diff --git a/.gitignore b/.gitignore
index 0f003b8..e2a5bd2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 node_modules
 sidebar.js
 /web-ext-artifacts/
+/artifacts/
 lib/*
 /yarn-error.log
 /rentgen.zip
diff --git a/Dockerfile b/Dockerfile
index 9b858bf..ba58371 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -79,42 +79,9 @@ RUN apt-get update && apt-get install -y \
 # Set display for Xvfb
 ENV DISPLAY=:99
 
-# Create startup script with verbose logging and verification
-RUN echo '#!/bin/bash\n\
-set -e\n\
-echo "Starting Xvfb on display :99..."\n\
-Xvfb :99 -screen 0 1024x768x24 &\n\
-XVFB_PID=$!\n\
-sleep 2\n\
-\n\
-echo "Xvfb started with PID: $XVFB_PID"\n\
-echo "Starting web-ext run with verbose logging..."\n\
-echo "========================================"\n\
-\n\
-# Run web-ext with verbose logging and capture output\n\
-npx web-ext run --verbose 2>&1 | tee /tmp/web-ext.log &\n\
-WEBEXT_PID=$!\n\
-\n\
-# Wait for extension installation confirmation\n\
-echo "Waiting for extension to install..."\n\
-for i in {1..30}; do\n\
-    if grep -q "Installed /app as a temporary add-on" /tmp/web-ext.log 2>/dev/null; then\n\
-        echo "========================================"\n\
-        echo "✓ SUCCESS: Extension installed!"\n\
-        echo "✓ Firefox is running in headless mode"\n\
-        echo "✓ Extension: rentgen@internet-czas-dzialac.pl"\n\
-        echo "✓ Process info:"\n\
-        ps aux | grep -E "(firefox|Xvfb)" | grep -v grep | head -3\n\
-        echo "========================================"\n\
-        echo "Extension is ready. Press Ctrl+C to stop."\n\
-        break\n\
-    fi\n\
-    sleep 1\n\
-done\n\
-\n\
-# Keep container running and show logs\n\
-wait $WEBEXT_PID\n\
-' > /app/start.sh && chmod +x /app/start.sh
+# Copy startup script for extension testing
+COPY scripts/test_start_extension.sh /app/test_start_extension.sh
+RUN chmod +x /app/test_start_extension.sh
 
 # Start script
-CMD ["/app/start.sh"]
+CMD ["/app/test_start_extension.sh"]
diff --git a/scripts/test_start_extension.sh b/scripts/test_start_extension.sh
new file mode 100644
index 0000000..a38dd0e
--- /dev/null
+++ b/scripts/test_start_extension.sh
@@ -0,0 +1,48 @@
+#!/bin/bash
+#
+# test_start_extension.sh - Uruchamia rozszerzenie Rentgen w headless Firefox z weryfikacją
+#
+# Ten skrypt jest używany przez Docker runtime stage do:
+# 1. Uruchomienia Xvfb (wirtualny X server) na display :99
+# 2. Uruchomienia web-ext run z verbose loggingiem
+# 3. Weryfikacji czy extension został poprawnie zainstalowany
+# 4. Wyświetlenia czytelnego komunikatu o statusie
+#
+# Używany w Dockerfile dla łatwego testowania extensiona bez GUI.
+# Przeniesiony z inline RUN echo do osobnego pliku dla czytelności.
+#
+
+set -e
+
+echo "Starting Xvfb on display :99..."
+Xvfb :99 -screen 0 1024x768x24 &
+XVFB_PID=$!
+sleep 2
+
+echo "Xvfb started with PID: $XVFB_PID"
+echo "Starting web-ext run with verbose logging..."
+echo "========================================"
+
+# Run web-ext with verbose logging and capture output
+npx web-ext run --verbose 2>&1 | tee /tmp/web-ext.log &
+WEBEXT_PID=$!
+
+# Wait for extension installation confirmation
+echo "Waiting for extension to install..."
+for i in {1..30}; do
+    if grep -q "Installed /app as a temporary add-on" /tmp/web-ext.log 2>/dev/null; then
+        echo "========================================"
+        echo "✓ SUCCESS: Extension installed!"
+        echo "✓ Firefox is running in headless mode"
+        echo "✓ Extension: rentgen@internet-czas-dzialac.pl"
+        echo "✓ Process info:"
+        ps aux | grep -E "(firefox|Xvfb)" | grep -v grep | head -3
+        echo "========================================"
+        echo "Extension is ready. Press Ctrl+C to stop."
+        break
+    fi
+    sleep 1
+done
+
+# Keep container running and show logs
+wait $WEBEXT_PID