diff --git a/android/src/main/java/com/group14/regicidechess/android/AndroidFirebase.java b/android/src/main/java/com/group14/regicidechess/android/AndroidFirebase.java
index b57bf72..4e311f6 100644
--- a/android/src/main/java/com/group14/regicidechess/android/AndroidFirebase.java
+++ b/android/src/main/java/com/group14/regicidechess/android/AndroidFirebase.java
@@ -22,6 +22,17 @@
 public class AndroidFirebase implements FirebaseAPI, API {
 
     private final DatabaseReference db = FirebaseDatabase.getInstance().getReference();
+    private final List<Runnable> cleanupActions = new ArrayList<>();
+
+    private ValueEventListener trackValue(DatabaseReference ref, ValueEventListener listener) {
+        cleanupActions.add(() -> ref.removeEventListener(listener));
+        return listener;
+    }
+
+    private ChildEventListener trackChild(DatabaseReference ref, ChildEventListener listener) {
+        cleanupActions.add(() -> ref.removeEventListener(listener));
+        return listener;
+    }
 
     // ── API (Legacy) ──────────────────────────────────────────────────────────
 
@@ -74,8 +85,8 @@ public void joinLobby(String gameId, Callback<Lobby> onSuccess, Callback<String>
 
     @Override
     public void listenForOpponentReady(String gameId, Runnable onReady) {
-        db.child("lobbies").child(gameId).child("status")
-            .addValueEventListener(new ValueEventListener() {
+        DatabaseReference statusRef = db.child("lobbies").child(gameId).child("status");
+        statusRef.addValueEventListener(trackValue(statusRef, new ValueEventListener() {
                 @Override
                 public void onDataChange(DataSnapshot snapshot) {
                     if ("joined".equals(snapshot.getValue(String.class))) {
@@ -84,7 +95,7 @@ public void onDataChange(DataSnapshot snapshot) {
                     }
                 }
                 @Override public void onCancelled(DatabaseError e) {}
-            });
+            }));
     }
 
     @Override
@@ -94,8 +105,8 @@ public void startGame(String gameId) {
 
     @Override
     public void listenForGameStart(String gameId, Runnable onStart) {
-        db.child("lobbies").child(gameId).child("status")
-            .addValueEventListener(new ValueEventListener() {
+        DatabaseReference statusRef = db.child("lobbies").child(gameId).child("status");
+        statusRef.addValueEventListener(trackValue(statusRef, new ValueEventListener() {
                 @Override
                 public void onDataChange(DataSnapshot snapshot) {
                     if ("started".equals(snapshot.getValue(String.class))) {
@@ -104,13 +115,13 @@ public void onDataChange(DataSnapshot snapshot) {
                     }
                 }
                 @Override public void onCancelled(DatabaseError e) {}
-            });
+            }));
     }
 
     // ── Setup ─────────────────────────────────────────────────────────────────
 
     @Override
-    public void confirmSetup(String gameId, boolean isWhite, int[][] board, Runnable onSuccess) {
+    public void confirmSetup(String gameId, boolean isWhite, int[][] board, Runnable onSuccess, Callback<String> onError) {
         String player = isWhite ? "white" : "black";
         DatabaseReference gameRef = db.child("games").child(gameId);
 
@@ -141,11 +152,12 @@ public void onDataChange(DataSnapshot snapshot) {
                                 }
                                 onSuccess.run();
                             }
-                            @Override public void onCancelled(DatabaseError e) { onSuccess.run(); }
+                            @Override public void onCancelled(DatabaseError e) { onError.call(e.getMessage()); }
                         })
                     )
+                    .addOnFailureListener(e -> onError.call(e.getMessage()))
             )
-            .addOnFailureListener(e -> onSuccess.run());
+            .addOnFailureListener(e -> onError.call(e.getMessage()));
     }
 
     @Override
@@ -172,8 +184,8 @@ public void getOpponentBoard(String gameId, boolean localIsWhite, Callback<int[]
 
