Next.js Health Check API - Essential Production Monitoring Endpoint

Problem

Docker and Kubernetes need a health check endpoint to verify your app is alive. Returning system metrics alongside the 200 status makes debugging much easier.

Solution

// app/api/health/route.ts
import { NextResponse } from 'next/server';

export async function GET() {
  try {
    return NextResponse.json({
      status: 'healthy',
      timestamp: new Date().toISOString(),
      uptime: process.uptime(),
      memory: process.memoryUsage(),
      version: process.env.NEXT_PUBLIC_VERSION || '1.0.0',
      node: process.version,
      platform: process.platform,
      arch: process.arch,
    });
  } catch (error) {
    return NextResponse.json(
      { status: 'error', timestamp: new Date().toISOString() },
      { status: 500 }
    );
  }
}

# Docker usage
healthcheck:
  test: ["CMD", "curl", "-f", "http://localhost:3000/api/health"]
  interval: 30s
  timeout: 10s
  retries: 3

Key Points

• process.memoryUsage() returns heapUsed, heapTotal, and rss. If heapUsed keeps growing, suspect a memory leak.
• process.uptime() is in seconds. If it’s frequently near zero, your app is crash-looping.
• Always return JSON even in the catch block. Monitoring tools need to parse the response regardless of status code.