diff --git a/ArrowVegaLiteChart.B5mh1aU6.js b/ArrowVegaLiteChart.B5mh1aU6.js
new file mode 100644
index 0000000..e69de29
diff --git a/requirements.txt b/requirements.txt
index e2ce93d..120898d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -42,3 +42,4 @@ urllib3==2.7.0
 uvicorn==0.47.0
 watchdog==6.0.0
 websockets==16.0
+python-dotenv>=1.0.0
\ No newline at end of file
diff --git a/src/__init__.py b/src/__init__.py
index 9c12fce..29c2b2b 100644
--- a/src/__init__.py
+++ b/src/__init__.py
@@ -1,12 +1,12 @@
-# # src/__init__.py
+# src/__init__.py
 
-# # Initialisierung des Pakets
-# __version__ = "1.0.0"
+# Initialisierung des Pakets
+__version__ = "1.0.0"
 
-# # Export der wichtigsten Module
-# from .backend.file_manager import FileManager
-# from .backend.chat_manager import ChatManager
-# from .backend.system_prompter import SystemPrompter
-# from .backend.search_manager import SearchManager
-# from .backend.execution_engine import ExecutionEngine
-# from .backend.debug_logger import DebugLogger
\ No newline at end of file
+# Export der wichtigsten Module
+from .backend.file_manager import FileManager
+from .backend.chat_manager import ChatManager
+from .backend.system_prompter import SystemPrompter
+from .backend.search_manager import SearchManager
+from .backend.execution_engine import ExecutionEngine
+from .backend.debug_logger import DebugLogger
\ No newline at end of file
diff --git a/src/backend/__init__.py b/src/backend/__init__.py
index e2a2ff7..43e455c 100644
--- a/src/backend/__init__.py
+++ b/src/backend/__init__.py
@@ -1,6 +1,6 @@
-# from .file_manager import FileManager
-# from .chat_manager import ChatManager
-# from .system_prompter import SystemPrompter
-# from .search_manager import SearchManager
-# from .execution_engine import ExecutionEngine
-# from .debug_logger import DebugLogger
\ No newline at end of file
+from .file_manager import FileManager
+from .chat_manager import ChatManager
+from .system_prompter import SystemPrompter
+from .search_manager import SearchManager
+from .execution_engine import ExecutionEngine
+from .debug_logger import DebugLogger
\ No newline at end of file
diff --git a/src/backend/chat_manager.py b/src/backend/chat_manager.py
index e69de29..4d01ea0 100644
--- a/src/backend/chat_manager.py
+++ b/src/backend/chat_manager.py
@@ -0,0 +1,15 @@
+class ChatManager:
+    """
+    Platzhalter für die Chat-Kommunikation [1]
+    """
+    def __init__(self):
+        self.conversation_history = []
+
+    def generate_response(self, prompt):
+        """
+        Gibt eine Dummy-Antwort zurück [1]
+        """
+        return "Antwort (Backend-Logik noch nicht implementiert)"
+
+    def get_history(self):
+        return []
\ No newline at end of file
diff --git a/src/backend/debug_logger.py b/src/backend/debug_logger.py
index e69de29..d45e9a2 100644
--- a/src/backend/debug_logger.py
+++ b/src/backend/debug_logger.py
@@ -0,0 +1,12 @@
+class DebugLogger:
+    """
+    Platzhalter für das Logging [1]
+    """
+    def __init__(self):
+        self.logs = []
+
+    def log(self, message):
+        self.logs.append(message)
+
+    def get_logs(self):
+        return self.logs
\ No newline at end of file
diff --git a/src/backend/execution_engine.py b/src/backend/execution_engine.py
index e69de29..67cfd1b 100644
--- a/src/backend/execution_engine.py
+++ b/src/backend/execution_engine.py
@@ -0,0 +1,12 @@
+class ExecutionEngine:
+    """
+    Platzhalter für die Code-Ausführung [1]
+    """
+    def __init__(self):
+        pass
+
+    def execute_code(self):
+        """
