HERO: Human-profile Enhanced Retrieval Optimization Framework for Long-term Agent Memory

AuthorsYuanhua Lin, Yile Li, Zhiyuan Zhao et al.

arXiv 20262026

TL;DR

HERO uses a human-profile guided heterogeneous memory graph with iterative cue activation to reach 56.06% F1 and 87.99% accuracy on LoCoMo.

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THE PROBLEM

Long-term agents lose details and drift semantically

HERO targets two issues: information loss from compression and semantic drift from rewriting, which discard fine-grained but later useful details.

When long-term agents rely on LLM summaries or profiles, they miss subtle temporal references and preference changes, degrading factual QA and personalized reasoning.

HOW IT WORKS

HERO — Human-profile Enhanced Retrieval Optimization

HERO’s core mechanism builds a heterogeneous memory graph with Episodic Traces, Episodic Units, Episodic Cues, Profile Insights, and Profile Cues plus Personalized PageRank retrieval.

You can think of HERO like a hippocampus-backed card catalog: raw dialogues stay as full episodes, while compact human profiles act as navigational signposts through the graph.

This design lets HERO follow multi-hop cue paths and profile-guided links across sessions, something a plain context window or vanilla RAG cannot support reliably.

DIAGRAM

Profile-aware memory retrieval pipeline in HERO

This diagram shows how HERO runs profile-aware cue activation and graph traversal over the heterogeneous memory graph to retrieve evidence for a query.

DIAGRAM

Evaluation setup and ablation design for HERO

This diagram shows how HERO is evaluated on LoCoMo and PERSONAMEM, including ablations without profiles and cue expansion.

PROCESS

How HERO Handles a Long-term Query Session

  1. 01

    Memory Construction

    HERO segments dialogue into Episodic Traces and Episodic Units, then extracts Episodic Cues plus Profile Insights and Profile Cues to build the heterogeneous graph.

  2. 02

    Initial Anchor Identification

    HERO encodes the query, extracts entities Eq, and matches them to cue nodes in the graph to form the initial active set S0.

  3. 03

    Iterative Context Expansion

    HERO repeatedly follows cue to Episodic Units and Profile Insights, filters by query relevance, and activates new Episodic Cues and Profile Cues.

  4. 04

    Global Relevance Propagation and Evidence Ranking

    HERO combines cue activations with dense similarity, runs Personalized PageRank over Episodic Traces, and returns top k raw traces to the LLM.

KEY CONTRIBUTIONS

Key Contributions

  • 01

    Human-profile enhanced retrieval optimization framework

    HERO introduces a human-cognition-inspired framework where Profile Insights and Profile Cues guide retrieval instead of replacing raw memories, enabling profile-aware reasoning.

  • 02

    Heterogeneous memory graph with episodic evidence

    HERO designs a graph over Episodic Traces, Episodic Units, and Episodic Cues that preserves complete dialogue text as final evidence for faithful reasoning.

  • 03

    Profile-aware cue activation and graph retrieval mechanism

    HERO’s iterative cue activation plus Personalized PageRank retrieves explicit facts and implicit cross-episodic dependencies, achieving 56.06% F1 on LoCoMo and 70.63% accuracy on PERSONAMEM.

RESULTS

By the Numbers

Overall ACC

87.99%

+3.96 over EverMemOS

Overall F1

56.06%

+10.58 over EverMemOS

Overall BLEU-1

48.38%

+11.44 over EverMemOS

PERSONAMEM Overall Avg

70.63%

+4.25 over EverMemOS

On LoCoMo, which tests single-hop, multi-hop, temporal, and open-domain QA over long conversations, HERO’s 87.99% accuracy and 56.06% F1 show strong factual grounding. On PERSONAMEM, HERO’s 70.63% overall accuracy demonstrates robust personalized reasoning over evolving user traits and preferences.

BENCHMARK

By the Numbers

On LoCoMo, which tests single-hop, multi-hop, temporal, and open-domain QA over long conversations, HERO’s 87.99% accuracy and 56.06% F1 show strong factual grounding. On PERSONAMEM, HERO’s 70.63% overall accuracy demonstrates robust personalized reasoning over evolving user traits and preferences.

BENCHMARK

Performance Comparison on the LoCoMo benchmark

Overall F1 on LoCoMo across HERO and strong long-term memory baselines.

KEY INSIGHT

The Counterintuitive Finding

HERO reaches 56.06% F1 on LoCoMo while using only 248 tokens on average and keeping retrieval latency under one second.

This is surprising because many assume better long-term memory requires larger prompts and heavier online LLM reasoning, but HERO shifts complexity into offline graph construction instead.

WHY IT MATTERS

What this unlocks for the field

HERO unlocks faithful, profile-aware long-term memory where agents reason over raw episodic text guided by human profiles rather than lossy summaries.

Builders can now create agents that track multi-session facts and evolving preferences over tens of thousands of tokens without bloated prompts or brittle one-shot summaries.

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