     @Override
     public void listenForBothSetupReady(String gameId, Runnable onBothReady) {
-        db.child("games").child(gameId).child("bothReady")
-            .addValueEventListener(new ValueEventListener() {
+        DatabaseReference bothReadyRef = db.child("games").child(gameId).child("bothReady");
+        bothReadyRef.addValueEventListener(trackValue(bothReadyRef, new ValueEventListener() {
                 @Override
                 public void onDataChange(DataSnapshot snapshot) {
                     Boolean bothReady = snapshot.getValue(Boolean.class);
@@ -183,7 +195,7 @@ public void onDataChange(DataSnapshot snapshot) {
                     }
                 }
                 @Override public void onCancelled(DatabaseError e) {}
-            });
+            }));
     }
 
     // ── Moves ─────────────────────────────────────────────────────────────────
@@ -221,8 +233,8 @@ public void listenForOpponentMove(String gameId, Callback<int[]> onMove) {
                     lastExistingKey[0] = child.getKey();
                 }
 
-                db.child("games").child(gameId).child("moves")
-                    .addChildEventListener(new ChildEventListener() {
+                DatabaseReference movesRef = db.child("games").child(gameId).child("moves");
+                movesRef.addChildEventListener(trackChild(movesRef, new ChildEventListener() {
                         private boolean seenStart = (lastExistingKey[0] == null);
 
                         @Override
@@ -257,12 +269,12 @@ public void onChildAdded(DataSnapshot snapshot, String prev) {
                         @Override public void onChildRemoved(DataSnapshot s) {}
                         @Override public void onChildMoved  (DataSnapshot s, String p) {}
                         @Override public void onCancelled   (DatabaseError e) {}
-                    });
+                    }));
             })
             .addOnFailureListener(e -> {
                 // Fallback: attach listener without filtering (original behaviour)
-                db.child("games").child(gameId).child("moves")
-                    .addChildEventListener(new ChildEventListener() {
+                DatabaseReference movesRef = db.child("games").child(gameId).child("moves");
+                movesRef.addChildEventListener(trackChild(movesRef, new ChildEventListener() {
                         @Override
                         public void onChildAdded(DataSnapshot snapshot, String prev) {
                             int fromCol  = getInt(snapshot, "fromCol");
@@ -277,7 +289,7 @@ public void onChildAdded(DataSnapshot snapshot, String prev) {
                         @Override public void onChildRemoved(DataSnapshot s) {}
                         @Override public void onChildMoved  (DataSnapshot s, String p) {}
                         @Override public void onCancelled   (DatabaseError e) {}
-                    });
+                    }));
             });
     }
 
@@ -296,12 +308,13 @@ public void listenForHeartbeat(String gameId, boolean listenForWhite,
         String player = listenForWhite ? "white" : "black";
         Handler handler = new Handler(Looper.getMainLooper());
         Runnable timeoutRunnable = onTimeout::run;
+        cleanupActions.add(() -> handler.removeCallbacks(timeoutRunnable));
 
         // Start timeout timer — reset each time a valid heartbeat arrives
         handler.postDelayed(timeoutRunnable, timeoutMs);
 
-        db.child("games").child(gameId).child("heartbeat").child(player)
-            .addValueEventListener(new ValueEventListener() {
+        DatabaseReference heartbeatRef = db.child("games").child(gameId).child("heartbeat").child(player);
+        heartbeatRef.addValueEventListener(trackValue(heartbeatRef, new ValueEventListener() {
                 @Override
                 public void onDataChange(DataSnapshot snapshot) {
                     Long timestamp = snapshot.getValue(Long.class);
@@ -319,7 +332,7 @@ public void onDataChange(DataSnapshot snapshot) {
                     onHeartbeat.call(latency);
                 }
                 @Override public void onCancelled(DatabaseError e) {}
-            });
+            }));
     }
 
     // ── Game over ─────────────────────────────────────────────────────────────
@@ -331,8 +344,8 @@ public void signalGameOver(String gameId, String reason) {
 
