diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5795199..9a59b58 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.0.2 - 2026-02-13
+- Validate and normalize KNX group addresses in subentry config flows.
+- Add options flow skeleton for future settings.
+- Add `bcs.yaml` metadata for BCS store listing.
+
 ## 0.0.1 - 2026-02-13
 - Initial HACS-ready scaffold with config flow and subentries for binary sensor and cover.
 - KNX bridge logic for basic send/receive mappings.
diff --git a/README.md b/README.md
index 3cf3574..94db37c 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,7 @@ Current minimal scope:
 - `angle_state_address` (DPT 5.001): KNX group address that receives HA tilt updates.
 
 If a group address is left empty, it is ignored.
+Group address format must be `X/Y/Z` (0-31/0-7/0-255) or `X/Y` (0-31/0-2047).
 
 ## Notes
 - For DPT 1.008 (Up/Down), the bridge treats `0 = Up/Open` and `1 = Down/Close`.
@@ -46,6 +47,6 @@ If a group address is left empty, it is ignored.
 - Advanced DPT mapping options and inversion settings.
 
 ## Versioning and Releases
-- Current version: 0.0.1
+- Current version: 0.0.2
 - `CHANGELOG.md` lists versions with the newest entries at the top.
 - Release creation is manual and only done when explicitly requested.
diff --git a/bcs.yaml b/bcs.yaml
new file mode 100644
index 0000000..a5472c8
--- /dev/null
+++ b/bcs.yaml
@@ -0,0 +1,21 @@
+name: HA KNX Bridge
+description: >
+  Home Assistant custom integration that mirrors Home Assistant entities
+  to KNX group addresses and accepts KNX actions to control Home Assistant
+  entities. It reuses an existing Home Assistant KNX integration and
+  provides per-entity "Ports" with automatic DPT selection and UI setup
+  via config flow.
+
+category: Integrations
+
+author: Bahmcloud
+maintainer: Bahmcloud
+
+domains:
+  - ha_knx_bridge
+
+min_ha_version: "2025.12.0"
+
+homepage: https://github.com/bahmcloud/HA-KNX-Bridge
+issues: https://github.com/bahmcloud/HA-KNX-Bridge/issues
+source: https://github.com/bahmcloud/HA-KNX-Bridge
diff --git a/custom_components/ha_knx_bridge/config_flow.py b/custom_components/ha_knx_bridge/config_flow.py
index 8ec5a16..1ea762b 100644
--- a/custom_components/ha_knx_bridge/config_flow.py
+++ b/custom_components/ha_knx_bridge/config_flow.py
@@ -54,6 +54,11 @@ class HAKnxBridgeConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         )
         return self.async_show_form(step_id="user", data_schema=schema)
 
+    @staticmethod
+    @callback
+    def async_get_options_flow(config_entry):
+        return HAKnxBridgeOptionsFlow(config_entry)
+
     @staticmethod
     @callback
     def async_get_supported_subentry_types(config_entry):
@@ -67,25 +72,34 @@ class HAKnxBridgeConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         }
 
 
+class HAKnxBridgeOptionsFlow(config_entries.OptionsFlow):
+    def __init__(self, config_entry: config_entries.ConfigEntry) -> None:
+        self._config_entry = config_entry
+
+    async def async_step_init(self, user_input: dict | None = None):
+        if user_input is not None:
+            return self.async_create_entry(title="", data=user_input)
+
+        schema = vol.Schema({})
+        return self.async_show_form(step_id="init", data_schema=schema)
+
+
 class BinarySensorPortSubentryFlow(config_entries.ConfigSubentryFlow):
     VERSION = 1
 
     async def async_step_user(self, user_input: dict | None = None):
         if user_input is not None:
+            user_input, errors = _validate_knx_addresses(
+                user_input, [CONF_STATE_ADDRESS]
+            )
+            if errors:
+                return self.async_show_form(
+                    step_id="user", data_schema=_binary_sensor_schema(), errors=errors
+                )
             title = _entity_title(self.hass, user_input[CONF_ENTITY_ID])
             return self.async_create_entry(title=title, data=user_input)
 
-        schema = vol.Schema(
-            {
-                vol.Required(CONF_ENTITY_ID): selector.EntitySelector(
-                    selector.EntitySelectorConfig(domain=["binary_sensor"])
-                ),
-                vol.Optional(CONF_STATE_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-            }
-        )
-        return self.async_show_form(step_id="user", data_schema=schema)
+        return self.async_show_form(step_id="user", data_schema=_binary_sensor_schema())
 
 
 class CoverPortSubentryFlow(config_entries.ConfigSubentryFlow):
@@ -93,38 +107,26 @@ class CoverPortSubentryFlow(config_entries.ConfigSubentryFlow):
 
     async def async_step_user(self, user_input: dict | None = None):
         if user_input is not None:
+            user_input, errors = _validate_knx_addresses(
+                user_input,
+                [
+                    CONF_MOVE_LONG_ADDRESS,
+                    CONF_MOVE_SHORT_ADDRESS,
+                    CONF_STOP_ADDRESS,
+                    CONF_POSITION_ADDRESS,
+                    CONF_POSITION_STATE_ADDRESS,
+                    CONF_ANGLE_ADDRESS,
+                    CONF_ANGLE_STATE_ADDRESS,
+                ],
+            )
+            if errors:
+                return self.async_show_form(
+                    step_id="user", data_schema=_cover_schema(), errors=errors
+                )
             title = _entity_title(self.hass, user_input[CONF_ENTITY_ID])
             return self.async_create_entry(title=title, data=user_input)
 
