feat: Add support for ToolConfig in the LangChain template

PiperOrigin-RevId: 633283927

Author: yeesian

vertexai/preview/reasoning_engines/templates/langchain.py

@@ -96,6 +96,7 @@ def _default_runnable_builder(
     prompt: Optional["RunnableSerializable"] = None,
     output_parser: Optional["RunnableSerializable"] = None,
     chat_history: Optional["GetSessionHistoryCallable"] = None,
+    model_tool_kwargs: Optional[Mapping[str, Any]] = None,
     agent_executor_kwargs: Optional[Mapping[str, Any]] = None,
     runnable_kwargs: Optional[Mapping[str, Any]] = None,
 ) -> "RunnableSerializable":
@@ -109,10 +110,11 @@ def _default_runnable_builder(
     has_history: bool = chat_history is not None
     prompt = prompt or _default_prompt(has_history)
     output_parser = output_parser or _default_output_parser()
+    model_tool_kwargs = model_tool_kwargs or {}
     agent_executor_kwargs = agent_executor_kwargs or {}
     runnable_kwargs = runnable_kwargs or _default_runnable_kwargs(has_history)
     if tools:
-        model = model.bind_tools(tools=tools)
+        model = model.bind_tools(tools=tools, **model_tool_kwargs)
     else:
         tools = []
     agent_executor = AgentExecutor(
@@ -202,6 +204,7 @@ def __init__(
         output_parser: Optional["RunnableSerializable"] = None,
         chat_history: Optional["GetSessionHistoryCallable"] = None,
         model_kwargs: Optional[Mapping[str, Any]] = None,
+        model_tool_kwargs: Optional[Mapping[str, Any]] = None,
         agent_executor_kwargs: Optional[Mapping[str, Any]] = None,
         runnable_kwargs: Optional[Mapping[str, Any]] = None,
         model_builder: Optional[Callable] = None,
@@ -233,8 +236,9 @@ def __init__(
         # runnable_builder
         from langchain import agents
         from langchain_core.runnables.history import RunnableWithMessageHistory
+        llm_with_tools = llm.bind_tools(tools=tools, **model_tool_kwargs)
         agent_executor = agents.AgentExecutor(
-            agent=prompt | llm.bind_tools(tools=tools) | output_parser,
+            agent=prompt | llm_with_tools | output_parser,
             tools=tools,
             **agent_executor_kwargs,
         )
@@ -282,6 +286,9 @@ def __init__(
                     "top_k": 40,
                 }
                 ```
+            model_tool_kwargs (Mapping[str, Any]):
+                Optional. Additional keyword arguments when binding tools to the
+                model using `model.bind_tools()`.
             agent_executor_kwargs (Mapping[str, Any]):
                 Optional. Additional keyword arguments for the constructor of
                 langchain.agents.AgentExecutor. An example would be
@@ -334,6 +341,7 @@ def __init__(
         self._output_parser = output_parser
         self._chat_history = chat_history
         self._model_kwargs = model_kwargs
+        self._model_tool_kwargs = model_tool_kwargs
         self._agent_executor_kwargs = agent_executor_kwargs
         self._runnable_kwargs = runnable_kwargs
         self._model = None
@@ -365,6 +373,7 @@ def set_up(self):
             tools=self._tools,
             output_parser=self._output_parser,
             chat_history=self._chat_history,
+            model_tool_kwargs=self._model_tool_kwargs,
             agent_executor_kwargs=self._agent_executor_kwargs,
             runnable_kwargs=self._runnable_kwargs,
         )