     @Override
     public void listenForGameOver(String gameId, Callback<String> onGameOver) {
-        db.child("games").child(gameId).child("gameOver")
-            .addValueEventListener(new ValueEventListener() {
+        DatabaseReference gameOverRef = db.child("games").child(gameId).child("gameOver");
+        gameOverRef.addValueEventListener(trackValue(gameOverRef, new ValueEventListener() {
                 @Override
                 public void onDataChange(DataSnapshot snapshot) {
                     String reason = snapshot.getValue(String.class);
@@ -342,7 +355,7 @@ public void onDataChange(DataSnapshot snapshot) {
                     }
                 }
                 @Override public void onCancelled(DatabaseError e) {}
-            });
+            }));
     }
 
     // ─────────────────────────────────────────────────────────────────────────
@@ -370,4 +383,10 @@ public void unconfirmSetup(String gameId, boolean isWhite, Runnable onSuccess, C
             })
             .addOnFailureListener(e -> onError.call(e.getMessage()));
     }
-}
\ No newline at end of file
+
+    @Override
+    public void removeAllListeners() {
+        for (Runnable cleanup : cleanupActions) cleanup.run();
+        cleanupActions.clear();
+    }
+}
diff --git a/core/src/main/java/com/group14/regicidechess/database/FirebaseAPI.java b/core/src/main/java/com/group14/regicidechess/database/FirebaseAPI.java
index c88bd7b..212ba4d 100644
--- a/core/src/main/java/com/group14/regicidechess/database/FirebaseAPI.java
+++ b/core/src/main/java/com/group14/regicidechess/database/FirebaseAPI.java
@@ -38,7 +38,7 @@ public interface FirebaseAPI {
      * Saves this player's board layout and marks them as setup-ready.
      * Sets games/{gameId}/bothReady = true once BOTH players have called this.
      */
-    void confirmSetup(String gameId, boolean isWhite, int[][] board, Runnable onSuccess);
+    void confirmSetup(String gameId, boolean isWhite, int[][] board, Runnable onSuccess, Callback<String> onError);
 
     /**
      * Unconfirms the setup, marking this player as not ready.
@@ -80,9 +80,11 @@ void listenForHeartbeat(String gameId, boolean listenForWhite, long timeoutMs,
     void signalGameOver(String gameId, String reason);
     void listenForGameOver(String gameId, Callback<String> onGameOver);
 
+    void removeAllListeners();
+
     // ─────────────────────────────────────────────────────────────────────────
 
     interface Callback<T> {
         void call(T value);
     }
-}
\ No newline at end of file
+}
diff --git a/core/src/main/java/com/group14/regicidechess/screens/game/GameNetworkHandler.java b/core/src/main/java/com/group14/regicidechess/screens/game/GameNetworkHandler.java
index 5839faf..a30b012 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/game/GameNetworkHandler.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/game/GameNetworkHandler.java
@@ -5,8 +5,8 @@
 import com.badlogic.gdx.math.Vector2;
 import com.badlogic.gdx.scenes.scene2d.ui.Image;
 import com.badlogic.gdx.scenes.scene2d.ui.Label;
-import com.group14.regicidechess.database.DatabaseManager;
 import com.group14.regicidechess.network.CircuitBreaker;
+import com.group14.regicidechess.database.FirebaseAPI;
 import com.group14.regicidechess.model.Move;
 import com.group14.regicidechess.model.Player;
 
@@ -45,6 +45,7 @@ public interface Listener {
     private final String  gameId;
     private final Player  localPlayer;
     private final Listener listener;
+    private final FirebaseAPI api;
 
     // Connection UI refs — updated directly here to keep GameScreen clean
     private final Image connectionIcon;
@@ -52,12 +53,13 @@ public interface Listener {
     private final CircuitBreaker circuitBreaker = new CircuitBreaker(3, 10_000L);
 
     public GameNetworkHandler(String gameId, Player localPlayer, Listener listener,
-                               Image connectionIcon, Label connectionLabel) {
+                               Image connectionIcon, Label connectionLabel, FirebaseAPI api) {
         this.gameId          = gameId;
         this.localPlayer     = localPlayer;
         this.listener        = listener;
         this.connectionIcon  = connectionIcon;
         this.connectionLabel = connectionLabel;
+        this.api             = api;
     }
 