+        Führt Code nicht aus, sondern gibt einen Status aus [1]
+        """
+        return "Code wurde nicht ausgeführt (Platzhalter)"
\ No newline at end of file
diff --git a/src/backend/file_manager.py b/src/backend/file_manager.py
index e69de29..8c9532e 100644
--- a/src/backend/file_manager.py
+++ b/src/backend/file_manager.py
@@ -0,0 +1,50 @@
+import os
+from pathlib import Path
+
+class FileManager:
+    """
+    Verwaltet das Laden, Speichern und Auflisten von Code-Dateien inklusive Ordnerstruktur [1]
+    """
+    def __init__(self, root_path="."):
+        self.root_path = Path(root_path).resolve()
+
+    def list_files(self, current_path=None):
+        """
+        Gibt eine verschachtelte Struktur zurück, um Ordner und Dateien darzustellen [1]
+        """
+        if current_path is None:
+            current_path = self.root_path
+        elif not isinstance(current_path, Path):
+            current_path = Path(current_path)
+            
+        items = []
+        try:
+            for item in current_path.iterdir():
+                if item.is_dir():
+                    items.append({"type": "folder", "name": item.name, "path": str(item)})
+                elif item.is_file() and item.suffix in {'.py', '.js', '.html', '.css', '.md'}:
+                    items.append({"type": "file", "name": item.name, "path": str(item)})
+        except PermissionError:
+            pass
+        return items
+
+    def read_file(self, file_path):
+        """
+        Liest und gibt den Inhalt einer Datei zurück [1]
+        """
+        try:
+            with open(file_path, 'r', encoding='utf-8') as f:
+                return f.read()
+        except Exception as e:
+            return None
+
+    def save_file(self, file_path, content):
+        """
+        Schreibt Inhalt in eine Datei [1]
+        """
+        try:
+            with open(file_path, 'w', encoding='utf-8') as f:
+                f.write(content)
+            return True
+        except Exception:
+            return False
\ No newline at end of file
diff --git a/src/backend/search_manager.py b/src/backend/search_manager.py
index e69de29..c8f1411 100644
--- a/src/backend/search_manager.py
+++ b/src/backend/search_manager.py
@@ -0,0 +1,30 @@
+class SearchManager:
+    """
+    Verwaltet Suchanfragen und integriert externe APIs [1]
+    """
+    def __init__(self, api_key=None):
+        self.api_key = api_key
+        self.search_history = []
+    
+    def perform_search(self, query):
+        """
+        Führt eine Internetsuche aus [1]
+        """
+        # Platzhalter-Implementierung für Startphase
+        return []
+    
+    def parse_results(self, raw_results):
+        """
+        Extrahiert und formatiert relevante Ergebnisse [1]
+        """
+        # Rückgabe einer formatierten Liste als Platzhalter
+        if isinstance(raw_results, list):
+            return raw_results
+        return []
+    
+    def search_context(self, query, context_type="web"):
+        """
+        Fügt Suchergebnisse dem Kontext hinzu
+        """
+        results = self.perform_search(query)
+        return f"Search results for '{query}': {results}"
\ No newline at end of file
diff --git a/src/backend/system_prompter.py b/src/backend/system_prompter.py
index e69de29..3187608 100644
--- a/src/backend/system_prompter.py
+++ b/src/backend/system_prompter.py
@@ -0,0 +1,28 @@
+class SystemPrompter:
+    """
+    Generiert System-Prompts mit Dateikontext für die KI [1]
+    """
+    def __init__(self):
+        self.default_prompt = "You are a code assistant helping to debug Python code."
