---
language:
  - en
pretty_name: MOSAIC
size_categories:
  - n<1K
tags:
  - benchmark
  - conversational-memory
  - multimodal
configs:
  - config_name: default
    data_files: []
---

# MOSAIC

**An omni-modal benchmark for long-term memory.** Remember what was said, shown, and conveyed, then find where the memory failed.

Paper: [arXiv:2610.29249](https://arxiv.org/abs/2610.29249) · Code: [HKUST-KnowComp/MOSAIC](https://github.com/HKUST-KnowComp/MOSAIC) · Project and leaderboard: [hkust-knowcomp.github.io/MOSAIC](https://hkust-knowcomp.github.io/MOSAIC/)

![MOSAIC overview. A five-session history of text, image, video, and audio, and the four places a system can lose that evidence: write, retrieve, deliver, and read.](figures/overview.png)

MOSAIC is 923 questions over histories of text, image, video, and audio. A single end-to-end score cannot say where the evidence was lost, so the benchmark holds the question fixed and separates four stages: **write**, **retrieve**, **deliver**, and **read**.

| | |
| --- | ---: |
| Questions | 923 |
| Answerable / refusal | 784 / 139 |
| Sessions per history | 11–24 |
| Modalities | Text, image, video, audio |

On the end-to-end leaderboard, ReAct with native multimodal memory and MiMo-V2.5 scores **0.732** on the 784 answerable questions. With the reader fixed at Gemini 3.5, A-MEM on caption text leads at **0.684**. Correct refusal and false refusal are reported beside the end-to-end score, because refusing everything is not a better memory.

## Layout

| Directory | Contents |
|---|---|
| `dataset/stage2_human_filtered/` | 923 questions |
| `dataset/media/` | images, audio, and video |
| `dataset/textualized_caption/` | caption-text corpus |
| `dataset/textualized_omni/` | omni-text corpus |
| `indexes/` | RAG, A-MEM, and MemoryOS indexes |
| `records/protocol_v1/` | paper evaluation records |

Question files store `media_path` values whose `clean_output/media/` suffix matches `dataset/media/`. The [evaluation code](https://github.com/HKUST-KnowComp/MOSAIC) maps those paths when `MOSAIC_DATA_ROOT` is set to this folder.

## Citation

```bibtex
@misc{tsang2026mosaic,
  title = {{MOSAIC}: An Omni-Modal Benchmark for Long-Term Memory and Cross-Modal Reasoning in Conversational Agents},
  author = {Tsang, Hong Ting and Zhang, Boyi and Huang, Haoyu and Bai, Jiaxin and Li, Yufei and Gao, Yisen and Xie, Zhongwei and Luo, Hongyu and Pan, Jeff Z. and Song, Yangqiu},
  year = {2026},
  eprint = {2610.29249},
  archivePrefix = {arXiv},
  primaryClass = {cs.CL},
  doi = {10.48550/arXiv.2610.29249},
  url = {https://arxiv.org/abs/2610.29249}
}
```