diff --git a/custom_components/dkncloudna/coordinator.py b/custom_components/dkncloudna/coordinator.py
new file mode 100644
index 0000000..78a2e7c
--- /dev/null
+++ b/custom_components/dkncloudna/coordinator.py
@@ -0,0 +1,71 @@
+"""DataUpdateCoordinator for DKN Cloud NA."""
+
+from __future__ import annotations
+
+import asyncio
+from datetime import timedelta
+from typing import Any
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import ConfigEntryAuthFailed
+from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
+
+from .api import DknAuthError, DknCloudNaClient, DknConnectionError
+from .const import DEFAULT_SCAN_INTERVAL, DOMAIN, LOGGER
+
+
+class DknCoordinator(DataUpdateCoordinator[dict[str, dict[str, Any]]]):
+    """Coordinator that polls all installations and exposes a flat device map.
+
+    ``data`` is ``{mac_address: device_dict}`` where device_dict matches the
+    shape returned by DknCloudNaClient.fetch_installations() device entries.
+
+    The coordinator owns the client instance used across all platforms.
+    Per-device asyncio.Lock objects for write serialization are stored in
+    ``hass.data[DOMAIN][entry_id]["device_locks"]``.
+    """
+
+    client: DknCloudNaClient
+
+    def __init__(
+        self,
+        hass: HomeAssistant,
+        entry: ConfigEntry,
+        client: DknCloudNaClient,
+    ) -> None:
+        scan_interval = int(entry.options.get("scan_interval", DEFAULT_SCAN_INTERVAL))
+        super().__init__(
+            hass,
+            LOGGER,
+            name=DOMAIN,
+            update_interval=timedelta(seconds=scan_interval),
+        )
+        self.client = client
+        self._entry = entry
+
+    async def _async_update_data(self) -> dict[str, dict[str, Any]]:
+        """Fetch all installations and flatten into {mac: device_dict}."""
+        try:
+            installations = await self.client.fetch_installations()
+        except DknAuthError as err:
+            # 401 — trigger the reauth UI and mark entities unavailable.
+            raise ConfigEntryAuthFailed("Token invalid or expired") from err
+        except DknConnectionError as err:
+            raise UpdateFailed(f"Cannot reach DKN Cloud NA: {err}") from err
+        except asyncio.CancelledError:
+            raise
+        except Exception as err:  # noqa: BLE001
+            raise UpdateFailed(f"Unexpected error: {type(err).__name__}") from err
+
+        devices: dict[str, dict[str, Any]] = {}
+        for installation in installations or []:
+            inst_id = installation.get("_id", "")
+            for device in installation.get("devices", []):
+                mac = str(device.get("mac") or "").strip().lower()
+                if not mac:
+                    continue
+                device["_installation_id"] = inst_id
+                devices[mac] = device
+
+        return devices