diff --git a/src/main/java/org/to/telegramfinalproject/Client/ActionHandler.java b/src/main/java/org/to/telegramfinalproject/Client/ActionHandler.java
index a23588c..55f2bfc 100644
--- a/src/main/java/org/to/telegramfinalproject/Client/ActionHandler.java
+++ b/src/main/java/org/to/telegramfinalproject/Client/ActionHandler.java
@@ -1237,6 +1237,7 @@ public class ActionHandler {
         return true;
     }
 
+
     private JSONObject getGroupPermissions(UUID groupId) {
         JSONObject req = new JSONObject();
         req.put("action", "get_group_permissions");
@@ -2013,7 +2014,7 @@ public class ActionHandler {
     private void deleteChat(UUID targetId, boolean both) {
         JSONObject req = new JSONObject();
         req.put("action", "delete_private_chat");
-        req.put("target_id", targetId.toString());
+        req.put("chat_id", targetId.toString());
         req.put("both", both);
         send(req);
 
diff --git a/src/main/java/org/to/telegramfinalproject/Database/MessageDatabase.java b/src/main/java/org/to/telegramfinalproject/Database/MessageDatabase.java
index 4b4e4b4..eea9f79 100644
--- a/src/main/java/org/to/telegramfinalproject/Database/MessageDatabase.java
+++ b/src/main/java/org/to/telegramfinalproject/Database/MessageDatabase.java
@@ -65,6 +65,54 @@ public class MessageDatabase {
         }
     }
 
+    public static void markGloballyDeleted(UUID chatId) {
+        String sql = "UPDATE messages SET deleted_globally = true WHERE receiver_id = ? AND receiver_type = 'private'";
+        try (Connection conn = ConnectionDb.connect(); PreparedStatement ps = conn.prepareStatement(sql)) {
+            ps.setObject(1, chatId);
+            ps.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void logDeletedMessagesFor(UUID chatId, UUID userId) {
+        List<Message> messages = MessageDatabase.privateChatHistory(chatId);
+        for (Message message : messages) {
+            if (!isMessageDeleted(message.getMessage_id(), userId)) {
+                String sql = """
+                INSERT INTO deleted_messages (message_id, user_id)
+                VALUES (?, ?)
+                ON CONFLICT (message_id, user_id) DO NOTHING
+                """;
+                try (Connection conn = ConnectionDb.connect();
+                     PreparedStatement ps = conn.prepareStatement(sql)) {
+                    ps.setObject(1, message.getMessage_id());
+                    ps.setObject(2, userId);
+                    ps.executeUpdate();
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+
+    public static boolean isMessageDeleted(UUID messageId, UUID userId) {
+        String sql = "SELECT 1 FROM deleted_messages WHERE message_id = ? AND user_id = ?";
+        try (Connection conn = ConnectionDb.connect();
+             PreparedStatement ps = conn.prepareStatement(sql)) {
+            ps.setObject(1, messageId);
+            ps.setObject(2, userId);
+            ResultSet rs = ps.executeQuery();
+            return rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+            return false;
+        }
+    }
+
+
+
+
     public void markMessageAsRead(UUID messageId, UUID userId) {
         String sql = "INSERT INTO message_receipts (message_id, user_id) VALUES (?, ?) ON CONFLICT DO NOTHING";
         try (Connection conn = ConnectionDb.connect();
diff --git a/src/main/java/org/to/telegramfinalproject/Database/PrivateChatDatabase.java b/src/main/java/org/to/telegramfinalproject/Database/PrivateChatDatabase.java
index d96258f..7487b1f 100644
--- a/src/main/java/org/to/telegramfinalproject/Database/PrivateChatDatabase.java
+++ b/src/main/java/org/to/telegramfinalproject/Database/PrivateChatDatabase.java
@@ -2,10 +2,7 @@ package org.to.telegramfinalproject.Database;
 
 import org.to.telegramfinalproject.Models.PrivateChat;
 
-import java.sql.Connection;
-import java.sql.PreparedStatement;
-import java.sql.ResultSet;
-import java.sql.SQLException;
+import java.sql.*;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -133,4 +130,129 @@ public class PrivateChatDatabase {
         return null;
     }
 
