Arize AI (branded as Arize AX) is an end-to-end observability and evaluation platform for LLM applications and multi-agent systems. It captures trace spans at every step of an agent run, supports online evaluations (LLM-as-judge), tracks token costs, and provides dashboards for monitoring production behavior. An open-source self-hosted version is available with no caps on spans or retention. Enterprise deployments include SOC2/HIPAA compliance, data fabric, custom retention, and self-hosting with data residency. Arize also offers Phoenix, its open-source observability library. Key features: - Distributed tracing for LLM calls, agent steps, and multi-agent graphs - Online evaluations with LLM-as-judge and custom metrics - Token cost tracking and budget monitoring - Alyx AI assistant for automated root-cause analysis - Open-source Phoenix library for self-hosted observability - SOC2/HIPAA compliance and data residency on enterprise tier
AX Free: free, 25k spans/month, 15-day retention. AX Pro: $50/month, 50k spans/month, 30-day retention. AX Enterprise: custom (typically $50,000+/year).