Retrieval-Augmented LLM Agents: Learning to Learn from Experience

Thomas Palmeira Ferraz, Romain Deffayet, Vassilina Nikoulina, Hervé Déjean, Stéphane Clinchant


Abstract
While large language models (LLMs) have advanced the development of general-purpose agents, robust generalization to unseen tasks remains challenging. Two common approaches are supervised fine-tuning and training-free memory-augmented generation using retrieved experience; yet both have limitations: fine-tuning often fails to extrapolate to new tasks, while experience retrieval often underperforms compared to supervised baselines. In this work, we combine these approaches and study how retrieval-augmented LLM agents can learn to use retrieved trajectories in-context. First, we establish a strong LoRA fine-tuning baseline that outperforms several state-of-the-art agent training pipelines. Second, we analyze key design choices for experience retrieval, including storage, querying, and trajectory selection. We then integrate experience retrieval directly into the fine-tuning process, finding that this substantially improves generalization to unseen tasks. Finally, we show that these gains often persist with imperfect experience and, even when agents reuse their own failed attempts without test-time parameter updates. Overall, our results establish simple episodic retrieval as a strong foundation for agent memory and **retrieval-aware fine-tuning as a practical and effective framework for building agents that learn to learn from experience**. Code and models are made available.
Anthology ID:
2026.emnlp-main.57
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1297–1335
Language:
URL:
https://aclanthology.org/2026.emnlp-main.57/
DOI:
Bibkey:
Cite (ACL):
Thomas Palmeira Ferraz, Romain Deffayet, Vassilina Nikoulina, Hervé Déjean, and Stéphane Clinchant. 2026. Retrieval-Augmented LLM Agents: Learning to Learn from Experience. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 1297–1335, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Retrieval-Augmented LLM Agents: Learning to Learn from Experience (Ferraz et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.57.pdf