diff --git a/stanley/__init__.py b/stanley/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/stanley/test_addition.py b/stanley/test_addition.py
new file mode 100644
index 0000000..bca0b4f
--- /dev/null
+++ b/stanley/test_addition.py
@@ -0,0 +1,9 @@
+def add(a, b):
+    """Add a and b"""
+    return a + b
+
+
+def test_add():
+    assert add(1, 1) == 2
+    assert add(0, 0) == 0
+    assert add(1, -1) == 0