getBooleanDetails("my-feature", false, {
  distinct_id: "user-123",
});

console.log(details.value);
console.log(details.variant);
console.log(details.reason);
console.log(details.errorCode);

const mixpanel = provider.mixpanel;
if (mixpanel) {
  mixpanel.track("button_clicked", { distinct_id: "user-123" });
}

await OpenFeature.close();