     // ─────────────────────────────────────────────────────────────────────────
@@ -70,6 +72,10 @@ public void start() {
         startHeartbeat();
     }
 
+    public void stop() {
+        DatabaseManager.getInstance().getApi().removeAllListeners();
+    }
+
     // ─────────────────────────────────────────────────────────────────────────
     // Outgoing
     // ─────────────────────────────────────────────────────────────────────────
@@ -79,18 +85,18 @@ public void saveMove(Move move) {
             Gdx.app.log("GameNetworkHandler", "Circuit breaker OPEN — move send blocked");
             return;
         }
-        DatabaseManager.getInstance().getApi().saveMove(gameId, move, () -> {});
+        api.saveMove(gameId, move, () -> {});
     }
 
     public void sendHeartbeat() {
         if (!circuitBreaker.allowRequest()) return;
-        DatabaseManager.getInstance().getApi().sendHeartbeat(gameId, localPlayer.isWhite());
+        api.sendHeartbeat(gameId, localPlayer.isWhite());
     }
 
     /** Signals that this player has forfeited. */
     public void signalForfeit() {
         String loser = localPlayer.isWhite() ? "white" : "black";
-        DatabaseManager.getInstance().getApi().signalGameOver(gameId, "forfeit:" + loser);
+        api.signalGameOver(gameId, "forfeit:" + loser);
     }
 
     // ─────────────────────────────────────────────────────────────────────────
@@ -103,8 +109,7 @@ public void signalForfeit() {
      * Own echoed moves are filtered out via coords[4].
      */
     private void startOpponentMoveListener() {
-        DatabaseManager.getInstance().getApi()
-            .listenForOpponentMove(gameId, coords -> {
+        api.listenForOpponentMove(gameId, coords -> {
                 boolean moveIsWhite = coords.length > 4 && coords[4] == 1;
                 if (moveIsWhite == localPlayer.isWhite()) return; // own echo
 
@@ -117,16 +122,13 @@ private void startOpponentMoveListener() {
     }
 
     private void startGameOverListener() {
-        DatabaseManager.getInstance().getApi()
-            .listenForGameOver(gameId, reason ->
+        api.listenForGameOver(gameId, reason ->
                 Gdx.app.postRunnable(() -> listener.onGameOver(reason)));
     }
 
     private void startHeartbeat() {
         sendHeartbeat();
-
-        DatabaseManager.getInstance().getApi()
-            .listenForHeartbeat(
+        api.listenForHeartbeat(
                 gameId,
                 !localPlayer.isWhite(),
                 HEARTBEAT_TIMEOUT_MS,
@@ -165,4 +167,4 @@ private void updateConnectionUI(long latencyMs) {
         else                      connectionIcon.setColor(Color.RED);
         connectionLabel.setText(latencyMs + " ms");
     }
-}
\ No newline at end of file
+}
diff --git a/core/src/main/java/com/group14/regicidechess/screens/game/GameScreen.java b/core/src/main/java/com/group14/regicidechess/screens/game/GameScreen.java
index 14cd5e5..5bce68e 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/game/GameScreen.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/game/GameScreen.java
@@ -18,6 +18,7 @@
 import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
 import com.badlogic.gdx.utils.Align;
 import com.badlogic.gdx.utils.viewport.FitViewport;
+import com.group14.regicidechess.database.FirebaseAPI;
 import com.group14.regicidechess.input.ScreenInputHandler;
 import com.group14.regicidechess.model.Board;
 import com.group14.regicidechess.model.Move;
@@ -97,7 +98,8 @@ public class GameScreen implements Screen,
     // ─────────────────────────────────────────────────────────────────────────
 
     public GameScreen(Game game, SpriteBatch batch,
-                      Board board, Player localPlayer, int boardSize, String gameId) {
+                      Board board, Player localPlayer, int boardSize, String gameId,
+                      FirebaseAPI api) {
         this.game        = game;
         this.batch       = batch;
         this.localPlayer = localPlayer;
@@ -129,7 +131,7 @@ public GameScreen(Game game, SpriteBatch batch,
 
         overlayManager = new GameOverlayManager(stage, skin, localPlayer, this);
         networkHandler = new GameNetworkHandler(gameId, localPlayer, this,
-                                                connectionIcon, connectionLabel);
+                                                connectionIcon, connectionLabel, api);
         boardRenderer  = new GameBoardRenderer(batch, localPlayer, boardSize);
         boardRenderer.computeGeometry(V_WIDTH, V_HEIGHT, TOP_BAR_HEIGHT, STATUS_BAR_HEIGHT);
 
