Merge pull request #953 from jlowin/claude-wt-20250625-195151

Fix parameter location enum handling in OpenAPI parser

src/fastmcp/utilities/openapi.py

@@ -302,11 +302,17 @@ class OpenAPIParser(
 
                 # Extract parameter info - handle both 3.0 and 3.1 parameter models
                 param_in = parameter.param_in  # Both use param_in
-                param_location = self._convert_to_parameter_location(param_in)
+                # Handle enum or string parameter locations
+                from enum import Enum
+
+                param_in_str = (
+                    param_in.value if isinstance(param_in, Enum) else param_in
+                )
+                param_location = self._convert_to_parameter_location(param_in_str)
                 param_schema_obj = parameter.param_schema  # Both use param_schema
 
                 # Skip duplicate parameters (same name and location)
-                param_key = (parameter.name, param_in)
+                param_key = (parameter.name, param_in_str)
                 if param_key in seen_params:
                     continue
                 seen_params[param_key] = True

tests/server/openapi/test_openapi_path_parameters.py

@@ -455,3 +455,31 @@ async def test_array_query_parameter_exploded_format(mock_client):
         json=None,
         timeout=None,
     )
+
+
+def test_parameter_location_enum_handling():
+    """Test that ParameterLocation enum values are handled correctly (issue #950)."""
+    from enum import Enum
+
+    # Create a mock ParameterLocation enum like the one from openapi_pydantic
+    class MockParameterLocation(Enum):
+        PATH = "path"
+        QUERY = "query"
+        HEADER = "header"
+        COOKIE = "cookie"
+
+    # Test the enum handling logic directly (reproduces the fix in openapi.py)
+    test_cases = [
+        (MockParameterLocation.PATH, "path"),
+        (MockParameterLocation.QUERY, "query"),
+        (MockParameterLocation.HEADER, "header"),
+        (MockParameterLocation.COOKIE, "cookie"),
+        ("path", "path"),  # Also test that strings work
+        ("query", "query"),
+    ]
+
+    for param_in, expected_str in test_cases:
+        # This is the enum handling logic from the fix
+        param_in_str = param_in.value if isinstance(param_in, Enum) else param_in
+        assert param_in_str == expected_str
+        assert isinstance(param_in_str, str)