APeB: Benchmarking Personalization Ability of Large Language Model Agents

A benchmark for agentic personalization under vague goals and noisy histories

Garry Yang1,*; Zizhe Chen1,*; Xinru Chen2; Yongqiang Chen1; Jianxiang Wang2; Deyu Zou1; Linyi Ding2; Jialiang Wu2; Yunzhong He2; Yu Gong2; James Cheng1,†; Huaixiao Tou2,†
1The Chinese University of Hong Kong     2ByteDance
Accepted by EMNLP 2026 Findings

Introduction

APeB benchmark overview

LLM-powered agents struggle with personalization, which requires resolving vanilla intents, inferring user-specific preferences, and finding useroptimal solutions from competing alternatives. Existing benchmarks largely fail to assess these challenges under vague goals and noisy interaction histories. We propose personalized product search (PPS) as a testbed for agentic personalization under raw queries and diverse histories. We construct Agent Personalized Benchmark (APeB) from holistic action logs, featuring rich histories, vanilla intents, and hard candidate sets. We benchmark eight state-of-the-art LLMs with agentic workflows. LLMs excel on user-refined explicit queries, but struggle on initial vague queries that require latent intent and preference discovery. Fine-grained analysis attribute this gap to ineffective use of historical interactions for intent and preference inference. We further find that a simple history-conditioned refinement of vague queries yields consistent gains, emphasizing the role of effective history utilization in personalization.

Leaderboard

Select architecture in the first row, then switch Intent Query or Refined Query in the second row to compare HR@1 and HR@5.

