Arize Phoenix
Arize Phoenix now updates LLM model prices automatically
Arize Phoenix, the open source agent observability tool, now updates its built-in model prices automatically, so servers no longer need a Phoenix upgrade to receive new…
Web page tricked a support agent into leaking another customer's data on 28 of 100 runs
A support agent built by Arize AI pulled up a different customer's record on 28 of 100 runs after reading a web page that framed the lookup as a routine step. According…
Arize AX adds Together AI to cut the cost of LLM-as-a-Judge evaluations
Arize AX now supports Together AI as an AI provider for evaluations, so teams can test open models as judges and look for cheaper alternatives to frontier models.…
Arize AX adds Cost Agent to trace down wasted LLM and agent spend
Arize AI has launched Cost Agent, a managed agent in Arize AX that analyzes application traces to find recurring sources of unnecessary LLM, coding agent and AI spend.…
tracelint checks agent traces for provable failures without an LLM judge
A guest post on the Arize AI blog introduces tracelint, a small open-source linter that checks OpenInference agent traces for failures the trace itself can prove, and…
Arize Benchmarks AI Agents With Harbor and Phoenix Plugin
Arize AI has described how it benchmarks its PXI coding agent, along with MCP servers, skills and CLIs, using the open-source Harbor framework and a plugin that records…
Arize benchmark: high prompt cache reuse does not guarantee lower agent cost
A prompt caching benchmark from Arize AI finds that a high cache-read rate does not always translate into lower cost. Claude Opus 5.5 read 89.8% of its prompt tokens…
Arize test: Jev's probabilities flag its own errors and hard cases for LLM judges
Arize AI says Jev, a model that returns a probability for each label instead of generating text, can show where an evaluation is likely wrong or hard from a single call.…
Arize puts code mode inside Phoenix's web UI, so its PXI agent can click through the app by script
Arize AI has built a code mode into the Phoenix web interface, letting its built-in agent PXI write short scripts that run in the user's browser tab and perform the same…