{"slug":"arize-phoenix","url":"https://www.altairalabs.ai/vs/arize-phoenix/","markdown":"https://www.altairalabs.ai/vs/arize-phoenix.md","name":"Arize Phoenix","vendor":"Arize AI","category":"Tracing and evaluation","checked":"2026-10-22","summary":"Omnia runs the agent, so it can redact, refuse a tool call, hold a release and roll back on live scores. Arize traces and scores agents on OpenTelemetry, and acting on the scores is left to you.","headline":"Arize shows you how the agent is doing. Omnia acts on it.","scene":{"setup":"A guardrail evaluator flags an agent leaking an account number.","omnia":"The account number was a named field in the tool response, so it was replaced before the model saw it. A request for someone else’s account was refused by policy before the tool ran. Both are in the audit.","omniaCaps":["tool-response-redaction","per-call-policy","audit-log"],"them":"Arize’s guidance for real-time guardrails: AX doesn’t block requests, your app does. Evaluators run after the fact, asynchronously.","source":"https://arize.com/docs/ax/cookbooks/observe/designing-realtime-guardrails","omniaEvidence":"https://omnia.altairalabs.ai/how-to/security/configure-tool-policies/"},"differences":[{"title":"Enforcement where the agent runs","body":"Policy compares each tool call’s arguments with the caller’s identity and fails closed. Named fields are redacted before they reach the model, the session recording or long-term memory.","caps":["per-call-policy","tool-response-redaction","pii-sessions"],"them":"Guardrails are recorded as spans; your application does the blocking.","source":"https://arize.com/docs/ax/cookbooks/observe/designing-realtime-guardrails","omniaEnterprise":true,"omniaEvidence":"https://omnia.altairalabs.ai/how-to/security/configure-tool-policies/"},{"title":"Tests that behave like users","body":"Simulated callers hold whole conversations with the agent through its real tools. Some try to break it, some call by duplex voice, and the release waits on the results.","caps":["selfplay","adversarial","voice-testing","deploy-gate"],"them":"Datasets, experiments and LLM, code and human evaluators. Simulated users aren’t documented.","source":"https://arize.com/docs/phoenix","omniaEnterprise":false,"omniaEvidence":"https://promptarena.altairalabs.ai/arena/explanation/scenario-design/"},{"title":"Live scores that move traffic","body":"A new version starts on part of the traffic. Its live metrics decide whether it gets more or is rolled back.","caps":["progressive-rollout","metric-gated-promotion"],"them":"Online evals score sampled sessions; acting on them is up to you.","source":"https://arize.com/docs/ax/evaluate/trace-and-session-evals","omniaEnterprise":true,"omniaEvidence":"https://omnia.altairalabs.ai/tutorials/progressive-rollouts/"}],"rows":[{"topic":"Licence","omnia":"PromptArena and PromptKit are Apache 2.0.","caps":["selfplay"],"them":"Phoenix is Elastic License 2.0.","coverage":"yes","source":"https://github.com/Arize-ai/phoenix","omniaEnterprise":false,"omniaEvidence":"https://promptarena.altairalabs.ai/arena/explanation/scenario-design/"},{"topic":"OpenTelemetry","omnia":"Emits and ingests.","caps":["tracing","observe-remote"],"them":"Built on OpenTelemetry.","coverage":"yes","source":"https://arize.com/docs/phoenix","omniaEnterprise":false,"omniaEvidence":"https://omnia.altairalabs.ai/reference/platform/telemetry/"},{"topic":"CI gate","omnia":"Built into the release.","caps":["deploy-gate"],"them":"pytest and Vitest plugins.","coverage":"yes","source":"https://arize.com/docs/phoenix/evaluation/integrations/pytest","omniaEnterprise":false,"omniaEvidence":"https://promptarena.altairalabs.ai/arena/how-to/interfaces/run-in-ci/"},{"topic":"Simulated users","omnia":"Against real tools.","caps":["selfplay"],"them":"Not documented.","coverage":"undocumented","source":"https://arize.com/docs/phoenix","omniaEnterprise":false,"omniaEvidence":"https://promptarena.altairalabs.ai/arena/explanation/scenario-design/"},{"topic":"Runtime enforcement","omnia":"Policy and redaction before the call.","caps":["per-call-policy"],"them":"Your app.","coverage":"undocumented","source":"https://arize.com/docs/ax/cookbooks/observe/designing-realtime-guardrails","omniaEnterprise":true,"omniaEvidence":"https://omnia.altairalabs.ai/how-to/security/configure-tool-policies/"},{"topic":"Runs and rolls out agents","omnia":"Yes.","caps":["progressive-rollout"],"them":"Observes only.","coverage":"undocumented","source":"https://arize.com/docs/phoenix","omniaEnterprise":false,"omniaEvidence":"https://omnia.altairalabs.ai/tutorials/progressive-rollouts/"}],"faq":[{"q":"Can I keep Phoenix and use Omnia?","a":"Yes. Omnia emits standard OpenTelemetry, which Phoenix ingests."}]}