fix(google-genai): prevent TypeError when handling Pydantic model classes

Author: Davi Campos

instrumentation-genai/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/dict_util.py

@@ -188,14 +188,22 @@ def _flatten_compound_value(
             rename_keys=rename_keys,
             flatten_functions=flatten_functions,
         )
-    if hasattr(value, "model_dump"):
+    if hasattr(value, "model_dump") and not isinstance(value, type):
         return _flatten_dict(
             value.model_dump(),
             key_prefix=key,
             exclude_keys=exclude_keys,
             rename_keys=rename_keys,
             flatten_functions=flatten_functions,
         )
+    if hasattr(value, "model_json_schema"):
+        return _flatten_dict(
+            value.model_json_schema(),
+            key_prefix=key,
+            exclude_keys=exclude_keys,
+            rename_keys=rename_keys,
+            flatten_functions=flatten_functions,
+        )
     return _flatten_compound_value_using_json(
         key,
         value,

instrumentation-genai/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/generate_content.py

@@ -161,8 +161,10 @@ def _determine_genai_system(models_object: Union[Models, AsyncModels]):
 def _to_dict(value: object):
     if isinstance(value, dict):
         return value
-    if hasattr(value, "model_dump"):
+    if hasattr(value, "model_dump") and not isinstance(value, type):
         return value.model_dump()
+    if hasattr(value, "model_json_schema"):
+        return value.model_json_schema()
     return json.loads(json.dumps(value))
 
 

instrumentation-genai/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/tool_call_wrapper.py

@@ -54,8 +54,12 @@ def _to_otel_value(python_value):
         return {
             key: _to_otel_value(val) for (key, val) in python_value.items()
         }
-    if hasattr(python_value, "model_dump"):
+    if hasattr(python_value, "model_dump") and not isinstance(
+        python_value, type
+    ):
         return python_value.model_dump()
+    if hasattr(python_value, "model_json_schema"):
+        return python_value.model_json_schema()
     if hasattr(python_value, "__dict__"):
         return _to_otel_value(python_value.__dict__)
     return repr(python_value)

instrumentation-genai/opentelemetry-instrumentation-google-genai/tests/utils/test_dict_util.py

@@ -207,6 +207,25 @@ def test_flatten_with_mixed_structures():
     }
 
 
+def test_flatten_with_pydantic_class_not_instance():
+    """Test that passing a Pydantic class (not instance) doesn't cause model_dump() error."""
+    input_dict = {
+        "foo": PydanticModel,  # Class, not instance
+        "bar": "value",
+    }
+
+    # Should not raise "BaseModel.model_dump() missing 1 required positional argument: 'self'"
+    output = dict_util.flatten_dict(input_dict)
+    # The class should be converted using JSON serialization fallback
+    assert "bar" in output
+    assert output["bar"] == "value"
+    assert "foo.description" in output
+    assert "foo.properties.int_value.title" in output
+    assert "foo.properties.int_value.default" in output
+    assert "foo.properties.str_value.title" in output
+    assert "foo.properties.str_value.default" in output
+
+
 def test_converts_tuple_with_json_fallback():
     input_dict = {
         "foo": ("abc", 123),

instrumentation-genai/opentelemetry-instrumentation-google-genai/tests/utils/test_tool_call_wrapper.py

@@ -17,6 +17,7 @@
 from unittest.mock import patch
 
 from google.genai import types as genai_types
+from pydantic import BaseModel
 
 from opentelemetry._logs import get_logger_provider
 from opentelemetry.instrumentation._semconv import (
@@ -35,6 +36,13 @@
 from ..common import otel_mocker
 
 
+class PydanticModel(BaseModel):
+    """Used to verify handling of pydantic models in the flattener."""
+
+    str_value: str = ""
+    int_value: int = 0
+
+
 class TestCase(unittest.TestCase):
     def setUp(self):
         self._otel = otel_mocker.OTelMocker()
@@ -329,3 +337,19 @@ def somefunction(arg=None):
                             span.attributes,
                         )
                 self.tearDown()
+
+    def test_handles_pydantic_class_not_instance(self):
+        """Test that passing a Pydantic class (not instance) doesn't cause model_dump() error."""
+
+        def somefunction(arg=None):
+            return arg
+
+        wrapped_somefunction = self.wrap(somefunction)
+        # Pass the class itself, not an instance
+        wrapped_somefunction(PydanticModel)
+
+        # Should not raise "BaseModel.model_dump() missing 1 required positional argument: 'self'"
+        span = self.otel.get_span_named("execute_tool somefunction")
+        self.assertIsNotNone(span)
+        # The class should be handled without error
+        self.assertIn("code.function.parameters.arg.type", span.attributes)