Arize Phoenix — Open-Source LLM Observability for DSPy

Guide the user through setting up Arize Phoenix for DSPy tracing, visualization, and evaluation.

What is Arize Phoenix

Phoenix is an open-source LLM observability platform that runs locally or in the cloud. It provides a trace viewer, evaluation tools, and dataset management — all with DSPy auto-instrumentation via the OpenInference plugin.

• Local mode: px.launch_app() starts a UI at http://localhost:6006 — no account needed
• Cloud mode: Hosted on the Arize platform
• Open source: github.com/Arize-ai/phoenix

What gets traced