# All traces with the same thread_id will be grouped together
opik_tracer = OpikTracer(thread_id="user-session-123")
```

## Distributed Tracing

For multi-service/thread/process applications, you can use distributed tracing headers to connect traces across services:

```python
from opik import opik_context
from opik.integrations.langchain import OpikTracer
from opik.types import DistributedTraceHeadersDict