diff --git a/src/tui/editor.py b/src/tui/editor.py
new file mode 100644
index 0000000..dfb2326
--- /dev/null
+++ b/src/tui/editor.py
@@ -0,0 +1,266 @@
+"""TUI editor module for interactive data editing."""
+
+from typing import Any
+from rich.console import Console
+from rich.text import Text
+from rich.prompt import Prompt
+from rich.box import ROUNDED
+from rich.panel import Panel
+
+
+class DataEditor:
+    """Interactive editor for data manipulation."""
+    
+    def __init__(self, console: Console = None):
+        """Initialize the data editor.
+        
+        Args:
+            console: Rich Console instance
+        """
+        self.console = console or Console()
+        self.data = None
+        self.format_name = None
+        self.modified = False
+    
+    def load_data(self, data: Any, format_name: str) -> None:
+        """Load data for editing.
+        
+        Args:
+            data: Data object to edit
+            format_name: Format of the data
+        """
+        self.data = data
+        self.format_name = format_name
+        self.modified = False
+    
+    def _display_header(self) -> None:
+        """Display editor header."""
+        header = Text()
+        header.append("Data Editor\n", style='bold cyan')
+        header.append("─" * 40 + "\n", style='dim')
+        header.append("Commands:\n", style='yellow')
+        header.append("  edit <path> <value>  - Edit a value\n", style='white')
+        header.append("  add <path> <value>   - Add a new key\n", style='white')
+        header.append("  delete <path>       - Delete a key\n", style='white')
+        header.append("  show                - Show current data\n", style='white')
+        header.append("  save                - Save changes\n", style='white')
+        header.append("  quit                - Exit without saving\n", style='white')
+        header.append("  help                - Show this help\n", style='white')
+        
+        panel = Panel(header, title="Help", box=ROUNDED, expand=False)
+        self.console.print(panel)
+    
+    def _parse_path(self, path: str) -> list:
+        """Parse a dot-separated path.
+        
+        Args:
+            path: Dot-separated path string
+            
+        Returns:
+            List of path segments
+        """
+        return path.split('.')
+    
+    def _get_nested_value(self, data: Any, path: list) -> Any:
+        """Get value from nested dictionary.
+        
+        Args:
+            data: Data structure
+            path: List of path segments
+            
+        Returns:
+            Value at the path
+        """
+        current = data
+        for segment in path:
+            if isinstance(current, dict) and segment in current:
+                current = current[segment]
+            else:
+                return None
+        return current
+    
+    def _set_nested_value(self, data: Any, path: list, value: Any) -> bool:
+        """Set value in nested dictionary.
+        
+        Args:
+            data: Data structure
+            path: List of path segments
+            value: Value to set
+            
+        Returns:
+            True if successful, False otherwise
+        """
+        current = data
+        for i, segment in enumerate(path[:-1]):
+            if isinstance(current, dict) and segment in current:
+                current = current[segment]
+            else:
+                return False
+        
+        if isinstance(current, dict):
+            current[path[-1]] = value
+            return True
+        return False
+    
+    def _delete_nested_value(self, data: Any, path: list) -> bool:
+        """Delete value from nested dictionary.
+        
+        Args:
+            data: Data structure
+            path: List of path segments
+            
+        Returns:
+            True if successful, False otherwise
+        """
+        current = data
+        for i, segment in enumerate(path[:-1]):
+            if isinstance(current, dict) and segment in current:
+                current = current[segment]
+            else:
+                return False
+        
+        if isinstance(current, dict) and path[-1] in current:
+            del current[path[-1]]
+            return True
+        return False
+    
+    def _cmd_edit(self, args: list) -> bool:
+        """Handle edit command.
+        
+        Args:
+            args: Command arguments
+            
+        Returns:
+            True if command was handled
+        """
+        if len(args) < 2:
+            self.console.print("Usage: edit <path> <value>", style='red')
+            return True
+        
+        path = self._parse_path(args[0])
+        value = ' '.join(args[1:])
+        
+        try:
+            import json
+            value = json.loads(value)
+        except json.JSONDecodeError:
+            pass
+        
+        if self._set_nested_value(self.data, path, value):
+            self.modified = True
+            self.console.print(f"Updated: {'.'.join(path)}", style='green')
+        else:
+            self.console.print(f"Path not found: {'.'.join(path)}", style='red')
+        
+        return True
+    
+    def _cmd_add(self, args: list) -> bool:
+        """Handle add command.
+        
+        Args:
+            args: Command arguments
+            
+        Returns:
+            True if command was handled
+        """
+        if len(args) < 2:
+            self.console.print("Usage: add <path> <value>", style='red')
+            return True
+        
+        path = self._parse_path(args[0])
+        value = ' '.join(args[1:])
+        
+        try:
+            import json
+            value = json.loads(value)
+        except json.JSONDecodeError:
+            pass
+        
+        if self._set_nested_value(self.data, path, value):
+            self.modified = True
+            self.console.print(f"Added: {'.'.join(path)}", style='green')
+        else:
+            self.console.print(f"Could not add: {'.'.join(path)}", style='red')
+        
+        return True
+    
+    def _cmd_delete(self, args: list) -> bool:
+        """Handle delete command.
+        
+        Args:
+            args: Command arguments
+            
+        Returns:
+            True if command was handled
+        """
+        if not args:
+            self.console.print("Usage: delete <path>", style='red')
+            return True
+        
+        path = self._parse_path(args[0])
+        
+        if self._delete_nested_value(self.data, path):
+            self.modified = True
+            self.console.print(f"Deleted: {'.'.join(path)}", style='green')
+        else:
+            self.console.print(f"Path not found: {'.'.join(path)}", style='red')
+        
+        return True
+    
+    def _cmd_show(self) -> bool:
+        """Handle show command."""
+        from .viewer import DataViewer
+        
+        viewer = DataViewer()
+        viewer.view_data(self.data, self.format_name, title="Current Data")
+        return True
+    
+    def _cmd_save(self) -> bool:
+        """Handle save command."""
+        self.console.print("Data saved (in-memory)", style='green')
+        return True
+    
+    def run(self) -> bool:
+        """Run the interactive editor.
+        
+        Returns:
+            True if data was modified, False otherwise
+        """
+        self._display_header()
+        self._cmd_show()
+        
+        while True:
+            try:
+                command = Prompt.ask("\n[cyan]Command[/cyan]").strip()
+                
+                if not command:
+                    continue
+                
+                parts = command.split()
+                cmd = parts[0].lower()
+                args = parts[1:]
+                
+                if cmd in ('quit', 'exit', 'q'):
+                    break
+                elif cmd in ('help', 'h', '?'):
+                    self._display_header()
+                elif cmd == 'edit':
+                    self._cmd_edit(args)
+                elif cmd == 'add':
+                    self._cmd_add(args)
+                elif cmd == 'delete':
+                    self._cmd_delete(args)
+                elif cmd in ('show', 's'):
+                    self._cmd_show()
+                elif cmd in ('save', 'w'):
+                    self._cmd_save()
+                else:
+                    self.console.print(f"Unknown command: {cmd}", style='red')
+            
+            except KeyboardInterrupt:
+                self.console.print("\nExiting...", style='yellow')
+                break
+            except Exception as e:
+                self.console.print(f"Error: {e}", style='red')
+        
+        return self.modified