Scaling External Knowledge Input Beyond Context Windows of LLMs via Multi-Agent Collaboration

Zijun Liu, Zhennan Wan, Peng Li, Ming Yan, Fei Huang, Yang Liu


Abstract
With the rapid advancement of post-training techniques for reasoning and information seeking, large language models (LLMs) can incorporate a large quantity of retrieved knowledge to solve complex tasks. However, the limited context window of LLMs obstructs scaling the amount of external knowledge input, prohibiting further improvement. Existing context window extension methods inevitably cause information loss. LLM-based multi-agent methods emerge as a new paradigm to handle massive input in a distributional manner, where we identify two core bottlenecks in existing agent orchestration designs. In this work, we develop a multi-agent framework, **ExtAgents**, to overcome the bottlenecks and enable better scalability in inference-time knowledge integration without longer-context training. Benchmarked with our enhanced multi-hop question answering test, **Bench+**, and other public test sets including long survey generation, ExtAgents significantly enhances the performance over existing non-training methods with the same amount of external knowledge input, regardless of whether it falls *within or exceeds the context window*. Moreover, the method maintains efficiency due to high parallelism. We believe further study in the coordination of LLM agents on increasing external knowledge input could benefit real-world applications.
Anthology ID:
2026.acl-long.468
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
10284–10314
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.468/
DOI:
Bibkey:
Cite (ACL):
Zijun Liu, Zhennan Wan, Peng Li, Ming Yan, Fei Huang, and Yang Liu. 2026. Scaling External Knowledge Input Beyond Context Windows of LLMs via Multi-Agent Collaboration. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 10284–10314, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Scaling External Knowledge Input Beyond Context Windows of LLMs via Multi-Agent Collaboration (Liu et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.468.pdf
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