support Langfuse

Author: ks6088ts

.env.template

@@ -5,10 +5,19 @@
 ## Project Settings
 PROJECT_NAME=template-langgraph
 
+# ---------
+# Observability
+# ---------
+
 ## LangSmith Settings
 LANGSMITH_TRACING="false" # Options: "true", "false"
 LANGSMITH_API_KEY="lsv2_xxx"
 
+## Langfuse Settings
+LANGFUSE_PUBLIC_KEY="pk-lf-..."
+LANGFUSE_SECRET_KEY="sk-lf-..."
+LANGFUSE_HOST="https://cloud.langfuse.com"
+
 # ---------
 # LLMs
 # ---------

docs/references.md

@@ -106,3 +106,7 @@
 ### [LiteLLM](https://docs.litellm.ai/)
 
 - [Azure OpenAI](https://docs.litellm.ai/docs/providers/azure/)
+
+### [Langfuse](https://langfuse.com/)
+
+- [Cookbook: LangGraph Integration](https://langfuse.com/guides/cookbook/integration_langgraph)

pyproject.toml

@@ -25,6 +25,7 @@ dependencies = [
     "langchain-ollama>=0.3.6",
     "langchain-openai>=0.3.28",
     "langchain-text-splitters>=0.3.9",
+    "langfuse>=3.6.2",
     "langgraph>=0.6.2",
     "langgraph-supervisor>=0.0.29",
     "mlflow>=3.4.0",

scripts/agent_operator.py

@@ -4,6 +4,7 @@
 import typer
 from dotenv import load_dotenv
 from langchain_core.runnables.config import RunnableConfig
+from langfuse.langchain import CallbackHandler
 
 from template_langgraph.agents.chat_with_tools_agent.agent import graph as chat_with_tools_agent_graph
 from template_langgraph.agents.image_classifier_agent.agent import graph as image_classifier_agent_graph
@@ -126,6 +127,9 @@ def run(
         },
         config=RunnableConfig(
             recursion_limit=recursion_limit,
+            callbacks=[
+                CallbackHandler(),
+            ],
         ),
     ):
         logger.info("-" * 20)
@@ -181,6 +185,9 @@ def news_summarizer_agent(
         ),
         config=RunnableConfig(
             recursion_limit=recursion_limit,
+            callbacks=[
+                CallbackHandler(),
+            ],
         ),
     ):
         logger.info("-" * 20)
@@ -242,6 +249,9 @@ def image_classifier_agent(
         ),
         config=RunnableConfig(
             recursion_limit=recursion_limit,
+            callbacks=[
+                CallbackHandler(),
+            ],
         ),
     ):
         logger.info("-" * 20)

template_langgraph/services/streamlits/pages/chat_with_tools_agent.py

@@ -8,6 +8,7 @@
 from langchain_community.callbacks.streamlit import (
     StreamlitCallbackHandler,
 )
+from langfuse.langchain import CallbackHandler
 
 from template_langgraph.agents.chat_with_tools_agent.agent import (
     AgentState,
@@ -296,7 +297,12 @@ def build_graph_messages() -> list:
 def invoke_agent(graph_messages: list) -> AgentState:
     return st.session_state["graph"].invoke(
         {"messages": graph_messages},
-        {"callbacks": [StreamlitCallbackHandler(st.container())]},
+        {
+            "callbacks": [
+                StreamlitCallbackHandler(st.container()),
+                CallbackHandler(),
+            ]
+        },
     )