diff --git a/tests/backend_api/test_api_contract.py b/tests/backend_api/test_api_contract.py
new file mode 100644
index 00000000..c0c491dc
--- /dev/null
+++ b/tests/backend_api/test_api_contract.py
@@ -0,0 +1,18 @@
+import pytest
+from backend.api_contract import APIContract
+
+@pytest.mark.parametrize("payload, expected_error", [
+    ({"missing_field": "value"}, "Missing required field: 'required_field'"),
+    ({"required_field": None}, "Invalid value for field: 'required_field'")
+])
+def test_api_contract_negative_cases(payload, expected_error):
+    with pytest.raises(APIContract.Error) as exc_info:
+        APIContract.validate(payload)
+    assert str(exc_info.value) == expected_error
+
+@pytest.mark.asyncio
+async def test_api_contract_async_wrapper():
+    async def async_helper():
+        return APIContract.validate({"required_field": "value"})
+    result = await async_helper()
+    assert result == {"required_field": "value"}