Library / SDK
Observability & Evaluation
Arize Phoenix
1Open-source 2tracing 3and 4evaluation 5for 6LLMs.
the six Ws · specification
W1
Who
Open-source project from Arize AI.
W2
What
Traces, evaluates, and debugs LLM and agent apps.
W3
Where
Self-hosted or a hosted instance.
W4
When
When measuring and debugging LLM quality.
W5
Why
Built-in evals and visualization for agent runs.
W6
With
OpenTelemetry instrumentation in your app.