@@ -438,12 +440,14 @@ public void resize(int width, int height) {
     @Override
     public void hide() {
         inputHandler.clearObservers();
+        networkHandler.stop();
         inMatchState.exit();
     }
 
     @Override
     public void dispose() {
+        networkHandler.stop();
         stage.dispose();
         boardRenderer.dispose();
     }
-}
\ No newline at end of file
+}
diff --git a/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyFlowController.java b/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyFlowController.java
index 93d7d20..882840a 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyFlowController.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyFlowController.java
@@ -2,7 +2,7 @@
 package com.group14.regicidechess.screens.lobby;
 
 import com.badlogic.gdx.Gdx;
-import com.group14.regicidechess.database.DatabaseManager;
+import com.group14.regicidechess.states.LobbyState;
 
 /**
  * Manages Firebase listeners and flow between host and joiner.
@@ -16,10 +16,12 @@ public interface FlowListener {
         void onError(String message);
     }
     
+    private final LobbyState lobbyState;
     private final FlowListener listener;
     private String activeGameId;
     
-    public LobbyFlowController(FlowListener listener) {
+    public LobbyFlowController(LobbyState lobbyState, FlowListener listener) {
+        this.lobbyState = lobbyState;
         this.listener = listener;
     }
     
@@ -29,8 +31,7 @@ public LobbyFlowController(FlowListener listener) {
      */
     public void listenForJoiner(String gameId) {
         this.activeGameId = gameId;
-        DatabaseManager.getInstance().getApi()
-            .listenForOpponentReady(gameId,
+        lobbyState.listenForOpponentReady(gameId,
                 () -> Gdx.app.postRunnable(() -> {
                     if (listener != null) {
                         listener.onJoinerArrived();
@@ -43,7 +44,7 @@ public void listenForJoiner(String gameId) {
      * Writes status = "started" to Firebase.
      */
     public void signalGameStart(String gameId) {
-        DatabaseManager.getInstance().getApi().startGame(gameId);
+        lobbyState.startGame(gameId);
     }
     
     /**
@@ -52,8 +53,7 @@ public void signalGameStart(String gameId) {
      */
     public void listenForGameStart(String gameId) {
         this.activeGameId = gameId;
-        DatabaseManager.getInstance().getApi()
-            .listenForGameStart(gameId,
+        lobbyState.listenForGameStart(gameId,
                 () -> Gdx.app.postRunnable(() -> {
                     if (listener != null) {
                         listener.onGameStarted();
diff --git a/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyScreen.java b/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyScreen.java
index 8259b72..52dfb98 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyScreen.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/lobby/LobbyScreen.java
@@ -64,7 +64,7 @@ public LobbyScreen(Game game, SpriteBatch batch, LobbyMode mode, Lobby lobby) {
             stateManager.setPrefetchedLobby(lobby);
         }
         
-        this.flowController = new LobbyFlowController(createFlowListener());
+        this.flowController = new LobbyFlowController(stateManager.getLobbyState(), createFlowListener());
         this.stateManager.setListener(createStateListener());
         
         // LibGDX setup
diff --git a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/JoinGamePanel.java b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/JoinGamePanel.java
index 959ef26..384526a 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/JoinGamePanel.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/JoinGamePanel.java
@@ -9,6 +9,7 @@
 import com.badlogic.gdx.scenes.scene2d.ui.TextField;
 import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
 import com.group14.regicidechess.model.Lobby;
+import com.group14.regicidechess.states.LobbyState;
 
