做推荐系统或对话智能体评估的团队，终于有了一个可复现、低成本的客观基准，直接拿来测自己的模型会看到真实差距。
推荐系统正转向多轮对话式智能体，但现有评估依赖“LLM作为裁判”，存在主观性、高成本和不一致问题。τ-Rec 基准用可验证奖励和揭示标签引导机制替代主观评估，通过结构化目录谓词和 pass^k 可靠性指标测试智能体的推理一致性。对 GPT-5.4、Claude Sonnet 4.6 等 9 种配置的评估显示，最佳模型 pass^1 仅约 57%，pass^4 约 38%，暴露了当前对话智能体部署中的可靠性悬崖。所有代码和数据已开源。
$τ$-Rec: A Verifiable Benchmark for Agentic Recommender Systems
As recommender systems transition toward agentic, multi-turn conversational interfaces, evaluation paradigms have struggled to keep pace. Current benchmarks often rely on "LLM-as-a-judge" evaluations, which introduce subjectivity, high costs and inconsistency. We present $τ$-Rec, a benchmark for agentic recommender systems that replaces subjective evaluation with verifiable rewards and a reveal-tagged elicitation (RTE) mechanism that controls how task constraints surface during dialogue. By testing agents against structured catalog predicates and employing a pass^k reliability metric, $τ$-Rec provides a systematic test for consistent reasoning. Our evaluation of nine configurations across five model families -- GPT-5.4, Claude Sonnet 4.6, Gemini 2.5 Flash, DeepSeek V4 Flash, Qwen3-32B and GPT-5 mini -- reveals a steep reliability cliff, where even the best model achieves only ~57% at pass^1 and ~38% at pass^4, highlighting a critical gap in current conversational agent deployment. All code and data are publicly available at https://github.com/nbharaths/tau-rec.