diff --git a/counter.py b/counter.py
new file mode 100644
index 0000000..cb776fe
--- /dev/null
+++ b/counter.py
@@ -0,0 +1,20 @@
+class Counter:
+    """
+    Simple counter with increment, decrement, and value retrieval.
+    """
+    def __init__(self, initial: int = 0):
+        self._value = int(initial)
+
+    def increment(self, amount: int = 1) -> int:
+        """Increase the counter by 'amount' (default 1) and return new value."""
+        self._value += int(amount)
+        return self._value
+
+    def decrement(self, amount: int = 1) -> int:
+        """Decrease the counter by 'amount' (default 1) and return new value."""
+        self._value -= int(amount)
+        return self._value
+
+    def get_value(self) -> int:
+        """Return the current value of the counter."""
+        return self._value