+
+    private static PrivateChat extractPrivateChat(ResultSet rs) throws SQLException {
+        UUID chatId = UUID.fromString(rs.getString("chat_id"));
+        UUID user1 = rs.getObject("user1_id", UUID.class);
+        UUID user2 = rs.getObject("user2_id", UUID.class);
+        boolean user1Deleted = rs.getBoolean("user1_deleted");
+        boolean user2Deleted = rs.getBoolean("user2_deleted");
+        LocalDateTime createdAt = rs.getTimestamp("created_at").toLocalDateTime();
+
+        return new PrivateChat(chatId, user1, user2, user1Deleted, user2Deleted, createdAt);
+    }
+
+    public static void markChatDeleted(UUID userId, UUID chatId) {
+        String sql = """
+        UPDATE private_chat 
+        SET user1_deleted = CASE WHEN user1_id = ? THEN true ELSE user1_deleted END,
+            user2_deleted = CASE WHEN user2_id = ? THEN true ELSE user2_deleted END
+        WHERE chat_id = ?
+    """;
+
+        try (Connection conn = ConnectionDb.connect();
+             PreparedStatement stmt = conn.prepareStatement(sql)) {
+            stmt.setObject(1, userId);
+            stmt.setObject(2, userId);
+            stmt.setObject(3, chatId);
+            stmt.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void unmarkChatDeleted(UUID userId, UUID chatId) {
+        String sql = """
+        UPDATE private_chat 
+        SET user1_deleted = CASE WHEN user1_id = ? THEN false ELSE user1_deleted END,
+            user2_deleted = CASE WHEN user2_id = ? THEN false ELSE user2_deleted END
+        WHERE chat_id = ?
+    """;
+
+        try (Connection conn = ConnectionDb.connect();
+             PreparedStatement stmt = conn.prepareStatement(sql)) {
+            stmt.setObject(1, userId);
+            stmt.setObject(2, userId);
+            stmt.setObject(3, chatId);
+            stmt.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void markUser1Deleted(UUID chatId) {
+        updateBoolField(chatId, "user1_deleted", true);
+    }
+
+    public static void markUser2Deleted(UUID chatId) {
+        updateBoolField(chatId, "user2_deleted", true);
+    }
+
+    public static void markBothDeleted(UUID chatId) {
+        String sql = "UPDATE private_chat SET user1_deleted = true, user2_deleted = true WHERE chat_id = ?";
+        try (Connection conn = ConnectionDb.connect(); PreparedStatement ps = conn.prepareStatement(sql)) {
+            ps.setObject(1, chatId);
+            ps.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static void updateBoolField(UUID chatId, String field, boolean value) {
+        String sql = "UPDATE private_chat SET " + field + " = ? WHERE chat_id = ?";
+        try (Connection conn = ConnectionDb.connect(); PreparedStatement ps = conn.prepareStatement(sql)) {
+            ps.setBoolean(1, value);
+            ps.setObject(2, chatId);
+            ps.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+
+    public static PrivateChat findById(UUID chatId) {
+        String sql = "SELECT * FROM private_chat WHERE chat_id = ?";
+        try (Connection conn = ConnectionDb.connect(); PreparedStatement ps = conn.prepareStatement(sql)) {
+            ps.setObject(1, chatId);
+            ResultSet rs = ps.executeQuery();
+            if (rs.next()) {
+                UUID user1_id = (UUID) rs.getObject("user1_id");
+                UUID user2_id = (UUID) rs.getObject("user2_id");
+                boolean user1_deleted = rs.getBoolean("user1_deleted");
+                boolean user2_deleted = rs.getBoolean("user2_deleted");
+                LocalDateTime created_at = rs.getTimestamp("created_at").toLocalDateTime();
+
+                return new PrivateChat(chatId, user1_id, user2_id, user1_deleted, user2_deleted, created_at);
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+
+    public static void clearDeletedFlag(UUID senderId, UUID receiverId) {
+        String sql = """
+        UPDATE private_chat
+        SET user1_deleted = CASE WHEN user1_id = ? THEN false ELSE user1_deleted END,
+        user2_deleted = CASE WHEN user2_id = ? THEN false ELSE user2_deleted END
+        WHERE (user1_id = ? AND user2_id = ?) OR (user1_id = ? AND user2_id = ?)
+        """;
+
+        try (Connection conn = ConnectionDb.connect(); PreparedStatement ps = conn.prepareStatement(sql)) {
+            ps.setObject(1, senderId);
+            ps.setObject(2, senderId);
+            ps.setObject(3, senderId);
+            ps.setObject(4, receiverId);
+            ps.setObject(5, receiverId);
+            ps.setObject(6, senderId);
+            ps.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+
+
+
 }
diff --git a/src/main/java/org/to/telegramfinalproject/Models/PrivateChat.java b/src/main/java/org/to/telegramfinalproject/Models/PrivateChat.java
index 20caa6d..17ca2a9 100644
--- a/src/main/java/org/to/telegramfinalproject/Models/PrivateChat.java
+++ b/src/main/java/org/to/telegramfinalproject/Models/PrivateChat.java
@@ -5,6 +5,8 @@ import java.util.UUID;
 
 public class PrivateChat {
     private final UUID chat_id;
+    private boolean user1_deleted;
+    private boolean user2_deleted;
     private UUID user1_id;
     private UUID user2_id;
     private LocalDateTime created_at;
@@ -16,6 +18,16 @@ public class PrivateChat {
         this.created_at =created_at;
     }
 