# Model Model
Param
Hist.
Len.
Date HR@1 HR@5
Personal
Care
Clothing Food &
Beverages
Other Avg. Personal
Care
Clothing Food &
Beverages
Other Avg.
1 UniSAR 0.1B 240 2024-04-15 -- -- -- -- 25.9 -- -- -- -- 59.2
2 GPT-5.5 -- 60 2026-04-23 -- -- -- -- 25.4 -- -- -- -- 78.1
3 GPT-5.5-Think -- 60 2026-04-23 -- -- -- -- 25.0 -- -- -- -- 78.2
4 GPT-4o -- 60 2024-11-20 -- -- -- -- 24.9 -- -- -- -- 75.7
5 DeepSeek-R1 671B 60 2025-05-28 -- -- -- -- 24.2 -- -- -- -- 74.7
6 Gemini-3-Pro - 60 2025-11-18 -- -- -- -- 24.1 -- -- -- -- 76.7
7 GPT-4.1 -- 60 2025-04-14 -- -- -- -- 23.9 -- -- -- -- 73.3
8 Qwen3.5 397B 60 2026-02-16 -- -- -- -- 22.9 -- -- -- -- 72.4
# Model Model
Param
Hist.
Len.
Date HR@1 HR@5
Personal
Care
Clothing Food &
Beverages
Other Avg. Personal
Care
Clothing Food &
Beverages
Other Avg.
1 GPT-5.5-Think - 60 2026-04-23 -- -- -- -- 37.3 -- -- -- -- 84.4
2 GPT-5.5 - 60 2026-04-23 -- -- -- -- 37.2 -- -- -- -- 84.2
3 GPT-4o - 60 2024-11-20 -- -- -- -- 37.0 -- -- -- -- 82.8
4 DeepSeek-R1 671B 60 2025-05-28 -- -- -- -- 36.2 -- -- -- -- 80.7
5 Qwen3.5 397B 60 2026-02-16 -- -- -- -- 36.1 -- -- -- -- 81.9
6 Gemini-3-Pro - 60 2025-11-18 -- -- -- -- 35.1 -- -- -- -- 83.2
7 GPT-4.1 - 60 2025-04-14 -- -- -- -- 34.5 -- -- -- -- 78.8
8 UniSAR 0.1B 60 2024-04-15 -- -- -- -- 29.2 -- -- -- -- 64.5
# Architecture Backbone Hist.
Len.
Date HR@1 HR@5
Personal
Care
Clothing Food &
Beverages
Other Avg. Personal
Care
Clothing Food &
Beverages
Other Avg.
1 VQRA-GPT5.2-Think GPT-5.2-Think 60 2025-12-11 -- -- -- -- 26.9 -- -- -- -- 78.2
2 ReAct-GPT5.5-Think GPT-5.5-Think 60 2026-04-23 -- -- -- -- 26.5 -- -- -- -- 78.1
3 ReAct-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 26.3 -- -- -- -- 75.8
4 VQRA-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 26.3 -- -- -- -- 75.7
5 VQRA-DeepSeek-R1 DeepSeek-R1 60 2025-05-28 -- -- -- -- 26.2 -- -- -- -- 76.3
6 Mem0-Gemini-3 Gemini-3-Pro 60 2025-11-18 -- -- -- -- 26.1 -- -- -- -- 78.5
7 Mem0-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 25.9 -- -- -- -- 76.5
8 UniSAR -- 240 2024-04-15 -- -- -- -- 25.9 -- -- -- -- 59.2
9 ReAct-GPT4.1 GPT-4.1 60 2025-04-14 -- -- -- -- 25.8 -- -- -- -- 77.9
10 Mem0-GPT4.1 GPT-4.1 60 2025-04-14 -- -- -- -- 25.8 -- -- -- -- 77.1
11 Mem0-Qwen3.5 Qwen3.5-397B 60 2026-02-16 -- -- -- -- 25.1 -- -- -- -- 74.9
12 MemAgent-GPT4.1 GPT-4.1 60 2025-4-14 -- -- -- -- 25.0 -- -- -- -- 76.1
13 VQRA-GPT4.1 GPT-4.1 60 2025-4-14 -- -- -- -- 24.9 -- -- -- -- 75.7
14 ReAcT-Gemini-3 Gemini-3-Pro 60 2025-11-18 -- -- -- -- 24.8 -- -- -- -- 76.9
15 ReAcT-DeepSeek-R1 DeepSeek-R1 60 2025-05-28 -- -- -- -- 24.8 -- -- -- -- 73.9
16 ReAct-Qwen3.5 Qwen3.5-397B 60 2026-02-16 -- -- -- -- 24.4 -- -- -- -- 71.3
17 MemAgent-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 24.2 -- -- -- -- 75.4
18 Mem0-GPT5.5 GPT-5.5 60 2026-04-23 -- -- -- -- 24.1 -- -- -- -- 76.9
19 MemAgent-GPT5.5 GPT-5.5 60 2026-04-23 -- -- -- -- 24.0 -- -- -- -- 77.1
20 MemAgent-Gemini-3 Gemini-3-Pro 60 2025-11-18 -- -- -- -- 23.8 -- -- -- -- 76.5
21 DeerFlow-GPT5.2-Think GPT-5.2-Think 60 2025-12-11 -- -- -- -- 23.5 -- -- -- -- 73.8
22 DeerFlow-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 23.2 -- -- -- -- 71.5
23 DeerFlow-DeepSeek-R1 DeepSeek-R1 60 2025-05-28 -- -- -- -- 22.9 -- -- -- -- 70.9
24 DeerFlow-GPT4.1 GPT-4.1 60 2025-04-14 -- -- -- -- 22.2 -- -- -- -- 72.3
25 MemAgent-Qwen3.5 Qwen3.5-397B 60 2026-02-16 -- -- -- -- 22.5 -- -- -- -- 70.5
# Architecture Backbone Hist.
Len.
Date HR@1 HR@5
Personal
Care
Clothing Food &
Beverages
Other Avg. Personal
Care
Clothing Food &
Beverages
Other Avg.
1 ReAct-GPT5.5 GPT-5.5 60 2026-04-23 -- -- -- -- 43.2 -- -- -- -- 84.8
2 ReAct-GPT5.5-Think GPT-5.5 60 2026-04-23 -- -- -- -- 43.0 -- -- -- -- 84.5
3 ReAct-GPT4.1 GPT-4.1 60 2025-04-14 -- -- -- -- 40.4 -- -- -- -- 83.2
4 MemAgent-GPT4.1 GPT-4.1 60 2025-04-14 -- -- -- -- 38.6 -- -- -- -- 82.8
5 Mem0-GPT4.1 GPT-4.1 60 2025-04-14 -- -- -- -- 38.2 -- -- -- -- 82.9
6 Mem0-GPT5.5 GPT-5.5 60 2026-04-23 -- -- -- -- 38.1 -- -- -- -- 82.1
7 MemAgent-GPT5.5 GPT-5.5 60 2026-04-23 -- -- -- -- 37.9 -- -- -- -- 82.5
8 ReAct-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 37.8 -- -- -- -- 84.2
9 Mem0-Qwen3.5 Qwen3.5-397B 60 2026-02-16 -- -- -- -- 37.9 -- -- -- -- 82.1
10 ReAct-Qwen3.5 Qwen3.5-397B 60 2026-02-16 -- -- -- -- 37.8 -- -- -- -- 82.1
11 Mem0-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 37.5 -- -- -- -- 83.9
12 MemAgent-GPT4o GPT-4o 60 2024-11-20 -- -- -- -- 37.3 -- -- -- -- 80.2
13 ReAcT-Gemini-3 Gemini-3-Pro 60 2025-11-18 -- -- -- -- 37.1 -- -- -- -- 83.5
14 ReAcT-DeepSeek-R1 DeepSeek-R1 60 2025-05-28 -- -- -- -- 36.0 -- -- -- -- 81.7
15 Mem0-Gemini-3 Gemini-3-Pro 60 2025-11-18 -- -- -- -- 34.3 -- -- -- -- 81.5
16 MemAgent-Gemini-3 Gemini-3-Pro 60 2025-11-18 -- -- -- -- 34.2 -- -- -- -- 82.0
17 MemAgent-Qwen3.5 Qwen3.5-397B 60 2026-02-16 -- -- -- -- 34.2 -- -- -- -- 79.9
18 UniSAR -- 240 2024-04-15 -- -- -- -- 29.2 -- -- -- -- 64.5

