diff --git a/README.md b/README.md
index 53f694c..d465b1f 100644
--- a/README.md
+++ b/README.md
@@ -40,11 +40,14 @@ How to setup:
  - On the website pick the slot you put your filament in
  - Done
 
+Notes:
+ - If you change the BASE_URL of this app, you will need to reconfigure all NFC TAGS
+
 TBD:
  - Filament remaining in AMS (I have only AMS lite, if you have AMS we can test together)
  - Filament spending based on printing
  - Evidently needed GUI improvements
  - Code cleanup
  - Deployment as Docker and Helm chart
- - Easy configuration via env properties
  - Video showcase
+ - TODOs
diff --git a/app.py b/app.py
index 155c19e..8db9657 100644
--- a/app.py
+++ b/app.py
@@ -1,16 +1,17 @@
 import json
 import uuid
 
-import requests
 from flask import Flask, request, render_template_string
 
-from config import BASE_URL, PRINTER_ID, SPOOLMAN_API_URL
+from config import BASE_URL
 from filament import generate_filament_brand_code, generate_filament_temperatures
 from messages import AMS_FILAMENT_SETTING
-from mqtt_bambulab import fetchSpools, getLastAMSConfig, publish, getMqttClient
+from mqtt_bambulab import fetchSpools, getLastAMSConfig, publish, getMqttClient, setActiveTray
+from spoolman_client import patchExtraTags, getSpoolById
 
 app = Flask(__name__)
 
+
 @app.route("/spool_info")
 def spool_info():
   tag_id = request.args.get("tag_id")
@@ -68,6 +69,7 @@ def spool_info():
 
   return render_template_string(html)
 
+
 @app.route("/tray_load")
 def tray_load():
   tag_id = request.args.get("tag_id")
@@ -80,25 +82,15 @@ def tray_load():
 
   try:
     # Update Spoolman with the selected tray
-    response = requests.patch(f"{SPOOLMAN_API_URL}/spool/{spool_id}", json={
-      "extra": {
-        "tag": json.dumps(tag_id),
-        "active_tray": json.dumps(f"{PRINTER_ID}_{ams_id}_{tray_id}"),
-      }
-    })
-    print(response.status_code)
-    print(response.text)
+    spool_data = getSpoolById(spool_id)
 
-    response = requests.get(f"{SPOOLMAN_API_URL}/spool/{spool_id}")
-    print(response.status_code)
-    print(response.text)
+    setActiveTray(spool_id, spool_data["extra"], ams_id, tray_id)
 
-    spool_data = json.loads(response.text)
     ams_message = AMS_FILAMENT_SETTING
     ams_message["print"]["sequence_id"] = 0
     ams_message["print"]["ams_id"] = int(ams_id)
     ams_message["print"]["tray_id"] = int(tray_id)
-    ams_message["print"]["tray_color"] = spool_data["filament"]["color_hex"].upper()+"FF"
+    ams_message["print"]["tray_color"] = spool_data["filament"]["color_hex"].upper() + "FF"
 
     if "nozzle_temperature" in spool_data["filament"]["extra"]:
       nozzle_temperature_range = spool_data["filament"]["extra"]["nozzle_temperature"].strip("[]").split(",")
@@ -112,11 +104,12 @@ def tray_load():
 
     ams_message["print"]["tray_type"] = spool_data["filament"]["material"]
     filament_brand_code = generate_filament_brand_code(spool_data["filament"]["material"],
-                                 spool_data["filament"]["vendor"]["name"],
-                                 spool_data["filament"]["extra"].get("type", ""))
+                                                       spool_data["filament"]["vendor"]["name"],
+                                                       spool_data["filament"]["extra"].get("type", ""))
     ams_message["print"]["tray_info_idx"] = filament_brand_code["brand_code"]
 
-    #ams_message["print"]["tray_sub_brands"] = filament_brand_code["sub_brand_code"]
+    # TODO: test sub_brand_code
+    # ams_message["print"]["tray_sub_brands"] = filament_brand_code["sub_brand_code"]
     ams_message["print"]["tray_sub_brands"] = ""
 
     print(ams_message)
@@ -129,10 +122,10 @@ def tray_load():
   except Exception as e:
     return f"<h1>Error</h1><p>{str(e)}</p>"
 
