diff --git a/.env b/.env
new file mode 100644
index 0000000..7eb8cc3
--- /dev/null
+++ b/.env
@@ -0,0 +1,16 @@
+# IN PORTS 
+WEB_PORT_IN=80
+MODBUS_ELEVATOR_PORT_IN=3179
+COAP_SIMPLE_PORT_IN=5683
+COAP_NEGOTIATION_PORT_IN=5684
+TRAEFIK_DASHBOARD_PORT_IN=8080
+
+# OUT PORTS
+WEB_PORT_OUT=80
+MODBUS_ELEVATOR_PORT_OUT=3179
+COAP_SIMPLE_PORT_OUT=5683
+COAP_NEGOTIATION_PORT_OUT=5684
+TRAEFIK_DASHBOARD_PORT_OUT=8080
+
+HOSTNAME="localhost"
+BROKER_URI="test.mosquitto.org"
\ No newline at end of file
diff --git a/docker-compose.yml b/docker-compose.yml
index c54c674..4a4621b 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -6,30 +6,50 @@ services:
     build:
       context: ./things/calculator/
       dockerfile: ./coap/js/Dockerfile-simple
+      args:
+        - PORT_ARG=${COAP_SIMPLE_PORT_OUT}
+    environment:
+      - HOSTNAME=${HOSTNAME}
   coap-calculator-content-negotiation:
     labels:
       - traefik.udp.routers.coap-calculator-content-negotiation.entrypoints=coap-calculator-content-negotiation
     build:
       context: ./things/calculator/
       dockerfile: ./coap/js/Dockerfile-contentneg
+      args:
+        - PORT_ARG=${COAP_NEGOTIATION_PORT_OUT}
+    environment:
+      - HOSTNAME=${HOSTNAME}
   http-express-calculator-simple:
     labels:
       - traefik.http.routers.http-express-calculator-simple.rule=PathPrefix(`/http-express-calculator-simple`)
     build:
       context: ./things/calculator/
       dockerfile: ./http/express/Dockerfile-simple
+      args:
+        - PORT_ARG=${WEB_PORT_OUT}
+    environment:
+      - HOSTNAME=${HOSTNAME}
   http-express-calculator-content-negotiation:
     labels:
       - traefik.http.routers.http-express-calculator-content-negotiation.rule=PathPrefix(`/http-express-calculator-content-negotiation`)
     build:
       context: ./things/calculator/
       dockerfile: ./http/express/Dockerfile-contentneg
+      args:
+        - PORT_ARG=${WEB_PORT_OUT}
+    environment:
+      - HOSTNAME=${HOSTNAME}
   http-flask-calculator:
     labels:
       - traefik.http.routers.http-flask-calculator.rule=PathPrefix(`/http-flask-calculator`)
     build:
       context: ./things/calculator/
       dockerfile: ./http/flask/Dockerfile
+      args:
+        - PORT_ARG=${WEB_PORT_OUT}
+    environment:
+      - HOSTNAME=${HOSTNAME}
   mqtt-calculator:
     build:
       context: ./things/calculator/
@@ -38,25 +58,29 @@ services:
     labels:
       - traefik.tcp.routers.modbus-elevator.entrypoints=modbus-elevator
       - traefik.tcp.routers.modbus-elevator.rule=HostSNI(`*`)
+    environment:
+      - BROKER_URI=${BROKER_URI}
     build:
       context: ./things/elevator/
       dockerfile: ./modbus/js/Dockerfile
+      args:
+        - PORT_ARG=${MODBUS_ELEVATOR_PORT_OUT}
   reverse-proxy:
     image: traefik:v3.0
     command: 
       - "--log.level=DEBUG"
       - "--api.insecure=true" 
       - "--providers.docker=true"
-      - "--entrypoints.web.address=:80"
-      - "--entrypoints.modbus-elevator.address=:3179"
-      - "--entrypoints.coap-calculator-simple.address=:5683/udp"
-      - "--entrypoints.coap-calculator-content-negotiation.address=:5684/udp"
+      - "--entrypoints.web.address=:${WEB_PORT_IN}"
+      - "--entrypoints.modbus-elevator.address=:${MODBUS_ELEVATOR_PORT_IN}"
+      - "--entrypoints.coap-calculator-simple.address=:${COAP_SIMPLE_PORT_IN}/udp"
+      - "--entrypoints.coap-calculator-content-negotiation.address=:${COAP_NEGOTIATION_PORT_IN}/udp"
     ports:
-      - "80:80"
-      - "3179:3179"
-      - "5683:5683/udp"
-      - "5684:5684/udp"
-      - "8080:8080"
+      - "${WEB_PORT_OUT}:${WEB_PORT_IN}"
+      - "${MODBUS_ELEVATOR_PORT_OUT}:${MODBUS_ELEVATOR_PORT_IN}"
+      - "${COAP_SIMPLE_PORT_OUT}:${COAP_SIMPLE_PORT_IN}/udp"
+      - "${COAP_NEGOTIATION_PORT_OUT}:${COAP_NEGOTIATION_PORT_IN}/udp"
+      - "${TRAEFIK_DASHBOARD_PORT_OUT}:${TRAEFIK_DASHBOARD_PORT_IN}"
     volumes:
       # So that Traefik can listen to the Docker events
       - /var/run/docker.sock:/var/run/docker.sock
diff --git a/package-lock.json b/package-lock.json
index 54df27f..7dc5f8e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,9 +10,9 @@
         "./things/*/*/*"
       ],
       "dependencies": {
-        "@node-wot/binding-coap": "^0.8.13",
-        "@node-wot/binding-http": "^0.8.13",
-        "@node-wot/core": "^0.8.13"
+        "@node-wot/binding-coap": "0.8.13",
+        "@node-wot/binding-http": "0.8.13",
+        "@node-wot/core": "0.8.13"
       },
       "devDependencies": {
         "@types/express": "^4.17.17",
diff --git a/things/calculator/coap/js/Dockerfile-contentneg b/things/calculator/coap/js/Dockerfile-contentneg
index 70f1c8e..bf7437a 100644
--- a/things/calculator/coap/js/Dockerfile-contentneg
+++ b/things/calculator/coap/js/Dockerfile-contentneg
@@ -6,8 +6,10 @@ COPY ./coap/js .
 