Benchmark

Benchmark Collection

All data are newly collected from user data on a leading content platform with shopping functionality, not from any existing dataset.

APeB benchmark collection user interaction timeline
APeB is collected from a large short-form video and livestream commerce platform. The benchmark follows users as they continuously browse content, search for videos, livestreams, or products, and open product pages, focusing on queries with at least weak e-commerce intent. All data collection complies with the platform’s privacy policies and contractual data-use requirements.

Data Examples

APeB data example 1

Construction Pipeline of APeB: from behavioral logs to benchmark components: curated heterogeneous interactions, non-trivial shopping session discovery (search refinement, extensive browsing, and intent-order alignment), and intent/refined query candidate pair identification.

Data Statistics

APeB data statistics
APeB contains 5K+ shopping sessions that covers various product categories. Each session is equipped with 10+ non-trivial candidates and rich interaction history.

Benchmark Comparison

APeB benchmark comparison

Citation

@misc{yang2026apebbenchmarkingpersonalizationability,
      title={APeB: Benchmarking Personalization Ability of Large Language Model Agents}, 
      author={Garry Yang and Zizhe Chen and Xinru Chen and Yongqiang Chen and Jianxiang Wang and Deyu Zou and Linyi Ding and Jialiang Wu and Yunzhong He and Yu Gong and James Cheng and Huaixiao Tou},
      year={2026},
      eprint={2607.03162},
      archivePrefix={arXiv},
      primaryClass={cs.AI},
      url={https://arxiv.org/abs/2607.03162}, 
}

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