Phoenix

Open-source platform for AI agent development and evaluation.

Pricing: open_source — Free to use · Visit website

Phoenix by Arize is an open-source platform designed for AI engineers and Fortune 500 companies to develop, trace, evaluate, and iterate on AI agents. It provides tools for tracing, evaluating agent quality, testing changes with evidence, and integrating coding agents.

Pros

Open-source
Comprehensive toolset for AI development
Self-hosted

Cons

Steep learning curve
Limited community support
Requires technical expertise

FAQ

Is Phoenix free?

Yes, it's open source.

Can I self-host Phoenix?

Yes, it supports self-hosting.

What is PXI?

PXI is the AI engineering agent inside Phoenix.

Last updated: 2026-06-21