HGP: An on-device personalized agent memory via hybrid graph storage

Ran Zhou, Xueming Han, Jiaheng Liu, Yuyao Zhang, Fanyu Meng, Junlan Feng, Yuxiang Ren


Abstract
LLM-based agents face challenges in personalized interactive tasks due to heterogeneous, multi-typed, and implicitly constrained long-term traces. Existing memory mechanisms struggle with accurate routing and retrieval, especially on-device where personalization is critical. Most methods use single-vector representations, blurring type distinctions and relational structure. We propose HGP, a hybrid graph memory framework. HGP employs a lightweight self-enhancement classifier for personalized memory routing and constructs episodic, semantic, and procedural memories as graphs. It also extracts working memory as a state trajectory to capture current state and implicit constraints, ensuring reliable decision- making. The classifier reduces large-model calls, enabling on-device deployment, while graph storage enables accurate retrieval and incremental user profile refinement. Experiments on two benchmarks show that on PAL-Set solution selection, HGP achieves an S-score of 35.58, nearly 7 points above the strongest baseline.
Anthology ID:
2026.findings-emnlp.406
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
8582–8598
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.406/
DOI:
Bibkey:
Cite (ACL):
Ran Zhou, Xueming Han, Jiaheng Liu, Yuyao Zhang, Fanyu Meng, Junlan Feng, and Yuxiang Ren. 2026. HGP: An on-device personalized agent memory via hybrid graph storage. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 8582–8598, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
HGP: An on-device personalized agent memory via hybrid graph storage (Zhou et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.406.pdf