+
 @app.route("/")
 def home():
   try:
-    # Update Spoolman with the selected tray
     spools = fetchSpools()
 
     last_ams_config = getLastAMSConfig()
@@ -176,6 +169,7 @@ def home():
   except Exception as e:
     return f"<h1>Error</h1><p>{str(e)}</p>"
 
+
 @app.route("/assign_tag")
 def assign_tag():
   spool_id = request.args.get("spool_id")
@@ -185,15 +179,10 @@ def assign_tag():
 
   myuuid = str(uuid.uuid4())
 
-  resp = requests.patch(f"{SPOOLMAN_API_URL}/spool/{spool_id}", json={
-    "extra": {
-      "tag": json.dumps(myuuid),
-    }
+  patchExtraTags(spool_id, {}, {
+    "tag": json.dumps(myuuid),
   })
 
-  print(resp.status_code)
-  print(resp.raw)
-
   return f"""
   <html>
   <header>
@@ -217,6 +206,7 @@ def assign_tag():
         </html>
         """
 
+
 @app.route('/', methods=['GET'])
 def health():
   return "OK", 200
diff --git a/mqtt_bambulab.py b/mqtt_bambulab.py
index 3975b1f..f52d35b 100644
--- a/mqtt_bambulab.py
+++ b/mqtt_bambulab.py
@@ -4,15 +4,16 @@ import traceback
 from threading import Thread
 
 import paho.mqtt.client as mqtt
-import requests
 
-from config import PRINTER_ID, PRINTER_CODE, PRINTER_IP, SPOOLMAN_API_URL
+from config import PRINTER_ID, PRINTER_CODE, PRINTER_IP
 from messages import GET_VERSION, PUSH_ALL
+from spoolman_client import fetchSpoolList, patchExtraTags
 
 
 def num2letter(num):
   return chr(ord("A") + int(num))
 
+
 def publish(client, msg):
   result = client.publish(f"device/{PRINTER_ID}/request", json.dumps(msg))
   status = result[0]
@@ -23,12 +24,14 @@ def publish(client, msg):
   print(f"Failed to send message to topic device/{PRINTER_ID}/request")
   return False
 
+
 # Inspired by https://github.com/Donkie/Spoolman/issues/217#issuecomment-2303022970
 def on_message(client, userdata, msg):
   global LAST_AMS_CONFIG
   # TODO: Consume spool
   try:
     data = json.loads(msg.payload.decode())
+    print(data)
     if "print" in data and "vt_tray" in data["print"]:
       print(data)
       LAST_AMS_CONFIG["vt_tray"] = data["print"]["vt_tray"]
@@ -42,7 +45,8 @@ def on_message(client, userdata, msg):
         print(f"AMS [{num2letter(ams['id'])}] (hum: {ams['humidity']}, temp: {ams['temp']}ºC)")
         for tray in ams["tray"]:
           if "tray_sub_brands" in tray:
-            print(f"    - [{num2letter(ams['id'])}{tray['id']}] {tray['tray_sub_brands']} {tray['tray_color']} ({str(tray['remain']).zfill(3)}%) [[ {tray['tag_uid']} ]]")
+            print(
+                f"    - [{num2letter(ams['id'])}{tray['id']}] {tray['tray_sub_brands']} {tray['tray_color']} ({str(tray['remain']).zfill(3)}%) [[ {tray['tag_uid']} ]]")
 
             found = False
             for spool in SPOOLS:
@@ -54,40 +58,45 @@ def on_message(client, userdata, msg):
 
               found = True
 
-              resp = requests.patch(f"{SPOOLMAN_API_URL}/spool/{spool['id']}", json={
-                "extra": {
-                  "tag": spool["extra"]["tag"],
-                  "active_tray": json.dumps(f"{PRINTER_ID}_{ams['id']}_{tray['id']}"),
-                }
-              })
+              setActiveTray(spool['id'], spool["extra"], ams['id'], tray["id"])
 
