# LangChain Python

## Install

```bash
pip install langchain-mcp-adapters
```

---

## Connect

```python
import asyncio
from langchain_mcp_adapters.client import MultiServerMCPClient

MEWCP_API_KEY = "API_KEY"

async def main():
    async with MultiServerMCPClient(
        {
            "mewcp": {
                "transport": "streamable_http",
                "url": "https://gateway.mewcp.com/personal/mcp",
                "headers": {"Authorization": f"Bearer {MEWCP_API_KEY}"},
            }
        }
    ) as client:
        tools = await client.get_tools()
        print("Available tools:", [t.name for t in tools])
        # -> ["search", "get_schema", "list_accounts", "call_tool"]

asyncio.run(main())
```

> Note: `transport` value is `"streamable_http"` (underscore).

You get four tools rather than the tools of each app. Your agent uses them to reach every app you have connected. See [How MewCP works](/mewcp/getting-started#how-mewcp-works).

---

## Call a tool directly

```python
call_tool = next(t for t in tools if t.name == "call_tool")

result = await call_tool.ainvoke(
    {
        "server_maskedId": "google-calendar",
        "tool_name": "list_events",
        "args": {
            "calendar_id": "primary",
            "time_min": "2026-01-15T00:00:00Z",
            "time_max": "2026-01-16T00:00:00Z",
        },
    }
)
print(result)
```

If you have connected more than one account for the same app, add `"alias": "work"` to select one.

---

## Use with a LangChain agent

Hand all four tools to the agent and let it work out the rest:

```python
import asyncio
from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain_openai import ChatOpenAI
from langgraph.prebuilt import create_react_agent

async def main():
    async with MultiServerMCPClient(
        {
            "mewcp": {
                "transport": "streamable_http",
                "url": "https://gateway.mewcp.com/personal/mcp",
                "headers": {"Authorization": f"Bearer {MEWCP_API_KEY}"},
            }
        }
    ) as client:
        tools = await client.get_tools()

        model = ChatOpenAI(model="gpt-4o")
        agent = create_react_agent(model, tools)

        result = await agent.ainvoke(
            {"messages": [{"role": "user", "content": "What is on my calendar tomorrow?"}]}
        )
        print(result["messages"][-1].content)

asyncio.run(main())
```

The agent will call `search` to find the calendar tool, `get_schema` for its parameters, then `call_tool` to run it.

---

## Where to find your values

| Value          | Where to get it       |
| -------------- | --------------------- |
| `API_KEY`      | Dashboard -> API Keys |
| Connected apps | Dashboard -> Servers  |