> ## Documentation Index
> Fetch the complete documentation index at: https://mcp-server-langgraph.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# LangSmith Integration

> Track LLM performance, prompts, and chain execution with LangSmith for comprehensive AI observability

### LangSmith Integration

#### Setup LangSmith

```python theme={null}
import os
from langsmith import Client

## Configure LangSmith
os.environ["LANGCHAIN_TRACING_V2"] = "true"
os.environ["LANGCHAIN_API_KEY"] = settings.langsmith_api_key
os.environ["LANGCHAIN_PROJECT"] = "mcp-agent-production"

## Initialize client
langsmith_client = Client()

## LangSmith will automatically trace LangChain calls
from langchain_anthropic import ChatAnthropic

llm = ChatAnthropic(
    model="claude-sonnet-4-5-20250929",
    anthropic_api_key=settings.anthropic_api_key
)

## This call is automatically traced
response = await llm.ainvoke("Hello!")
```

#### Custom LangSmith Runs

```python theme={null}
from langsmith import traceable

@traceable(run_type="chain", name="chat_with_auth")
async def chat_with_auth(query: str, user_id: str):
    """Chat with authorization check"""

    # Check permission (traced)
    allowed = await check_permission(user_id, "tool:chat")

    if not allowed:
        raise PermissionError("User not authorized")

    # Call LLM (traced)
    response = await llm.ainvoke(query)

    return response

## Call function
result = await chat_with_auth("What is AI?", user_id="alice")
```

#### Feedback Collection

```python theme={null}
from langsmith import Client

client = Client()

## Collect user feedback
@app.post("/feedback")
async def submit_feedback(
    run_id: str,
    score: float,
    comment: str = None
):
    """Submit feedback for a LangSmith run"""

    client.create_feedback(
        run_id=run_id,
        key="user_rating",
        score=score,
        comment=comment
    )

    return {"status": "feedback_recorded"}
```

## Next Steps

<CardGroup cols={2}>
  <Card title="Grafana Dashboards" icon="gauge" href="./dashboards">
    Visualize LLM metrics
  </Card>

  <Card title="Prometheus Metrics" icon="chart-bar" href="./prometheus">
    Track LLM usage metrics
  </Card>

  <Card title="Alerting" icon="bell" href="./alerting">
    Set up LLM performance alerts
  </Card>

  <Card title="Back to Overview" icon="arrow-left" href="./overview">
    Return to monitoring overview
  </Card>
</CardGroup>