diff --git a/tests/test_sdk_api_parity.py b/tests/test_sdk_api_parity.py
new file mode 100644
index 0000000..938fd1d
--- /dev/null
+++ b/tests/test_sdk_api_parity.py
@@ -0,0 +1,57 @@
+"""Tests that SDK response handling does not expose internal API fields to callers."""
+
+from unittest.mock import MagicMock, patch
+
+from valyu import Valyu
+
+
+def test_py_sdk_data_leak():
+    """SDK must not expose internal API fields to callers via SearchResult.metadata.
+
+    The search API may return internal data (cost IDs, routing keys, secrets)
+    in the 'metadata' field of each result. The SDK must strip these before
+    returning results to callers.
+    """
+    internal_metadata = {
+        "_internal_cost_id": "cost-abc-123",
+        "_routing_key": "us-east-1:bucket:key",
+        "_provider_secret": "secret-value",
+    }
+
+    mock_response = MagicMock()
+    mock_response.ok = True
+    mock_response.status_code = 200
+    mock_response.json.return_value = {
+        "success": True,
+        "tx_id": "tx-test-123",
+        "query": "test query",
+        "results": [
+            {
+                "title": "Test Result",
+                "url": "https://example.com/test",
+                "content": "Test content here",
+                "source": "web",
+                "price": 0.001,
+                "length": 17,
+                "metadata": internal_metadata,
+            }
+        ],
+        "results_by_source": {"web": 1, "proprietary": 0},
+        "total_deduction_dollars": 0.001,
+        "total_characters": 17,
+    }
+
+    client = Valyu(api_key="test-key")
+    with patch.object(client._session, "post", return_value=mock_response):
+        response = client.search("test query")
+
+    assert response is not None
+    assert response.success is True
+    assert len(response.results) == 1
+    result = response.results[0]
+
+    # Internal API data must not be accessible via the SDK response
+    exposed_metadata = getattr(result, "metadata", None)
+    assert (
+        exposed_metadata is None
+    ), f"SearchResult.metadata exposes internal API data to callers: {exposed_metadata}"
diff --git a/valyu/types/response.py b/valyu/types/response.py
index a3e7fa2..127e06a 100644
--- a/valyu/types/response.py
+++ b/valyu/types/response.py
@@ -24,7 +24,6 @@ class SearchResult(BaseModel):
     citation_count: Optional[int] = None
     authors: Optional[List[str]] = None
     references: Optional[str] = None
-    metadata: Optional[Dict[str, Any]] = None
 
 
 class ResultsBySource(BaseModel):