add langfuse observability

app.py

@@ -7,6 +7,24 @@ from tools.final_answer import FinalAnswerTool
 
 from Gradio_UI import GradioUI
 
+from opentelemetry.sdk.trace import TracerProvider
+from openinference.instrumentation.smolagents import SmolagentsInstrumentor
+from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
+from opentelemetry.sdk.trace.export import SimpleSpanProcessor
+
+os.environ["PYTHONIOENCODING"] ="utf-8"
+LANGFUSE_PUBLIC_KEY = os.getenv("LANGFUSE_PUBLIC_KEY", "")
+LANGFUSE_SECRET_KEY = os.getenv("LANGFUSE_SECRET_KEY", "")
+LANGFUSE_AUTH=base64.b64encode(f"{LANGFUSE_PUBLIC_KEY}:{LANGFUSE_SECRET_KEY}".encode()).decode()
+os.environ["OTEL_EXPORTER_OTLP_ENDPOINT"] = "https://cloud.langfuse.com/api/public/otel"
+os.environ["OTEL_EXPORTER_OTLP_HEADERS"] = f"Authorization=Basic {LANGFUSE_AUTH}"
+
+# add langfuse observability to this factchecking agent
+trace_provider = TracerProvider()
+trace_provider.add_span_processor(SimpleSpanProcessor(OTLPSpanExporter()))
+SmolagentsInstrumentor().instrument(tracer_provider=trace_provider)
+
+
 # Below is an example of a tool that does nothing. Amaze us with your creativity !
 @tool
 def my_cutom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return type