support MCP async calls

Author: ks6088ts

docs/references.md

@@ -7,6 +7,8 @@
 - [🤖 LangGraph Multi-Agent Supervisor](https://github.com/langchain-ai/langgraph-supervisor-py)
 - [Software Design 誌「実践 LLM アプリケーション開発」第 24 回サンプルコード](https://github.com/mahm/softwaredesign-llm-application/tree/main/24)
 - [Streamlit](https://python.langchain.com/docs/integrations/callbacks/streamlit/)
+- [LangChain MCP Adapters](https://github.com/langchain-ai/langchain-mcp-adapters)
+  - [Research Agent with MCP Integration.](https://github.com/langchain-ai/deep_research_from_scratch/blob/main/src/deep_research_from_scratch/research_agent_mcp.py)
 
 ### Sample Codes
 

template_langgraph/agents/chat_with_tools_agent/agent.py

@@ -1,3 +1,4 @@
+import asyncio
 import json
 
 from langchain_core.messages import ToolMessage
@@ -6,7 +7,7 @@
 from template_langgraph.agents.chat_with_tools_agent.models import AgentState
 from template_langgraph.llms.azure_openais import AzureOpenAiWrapper
 from template_langgraph.loggers import get_logger
-from template_langgraph.tools.common import get_default_tools
+from template_langgraph.tools.common import get_default_tools, is_async_call_required
 
 logger = get_logger(__name__)
 
@@ -25,10 +26,13 @@ def __call__(self, inputs: dict):
         outputs = []
         for tool_call in message.tool_calls:
             try:
-                tool_result = self.tools_by_name[tool_call["name"]].invoke(tool_call["args"])
+                if is_async_call_required(tool_call["name"]):
+                    observation = asyncio.run(self.tools_by_name[tool_call["name"]].ainvoke(tool_call["args"]))
+                else:
+                    observation = self.tools_by_name[tool_call["name"]].invoke(tool_call["args"])
                 outputs.append(
                     ToolMessage(
-                        content=json.dumps(tool_result.__str__(), ensure_ascii=False),
+                        content=json.dumps(observation.__str__(), ensure_ascii=False),
                         name=tool_call["name"],
                         tool_call_id=tool_call["id"],
                     )

template_langgraph/tools/common.py

@@ -25,3 +25,14 @@ def get_default_tools():
         )
         + McpClientWrapper().get_tools()
     )
+
+
+def is_async_call_required(tool_name: str) -> bool:
+    # FIXME: adhoc impl
+    if tool_name.startswith("browser_"):
+        return True
+    return tool_name in [
+        "echo",
+        "add",
+        # add async tool names here
+    ]