Top 5 AI Agent Eval Tools After Promptfoo's Exit

After OpenAI acquired Promptfoo for $86 million, teams using non-OpenAI models face uncertainty about vendor neutrality in their LLM eval tooling. The article recommends five independent alternatives: DeepEval for pytest-native open-source evaluation, Braintrust for full-lifecycle eval with CI/CD quality gates, Arize Phoenix for self-hosted tracing, LangSmith for LangChain-committed teams, and Comet Opik for budget-conscious high-volume tracing.