Phoenix by Arize
An open-source tool for tracing, evaluating, and debugging LLM applications and AI agents.
Description
Phoenix is Arize’s locally runnable observability and evaluation platform for AI applications. It collects traces of requests, tools, and model responses.
Developers can inspect executions, create datasets and experiments, and evaluate response quality. Phoenix is open source; Arize offers separate cloud products.
Sources: https://arize.com/phoenix/, https://arize.com/pricing/ (official sources; reviewed 2026-11-01).
