How to use the python LlamaIndexInstrumentor to trace LlamaIndex
LlamaIndex is a data framework for your LLM application. It's a powerful framework by which you can build an application that leverages RAG (retrieval-augmented generation) to super-charge an LLM with your own data. RAG is an extremely powerful LLM application model because it lets you harness the power of LLMs such as OpenAI's GPT but tuned to your data and use-case.
For LlamaIndex, tracing instrumentation is added via an OpenTelemetry instrumentor aptly named the LlamaIndexInstrumentor
. This callback is what is used to create spans and send them to the Phoenix collector.
Phoenix supports LlamaIndex's latest instrumentation paradigm. This paradigm requires LlamaIndex >= 0.10.43. For legacy support, see below.
pip install openinference-instrumentation-llama_index llama-index>=0.11.0
Initialize the LlamaIndexInstrumentor before your application code.
from openinference.instrumentation.llama_index import LlamaIndexInstrumentor
from phoenix.otel import register
tracer_provider = register()
LlamaIndexInstrumentor().instrument(tracer_provider=tracer_provider)
You can now use LlamaIndex as normal, and tracing will be automatically captured and sent to your Phoenix instance.
from llama_index.core import VectorStoreIndex, SimpleDirectoryReader
import os
os.environ["OPENAI_API_KEY"] = "YOUR OPENAI API KEY"
documents = SimpleDirectoryReader("data").load_data()
index = VectorStoreIndex.from_documents(documents)
query_engine = index.as_query_engine()
response = query_engine.query("Some question about the data should go here")
print(response)
View your traces in Phoenix:
How to use the python LlamaIndexInstrumentor to trace LlamaIndex Workflows
LlamaIndex Workflows are a subset of the LlamaIndex package specifically designed to support agent development.
Our LlamaIndexInstrumentor automatically captures traces for LlamaIndex Workflows agents. If you've already enabled that instrumentor, you do not need to complete the steps below.
pip install openinference-instrumentation-llama_index
Initialize the LlamaIndexInstrumentor before your application code. This instrumentor will trace both LlamaIndex Workflows calls, as well as calls to the general LlamaIndex package.
from openinference.instrumentation.llama_index import LlamaIndexInstrumentor
from phoenix.otel import register
tracer_provider = register()
LlamaIndexInstrumentor().instrument(tracer_provider=tracer_provider)
By instrumenting LlamaIndex, spans will be created whenever an agent is invoked and will be sent to the Phoenix server for collection.
Now that you have tracing setup, all invocations of chains will be streamed to your running Phoenix for observability and evaluation.
Sign up for Phoenix:
Sign up for an Arize Phoenix account at https://app.phoenix.arize.com/login
Click Create Space
, then follow the prompts to create and launch your space.
Install packages:
pip install arize-phoenix-otel
Set your Phoenix endpoint and API Key:
From your new Phoenix Space
Create your API key from the Settings page
Copy your Hostname
from the Settings page
In your code, set your endpoint and API key:
import os
os.environ["PHOENIX_API_KEY"] = "ADD YOUR PHOENIX API KEY"
os.environ["PHOENIX_COLLECTOR_ENDPOINT"] = "ADD YOUR PHOENIX HOSTNAME"
# If you created your Phoenix Cloud instance before June 24th, 2025,
# you also need to set the API key as a header:
# os.environ["PHOENIX_CLIENT_HEADERS"] = f"api_key={os.getenv('PHOENIX_API_KEY')}"
Launch your local Phoenix instance:
pip install arize-phoenix
phoenix serve
For details on customizing a local terminal deployment, see Terminal Setup.
Install packages:
pip install arize-phoenix-otel
Set your Phoenix endpoint:
import os
os.environ["PHOENIX_COLLECTOR_ENDPOINT"] = "http://localhost:6006"
See Terminal for more details.
Pull latest Phoenix image from Docker Hub:
docker pull arizephoenix/phoenix:latest
Run your containerized instance:
docker run -p 6006:6006 arizephoenix/phoenix:latest
This will expose the Phoenix on localhost:6006
Install packages:
pip install arize-phoenix-otel
Set your Phoenix endpoint:
import os
os.environ["PHOENIX_COLLECTOR_ENDPOINT"] = "http://localhost:6006"
For more info on using Phoenix with Docker, see Docker.
Install packages:
pip install arize-phoenix
Launch Phoenix:
import phoenix as px
px.launch_app()
Sign up for Phoenix:
Sign up for an Arize Phoenix account at https://app.phoenix.arize.com/login
Click Create Space
, then follow the prompts to create and launch your space.
Install packages:
pip install arize-phoenix-otel
Set your Phoenix endpoint and API Key:
From your new Phoenix Space
Create your API key from the Settings page
Copy your Hostname
from the Settings page
In your code, set your endpoint and API key:
import os
os.environ["PHOENIX_API_KEY"] = "ADD YOUR PHOENIX API KEY"
os.environ["PHOENIX_COLLECTOR_ENDPOINT"] = "ADD YOUR PHOENIX HOSTNAME"
# If you created your Phoenix Cloud instance before June 24th, 2025,
# you also need to set the API key as a header:
# os.environ["PHOENIX_CLIENT_HEADERS"] = f"api_key={os.getenv('PHOENIX_API_KEY')}"
Launch your local Phoenix instance:
pip install arize-phoenix
phoenix serve
For details on customizing a local terminal deployment, see Terminal Setup.
Install packages:
pip install arize-phoenix-otel
Set your Phoenix endpoint:
import os
os.environ["PHOENIX_COLLECTOR_ENDPOINT"] = "http://localhost:6006"
See Terminal for more details.
Pull latest Phoenix image from Docker Hub:
docker pull arizephoenix/phoenix:latest
Run your containerized instance:
docker run -p 6006:6006 arizephoenix/phoenix:latest
This will expose the Phoenix on localhost:6006
Install packages:
pip install arize-phoenix-otel
Set your Phoenix endpoint:
import os
os.environ["PHOENIX_COLLECTOR_ENDPOINT"] = "http://localhost:6006"
For more info on using Phoenix with Docker, see Docker.
Install packages:
pip install arize-phoenix
Launch Phoenix:
import phoenix as px
px.launch_app()