JS Client SDK for Feature Flags API

Install

npm i flags-js

Usage

import Features from "flags-js";
const apiKey = "123456790";

async function Example() {
  const user = {
    key: "johnDoe@gmail.com", // must be unique
    attributes: {
      age: 25,
      gender: "male",
      sports: ["basketball", "hockey"],
    },
  };

  const features = await Features.initializeClient(apiKey, user);

  // simple on/off flag
  const shouldShowNewModal = features.isEnabled("new-modal-flag-key");
  // string flag
  const newToolbarColor = features.getFlagVariation("new-toolbar-flag");
}

• initializeClient makes api call to fetch all flags
• attributes are what is matched in user targeting / segments

isEnabled(flagKey): Boolean

Returns evaluation of flag for user. If flag is disabled or client initialization fails it returns false by default.

getFlagVariation(flagKey): String

Returns name of variation if exists, otherwise null. Using this for flag keys associated with boolean flags will return "On" or "Off".