 /**
  * Join game panel UI component.
@@ -33,10 +34,10 @@ public interface JoinPanelListener {
     
     private boolean visible = false;
     
-    public JoinGamePanel(Skin skin, JoinPanelListener listener) {
+    public JoinGamePanel(Skin skin, LobbyState lobbyState, JoinPanelListener listener) {
         this.skin = skin;
         this.listener = listener;
-        this.validator = new LobbyValidator(createValidationListener());
+        this.validator = new LobbyValidator(lobbyState, createValidationListener());
         buildPanel();
     }
     
diff --git a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/LobbyValidator.java b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/LobbyValidator.java
index 33d1d87..14177d8 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/LobbyValidator.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/LobbyValidator.java
@@ -2,8 +2,8 @@
 package com.group14.regicidechess.screens.mainmenu;
 
 import com.badlogic.gdx.Gdx;
-import com.group14.regicidechess.database.DatabaseManager;
 import com.group14.regicidechess.model.Lobby;
+import com.group14.regicidechess.states.LobbyState;
 
 /**
  * Validates lobby existence in Firebase before navigating.
@@ -17,10 +17,12 @@ public interface ValidationListener {
         void onValidationError(String message);
     }
     
+    private final LobbyState lobbyState;
     private final ValidationListener listener;
     private boolean isValidating = false;
     
-    public LobbyValidator(ValidationListener listener) {
+    public LobbyValidator(LobbyState lobbyState, ValidationListener listener) {
+        this.lobbyState = lobbyState;
         this.listener = listener;
     }
     
@@ -48,7 +50,7 @@ public void validate(String gameId) {
         
         isValidating = true;
         
-        DatabaseManager.getInstance().getApi().fetchLobby(trimmedId,
+        lobbyState.validateLobby(trimmedId,
             // Lobby found
             lobby -> Gdx.app.postRunnable(() -> {
                 isValidating = false;
diff --git a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuScreen.java b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuScreen.java
index dbe5e68..c9ab26c 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuScreen.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuScreen.java
@@ -13,6 +13,7 @@
 import com.group14.regicidechess.model.Lobby;
 import com.group14.regicidechess.screens.lobby.LobbyMode;
 import com.group14.regicidechess.screens.lobby.LobbyScreen;
+import com.group14.regicidechess.states.LobbyState;
 import com.group14.regicidechess.states.MainMenuState;
 import com.group14.regicidechess.utils.ResourceManager;
 
@@ -36,6 +37,7 @@ public class MainMenuScreen implements Screen, ScreenInputHandler.ScreenInputObs
     
     // State and UI
     private final MainMenuState mainMenuState;
+    private final LobbyState lobbyState;
     private final MainMenuUI mainMenuUI;
     
     public MainMenuScreen(Game game, SpriteBatch batch) {
@@ -44,6 +46,7 @@ public MainMenuScreen(Game game, SpriteBatch batch) {
         
         // Initialize state
         this.mainMenuState = new MainMenuState();
+        this.lobbyState = new LobbyState();
         mainMenuState.enter();
         
         // LibGDX setup
@@ -56,7 +59,7 @@ public MainMenuScreen(Game game, SpriteBatch batch) {
         inputHandler.addObserver(this);
         
         // Build UI with listener
-        this.mainMenuUI = new MainMenuUI(skin, createUIListener());
+        this.mainMenuUI = new MainMenuUI(skin, lobbyState, createUIListener());
         
         // Add UI to stage
         stage.addActor(mainMenuUI.build());
@@ -97,9 +100,7 @@ public void onBack() {
     private void fetchLobbyAndNavigate(String gameId) {
         mainMenuUI.showError("Loading...");
         
-        com.group14.regicidechess.database.DatabaseManager.getInstance()
-            .getApi()
-            .fetchLobby(gameId,
+        lobbyState.validateLobby(gameId,
                 // Success - lobby found
                 lobby -> Gdx.app.postRunnable(() -> {
                     mainMenuUI.clearError();
diff --git a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuUI.java b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuUI.java
index 4222be7..ed1ab45 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuUI.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/mainmenu/MainMenuUI.java
@@ -8,6 +8,7 @@
 import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
 import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
 import com.badlogic.gdx.utils.Align;
+import com.group14.regicidechess.states.LobbyState;
 
