diff --git a/lib/cron/index.js b/lib/cron/index.js
index 1dcc6ed..5334e0c 100644
--- a/lib/cron/index.js
+++ b/lib/cron/index.js
@@ -2,6 +2,9 @@ import cron from 'node-cron';
 import { runSync } from './sync_source_docs.js';
 import { log } from '../log.js';
 import { enqueue } from '../jobs/queue.js';
+import { load } from '../health/registry.js';
+import { checkAll } from '../health/checker.js';
+import * as statusRepo from '../db/repos/service_status.js';
 
 export function startCron() {
   // Daily at 03:00 local time
@@ -20,5 +23,13 @@ export function startCron() {
     catch (e) { log.error({ err: e }, 'cron speedtest failed'); }
   });
 
+  cron.schedule('*/1 * * * *', async () => {
+    try {
+      const results = await checkAll(load());
+      for (const r of results) await statusRepo.upsert(r);
+      log.info({ n: results.length }, 'health check complete');
+    } catch (e) { log.error({ err: e }, 'health check failed'); }
+  });
+
   log.info('cron started');
 }
diff --git a/lib/health/checker.js b/lib/health/checker.js
new file mode 100644
index 0000000..df11e41
--- /dev/null
+++ b/lib/health/checker.js
@@ -0,0 +1,41 @@
+import net from 'node:net';
+const SLOW_MS = 3000;
+
+export function classify({ ok, reachable, latency, error }) {
+  if (ok) return { status: latency > SLOW_MS ? 'warn' : 'ok', latency_ms: latency, detail: `${latency}ms` };
+  if (reachable) return { status: 'warn', latency_ms: latency ?? null, detail: 'degraded' };
+  return { status: 'down', latency_ms: null, detail: error || 'unreachable' };
+}
+
+// Default probe: HTTP (status 2xx/3xx) or TCP connect. Only called with
+// operator-configured URLs from the registry — never user input.
+export async function probe(svc) {
+  const started = Date.now();
+  const type = svc.check?.type || 'http';
+  try {
+    if (type === 'tcp') {
+      const u = new URL(svc.url);
+      await new Promise((resolve, reject) => {
+        const sock = net.connect({ host: u.hostname, port: Number(u.port) }, () => { sock.end(); resolve(); });
+        sock.setTimeout(5000); sock.on('timeout', () => { sock.destroy(); reject(new Error('timeout')); });
+        sock.on('error', reject);
+      });
+      return { ok: true, latency: Date.now() - started };
+    }
+    const base = svc.url.replace(/\/$/, '');
+    const url = base + (svc.check?.path || '');
+    const res = await fetch(url, { redirect: 'manual', signal: AbortSignal.timeout(6000) });
+    const reachable = true;
+    const ok = res.status >= 200 && res.status < 400;
+    return { ok, reachable, latency: Date.now() - started };
+  } catch (e) {
+    return { ok: false, reachable: false, latency: Date.now() - started, error: e.code || e.message };
+  }
+}
+
+export async function checkAll(services, probeFn = probe) {
+  return Promise.all(services.map(async svc => {
+    const c = classify(await probeFn(svc));
+    return { service_id: svc.id, ...c };
+  }));
+}
diff --git a/tests/health/checker.test.js b/tests/health/checker.test.js
new file mode 100644
index 0000000..1fb3f5a
--- /dev/null
+++ b/tests/health/checker.test.js
@@ -0,0 +1,19 @@
+import { describe, it, expect, vi } from 'vitest';
+import { classify, checkAll } from '../../lib/health/checker.js';
+
+describe('health classify', () => {
+  it('ok when reachable and fast', () => expect(classify({ ok: true, latency: 120 }).status).toBe('ok'));
+  it('warn when reachable but slow', () => expect(classify({ ok: true, latency: 4000 }).status).toBe('warn'));
+  it('warn on non-2xx/3xx reachable', () => expect(classify({ ok: false, reachable: true, latency: 50 }).status).toBe('warn'));
+  it('down when unreachable', () => expect(classify({ ok: false, reachable: false, error: 'ECONN' }).status).toBe('down'));
+});
+
+describe('checkAll', () => {
+  it('probes each service and returns a status per id', async () => {
+    const probe = vi.fn().mockResolvedValue({ ok: true, latency: 30 });
+    const svcs = [{ id: 'a', url: 'http://x' }, { id: 'b', url: 'http://y' }];
+    const out = await checkAll(svcs, probe);
+    expect(out.map(o => o.service_id).sort()).toEqual(['a', 'b']);
+    expect(out.every(o => o.status === 'ok')).toBe(true);
+  });
+});