 RUN npm install
 
+ARG PORT_ARG=5684
+ENV PORT=${PORT_ARG}
 ENV TM_PATH="./calculator.tm.json"
 
 CMD ["node", "coap-content-negotiation-calculator.js"]
 
-EXPOSE 5684/udp
\ No newline at end of file
+EXPOSE ${PORT}/udp
\ No newline at end of file
diff --git a/things/calculator/coap/js/Dockerfile-simple b/things/calculator/coap/js/Dockerfile-simple
index 2cb265c..e04b669 100644
--- a/things/calculator/coap/js/Dockerfile-simple
+++ b/things/calculator/coap/js/Dockerfile-simple
@@ -6,8 +6,10 @@ COPY ./coap/js .
 
 RUN npm install
 
+ARG PORT_ARG=5683
+ENV PORT=${PORT_ARG}
 ENV TM_PATH="./calculator.tm.json"
 
 CMD ["node", "coap-simple-calculator.js"]
 
-EXPOSE 5683/udp
\ No newline at end of file
+EXPOSE ${PORT}/udp
\ No newline at end of file
diff --git a/things/calculator/coap/js/coap-content-negotiation-calculator.js b/things/calculator/coap/js/coap-content-negotiation-calculator.js
index c5e5138..a16b668 100644
--- a/things/calculator/coap/js/coap-content-negotiation-calculator.js
+++ b/things/calculator/coap/js/coap-content-negotiation-calculator.js
@@ -7,8 +7,8 @@ const cbor = require('cbor')
 require('dotenv').config()
 
 const server = coap.createServer()
-const hostname = 'localhost'
-let portNumber = 5684
+const hostname = process.env.HOSTNAME ?? 'localhost'
+let portNumber = process.env.PORT ?? 5684
 const thingName = 'coap-calculator-content-negotiation'
 
 const { values: { port } } = parseArgs({
@@ -217,6 +217,7 @@ server.on('request', (req, res) => {
   } else {
     if (!segments[2]) {
       if (req.method === 'GET') {
+        //FIXME: No null check for acceptHeaders
         if (acceptHeaders.includes('application/json') || acceptHeaders.includes('application/td+json') || acceptHeaders.includes('application/*') || acceptHeaders === '*/*') {
           res.setOption('Content-Format', 'application/json')
           res.end(JSON.stringify(thingDescription))
diff --git a/things/calculator/coap/js/coap-simple-calculator.js b/things/calculator/coap/js/coap-simple-calculator.js
index 802888d..d347803 100644
--- a/things/calculator/coap/js/coap-simple-calculator.js
+++ b/things/calculator/coap/js/coap-simple-calculator.js
@@ -6,8 +6,8 @@ const { JsonPlaceholderReplacer } = require('json-placeholder-replacer')
 require('dotenv').config()
 
