LangGraph

Phoenix has first-class support for LangGraph applications.

LangGraph is supported by our LangChain instrumentor. If you've already set up instrumentation with LangChain, you don't need to complete the set up below

Launch Phoenix

Sign up for Phoenix:

Sign up for an Arize Phoenix account at https://app.phoenix.arize.com/login

Install packages:

pip install arize-phoenix-otel

Connect your application to your cloud instance:

import os
from phoenix.otel import register

# Add Phoenix API Key for tracing
PHOENIX_API_KEY = "ADD YOUR API KEY"
os.environ["PHOENIX_CLIENT_HEADERS"] = f"api_key={PHOENIX_API_KEY}"

# configure the Phoenix tracer
tracer_provider = register(
  project_name="my-llm-app", # Default is 'default'
  endpoint="https://app.phoenix.arize.com/v1/traces",
)

Your Phoenix API key can be found on the Keys section of your dashboard.

Install

pip install openinference-instrumentation-langchain

Setup

Initialize the LangChainInstrumentor before your application code. Our LangChainInstrumentor works for both standard LangChain applications and for LangGraph agents.

from openinference.instrumentation.langchain import LangChainInstrumentor

LangChainInstrumentor().instrument(tracer_provider=tracer_provider)

Run LangGraph

By instrumenting LangGraph, spans will be created whenever an agent is invoked and will be sent to the Phoenix server for collection.

Observe

Now that you have tracing setup, all invocations of chains will be streamed to your running Phoenix for observability and evaluation.

Resources

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