Phoenix (Arize)

Phoenix by Arize AI is an open-source observability and evaluation platform for AI applications that captures traces, runs evaluations, manages datasets, and supports experimentation. It is vendor and language agnostic with out-of-the-box instrumentation for frameworks like LangGraph, CrewAI, LlamaIndex, and DSPy and providers including OpenAI, Anthropic, and Bedrock through the OpenInference project. It runs locally, in notebooks, or in the cloud. Released under the Apache 2.0 license.