 const server = coap.createServer()
-const hostname = 'localhost'
-let portNumber = 5683
+const hostname = process.env.HOSTNAME ?? 'localhost'
+let portNumber = process.env.PORT ?? 5683
 const thingName = 'coap-calculator-simple'
 
 const { values: { port } } = parseArgs({
diff --git a/things/calculator/http/express/Dockerfile-contentneg b/things/calculator/http/express/Dockerfile-contentneg
index 4c304ad..0ff6da9 100644
--- a/things/calculator/http/express/Dockerfile-contentneg
+++ b/things/calculator/http/express/Dockerfile-contentneg
@@ -6,8 +6,10 @@ COPY ./http/express .
 
 RUN npm install
 
+ARG PORT_ARG=3001
+ENV PORT=${PORT_ARG}
 ENV TM_PATH="./calculator.tm.json"
 
 CMD ["node", "http-content-negotiation-calculator.js"]
 
-EXPOSE 3001
\ No newline at end of file
+EXPOSE ${PORT}
\ No newline at end of file
diff --git a/things/calculator/http/express/Dockerfile-simple b/things/calculator/http/express/Dockerfile-simple
index 8382623..b194e7e 100644
--- a/things/calculator/http/express/Dockerfile-simple
+++ b/things/calculator/http/express/Dockerfile-simple
@@ -6,8 +6,10 @@ COPY ./http/express .
 
 RUN npm install
 
+ARG PORT_ARG=3000
+ENV PORT=${PORT_ARG}
 ENV TM_PATH="./calculator.tm.json"
 
 CMD ["node", "http-simple-calculator.js"]
 
-EXPOSE 3000
\ No newline at end of file
+EXPOSE ${PORT}
\ No newline at end of file
diff --git a/things/calculator/http/express/http-content-negotiation-calculator.js b/things/calculator/http/express/http-content-negotiation-calculator.js
index bbc15b0..e51644d 100644
--- a/things/calculator/http/express/http-content-negotiation-calculator.js
+++ b/things/calculator/http/express/http-content-negotiation-calculator.js
@@ -10,8 +10,8 @@ require('dotenv').config()
 const app = express()
 app.use(express.json({ strict: false }));
 
-const hostname = 'localhost'
-let portNumber = 3001
+const hostname = process.env.HOSTNAME ?? 'localhost'
+let portNumber = process.env.PORT ?? 3001
 const thingName = 'http-express-calculator-content-negotiation'
 
 const TDEndPoint = `/${thingName}`,
diff --git a/things/calculator/http/express/http-simple-calculator.js b/things/calculator/http/express/http-simple-calculator.js
index 8f414be..84763e2 100644
--- a/things/calculator/http/express/http-simple-calculator.js
+++ b/things/calculator/http/express/http-simple-calculator.js
@@ -9,8 +9,8 @@ require("dotenv").config();
 const app = express();
 app.use(express.json({ strict: false }));
 
-const hostname = "localhost";
-let portNumber = 3000;
+const hostname = process.env.HOSTNAME ?? "localhost";
+let portNumber = process.env.PORT ?? 3000;
 const thingName = "http-express-calculator-simple";
 
 const TDEndPoint = `/${thingName}`,
diff --git a/things/calculator/http/flask/Dockerfile b/things/calculator/http/flask/Dockerfile
index fecd32c..00866c7 100644
--- a/things/calculator/http/flask/Dockerfile
+++ b/things/calculator/http/flask/Dockerfile
@@ -7,10 +7,12 @@ WORKDIR /app
 COPY ./calculator.tm.json .
 COPY ./http/flask .
 
