diff --git a/custom_components/ha_probe/__pycache__/__init__.cpython-312.pyc b/custom_components/ha_probe/__pycache__/__init__.cpython-312.pyc
new file mode 100644
index 0000000..d35665d
Binary files /dev/null and b/custom_components/ha_probe/__pycache__/__init__.cpython-312.pyc differ
diff --git a/custom_components/ha_probe/__pycache__/config_flow.cpython-312.pyc b/custom_components/ha_probe/__pycache__/config_flow.cpython-312.pyc
new file mode 100644
index 0000000..6047a3e
Binary files /dev/null and b/custom_components/ha_probe/__pycache__/config_flow.cpython-312.pyc differ
diff --git a/custom_components/ha_probe/__pycache__/const.cpython-312.pyc b/custom_components/ha_probe/__pycache__/const.cpython-312.pyc
new file mode 100644
index 0000000..4e6db1f
Binary files /dev/null and b/custom_components/ha_probe/__pycache__/const.cpython-312.pyc differ
diff --git a/custom_components/ha_probe/__pycache__/device.cpython-312.pyc b/custom_components/ha_probe/__pycache__/device.cpython-312.pyc
new file mode 100644
index 0000000..886ec2f
Binary files /dev/null and b/custom_components/ha_probe/__pycache__/device.cpython-312.pyc differ
diff --git a/custom_components/ha_probe/__pycache__/sensor.cpython-312.pyc b/custom_components/ha_probe/__pycache__/sensor.cpython-312.pyc
new file mode 100644
index 0000000..72715a7
Binary files /dev/null and b/custom_components/ha_probe/__pycache__/sensor.cpython-312.pyc differ
diff --git a/custom_components/ha_probe/brand/icon.png b/custom_components/ha_probe/brand/icon.png
new file mode 100644
index 0000000..5954b0a
Binary files /dev/null and b/custom_components/ha_probe/brand/icon.png differ
diff --git a/custom_components/ha_probe/brand/icon@2x.png b/custom_components/ha_probe/brand/icon@2x.png
new file mode 100644
index 0000000..29b4747
Binary files /dev/null and b/custom_components/ha_probe/brand/icon@2x.png differ
diff --git a/custom_components/ha_probe/device.py b/custom_components/ha_probe/device.py
new file mode 100644
index 0000000..6245ab3
--- /dev/null
+++ b/custom_components/ha_probe/device.py
@@ -0,0 +1,92 @@
+"""Device metadata helpers for the HA Probe integration."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers import device_registry as dr
+from homeassistant.helpers.device_registry import DeviceInfo
+
+from .const import DOMAIN
+
+DEFAULT_MANUFACTURER = "gerviba/systemmonitor"
+DEFAULT_MODEL = "Probe"
+
+# Probe payload key -> normalized metadata key.
+_PAYLOAD_KEYS = {
+    "manufacturer": "manufacturer",
+    "model": "model",
+    "configurationUrl": "configuration_url",
+    "swVersion": "sw_version",
+    "viaDevice": "via_device",
+}
+
+
+def parse_device_meta(device: dict[str, Any]) -> dict[str, str]:
+    """Pick the optional metadata fields a probe device record carries."""
+    return {
+        key: value
+        for payload_key, key in _PAYLOAD_KEYS.items()
+        if isinstance(value := device.get(payload_key), str) and value
+    }
+
+
+def device_identifier(entry_id: str, device_ha_id: str) -> tuple[str, str]:
+    """Registry identifier of a probe device."""
+    return (DOMAIN, f"{entry_id}_{device_ha_id}")
+
+
+def build_device_info(
+    entry_id: str, device_ha_id: str, name: str, meta: dict[str, str]
+) -> DeviceInfo:
+    """DeviceInfo for a probe device, using whatever metadata is known."""
+    info = DeviceInfo(
+        identifiers={device_identifier(entry_id, device_ha_id)},
+        name=name,
+        manufacturer=meta.get("manufacturer") or DEFAULT_MANUFACTURER,
+        model=meta.get("model") or DEFAULT_MODEL,
+    )
+    if sw_version := meta.get("sw_version"):
+        info["sw_version"] = sw_version
+    if configuration_url := meta.get("configuration_url"):
+        info["configuration_url"] = configuration_url
+    if via_device := meta.get("via_device"):
+        info["via_device"] = device_identifier(entry_id, via_device)
+    return info
+
+
+def sync_device_registry(
+    hass: HomeAssistant,
+    entry_id: str,
+    device_ha_id: str,
+    meta: dict[str, str],
+) -> None:
+    """Push changed metadata (e.g. a new docker image) to an existing device.
+
+    Entities only hand their DeviceInfo to HA when first created, so later
+    changes from the probe have to be applied to the registry directly.
