Example: Using OpenTelemetry SDK with Langfuse OTel API
This notebook demonstrates how to use any OpenTelemetry SDK to send traces to Langfuse. OpenTelemetry is a CNCF project that provides a standard way to collect distributed traces and metrics from applications.
Langfuse operates as an OpenTelemetry Backend and maps the received traces to the Langfuse data model according to the OpenTelemetry Gen AI Conventions. See the property mapping documentation for details on how attributes are parsed.
In this example, we’ll use the Python OpenTelemetry SDK to send traces with GenAI attributes to Langfuse.
Setup
%pip install opentelemetry-sdk opentelemetry-exporter-otlp opentelemetry-apiimport json
import base64
from opentelemetry import trace
from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import BatchSpanProcessor
LANGFUSE_OTEL_API = "https://cloud.langfuse.com/api/public/otel" # EU Data Region
# LANGFUSE_OTEL_API = "https://us.cloud.langfuse.com/api/public/otel" # US Data Region
LANGFUSE_PUBLIC_KEY="pk-lf-xxx"
LANGFUSE_SECRET_KEY="sk-lf-xxx"
LANGFUSE_AUTH = base64.b64encode(f"{LANGFUSE_PUBLIC_KEY}:{LANGFUSE_SECRET_KEY}".encode()).decode()
provider = TracerProvider()
processor = BatchSpanProcessor(
OTLPSpanExporter(
endpoint=f"{LANGFUSE_OTEL_API}/v1/traces",
headers={"Authorization": f"Basic {LANGFUSE_AUTH}"},
)
)
provider.add_span_processor(processor)
trace.set_tracer_provider(provider)
tracer = trace.get_tracer(__name__)Flattened attributes
Export a span with flattened attribute names following the GenAI semantic conventions
with tracer.start_as_current_span("GenAI Attributes") as span:
span.set_attribute("gen_ai.prompt.0.role", "system")
span.set_attribute("gen_ai.prompt.0.content", "You are a coding assistant that helps write Python code.")
span.set_attribute("gen_ai.prompt.1.role", "user")
span.set_attribute("gen_ai.prompt.1.content", "Write a function that calculates the factorial of a number.")
span.set_attribute("gen_ai.completion.0.role", "assistant")
span.set_attribute("gen_ai.completion.0.content", """def factorial(n):
if n == 0:
return 1
return n * factorial(n-1)""")
span.set_attribute("gen_ai.request.model", "gpt-4")
span.set_attribute("gen_ai.request.temperature", 0.7)
span.set_attribute("gen_ai.usage.prompt_tokens", 25)
span.set_attribute("gen_ai.usage.completion_tokens", 45)JSON-serialized attributes
Export a span using JSON-serialized attributes
with tracer.start_as_current_span("GenAI JSON-Serialized Attributes") as span:
span.set_attribute(
"gen_ai.prompt_json",
json.dumps(
[
{"role": "system", "content": "You are an expert art historian and critic."},
{"role": "user", "content": "Describe Vincent van Gogh's 'The Starry Night' painting in detail."},
]
),
)
span.set_attribute(
"gen_ai.completion_json",
json.dumps(
[
{"role": "assistant", "content": "The Starry Night (1889) is one of Van Gogh's most famous works, painted during his stay at the Saint-Paul-de-Mausole asylum. The painting depicts a night scene with a swirling sky filled with stars and a crescent moon over a village. The sky is dominated by luminous yellow stars and a spiral pattern of blue clouds. In the foreground, a dark cypress tree reaches toward the sky like a flame. The village below is quiet and peaceful, with a prominent church spire piercing the night. The brushwork is bold and expressive, with thick impasto strokes creating a sense of movement and energy throughout the composition."},
]
),
)