 /**
  * Builds and manages the main menu UI.
@@ -30,10 +31,10 @@ public interface MainMenuUIListener {
     private TextButton joinBtn;
     private Label mainErrorLabel;
     
-    public MainMenuUI(Skin skin, MainMenuUIListener listener) {
+    public MainMenuUI(Skin skin, LobbyState lobbyState, MainMenuUIListener listener) {
         this.skin = skin;
         this.listener = listener;
-        this.joinPanel = new JoinGamePanel(skin, createJoinPanelListener());
+        this.joinPanel = new JoinGamePanel(skin, lobbyState, createJoinPanelListener());
     }
     
     public Table build() {
diff --git a/core/src/main/java/com/group14/regicidechess/screens/setup/SetupFlowController.java b/core/src/main/java/com/group14/regicidechess/screens/setup/SetupFlowController.java
index 99dc3f5..4d9e018 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/setup/SetupFlowController.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/setup/SetupFlowController.java
@@ -2,7 +2,6 @@
 package com.group14.regicidechess.screens.setup;
 
 import com.badlogic.gdx.Gdx;
-import com.group14.regicidechess.database.DatabaseManager;
 import com.group14.regicidechess.model.Board;
 import com.group14.regicidechess.model.Player;
 import com.group14.regicidechess.states.SetupState;
@@ -65,11 +64,12 @@ public void confirm() {
         listener.onUploadComplete();
 
         int[][] encoded = SetupBoardCodec.encode(setupState.getBoard());
-        DatabaseManager.getInstance().getApi().confirmSetup(
+        setupState.confirmSetup(
             gameId,
             localPlayer.isWhite(),
             encoded,
-            this::listenForBothReady
+            this::listenForBothReady,
+            error -> Gdx.app.postRunnable(() -> listener.onError("Setup failed: " + error))
         );
     }
     
@@ -83,7 +83,7 @@ public void unconfirm() {
         setupState.getPlayer().resetReady();
         isConfirmed = false;
         
-        DatabaseManager.getInstance().getApi().unconfirmSetup(
+        setupState.unconfirmSetup(
             gameId,
             localPlayer.isWhite(),
             () -> Gdx.app.postRunnable(() -> {
@@ -99,7 +99,7 @@ public void unconfirm() {
     }
 
     private void listenForBothReady() {
-        DatabaseManager.getInstance().getApi().listenForBothSetupReady(
+        setupState.listenForBothSetupReady(
             gameId,
             () -> Gdx.app.postRunnable(() -> {
                 listener.onBothReady();
@@ -113,7 +113,7 @@ private void fetchOpponentBoardWithRetry() {
     }
 
     private void fetchOpponentBoard() {
-        DatabaseManager.getInstance().getApi().getOpponentBoard(
+        setupState.getOpponentBoard(
             gameId,
             localPlayer.isWhite(),
             opponentBoard -> Gdx.app.postRunnable(() -> {
@@ -144,4 +144,4 @@ private void fetchOpponentBoard() {
     public boolean isConfirmed() {
         return isConfirmed;
     }
-}
\ No newline at end of file
+}
diff --git a/core/src/main/java/com/group14/regicidechess/screens/setup/SetupScreen.java b/core/src/main/java/com/group14/regicidechess/screens/setup/SetupScreen.java
index d64d1f3..e490d1c 100644
--- a/core/src/main/java/com/group14/regicidechess/screens/setup/SetupScreen.java
+++ b/core/src/main/java/com/group14/regicidechess/screens/setup/SetupScreen.java
@@ -304,7 +304,8 @@ public void onOpponentBoardFetched(com.group14.regicidechess.model.Board finalBo
                             finalBoard,
                             localPlayer,
                             setupState.getBoardSize(),
-                            gameId));
+                            gameId,
+                            setupState.getFirebaseApi()));
                     } catch (Exception e) {
                         Gdx.app.error("SetupScreen", "Error navigating to GameScreen: " + e.getMessage(), e);
                         showStatus("Error starting game: " + e.getMessage());
diff --git a/core/src/main/java/com/group14/regicidechess/states/LobbyState.java b/core/src/main/java/com/group14/regicidechess/states/LobbyState.java
index 660e7d5..66c884c 100644
--- a/core/src/main/java/com/group14/regicidechess/states/LobbyState.java
+++ b/core/src/main/java/com/group14/regicidechess/states/LobbyState.java
@@ -1,6 +1,7 @@
 package com.group14.regicidechess.states;
 
