Sending logs

SDKs send logs to Hypertune Edge in the background. This allows you to:

• See how often different parts of your flag logic are called, e.g. to see how often different targeting rules are evaluated and passed in realtime

• Log events and exposures for your A/B tests and machine learning loops

• See any SDK errors from the Hypertune UI

Manually flush logs

You can manually trigger and wait for logs to be flushed with hypertune.flushLogs():

import { NextFetchEvent, NextRequest } from "next/server";
import hypertune from "./lib/hypertune";

export async function middleware(
  req: NextRequest,
  context: NextFetchEvent
): Promise<void> {
  await hypertune.initIfNeeded();

  const rootNode = hypertune.root({
    args: {
      context: {
        user: { id: "test", name: "Test", email: "[e-mail]" },
      },
    },
  });
  const exampleFlag = rootNode.exampleFlag({ fallback: false });
  console.log("Edge Middleware flag:", exampleFlag);

  context.waitUntil(hypertune.flushLogs());
}

This is particularly useful in serverless environments, e.g. Vercel deployments, where background SDK tasks like fetching updates aren't guaranteed to execute.