Framework guides

Use these examples to wire healthzkit into common runtimes. Fetch-based frameworks can use toFetchResponse or createFetchHandler; Express and Node http map status, headers, and body onto the native response. For a runnable long-lived Node.js deployment, see the production Hono + Postgres example. It includes Kubernetes probes, shared-pool ownership, error redaction, and bounded graceful shutdown.

Hono
Express
Elysia
Next.js
Node HTTP

import { Hono } from "hono";
import { createHealthKit, toFetchResponse } from "healthzkit";

const kit = createHealthKit({
  checks: [
    {
      name: "process",
      type: ["liveness", "readiness"],
      adapter: { check: async () => ({ status: "ok" }) },
    },
  ],
});

const app = new Hono();

app.get("/healthz/live", async () => toFetchResponse(await kit.handleLiveness()));
app.get("/healthz/ready", async () => toFetchResponse(await kit.handleReadiness()));

export default app;

import express from "express";
import { createHealthKit } from "healthzkit";

const kit = createHealthKit({
  checks: [
    {
      name: "process",
      type: ["liveness", "readiness"],
      adapter: { check: async () => ({ status: "ok" }) },
    },
  ],
});

const app = express();

app.get("/healthz/live", async (_req, res) => {
  const out = await kit.handleLiveness();
  res.status(out.status).set(out.headers).send(out.body);
});

app.get("/healthz/ready", async (_req, res) => {
  const out = await kit.handleReadiness();
  res.status(out.status).set(out.headers).send(out.body);
});

const server = app.listen(3000);

process.on("SIGTERM", () => {
  kit.stop();
  server.close();
});

Bun + Elysia with a scheduled Postgres check:

import { createHealthKit, toFetchResponse } from "healthzkit";
import { Elysia } from "elysia";
import { pgAdapter } from "@healthzkit/postgres/pg";
import { env } from "../env";

export const kit = createHealthKit({
  checks: [
    {
      name: "database",
      type: ["readiness"],
      adapter: pgAdapter({
        connectionString: env.DATABASE_URL,
      }),
      schedule: { intervalMs: 60_000 },
    },
  ],
});

kit.start();

const healthRoutes = new Elysia({ prefix: "/healthz", tags: ["Healthzkit"] })
  .get("/live", async () => toFetchResponse(await kit.handleLiveness()))
  .get("/ready", async () => toFetchResponse(await kit.handleReadiness()));

const app = new Elysia().use(healthRoutes).listen(8000);

process.on("SIGINT", async () => {
  kit.stop();
  await app.stop();
  process.exit(0);
});

For serverless deployments, skip kit.start() and run checks on demand. If you run Next.js in a long-lived Node process, you can enable scheduling with kit.start() in process bootstrap code and kit.stop() on shutdown.

app/healthz/kit.ts

import { createHealthKit } from "healthzkit";

export const kit = createHealthKit({
  checks: [
    {
      name: "process",
      type: ["liveness", "readiness"],
      adapter: { check: async () => ({ status: "ok" }) },
    },
  ],
});

app/healthz/live/route.ts

import { toFetchResponse } from "healthzkit";
import { kit } from "../kit";

export const dynamic = "force-dynamic";

export async function GET() {
  return toFetchResponse(await kit.handleLiveness());
}

export async function HEAD() {
  return toFetchResponse(await kit.handleLiveness(), "HEAD");
}

app/healthz/ready/route.ts

import { toFetchResponse } from "healthzkit";
import { kit } from "../kit";

export const dynamic = "force-dynamic";

export async function GET() {
  return toFetchResponse(await kit.handleReadiness());
}

export async function HEAD() {
  return toFetchResponse(await kit.handleReadiness(), "HEAD");
}

import http from "node:http";
import { createHealthKit } from "healthzkit";

const kit = createHealthKit({
  checks: [
    { name: "process", type: ["liveness"], adapter: { check: async () => ({ status: "ok" }) } },
  ],
});

const server = http.createServer(async (req, res) => {
  const out = await kit.handleRequest({
    method: req.method ?? "GET",
    path: req.url ?? "/",
  });

  if (!out) {
    res.statusCode = 404;
    res.end("not found");
    return;
  }

  res.writeHead(out.status, out.headers);
  res.end(out.body);
});

server.listen(3000);

Guide

Adapters