 import com.group14.regicidechess.database.DatabaseManager;
+import com.group14.regicidechess.database.FirebaseAPI;
 import com.group14.regicidechess.model.Lobby;
 import com.group14.regicidechess.model.Player;
 
@@ -64,6 +65,22 @@ public void setPrefetchedLobby(Lobby prefetched) {
         }
     }
 
+    public void validateLobby(String gameId, FirebaseAPI.Callback<Lobby> onSuccess, FirebaseAPI.Callback<String> onError) {
+        DatabaseManager.getInstance().getApi().fetchLobby(gameId, onSuccess, onError);
+    }
+
+    public void listenForOpponentReady(String gameId, Runnable onReady) {
+        DatabaseManager.getInstance().getApi().listenForOpponentReady(gameId, onReady);
+    }
+
+    public void startGame(String gameId) {
+        DatabaseManager.getInstance().getApi().startGame(gameId);
+    }
+
+    public void listenForGameStart(String gameId, Runnable onStart) {
+        DatabaseManager.getInstance().getApi().listenForGameStart(gameId, onStart);
+    }
+
     public Lobby  getLobby()             { return lobby; }
     public Player getPlayerOne()         { return playerOne; }
     public Player getPlayerTwo()         { return playerTwo; }
diff --git a/core/src/main/java/com/group14/regicidechess/states/SetupState.java b/core/src/main/java/com/group14/regicidechess/states/SetupState.java
index 46485ea..c48f641 100644
--- a/core/src/main/java/com/group14/regicidechess/states/SetupState.java
+++ b/core/src/main/java/com/group14/regicidechess/states/SetupState.java
@@ -1,6 +1,8 @@
 // File: core/src/main/java/com/group14/regicidechess/states/SetupState.java
 package com.group14.regicidechess.states;
 
+import com.group14.regicidechess.database.DatabaseManager;
+import com.group14.regicidechess.database.FirebaseAPI;
 import com.group14.regicidechess.model.Board;
 import com.group14.regicidechess.model.Player;
 import com.group14.regicidechess.model.pieces.ChessPiece;
@@ -155,6 +157,26 @@ private boolean isInHomeZone(int row) {
     public int     getHomeRowMin() { return homeRowMin; }
     public int     getHomeRowMax() { return homeRowMax; }
     
+    public FirebaseAPI getFirebaseApi() {
+        return DatabaseManager.getInstance().getApi();
+    }
+
+    public void confirmSetup(String gameId, boolean isWhite, int[][] board, Runnable onSuccess) {
+        DatabaseManager.getInstance().getApi().confirmSetup(gameId, isWhite, board, onSuccess);
+    }
+
+    public void unconfirmSetup(String gameId, boolean isWhite, Runnable onSuccess, FirebaseAPI.Callback<String> onError) {
+        DatabaseManager.getInstance().getApi().unconfirmSetup(gameId, isWhite, onSuccess, onError);
+    }
+
+    public void listenForBothSetupReady(String gameId, Runnable onBothReady) {
+        DatabaseManager.getInstance().getApi().listenForBothSetupReady(gameId, onBothReady);
+    }
+
+    public void getOpponentBoard(String gameId, boolean localIsWhite, FirebaseAPI.Callback<int[][]> onBoard) {
+        DatabaseManager.getInstance().getApi().getOpponentBoard(gameId, localIsWhite, onBoard);
+    }
+
     /**
      * @deprecated Use isReadyForConfirm() for UI readiness, or isPlayerReady() for Firebase readiness.
      */