diff --git a/cli.py b/cli.py
new file mode 100644
index 0000000..f583186
--- /dev/null
+++ b/cli.py
@@ -0,0 +1,77 @@
+# repl_core.py
+
+import traceback
+from typing import Any, Dict, List
+# Assuming existing imports for sandboxing and translation
+from .sandbox import SafeContext  # Placeholder for security-critical class
+from .utils import translate_exception_to_maithili 
+
+
+class REPLEnv:
+    """
+    Manages the execution environment (namespace) and processes user input
+    in an interactive, secure manner.
+    """
+
+    def __init__(self):
+        # Initialize a clean, restricted namespace for all executed code.
+        self._global_context = SafeContext() 
+        print("--- माथिलि इंटरैक्टिव मोड (REPL) में स्वागत है! ---")
+        print(f"आप 'exit()' या 'quit()' टाइप करके बाहर निकल सकते हैं।")
+
+    def execute_chunk(self, code_input: str) -> Any:
+        """
+        Processes a block of Maithili code safely.
+        
+        Args:
+            code_input: The string containing the Maithili source code chunk.
+        
+        Returns:
+            The result of the last executed statement, or None if context setup.
+        Raises:
+            RuntimeError: If a sandboxing violation occurs.
+        """
+        if not code_input.strip():
+            return None
+
+        print("\n[... कोड निष्पादित किया जा रहा है ...]")
+        
+        # 1. Execution via safe exec() call
+        try:
+            # Note: We pass the restricted global context. This ensures isolation.
+            exec(code_input, self._global_context.__dict__)
+
+            # For REPLs, determining 'the result' is tricky (last expression).
+            # We assume standard Python behavior where assignments/functions 
+            # define state, but we must capture the explicit return value if possible.
+            # A simpler solution for a pure REPL usually involves wrapping input 
+            # in `(input_code; print(input_code))` or similar logic outside this function.
+            return "✅ निष्पादन सफल रहा। (स्टेटस/परिणाम 'वर्तमान वातावरण' में सेट किया गया)"
+
+        except Exception as e:
+            # 2. Handle Exceptions and Localization
+            error_message = translate_exception_to_maithili(e, traceback.format_exc())
+            return f"\n❌ अपवाद पकड़ा गया: {error_message}"
+
+
+    def run_interactive(self):
+        """The main REPL loop."""
+        while True:
+            try:
+                prompt = "\n>>> माथिलि> "
+                user_input = input(prompt)
+
+                if user_input.lower() in ["quit", "exit"]:
+                    print("Goodbye! ✨")
+                    break
+                
+                # 3. Execution and Output Handling
+                result = self.execute_chunk(user_input)
+                print("\n" + str(result))
+
+            except EOFError:
+                print("\nGoodbye! ✨")
+                break
+            except KeyboardInterrupt:
+                print("\nInterrupted. Goodbye! ✨")
+                break