How to add MCP tools to Langgraph Graph Definition

[magallardo]

I am defining a Graph and I am trying to add a node with tools coming from an MCP Server. Is there any example of how to do this?
I have tried several things but the issue is that the MultiServerMCPClient getTools is async.

I have tried the following as indicated in the docs but it does not work because the getTools is async and it is expected to be called within an async function.

Any recommendation on how to modify the graph below to include MCP tools?

==========================

from pydantic import BaseModel
from langgraph.graph import StateGraph
from langgraph.prebuilt import ToolNode

def something():
pass

client = MultiServerMCPClient(
{
"math": {
"command": "python",
# Replace with absolute path to your math_server.py file
"args": ["/path/to/math_server.py"],
"transport": "stdio",
},
"weather": {
# Ensure your start your weather server on port 8000
"url": "http://localhost:8000/mcp",
"transport": "streamable_http",
}
}
)
tools = await client.get_tools()

workflow = StateGraph(BaseModel)

workflow.add_node("node_1", something)
workflow.add_node("node_2", something)
workflow.add_node("tools", ToolNode(tools))

...
...

graph = workflow.compile()
graph.name = "My Agent"

==============

Thanks in advance,
Marcelo

[Xanaxiel]

I too need help on this - where I'm having trouble is injecting tools into the agent (since the client.get_tools() call needs to be in an async context but the node definitions are not, therefore causing the SyntaxError: 'await' outside async function error.

I am not sure if including it inside an asyncio.run() call with help resolve this but I will try later today.

[droxer]

from pydantic import BaseModel
from langgraph.graph import StateGraph
from langgraph.prebuilt import ToolNode

def something():
    pass

client = MultiServerMCPClient(
{
    "math": {
        "command": "python",
        "args": ["/path/to/math_server.py"],
        "transport": "stdio",
    },
     "weather": {
        "url": "http://localhost:8000/mcp",
        "transport": "streamable_http",
    }
}
)

async def get_tools():
    tools = await client.get_tools()
    return ToolNode(tools, name="tools")


workflow = StateGraph(BaseModel)

workflow.add_node("node_1", something)
workflow.add_node("node_2", something)
workflow.add_node("tools", get_tools)

...
...

graph = workflow.compile()
graph.name = "My Agent"