MindMemOS: A Portable and Self-Evolving Memory Operating Layer for AI Agents

AuthorsKaichao Liang, Yuqi Cui, Hao Kong et al.

arXiv 20262026

TL;DR

MindMemOS uses an entity–property–time memory OS with MindMemEvolve and dreaming to reach 94.03% LOCOMO accuracy and 70.63% PersonaMem accuracy.

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THE PROBLEM

Fixed memory schemas and redundant stores cap agent performance at 93.05% on LOCOMO

Existing memory systems remain largely fixed after deployment, limiting adaptation of memory models, organization strategies, and procedural knowledge over time.

This rigidity leaves systems like EverOS at 93.05% LOCOMO accuracy and 67.57% PersonaMem accuracy, with redundant, outdated, and conflicting memories degrading long-term personalization, reasoning, and skill reuse.

HOW IT WORKS

MindMemOS — a self-evolving entity–property–time memory OS

MindMemOS combines a 3D entity–property–time memory structure with MindVanilla, MindSchema, MindMemEvolve, dreaming, feedback, and MindSkillEvolve to manage the full memory lifecycle.

You can think of MindMemOS as an OS where the entity–property–time graph is disk, compact search is the index, and MindMemEvolve plus dreaming are background defrag and schema-tuning daemons.

This design lets MindMemOS adapt schemas, consolidate conflicts, and turn trajectories into skills, going far beyond what a static context window or fixed vector store can express.

DIAGRAM

Compact search over the 3D memory structure

This diagram shows how MindMemOS performs hybrid bidirectional compact search over the entity–property–time graph for a query.

DIAGRAM

Evaluation pipeline across LOCOMO, PersonaMem, MemoryAgentBench, and SpreadsheetBench

This diagram shows how MindMemOS is evaluated on dialogue memory, personalization, consolidation, and skill evolution benchmarks.

PROCESS

How MindMemOS Handles a Dialogue Session

  1. 01

    Memory-Add MindVanilla

    MindMemOS uses MindVanilla to segment turns, retrieve related memories, and extract flat records with coarse types before writing into the entity–property–time graph.

  2. 02

    Memory-Add MindSchema

    MindMemOS applies MindSchema to map dialogue to scenario-adaptive entities and properties, build an episodic memory subgraph, and perform entity fusion and graph merge.

  3. 03

    Compact Search

    MindMemOS runs compact search with hybrid BM25 and embedding retrieval plus forward and reverse traversal over the 3D memory structure to gather relevant evidence.

  4. 04

    Dreaming and Feedback

    MindMemOS periodically runs dreaming to consolidate conflicts and redundancy, and uses explicit and implicit feedback to add, update, or delete memories and drive MindMemEvolve and MindSkillEvolve.

KEY CONTRIBUTIONS

Key Contributions

  • 01

    Scenario-Adaptive Memory Modeling

    MindMemOS introduces a unified entity–property–time structure with MindVanilla and MindSchema, achieving 94.03% overall accuracy on LOCOMO and 70.63% on PersonaMem.

  • 02

    Active Memory Pattern Discovery

    MindMemOS uses MindMemEvolve, an LLM-guided evolutionary search over schemas, to add first-order and higher-order properties that raise PersonaMem test accuracy from 61.07% to 64.63%.

  • 03

    Experience-Driven Skill Evolution

    MindMemOS introduces MindSkillEvolve to turn execution trajectories into versioned skills, improving SpreadsheetBench success from 48.0% with Init-skill to 57.2% with MindSkillEvolve-Sup.

RESULTS

By the Numbers

Overall accuracy

94.03%

+0.98 over EverOS on LOCOMO

PersonaMem overall

70.63%

+3.06 over EverOS

FactConsolidation overall

0.585

+0.075 over Infini Memory with gpt-5-mini

SpreadsheetBench success

57.2%

+9.2 over Init-skill baseline

MindMemOS is evaluated on LOCOMO, PersonaMem, MemoryAgentBench FactConsolidation, and SpreadsheetBench, showing consistent gains in recall, personalization, consolidation, and skill execution. The 94.03% LOCOMO and 70.63% PersonaMem scores demonstrate that MindMemOS’s evolving memory OS can match or exceed specialized baselines across diverse long-term tasks.

BENCHMARK

By the Numbers

MindMemOS is evaluated on LOCOMO, PersonaMem, MemoryAgentBench FactConsolidation, and SpreadsheetBench, showing consistent gains in recall, personalization, consolidation, and skill execution. The 94.03% LOCOMO and 70.63% PersonaMem scores demonstrate that MindMemOS’s evolving memory OS can match or exceed specialized baselines across diverse long-term tasks.

BENCHMARK

LOCOMO — Effectiveness. Per-category QA Accuracy (%)

Overall accuracy (%) on LOCOMO across memory systems.

BENCHMARK

PersonaMem — Effectiveness. Per-category Accuracy (%)

Overall accuracy (%) on PersonaMem across memory systems.

KEY INSIGHT

The Counterintuitive Finding

Dreaming in MindMemOS archives roughly 22.5% of active memories yet increases FactConsolidation overall accuracy from 0.545 to 0.585 with gpt-5-mini.

This is surprising because aggressively compressing memory is usually expected to hurt retrieval, but MindMemOS shows that targeted consolidation can both shrink and sharpen long-term stores.

WHY IT MATTERS

What this unlocks for the field

MindMemOS makes it practical to run agents with a self-evolving, schema-aware memory OS that refines both content and skills over time.

Builders can now plug MindMemOS behind diverse agents and get portable long-term memory, automatic schema tuning, and trajectory-driven skill upgrades without redesigning their runtimes.

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