+ARG PORT_ARG=5000
+ENV PORT=${PORT_ARG}
 ENV TM_PATH=./calculator.tm.json 
 
 RUN poetry install
 
 CMD [ "poetry", "run", "python", "main.py" ]
 
-EXPOSE 5000
\ No newline at end of file
+EXPOSE ${PORT}
\ No newline at end of file
diff --git a/things/calculator/http/flask/main.py b/things/calculator/http/flask/main.py
index 7fd2eec..6a348ab 100644
--- a/things/calculator/http/flask/main.py
+++ b/things/calculator/http/flask/main.py
@@ -25,6 +25,12 @@
 hostname = "0.0.0.0"
 portNumber = 5000
 
+if "HOSTNAME" in os.environ:
+    hostname = os.environ["HOSTNAME"]
+
+if "PORT" in os.environ:
+    portNumber = os.environ["PORT"]
+
 thingName = "http-flask-calculator"
 PROPERTIES = "properties"
 ACTIONS = "actions"
diff --git a/things/calculator/mqtt/js/Dockerfile b/things/calculator/mqtt/js/Dockerfile
index 6862080..09e09b6 100644
--- a/things/calculator/mqtt/js/Dockerfile
+++ b/things/calculator/mqtt/js/Dockerfile
@@ -9,5 +9,3 @@ RUN npm install
 ENV TM_PATH="./calculator.tm.json"
 
 CMD ["node", "main.js"]
-
-EXPOSE 1883
\ No newline at end of file
diff --git a/things/calculator/mqtt/js/main.js b/things/calculator/mqtt/js/main.js
index 2c6ff73..9d86cd0 100644
--- a/things/calculator/mqtt/js/main.js
+++ b/things/calculator/mqtt/js/main.js
@@ -5,8 +5,8 @@ const path = require('path')
 const { JsonPlaceholderReplacer } = require('json-placeholder-replacer')
 require('dotenv').config()
 
-const hostname = 'test.mosquitto.org'
-let portNumber = 1883
+const brokerURI = process.env.BROKER_URI ?? 'test.mosquitto.org'
+let portNumber = process.env.PORT ?? 1883
 
 const { values: { port } } = parseArgs({
   options: {
@@ -26,7 +26,7 @@ const PROPERTIES = 'properties'
 const ACTIONS = 'actions'
 const EVENTS = 'events'
 
-const broker = mqtt.connect(`mqtt://${hostname}`, { port: portNumber })
+const broker = mqtt.connect(`mqtt://${brokerURI}`, { port: portNumber })
 
 const tmPath = process.env.TM_PATH
 
@@ -43,7 +43,7 @@ placeholderReplacer.addVariableMap({
   PROPERTIES,
   ACTIONS,
   EVENTS,
-  HOSTNAME: hostname,
+  HOSTNAME: brokerURI,
   PORT_NUMBER: portNumber,
   RESULT_OBSERVABLE: true,
   LAST_CHANGE_OBSERVABLE: true
diff --git a/things/elevator/modbus/js/Dockerfile b/things/elevator/modbus/js/Dockerfile
index 7cf9f84..6bb1698 100644
--- a/things/elevator/modbus/js/Dockerfile
+++ b/things/elevator/modbus/js/Dockerfile
@@ -6,7 +6,10 @@ COPY ./modbus/js .
 
 RUN npm install
 
+ARG PORT_ARG=8502
+ENV PORT=${PORT_ARG}
 ENV TM_PATH="./elevator.tm.json"
 
 CMD ["node", "main.js"]
-EXPOSE 8502
+
+EXPOSE ${PORT}
diff --git a/things/elevator/modbus/js/main.js b/things/elevator/modbus/js/main.js
index 378beff..c3f8647 100644
--- a/things/elevator/modbus/js/main.js
+++ b/things/elevator/modbus/js/main.js
@@ -6,8 +6,11 @@ const { parseArgs } = require('node:util')
 require('dotenv').config()
 
 const thingName = "modbus-elevator"
-const hostname = "0.0.0.0"
-let portNumber = "8502"
+// The following is needed since the modbus library we use does not support localhost but does support 0.0.0.0
+const hostname = process.env.HOSTNAME 
+    ? process.env.HOSTNAME === "localhost" ? "0.0.0.0" : process.env.HOSTNAME   
+    : "0.0.0.0"
+let portNumber = process.env.PORT ?? "8502"
 const thingUnitID = 1
 
 const { values: { port } } = parseArgs({
@@ -189,4 +192,4 @@ const serverTCP = new ServerTCP(vector, { host: hostname, port: portNumber, debu
 serverTCP.on("socketError", function(err){
     // Handle socket error if needed, can be ignored
     console.error(err)
-});
\ No newline at end of file
+});