Add Graph Definition tracking to our LangGraph integration

apps/opik-documentation/documentation/docs/tracing/integrations/langgraph.md

@@ -34,18 +34,19 @@ You can use the [`OpikTracer`](https://www.comet.com/docs/opik/python-sdk-refere
 ```python
 from opik.integrations.langchain import OpikTracer
 
-opik_tracer = OpikTracer()
-
 # create your LangGraph graph
 graph = ...
+app = graph.compile(...)
+
+opik_tracer = OpikTracer(graph=app.get_graph(xray=True))
 
-# Pass the OpikTracer callback to the graph.stream function
-for s in graph.stream({"messages": [HumanMessage(content = QUESTION)]},
+# Pass the OpikTracer callback to the Graph.stream function
+for s in app.stream({"messages": [HumanMessage(content = QUESTION)]},
                       config={"callbacks": [opik_tracer]}):
     print(s)
 
-# Pass the OpikTracer callback to the graph.invoke function
-result = graph.invoke({"messages": [HumanMessage(content = QUESTION)]},
+# Pass the OpikTracer callback to the Graph.invoke function
+result = app.invoke({"messages": [HumanMessage(content = QUESTION)]},
                       config={"callbacks": [opik_tracer]})
 ```
 

sdks/python/src/opik/integrations/langchain/opik_tracer.py

@@ -14,6 +14,7 @@
     from uuid import UUID
 
     from langchain_core.tracers.schemas import Run
+    from langchain_core.runnables.graph import Graph
 
 LOGGER = logging.getLogger(__name__)
 
@@ -35,18 +36,27 @@ class OpikTracer(BaseTracer):
     Args:
         tags: List of tags to be applied to each trace logged by the tracer.
         metadata: Additional metadata for each trace logged by the tracer.
+        graph: A LangGraph Graph object to track the Graph Definition in Opik.
         project_name: The name of the project to log data.
     """
 
     def __init__(
         self,
         tags: Optional[List[str]] = None,
         metadata: Optional[Dict[str, Any]] = None,
+        graph: Optional["Graph"] = None,
         project_name: Optional[str] = None,
         **kwargs: Any,
     ) -> None:
         super().__init__(**kwargs)
         self._trace_default_metadata = metadata if metadata is not None else {}
+
+        if graph:
+            self._trace_default_metadata["_opik_graph_definition"] = {
+                "format": "mermaid",
+                "data": graph.draw_mermaid(),
+            }
+
         self._trace_default_tags = tags
 
         self._span_data_map: Dict["UUID", span.SpanData] = {}