+    """
+    registry = dr.async_get(hass)
+    device = registry.async_get_device(
+        identifiers={device_identifier(entry_id, device_ha_id)}
+    )
+    if device is None:
+        return
+
+    changes: dict[str, Any] = {
+        "manufacturer": meta.get("manufacturer") or DEFAULT_MANUFACTURER,
+        "model": meta.get("model") or DEFAULT_MODEL,
+    }
+    if sw_version := meta.get("sw_version"):
+        changes["sw_version"] = sw_version
+    if configuration_url := meta.get("configuration_url"):
+        changes["configuration_url"] = configuration_url
+    if via_device := meta.get("via_device"):
+        parent = registry.async_get_device(
+            identifiers={device_identifier(entry_id, via_device)}
+        )
+        if parent is not None:
+            changes["via_device_id"] = parent.id
+
+    registry.async_update_device(device.id, **changes)
diff --git a/src/main/kotlin/hu/gerviba/probe/DeviceLinker.kt b/src/main/kotlin/hu/gerviba/probe/DeviceLinker.kt
new file mode 100644
index 0000000..3d0dbb5
--- /dev/null
+++ b/src/main/kotlin/hu/gerviba/probe/DeviceLinker.kt
@@ -0,0 +1,30 @@
+package hu.gerviba.probe
+
+import org.slf4j.LoggerFactory
+
+/**
+ * Nests devices that represent a Docker container under the host device.
+ *
+ * The host is the first non-container device whose haDisplayName or haId matches the
+ * config root's haDisplayName / haId, falling back to the device with haId "default".
+ */
+object DeviceLinker {
+
+    private val log = LoggerFactory.getLogger(DeviceLinker::class.java)
+
+    fun link(config: ConfigRecord): List<DeviceRecord> {
+        val hosts = config.devices.filter { it.dockerContainer == null }
+        val host = hosts.firstOrNull {
+            it.haDisplayName.equals(config.haDisplayName, ignoreCase = true) ||
+                it.haId.equals(config.haId, ignoreCase = true)
+        } ?: hosts.firstOrNull { it.haId == "default" }
+
+        if (host == null && config.devices.any { it.dockerContainer != null })
+            log.warn("No host device matches the config root; container devices will not be nested")
+
+        return config.devices.map {
+            if (it.dockerContainer != null && host != null) it.copy(viaDevice = host.haId) else it
+        }
+    }
+
+}
diff --git a/src/main/kotlin/hu/gerviba/probe/DeviceService.kt b/src/main/kotlin/hu/gerviba/probe/DeviceService.kt
new file mode 100644
index 0000000..6b87c8a
--- /dev/null
+++ b/src/main/kotlin/hu/gerviba/probe/DeviceService.kt
@@ -0,0 +1,84 @@
+package hu.gerviba.probe
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.github.dockerjava.core.DefaultDockerClientConfig
+import com.github.dockerjava.httpclient5.ApacheDockerHttpClient
+import com.github.dockerjava.transport.DockerHttpClient
+import hu.gerviba.probe.api.ApiService
+import org.slf4j.LoggerFactory
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
+
+/**
+ * Keeps the sw_version of Docker container devices in sync with the image the
+ * container currently runs, re-checking periodically.
+ */
+class DeviceService(
+    private val apiService: ApiService,
+) {
+
+    private val log = LoggerFactory.getLogger(DeviceService::class.java)
+    private val mapper = ObjectMapper()
+    private val scheduler = Executors.newSingleThreadScheduledExecutor { runnable ->
+        Thread(runnable, "device-refresh").apply { isDaemon = true }
+    }
+
+    private val httpClient: DockerHttpClient by lazy {
+        val config = DefaultDockerClientConfig.createDefaultConfigBuilder().build()
+        ApacheDockerHttpClient.Builder()
+            .dockerHost(config.dockerHost)
+            .sslConfig(config.sslConfig)
+            .build()
+    }
+
+    /** Resolves images once (before the first push), then refreshes them periodically. */
+    fun start() {
+        if (apiService.currentDevices().none { it.dockerContainer != null })
+            return
+
+        refresh(push = false)
+        scheduler.scheduleWithFixedDelay({ refresh(push = true) }, REFRESH_HOURS, REFRESH_HOURS, TimeUnit.HOURS)
+    }
+
+    private fun refresh(push: Boolean) {
+        try {
+            val current = apiService.currentDevices()
+            val updated = current.map { device ->
+                val container = device.dockerContainer ?: return@map device
+                val image = imageOf(container) ?: return@map device
+                device.copy(swVersion = image)
+            }
+            if (updated == current)
+                return
+
+            if (push) {
+                apiService.updateDevices(updated)
+            } else {
+                apiService.setDevicesSilently(updated)
+            }
+        } catch (e: Exception) {
+            log.warn("Failed to refresh device versions: {}", e.message)
+        }
+    }
+
+    /** Image of a container (as configured, e.g. "gitea/gitea:1.22"), or null if unavailable. */
+    private fun imageOf(container: String): String? {
+        return try {
+            val request = DockerHttpClient.Request.builder()
+                .method("GET")
+                .path("/containers/$container/json")
+                .build()
+            httpClient.execute(request).use { response ->
+                mapper.readTree(response.body).get("Config")?.get("Image")?.asText()
+            }
+        } catch (e: Exception) {
+            log.warn("Failed to inspect container {}: {}", container, e.message)
+            null
+        }
+    }
+
+    private companion object {
+        const val REFRESH_HOURS = 1L
+    }
+
+}