+    
+    def generate_prompt(self, user_message, file_context):
+        """
+        Baut ein vollständiges Prompt mit Dateiinhalten oder Kontextinformationen auf [1]
+        """
+        # Platzhalter-Implementierung für Startphase
+        return f"User: {user_message}\nContext: {file_context}"
+    
+    def add_context(self, file_name, code_snippet=None):
+        """
+        Fügt Dateikontext hinzu (Dateiname, Änderungen oder markierte Code-Abschnitte) [1]
+        """
+        context = f"File: {file_name}"
+        if code_snippet:
+            context += f"\nCode:\n{code_snippet}"
+        return context
+    
+    def summarize_context(self, context):
+        """
+        Fasst Kontext zusammen, um den Prompt nicht zu überladen [1]
+        """
+        return context[:500] if len(context) > 500 else context
\ No newline at end of file
diff --git a/src/main.py b/src/main.py
index e69de29..ef431ac 100644
--- a/src/main.py
+++ b/src/main.py
@@ -0,0 +1,72 @@
+import sys
+import os
+project_root = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
+if project_root not in sys.path:
+    sys.path.insert(0, project_root)
+
+import streamlit as st
+
+# Backend-Imports
+from src.backend.file_manager import FileManager
+from src.backend.chat_manager import ChatManager
+from src.backend.execution_engine import ExecutionEngine
+
+# UI-Imports
+from src.ui.navigation import FileNavigation
+from src.ui.editor import CodeEditor
+from src.ui.chat import ChatInterface
+from src.ui.output import OutputDisplay
+
+def main():
+    st.set_page_config(
+        page_title="AI Code Editor",
+        page_icon="💻",
+        layout="wide"
+    )
+
+    # Initialisiere Manager-Klassen
+    file_manager = FileManager()
+    chat_manager = ChatManager()
+    execution_engine = ExecutionEngine()
+    
+
+    if "selected_file" not in st.session_state:
+        st.session_state.selected_file = None
+    if "file_history" not in st.session_state:
+        st.session_state.file_history = []
+
+    # Sidebar für Dateinavigation
+    st.sidebar.title("📁 Datei-Explorer")
+    st.sidebar.subheader("Wähle eine Datei aus")
+
+    navigation = FileNavigation()
+    file_list = navigation.list_files()
+
+    if file_list:
+        selected_file = st.sidebar.selectbox("Dateien", file_list)
+        if selected_file:
+            content = file_manager.read_file(selected_file)
+            st.session_state.selected_file = selected_file
+
+            col1, col2 = st.columns([3, 2])
+
+            with col1:
+                editor = CodeEditor()
+                editor.display_code(content)
+
+                if st.button("💾 Speichern"):
+                    file_manager.save_file(selected_file, content)
+                    st.success("Datei gespeichert!")
+
+            with col2:
+                chat = ChatInterface()
+                chat.display_chat(chat_manager)
+
+                output = OutputDisplay()
+                output.display_execution(execution_engine)
+
+    st.sidebar.markdown("---")
+    st.sidebar.caption("AISE501 – AI in Software Engineering")
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file
diff --git a/src/ui/__init__.py b/src/ui/__init__.py
index eac8644..6003886 100644
--- a/src/ui/__init__.py
+++ b/src/ui/__init__.py
@@ -1,6 +1,6 @@
-# # src/ui/__init__.py
+# src/ui/__init__.py
 
-# from .navigation import FileNavigation
-# from .editor import CodeEditor
-# from .chat import ChatInterface
-# from .output import OutputDisplay
\ No newline at end of file
+from .navigation import FileNavigation
+from .editor import CodeEditor
+from .chat import ChatInterface
+from .output import OutputDisplay
\ No newline at end of file
diff --git a/src/ui/chat.py b/src/ui/chat.py
index e69de29..a5711fd 100644
--- a/src/ui/chat.py
+++ b/src/ui/chat.py
@@ -0,0 +1,45 @@
+import streamlit as st
+
+class ChatInterface:
+    """
+    Chat Interface für KI-Interaktion [1]
+    """
+    
+    def __init__(self):
+        self.chat_messages = []
+    
+    def display_chat(self, chat_manager):
+        """
+        Zeigt die Chat-Schnittstelle mit Konversationsverlauf [1]
+        """
+        st.title("🤖 KI-Assistent")
+        
+        # Chat History anzeigen
+        for message in self.chat_messages:
+            with st.chat_message(message["role"]):
+                st.markdown(message["content"])
+        
+        # User Input
