diff --git a/scripts/extract_gateway3_homekey.py b/scripts/extract_gateway3_homekey.py
index fbcb2ff..ff5058b 100644
--- a/scripts/extract_gateway3_homekey.py
+++ b/scripts/extract_gateway3_homekey.py
@@ -1,71 +1,99 @@
-import requests
-import json
+"""Extract PowerView homekey from a G3 PowerView Gateway"""
+
 import base64
+import json
 import struct
+from typing import Any, Final
 
-HUB = "http://192.168.0.184"
+import requests
 
-def create_request(sid, cid, sequenceId, data):
-    data = struct.pack("<BBBB", sid, cid, sequenceId, len(data)) + data
-    return data
+HUB: Final[str] = "http://powerview-g3.local"
+TIMEOUT: Final[int] = 10
 
-def decode_response(packet):
+
+def create_request(sid: int, cid: int, sequence_id: int, data: bytes) -> bytes:
+    """Assemble a request frame for the PowerView protocol."""
+    return struct.pack("<BBBB", sid, cid, sequence_id, len(data)) + data
+
+
+def decode_response(packet: bytes) -> dict[str, Any]:
     if len(packet) < 4:
-        raise Exception('Packet size too small')
-    sid, cid, sequenceId, length = struct.unpack("<BBBB", packet[0:4])
+        raise ValueError("Packet size too small")
+    sid, cid, sequence_id, length = struct.unpack("<BBBB", packet[0:4])
     if len(packet) != 4 + length:
-        raise Exception('Not all data present')
+        raise ValueError("Not all data present")
     if length < 1:
-        raise Exception('No errorCode present')
-    errorCode, = struct.unpack("<B", packet[4:5])
-    data = packet[5:]
+        raise ValueError("No errorCode present")
+    (error_code,) = struct.unpack("<B", packet[4:5])
+    data: Final[bytes] = packet[5:]
     return {
-            'cid': cid,
-            'sid': sid,
-            'sequenceId': sequenceId,
-            'errorCode': errorCode,
-            'data': data
-            }
-
-def create_get_shade_key_request(sequenceId):
-    return create_request(251, 18, sequenceId, b"")
-
-def get_shade_key(hub, bleName):
-    shades_exec_resp = requests.post(hub + "/home/shades/exec?shades=" + bleName, json={"hex":create_get_shade_key_request(1).hex()})
-    if shades_exec_resp.status_code != 200:
-        raise Exception('Unable to send GetShadeKey')
-    result = json.loads(shades_exec_resp.content)
-    if not 'err' in result or result['err'] != 0 or not 'responses' in result or len(result['responses']) != 1:
-        raise Exception('Error when attempting GetShadeKey')
-    result = result['responses'][0]
-    result = bytes.fromhex(result['hex'])
-    result = decode_response(result)
-    if result['errorCode'] != 0:
-        raise Exception('BLE errorCode is not 0')
-    if len(result['data']) != 16:
-        raise Exception('Expected 16 byte homekey')
-    return result['data']
+        "cid": cid,
+        "sid": sid,
+        "sequenceId": sequence_id,
+        "errorCode": error_code,
+        "data": data,
+    }
 
 
-def main(hub):
-    shades_resp = requests.get(hub + "/home/shades")
-    if shades_resp.status_code != 200:
-        raise Exception('Unable to get list of shades')
+def create_get_shade_key_request(sequence_id) -> bytes:
+    """Create a GetShadeKey request frame."""
+    return create_request(251, 18, sequence_id, b"")
+
+
+def get_shade_key(hub: str, ble_name) -> bytes:
+    """Get the homekey for a shade."""
+    try:
+        shades_exec_resp: requests.Response = requests.post(
+            hub + "/home/shades/exec?shades=" + ble_name,
+            json={"hex": create_get_shade_key_request(1).hex()},
+            timeout=TIMEOUT,
+        )
+        shades_exec_resp.raise_for_status()
+    except requests.exceptions.RequestException as ex:
+        print(f"Unable to send GetShadeKey {ex!s}")
+        raise
+
+    result: dict = json.loads(shades_exec_resp.content)
+    if result.get("err") != 0 or len(result.get("responses", [])) != 1:
+        raise IOError("Error when attempting GetShadeKey")
+    response: Final[bytes] = bytes.fromhex(result["responses"][0]["hex"])
+    dec_resp: Final[dict[str, Any]] = decode_response(response)
+    if dec_resp["errorCode"] != 0:
+        raise ValueError("BLE errorCode is not 0")
+    if len(dec_resp["data"]) != 16:
+        raise ValueError("Expected 16 byte homekey")
+    return dec_resp["data"]
+
+
+def main(hub: str) -> None:
+    """Main function, extract homekeys from all shades."""
+    try:
+        shades_resp: requests.Response = requests.get(
+            hub + "/home/shades", timeout=TIMEOUT
+        )
+        shades_resp.raise_for_status()
+    except requests.exceptions.RequestException as ex:
+        print(f"Unable to get list of shades:\n\t{ex!s}")
+        return
+
     shades = json.loads(shades_resp.content)
     print(f"Found {len(shades)} shades, interrogating")
     for shade in shades:
-        name = base64.b64decode(shade['name']).decode('utf-8')
+        name: str = base64.b64decode(shade["name"]).decode("utf-8")
+        key: bytes = get_shade_key(hub, shade["bleName"])
+
         print(f"Shade '{name}':")
         print(f"\tBLE name: '{shade['bleName']}'")
-
-        key = get_shade_key(hub, shade['bleName'])
         print(f"\tHomeKey: {key.hex()}")
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     import argparse
     import sys
-    parser = argparse.ArgumentParser(description="Extract PowerView homekey from a G3 PowerView Gateway")
-    parser.add_argument("hub", help="URL to HUB", default="http://powerview-g3.local")
+
+    parser = argparse.ArgumentParser(
+        description="Extract PowerView homekey from a G3 PowerView Gateway"
+    )
+    parser.add_argument("hub", nargs="?", help="URL to HUB", default=HUB)
     args = parser.parse_args()
     sys.exit(main(**vars(args)))