+    public PrivateChat(UUID chatId, UUID user1, UUID user2, boolean user1Deleted, boolean user2Deleted, LocalDateTime createdAt) {
+        this.chat_id = chatId;
+        this.user1_id = user1;
+        this.user2_id = user2;
+        this.user1_deleted = user1Deleted;
+        this.user2_deleted = user2Deleted;
+        this.created_at = createdAt;
+    }
+
+
     public void setUser1_id(UUID user1_id){this.user1_id =user1_id;}
     public void setUser2_id(UUID user2_id){this.user2_id =user2_id;}
     public void setCreated_at(LocalDateTime created_at){this.created_at = created_at;}
diff --git a/src/main/java/org/to/telegramfinalproject/Server/ClientHandler.java b/src/main/java/org/to/telegramfinalproject/Server/ClientHandler.java
index 5b611e2..49862fb 100644
--- a/src/main/java/org/to/telegramfinalproject/Server/ClientHandler.java
+++ b/src/main/java/org/to/telegramfinalproject/Server/ClientHandler.java
@@ -1432,26 +1432,33 @@ public class ClientHandler implements Runnable {
 
 
 
-                    case "delete_private_chat" : {
+                    case "delete_private_chat": {
                         if (currentUser == null) {
                             response = new ResponseModel("error", "Unauthorized. Please login first.");
                             break;
                         }
-                        UUID targetId = UUID.fromString(requestJson.getString("target_id"));
+
+                        // دریافت شناسه چت و نوع حذف (یک‌طرفه یا دوطرفه)
+                        UUID targetId = UUID.fromString(requestJson.getString("chat_id"));
                         boolean both = requestJson.getBoolean("both");
 
-                        //RealTime
+                        // Real-Time Event Dispatch (اطلاع‌رسانی ریل تایم)
                         if (both) {
+                            // حذف دوطرفه
                             RealTimeEventDispatcher.notifyChatDeleted("private", targetId, List.of(currentUser.getInternal_uuid()));
                             RealTimeEventDispatcher.notifyChatDeleted("private", currentUser.getInternal_uuid(), List.of(targetId));
                         } else {
+                            // حذف یک‌طرفه
                             RealTimeEventDispatcher.notifyChatDeleted("private", targetId, List.of(currentUser.getInternal_uuid()));
                         }
-                        response = PrivateChatService.deletePrivateChat(currentUser.getInternal_uuid(), targetId, both);
+
+                        // فراخوانی متد حذف چت
+                        response = handleDeleteChat(requestJson);
                         break;
                     }
 
 
+
                     case "get_group_permissions": {
                         if (currentUser == null) {
                             response = new ResponseModel("error", "Unauthorized. Please login first.");
@@ -2025,8 +2032,6 @@ public class ClientHandler implements Runnable {
 
 
 
-
-
                     default:
                         response = new ResponseModel("error", "Unknown action: " + action);
                 }
@@ -2085,6 +2090,7 @@ public class ClientHandler implements Runnable {
 
 
     private ResponseModel handleSendMessage(JSONObject json) {
+
         try {
             if (currentUser == null)
                 return new ResponseModel("error", "Unauthorized. Please login first.");
@@ -2093,9 +2099,13 @@ public class ClientHandler implements Runnable {
             UUID senderId = currentUser.getInternal_uuid();
             String receiverType = json.getString("receiver_type");
             UUID receiverId;
-
             receiverId = UUID.fromString(json.getString("receiver_id"));
 
+            if(Objects.equals(receiverType, "private")){
+                PrivateChatDatabase.clearDeletedFlag(senderId, receiverId);
+            }
+
+
             String content = json.optString("content", "");
             String messageType = json.optString("message_type", "TEXT");
 
@@ -2165,5 +2175,42 @@ public class ClientHandler implements Runnable {
     }
 
 
+    private ResponseModel handleDeleteChat(JSONObject json) {
+        try {
+            if (currentUser == null)
+                return new ResponseModel("error", "Unauthorized");
+
+            UUID chatId = UUID.fromString(json.getString("chat_id"));
+            boolean bothSides = json.optBoolean("both_sides", false);
+
+            PrivateChat chat = PrivateChatDatabase.findById(chatId);
+            if (chat == null) return new ResponseModel("error", "Chat not found.");
+
+            UUID self = currentUser.getInternal_uuid();
+            UUID other = chat.getUser1_id().equals(self) ? chat.getUser2_id() : chat.getUser1_id();
+
+            if (bothSides) {
+                PrivateChatDatabase.markBothDeleted(chatId);
+                MessageDatabase.markGloballyDeleted(chatId);
+                MessageDatabase.logDeletedMessagesFor(chatId, self);
+                MessageDatabase.logDeletedMessagesFor(chatId, other);
+                return new ResponseModel("success", "Chat deleted for both sides.");
+            } else {
+                if (chat.getUser1_id().equals(self))
+                    PrivateChatDatabase.markUser1Deleted(chatId);
+                else
+                    PrivateChatDatabase.markUser2Deleted(chatId);
+
+                MessageDatabase.logDeletedMessagesFor(chatId, self);
+                return new ResponseModel("success", "Chat deleted (one-sided).");
+            }
+
+        } catch (Exception e) {
+            e.printStackTrace();
+            return new ResponseModel("error", "Exception while deleting chat.");
+        }
+    }
+
+
 
 }
\ No newline at end of file