diff --git a/server/src/plugins/service-admin-http/index.ts b/server/src/plugins/service-admin-http/index.ts
index b343002..1561b1b 100644
--- a/server/src/plugins/service-admin-http/index.ts
+++ b/server/src/plugins/service-admin-http/index.ts
@@ -103,6 +103,7 @@ export class Plugin extends BSBService<InstanceType<typeof Config>, typeof Event
   runAfterPlugins?: string[];
 
   private server?: Server;
+  private cameraHealthChecker?: { stop: () => void };
 
   constructor(cfg: BSBServiceConstructor<InstanceType<typeof Config>, typeof EventSchemas>) {
     super(cfg);
@@ -228,6 +229,13 @@ export class Plugin extends BSBService<InstanceType<typeof Config>, typeof Event
       port: this.config.port,
     });
 
+    // Camera health checker — periodic TCP probe to mark cameras online/offline.
+    const { startCameraHealthChecker } = await import("../../shared/camera-health.js");
+    this.cameraHealthChecker = startCameraHealthChecker(repo, {}, {
+      info: (m) => obs.log.info(m as any, {}),
+      warn: (m) => obs.log.warn(m as any, {}),
+    });
+
     // Auto-provision the Node-RED bf-server-config so the user doesn't have
     // to set server URL + API key manually. Best-effort with retries because
     // Node-RED may still be starting.
@@ -296,6 +304,7 @@ export class Plugin extends BSBService<InstanceType<typeof Config>, typeof Event
   }
 
   async dispose(): Promise<void> {
+    this.cameraHealthChecker?.stop();
     if (this.server) {
       await this.server.close();
     }
diff --git a/server/src/shared/camera-health.ts b/server/src/shared/camera-health.ts
new file mode 100644
index 0000000..6043104
--- /dev/null
+++ b/server/src/shared/camera-health.ts
@@ -0,0 +1,128 @@
+/**
+ * Periodic camera health checker.
+ *
+ * Probes each camera's RTSP stream or ONVIF endpoint to determine if
+ * it's reachable. Updates cameras.last_seen_at on success. Emits an
+ * event when a camera goes offline (was seen recently, now unreachable).
+ *
+ * Runs server-side on a configurable interval (default 60s). Uses the
+ * ffprobe-style approach: open a TCP connection to the RTSP port, send
+ * OPTIONS, check for 200. No actual stream decode — just reachability.
+ */
+import { createConnection, type Socket } from "node:net";
+import type { Repository } from "../plugins/service-store/repository.js";
+
+export interface CameraHealthConfig {
+  intervalMs: number;
+  timeoutMs: number;
+}
+
+const DEFAULT_CONFIG: CameraHealthConfig = {
+  intervalMs: 60_000,
+  timeoutMs: 5_000,
+};
+
+export function startCameraHealthChecker(
+  repo: Repository,
+  config: Partial<CameraHealthConfig> = {},
+  log: { info: (m: string) => void; warn: (m: string) => void },
+): { stop: () => void } {
+  const cfg = { ...DEFAULT_CONFIG, ...config };
+  let timer: ReturnType<typeof setInterval> | null = null;
+
+  async function checkAll(): Promise<void> {
+    const cameras = repo.listCameras().filter((c) => c.enabled);
+    for (const cam of cameras) {
+      const host = cam.type === "onvif"
+        ? cam.onvif_host
+        : parseRtspHost(cam.rtsp_url);
+      const port = cam.type === "onvif"
+        ? (cam.onvif_port ?? 80)
+        : parseRtspPort(cam.rtsp_url);
+
+      if (!host) continue;
+
+      const reachable = await tcpProbe(host, port, cfg.timeoutMs);
+      const wasOnline = cam.last_seen_at
+        ? Date.now() - new Date(cam.last_seen_at).getTime() < cfg.intervalMs * 3
+        : false;
+
+      if (reachable) {
+        repo.updateCamera(cam.id, { last_seen_at: new Date().toISOString() } as any);
+      } else if (wasOnline) {
+        // Camera just went offline — log event for Node-RED / admin visibility.
+        log.warn(`camera ${cam.id} (${cam.name}) went offline`);
+        try {
+          repo.insertEvent({
+            source_kiosk_id: null,
+            source_camera_id: cam.id,
+            source_type: "system",
+            topic: "camera.offline",
+            property_op: null,
+            payload: {
+              camera_id: cam.id,
+              camera_name: cam.name,
+              last_seen_at: cam.last_seen_at,
+            },
+            forwarded_to_nodered: false,
+          });
+        } catch {
+          // Event insert failure shouldn't break the health loop.
+        }
+      }
+    }
+  }
+
+  // Run immediately then on interval.
+  checkAll().catch(() => {});
+  timer = setInterval(() => { checkAll().catch(() => {}); }, cfg.intervalMs);
+
+  return {
+    stop() {
+      if (timer) { clearInterval(timer); timer = null; }
+    },
+  };
+}
+
+function tcpProbe(host: string, port: number, timeoutMs: number): Promise<boolean> {
+  return new Promise((resolve) => {
+    let resolved = false;
+    const done = (result: boolean) => {
+      if (resolved) return;
+      resolved = true;
+      try { sock.destroy(); } catch { /* ignore */ }
+      resolve(result);
+    };
+
+    const sock: Socket = createConnection({ host, port, timeout: timeoutMs }, () => {
+      done(true);
+    });
+    sock.on("error", () => done(false));
+    sock.on("timeout", () => done(false));
+    setTimeout(() => done(false), timeoutMs + 500);
+  });
+}
+
+function parseRtspHost(url: string | null): string | null {
+  if (!url) return null;
+  try {
+    const match = url.match(/@([^:/]+)/);
+    if (match) return match[1]!;
+    const u = new URL(url.replace("rtsp://", "http://"));
+    return u.hostname || null;
+  } catch {
+    return null;
+  }
+}
+
+function parseRtspPort(url: string | null): number {
+  if (!url) return 554;
+  try {
+    const match = url.match(/@[^:]+:(\d+)/);
+    if (match) return Number(match[1]);
+    const u = new URL(url.replace("rtsp://", "http://"));
+    return u.port ? Number(u.port) : 554;
+  } catch {
+    return 554;
+  }
+}