aws[patch]: retain snake case for input schemas (#114)

libs/aws/langchain_aws/chat_models/bedrock_converse.py

@@ -403,7 +403,9 @@ def _generate(
     ) -> ChatResult:
         """Top Level call"""
         bedrock_messages, system = _messages_to_bedrock(messages)
-        params = self._converse_params(stop=stop, **_snake_to_camel_keys(kwargs))
+        params = self._converse_params(
+            stop=stop, **_snake_to_camel_keys(kwargs, excluded_keys={"inputSchema"})
+        )
         response = self.client.converse(
             messages=bedrock_messages, system=system, **params
         )
@@ -418,7 +420,9 @@ def _stream(
         **kwargs: Any,
     ) -> Iterator[ChatGenerationChunk]:
         bedrock_messages, system = _messages_to_bedrock(messages)
-        params = self._converse_params(stop=stop, **_snake_to_camel_keys(kwargs))
+        params = self._converse_params(
+            stop=stop, **_snake_to_camel_keys(kwargs, excluded_keys={"inputSchema"})
+        )
         response = self.client.converse_stream(
             messages=bedrock_messages, system=system, **params
         )
@@ -814,13 +818,21 @@ def _camel_to_snake_keys(obj: _T) -> _T:
         return obj
 
 
-def _snake_to_camel_keys(obj: _T) -> _T:
+def _snake_to_camel_keys(obj: _T, excluded_keys: set = set()) -> _T:
     if isinstance(obj, list):
-        return cast(_T, [_snake_to_camel_keys(e) for e in obj])
-    elif isinstance(obj, dict):
         return cast(
-            _T, {_snake_to_camel(k): _snake_to_camel_keys(v) for k, v in obj.items()}
+            _T, [_snake_to_camel_keys(e, excluded_keys=excluded_keys) for e in obj]
         )
+    elif isinstance(obj, dict):
+        _dict = {}
+        for k, v in obj.items():
+            if k in excluded_keys:
+                _dict[k] = v
+            else:
+                _dict[_snake_to_camel(k)] = _snake_to_camel_keys(
+                    v, excluded_keys=excluded_keys
+                )
+        return cast(_T, _dict)
     else:
         return obj
 

libs/aws/tests/integration_tests/chat_models/test_bedrock_converse.py

@@ -1,10 +1,11 @@
 """Standard LangChain interface tests"""
 
-from typing import Type
+from typing import Literal, Type
 
 import pytest
 from langchain_core.language_models import BaseChatModel
 from langchain_core.messages import HumanMessage
+from langchain_core.pydantic_v1 import BaseModel, Field
 from langchain_standard_tests.integration_tests import ChatModelIntegrationTests
 
 from langchain_aws import ChatBedrockConverse
@@ -31,6 +32,18 @@ def standard_chat_model_params(self) -> dict:
     def supports_image_inputs(self) -> bool:
         return True
 
+    def test_structured_output_snake_case(self, model: BaseChatModel) -> None:
+        class ClassifyQuery(BaseModel):
+            """Classify a query."""
+
+            query_type: Literal["cat", "dog"] = Field(
+                description="Classify a query as related to cats or dogs."
+            )
+
+        chat = model.with_structured_output(ClassifyQuery)
+        for chunk in chat.stream("How big are cats?"):
+            assert isinstance(chunk, ClassifyQuery)
+
 
 @pytest.mark.skip(reason="Needs guardrails setup to run.")
 def test_guardrails() -> None: