aws[patch]: support ChatBedrock(model=...) (#211)

per langchain-ai/langchain#20085

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

libs/aws/langchain_aws/chat_models/bedrock.py

@@ -418,6 +418,7 @@ def lc_attributes(self) -> Dict[str, Any]:
 
     model_config = ConfigDict(
         extra="forbid",
+        populate_by_name=True,
     )
 
     def _get_ls_params(

libs/aws/langchain_aws/llms/bedrock.py

@@ -514,7 +514,7 @@ class BedrockBase(BaseLanguageModel, ABC):
     not have the provider in them, e.g., custom and provisioned models that have an ARN
     associated with them."""
 
-    model_id: str
+    model_id: str = Field(alias="model")
     """Id of the model to call, e.g., amazon.titan-text-express-v1, this is
     equivalent to the modelId property in the list-foundation-models api. For custom and
     provisioned models, an ARN value is expected."""
@@ -1065,6 +1065,7 @@ def _get_ls_params(
 
     model_config = ConfigDict(
         extra="forbid",
+        populate_by_name=True,
     )
 
     def _stream(

libs/aws/tests/integration_tests/llms/test_bedrock.py

@@ -2,7 +2,7 @@
 
 
 def test_bedrock_llm() -> None:
-    llm = BedrockLLM(model_id="anthropic.claude-v2:1")
+    llm = BedrockLLM(model_id="anthropic.claude-v2:1")  # type: ignore[call-arg]
     response = llm.invoke("Hello")
     assert isinstance(response, str)
     assert len(response) > 0

libs/aws/tests/unit_tests/chat_models/test_bedrock.py

@@ -405,12 +405,16 @@ def test_anthropic_bind_tools_tool_choice() -> None:
 
 def test_standard_tracing_params() -> None:
     llm = ChatBedrock(model_id="foo", region_name="us-west-2")  # type: ignore[call-arg]
-    ls_params = llm._get_ls_params()
-    assert ls_params == {
+    expected = {
         "ls_provider": "amazon_bedrock",
         "ls_model_type": "chat",
         "ls_model_name": "foo",
     }
+    assert llm._get_ls_params() == expected
+
+    # Test initialization with `model` alias
+    llm = ChatBedrock(model="foo", region_name="us-west-2")
+    assert llm._get_ls_params() == expected
 
     llm = ChatBedrock(
         model_id="foo", model_kwargs={"temperature": 0.1}, region_name="us-west-2"