How to use feature flags in Node.js

import { createFlagFix, installShutdownHandlers } from "@flagfix/node";

const flagfix = createFlagFix({
  serverKey: process.env.FLAGFIX_SERVER_KEY!,
  apiHost: process.env.FLAGFIX_API_HOST!,
});
installShutdownHandlers({ client: flagfix });
await flagfix.start();

export function flagsFor(userId: string, plan: string) {
  return flagfix.withIdentity({ userId, traits: { plan } });
}

Call start() on the per-request client before hasFeature. Do not identify the shared client inside a request. shutdown is for process exit, not for the end of one request. flush is the per-request drain.