# Graphsignal

This page covers how to use [Graphsignal](https://app.graphsignal.com) to trace and monitor LangChain. Graphsignal enables full visibility into your application. It provides latency breakdowns by chains and tools, exceptions with full context, data monitoring, compute/GPU utilization, OpenAI cost analytics, and more.

## Installation and Setup

- Install the Python library with `pip install graphsignal`
- Create free Graphsignal account [here](https://graphsignal.com)
- Get an API key and set it as an environment variable (`GRAPHSIGNAL_API_KEY`)

## Tracing and Monitoring

Graphsignal automatically instruments and starts tracing and monitoring chains. Traces and metrics are then available in your [Graphsignal dashboards](https://app.graphsignal.com).

Initialize the tracer by providing a deployment name:

```python
import graphsignal

graphsignal.configure(deployment='my-langchain-app-prod')
```

To additionally trace any function or code, you can use a decorator or a context manager:

```python
@graphsignal.trace_function
def handle_request():    
    chain.run("some initial text")
```

```python
with graphsignal.start_trace('my-chain'):
    chain.run("some initial text")
```

Optionally, enable profiling to record function-level statistics for each trace.

```python
with graphsignal.start_trace(
        'my-chain', options=graphsignal.TraceOptions(enable_profiling=True)):
    chain.run("some initial text")
```

See the [Quick Start](https://graphsignal.com/docs/guides/quick-start/) guide for complete setup instructions.