Link meter devices to add-on via_device using supervisor slug

Resolve the add-on slug from the supervisor (`/store/addons/self`) in
run.sh and forward it as `ADDON_SLUG` in the `[MQTT_INSIGHTS]` section.
The MQTT Insights service then sets `via_device: <addon_slug>` on the
CT002 and Shelly meter discovery payloads so Home Assistant nests them
under the AstraMeter add-on device.

Author: claude

ha_addon/run.sh

@@ -143,12 +143,23 @@ else
             echo "POWER_MULTIPLIER=$power_multiplier"
         fi
 
+        # Fetch this add-on's slug from the supervisor so MQTT discovery can
+        # link discovered meter devices to the add-on device via_device.
+        addon_slug=""
+        if addon_slug="$(bashio::api.supervisor GET '/store/addons/self' false '.slug')" && [ -n "$addon_slug" ]; then
+            bashio::log.info "Resolved add-on slug for HA discovery: $addon_slug"
+        else
+            bashio::log.warning "Failed to resolve add-on slug from supervisor; meter devices will not be linked via_device"
+            addon_slug=""
+        fi
+
         if bashio::config.has_value 'mqtt_uri'; then
             bashio::log.info "Using custom MQTT broker URL from configuration"
             echo ""
             echo "[MQTT_INSIGHTS]"
             echo "URI=$(bashio::config 'mqtt_uri')"
             echo "HA_DISCOVERY=True"
+            [ -n "$addon_slug" ] && echo "ADDON_SLUG=$addon_slug"
         elif bashio::services.available "mqtt"; then
             bashio::log.info "Using Home Assistant's internal MQTT broker"
             echo ""
@@ -159,6 +170,7 @@ else
             echo "PASSWORD=$(bashio::services 'mqtt' 'password')"
             echo "TLS=$(bashio::services 'mqtt' 'ssl')"
             echo "HA_DISCOVERY=True"
+            [ -n "$addon_slug" ] && echo "ADDON_SLUG=$addon_slug"
         fi
     } > "$CONFIG"
 fi

src/astrameter/config/config_loader.py

@@ -570,5 +570,6 @@ def read_mqtt_insights_config(
                     section, "HA_DISCOVERY_PREFIX", fallback=""
                 )
                 or "homeassistant",
+                addon_slug=config.get(section, "ADDON_SLUG", fallback="") or None,
             )
     return None

src/astrameter/mqtt_insights/discovery.py

@@ -239,6 +239,7 @@ def build_ct002_device_discovery(
     base_topic: str,
     device_id: str,
     ha_prefix: str,
+    addon_slug: str | None = None,
 ) -> tuple[str, dict]:
     safe_dev = _sanitize_id(device_id)
     node_id = f"astrameter_ct002_{safe_dev}"
@@ -283,12 +284,16 @@ def build_ct002_device_discovery(
         },
     }
 
+    device_info: dict = {
+        "identifiers": node_id,
+        "name": f"AstraMeter CT002 {device_id}",
+        "manufacturer": "astrameter",
+    }
+    if addon_slug:
+        device_info["via_device"] = addon_slug
+
     payload = {
-        "device": {
-            "identifiers": node_id,
-            "name": f"AstraMeter CT002 {device_id}",
-            "manufacturer": "astrameter",
-        },
+        "device": device_info,
         "origin": _origin(),
         "components": components,
         "availability": [_system_availability(base_topic)],
@@ -403,6 +408,7 @@ def build_shelly_device_discovery(
     base_topic: str,
     device_id: str,
     ha_prefix: str,
+    addon_slug: str | None = None,
 ) -> tuple[str, dict]:
     safe_dev = _sanitize_id(device_id)
     node_id = f"astrameter_shelly_{safe_dev}"
@@ -420,12 +426,16 @@ def build_shelly_device_discovery(
         },
     }
 