-        schema = vol.Schema(
-            {
-                vol.Required(CONF_ENTITY_ID): selector.EntitySelector(
-                    selector.EntitySelectorConfig(domain=["cover"])
-                ),
-                vol.Optional(CONF_MOVE_LONG_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-                vol.Optional(CONF_MOVE_SHORT_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-                vol.Optional(CONF_STOP_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-                vol.Optional(CONF_POSITION_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-                vol.Optional(CONF_POSITION_STATE_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-                vol.Optional(CONF_ANGLE_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-                vol.Optional(CONF_ANGLE_STATE_ADDRESS): selector.TextSelector(
-                    selector.TextSelectorConfig(type="text")
-                ),
-            }
-        )
-        return self.async_show_form(step_id="user", data_schema=schema)
+        return self.async_show_form(step_id="user", data_schema=_cover_schema())
 
 
 def _entity_title(hass, entity_id: str) -> str:
@@ -132,3 +134,100 @@ def _entity_title(hass, entity_id: str) -> str:
     if state is None:
         return entity_id
     return state.attributes.get("friendly_name", entity_id)
+
+
+def _binary_sensor_schema() -> vol.Schema:
+    return vol.Schema(
+        {
+            vol.Required(CONF_ENTITY_ID): selector.EntitySelector(
+                selector.EntitySelectorConfig(domain=["binary_sensor"])
+            ),
+            vol.Optional(CONF_STATE_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+        }
+    )
+
+
+def _cover_schema() -> vol.Schema:
+    return vol.Schema(
+        {
+            vol.Required(CONF_ENTITY_ID): selector.EntitySelector(
+                selector.EntitySelectorConfig(domain=["cover"])
+            ),
+            vol.Optional(CONF_MOVE_LONG_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+            vol.Optional(CONF_MOVE_SHORT_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+            vol.Optional(CONF_STOP_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+            vol.Optional(CONF_POSITION_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+            vol.Optional(CONF_POSITION_STATE_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+            vol.Optional(CONF_ANGLE_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+            vol.Optional(CONF_ANGLE_STATE_ADDRESS): selector.TextSelector(
+                selector.TextSelectorConfig(type="text")
+            ),
+        }
+    )
+
+
+def _validate_knx_addresses(
+    user_input: dict, keys: list[str]
+) -> tuple[dict, dict[str, str]]:
+    errors: dict[str, str] = {}
+    cleaned = dict(user_input)
+    for key in keys:
+        if key not in cleaned:
+            continue
+        value = cleaned.get(key)
+        if value is None:
+            cleaned.pop(key, None)
+            continue
+        try:
+            normalized = _normalize_group_address(str(value))
+        except ValueError:
+            errors[key] = "invalid_ga"
+            continue
+        if normalized == "":
+            cleaned.pop(key, None)
+        else:
+            cleaned[key] = normalized
+    return cleaned, errors
+
+
+def _normalize_group_address(value: str) -> str:
+    text = value.strip()
+    if not text:
+        return ""
+    parts = text.split("/")
+    if len(parts) == 2:
+        main, sub = _parse_int(parts[0]), _parse_int(parts[1])
+        if not (0 <= main <= 31 and 0 <= sub <= 2047):
+            raise ValueError("group address out of range")
+        return f"{main}/{sub}"
+    if len(parts) == 3:
+        main, middle, sub = (
+            _parse_int(parts[0]),
+            _parse_int(parts[1]),
+            _parse_int(parts[2]),
+        )
+        if not (0 <= main <= 31 and 0 <= middle <= 7 and 0 <= sub <= 255):
+            raise ValueError("group address out of range")
+        return f"{main}/{middle}/{sub}"
+    raise ValueError("invalid group address format")
+
+
+def _parse_int(value: str) -> int:
+    text = value.strip()
+    if text == "":
+        raise ValueError("empty group address part")
+    return int(text)
diff --git a/custom_components/ha_knx_bridge/manifest.json b/custom_components/ha_knx_bridge/manifest.json
index 9eb57a4..31f499f 100644
--- a/custom_components/ha_knx_bridge/manifest.json
+++ b/custom_components/ha_knx_bridge/manifest.json
@@ -1,7 +1,7 @@
 {
   "domain": "ha_knx_bridge",
   "name": "HA KNX Bridge",
-  "version": "0.0.1",
+  "version": "0.0.2",
   "config_flow": true,
   "documentation": "https://github.com/bahmcloud/HA-KNX-Bridge",
   "issue_tracker": "https://github.com/bahmcloud/HA-KNX-Bridge/issues",
diff --git a/custom_components/ha_knx_bridge/strings.json b/custom_components/ha_knx_bridge/strings.json
index 265a7b4..9c0c757 100644
--- a/custom_components/ha_knx_bridge/strings.json
+++ b/custom_components/ha_knx_bridge/strings.json
@@ -3,6 +3,9 @@
     "abort": {
       "knx_not_configured": "Set up the Home Assistant KNX integration first."
     },
+    "error": {
+      "invalid_ga": "Invalid KNX group address. Use X/Y/Z (0-31/0-7/0-255) or X/Y (0-31/0-2047)."
+    },
     "step": {
       "user": {
         "title": "HA KNX Bridge",
@@ -13,7 +16,18 @@
       }
     }
   },
+  "options": {
+    "step": {
+      "init": {
+        "title": "HA KNX Bridge Options",
+        "description": "No options available yet."
+      }
+    }
+  },
   "config_subentries": {
+    "error": {
+      "invalid_ga": "Invalid KNX group address. Use X/Y/Z (0-31/0-7/0-255) or X/Y (0-31/0-2047)."
+    },
     "binary_sensor": {
       "step": {
         "user": {