-              print(resp.text)
-              print(resp.status_code)
-
-              #TODO: remove active_tray from inactive spools
-              #Doesn't work for AMS Lite
-              #requests.patch(f"http://{SPOOLMAN_IP}:7912/api/v1/spool/{spool['id']}", json={
+              # TODO: filament remaining - Doesn't work for AMS Lite
+              # requests.patch(f"http://{SPOOLMAN_IP}:7912/api/v1/spool/{spool['id']}", json={
               #  "remaining_weight": tray["remain"] / 100 * tray["tray_weight"]
-              #})
+              # })
 
-          if not found:
-            print("      - Not found. Update spool tag!")
+            if not found:
+              print("      - Not found. Update spool tag!")
   except Exception as e:
     traceback.print_exc()
 
+
 def on_connect(client, userdata, flags, rc):
-  print("Connected with result code "+str(rc))
+  print("Connected with result code " + str(rc))
   client.subscribe(f"device/{PRINTER_ID}/report")
   publish(client, GET_VERSION)
   publish(client, PUSH_ALL)
 
+
+def setActiveTray(spool_id, spool_extra, ams_id, tray_id):
+  patchExtraTags(spool_id, spool_extra, {
+    "active_tray": json.dumps(f"{PRINTER_ID}_{ams_id}_{tray_id}"),
+  })
+
+  # Remove active tray from inactive spools
+  for old_spool in SPOOLS:
+    if spool_id != old_spool["id"] and old_spool["extra"]["active_tray"] == json.dumps(
+        f"{PRINTER_ID}_{ams_id}_{tray_id}"):
+      patchExtraTags(old_spool["id"], old_spool["extra"], {"active_tray": json.dumps("")})
+
+
 # Fetch spools from spoolman
 def fetchSpools():
   global SPOOLS
-  response = requests.get(f"{SPOOLMAN_API_URL}/spool")
-  SPOOLS = response.json()
+  SPOOLS = fetchSpoolList()
   return SPOOLS
 
+
 def async_subscribe():
   global MQTT_CLIENT
   MQTT_CLIENT = mqtt.Client()
@@ -102,18 +111,22 @@ def async_subscribe():
   MQTT_CLIENT.connect(PRINTER_IP, 8883)
   MQTT_CLIENT.loop_forever()
 
+
 # Start the asynchronous processing in a separate thread
 thread = Thread(target=async_subscribe)
 thread.start()
 
+
 def getLastAMSConfig():
   global LAST_AMS_CONFIG
   return LAST_AMS_CONFIG
 
+
 def getMqttClient():
   global MQTT_CLIENT
   return MQTT_CLIENT
 
-MQTT_CLIENT = {} # Global variable storing MQTT Client
+
+MQTT_CLIENT = {}  # Global variable storing MQTT Client
 LAST_AMS_CONFIG = {}  # Global variable storing last AMS configuration
-SPOOLS = fetchSpools() # Global variable storing latest spool from spoolman
+SPOOLS = fetchSpools()  # Global variable storing latest spool from spoolman
diff --git a/spoolman_client.py b/spoolman_client.py
new file mode 100644
index 0000000..930a39b
--- /dev/null
+++ b/spoolman_client.py
@@ -0,0 +1,27 @@
+import requests
+from config import SPOOLMAN_API_URL
+
+
+def patchExtraTags(spool_id, old_extras, new_extras):
+  for key, value in new_extras.items():
+    old_extras[key] = value
+
+  resp = requests.patch(f"{SPOOLMAN_API_URL}/spool/{spool_id}", json={
+    "extra": old_extras
+  })
+  print(resp.text)
+  print(resp.status_code)
+
+
+def getSpoolById(spool_id):
+  response = requests.get(f"{SPOOLMAN_API_URL}/spool/{spool_id}")
+  print(response.status_code)
+  print(response.text)
+  return response.json()
+
+
+def fetchSpoolList():
+  response = requests.get(f"{SPOOLMAN_API_URL}/spool")
+  print(response.status_code)
+  print(response.text)
+  return response.json()