+        if prompt := st.chat_input("Frage zum Code stellen..."):
+            # User Nachricht anzeigen
+            self.chat_messages.append({"role": "user", "content": prompt})
+            with st.chat_message("user"):
+                st.markdown(prompt)
+            
+            # AI Antwort generieren (via ChatManager)
+            with st.chat_message("assistant"):
+                response = chat_manager.generate_response(prompt)
+                st.markdown(response)
+                self.chat_messages.append({"role": "assistant", "content": response})
+    
+    def add_message(self, role, content):
+        """
+        Fügt eine Nachricht zur Konversation hinzu
+        """
+        self.chat_messages.append({"role": role, "content": content})
+    
+    def clear_history(self):
+        """
+        Löscht den Chat-Verlauf
+        """
+        self.chat_messages.clear()
\ No newline at end of file
diff --git a/src/ui/editor.py b/src/ui/editor.py
index e69de29..63f9ec2 100644
--- a/src/ui/editor.py
+++ b/src/ui/editor.py
@@ -0,0 +1,30 @@
+import streamlit as st
+
+class CodeEditor:
+    """
+    Code Editor & Anzeige Komponente [1]
+    """
+    def __init__(self):
+        self.language = "python"
+        self.show_line_numbers = True
+    
+    def display_code(self, code_content):
+        """
+        Zeigt den Code-Editor mit Inhalt an
+        """
+        if code_content:
+            st.code(code_content, language=self.language)
+        else:
+            st.info("Bitte wählen Sie eine Datei aus der Sidebar aus")
+    
+    def get_code_content(self):
+        """
+        Liest den aktuellen Code-Inhalt vom Editor
+        """
+        return st.session_state.get("code_content", "")
+    
+    def update_code_content(self, new_content):
+        """
+        Aktualisiert den Code-Inhalt im Session State
+        """
+        st.session_state.code_content = new_content
\ No newline at end of file
diff --git a/src/ui/navigation.py b/src/ui/navigation.py
index e69de29..81d4bd8 100644
--- a/src/ui/navigation.py
+++ b/src/ui/navigation.py
@@ -0,0 +1,30 @@
+import os
+from pathlib import Path
+
+class FileNavigation:
+    """
+    Navigation für die Dateiauswahl in der Sidebar [1]
+    """
+    
+    def __init__(self):
+        self.supported_extensions = {'.py', '.js', '.html', '.css', '.json', '.md'}
+    
+    def list_files(self, path=None):
+        """
+        Listet alle Code-Dateien im aktuellen Verzeichnis auf [1]
+        """
+        if path is None:
+            path = Path.cwd()
+        
+        file_list = []
+        for root, dirs, files in os.walk(path):
+            for file in files:
+                if os.path.splitext(file)[1] in self.supported_extensions:
+                    file_list.append(file)
+        return sorted(file_list)
+    
+    def get_full_path(self, filename):
+        """
+        Gibt den vollständigen Pfad der Datei zurück
+        """
+        return Path(filename)
\ No newline at end of file
diff --git a/src/ui/output.py b/src/ui/output.py
index e69de29..b0e16df 100644
--- a/src/ui/output.py
+++ b/src/ui/output.py
@@ -0,0 +1,42 @@
+import streamlit as st
+
+class OutputDisplay:
+    """
+    Display für Execution Results und Debugging [1]
+    """
+    
+    def __init__(self):
+        self.execution_output = []
+    
+    def display_execution(self, execution_engine):
+        """
+        Zeigt die Ergebnisse der Code-Ausführung an [1]
+        """
+        st.title("🔍 Execution Output")
+        
+        # Ausgabe-Fenster erstellen
+        output_area = st.empty()
+        
+        # Code Execution Button
+        if st.button("▶️ Code ausführen"):
+            with output_area:
+                with st.spinner("Code wird ausgeführt..."):
+                    result = execution_engine.execute_code()
+                    output_area.code(result, language="python")
+        
+        # Fehler-Logging anzeigen
+        if st.checkbox("Debug Logs anzeigen"):
+            st.subheader("🐛 Debug Logs")
+            st.text_area("Logs", height=200)
+    
+    def display_error(self, error_message):
+        """
+        Zeigt Fehlermeldungen an
+        """
+        st.error(f"❌ Fehler: {error_message}")
+    
+    def display_warning(self, warning_message):
+        """
+        Zeigt Warnungen an
+        """
+        st.warning(f"⚠️ Warnung: {warning_message}")
\ No newline at end of file