+    device_info: dict = {
+        "identifiers": node_id,
+        "name": f"AstraMeter Shelly {device_id}",
+        "manufacturer": "astrameter",
+    }
+    if addon_slug:
+        device_info["via_device"] = addon_slug
+
     payload = {
-        "device": {
-            "identifiers": node_id,
-            "name": f"AstraMeter Shelly {device_id}",
-            "manufacturer": "astrameter",
-        },
+        "device": device_info,
         "origin": _origin(),
         "components": components,
         "availability": [_system_availability(base_topic)],

src/astrameter/mqtt_insights/mqtt_insights_test.py

@@ -152,9 +152,12 @@ def test_ct002_consumer_discovery_network_mac_and_ip():
 
 
 def test_ct002_device_discovery_structure():
-    topic, payload = build_ct002_device_discovery("astrameter", "dev1", "homeassistant")
+    topic, payload = build_ct002_device_discovery(
+        "astrameter", "dev1", "homeassistant", addon_slug="34dea19a_astrameter"
+    )
     _assert_discovery_structure(topic, payload)
     assert "AstraMeter" in payload["device"]["name"]
+    assert payload["device"]["via_device"] == "34dea19a_astrameter"
     comps = payload["components"]
     assert "smooth_target" in comps
     assert "active_control" in comps
@@ -190,13 +193,21 @@ def test_shelly_battery_discovery_structure():
 
 def test_shelly_device_discovery_structure():
     topic, payload = build_shelly_device_discovery(
-        "astrameter", "shelly1", "homeassistant"
+        "astrameter", "shelly1", "homeassistant", addon_slug="34dea19a_astrameter"
     )
     _assert_discovery_structure(topic, payload)
     assert "AstraMeter" in payload["device"]["name"]
+    assert payload["device"]["via_device"] == "34dea19a_astrameter"
     assert "battery_count" in payload["components"]
 
 
+def test_meter_device_discovery_omits_via_device_without_addon_slug():
+    _, ct002 = build_ct002_device_discovery("astrameter", "dev1", "homeassistant")
+    assert "via_device" not in ct002["device"]
+    _, shelly = build_shelly_device_discovery("astrameter", "shelly1", "homeassistant")
+    assert "via_device" not in shelly["device"]
+
+
 def test_unique_ids_are_unique():
     """All unique_ids within a single discovery payload must be distinct."""
     _, payload = build_ct002_consumer_discovery(
@@ -295,6 +306,7 @@ def test_read_mqtt_insights_config_present():
 BASE_TOPIC = my_topic
 HA_DISCOVERY = true
 HA_DISCOVERY_PREFIX = ha
+ADDON_SLUG = 34dea19a_astrameter
 """
     )
     result = read_mqtt_insights_config(cfg)
@@ -307,6 +319,7 @@ def test_read_mqtt_insights_config_present():
     assert result.base_topic == "my_topic"
     assert result.ha_discovery is True
     assert result.ha_discovery_prefix == "ha"
+    assert result.addon_slug == "34dea19a_astrameter"
 
 
 def test_read_mqtt_insights_config_defaults():

src/astrameter/mqtt_insights/service.py

@@ -58,6 +58,7 @@ class MqttInsightsConfig:
     base_topic: str = "astrameter"
     ha_discovery: bool = True
     ha_discovery_prefix: str = "homeassistant"
+    addon_slug: str | None = None
 
 
 @dataclass
@@ -341,7 +342,7 @@ async def _handle_ct002_event(
             if did not in self._discovered_ct002_devices:
                 self._discovered_ct002_devices.add(did)
                 topic, payload = build_ct002_device_discovery(
-                    base, did, cfg.ha_discovery_prefix
+                    base, did, cfg.ha_discovery_prefix, addon_slug=cfg.addon_slug
                 )
                 await client.publish(
                     topic, payload=json.dumps(payload).encode(), retain=True
@@ -437,7 +438,7 @@ async def _handle_shelly_event(
             if did not in self._discovered_shelly_devices:
                 self._discovered_shelly_devices.add(did)
                 topic, payload = build_shelly_device_discovery(
-                    base, did, cfg.ha_discovery_prefix
+                    base, did, cfg.ha_discovery_prefix, addon_slug=cfg.addon_slug
                 )
                 await client.publish(
                     topic, payload=json.dumps(payload).encode(), retain=True