titleTokenRouter: Efficient Serving System for Token-Level LLM Routing
authorsTianyu Fu, Tengxuan Liu, Ruoxi Wang, Yixin Dong, Yi Ge, Yichen You, Yu Wang
date2026-10-08
venuearXiv (preprint, not peer reviewed)
idarXiv:2610.12242
affiliationTsinghua-NICS-EFC
upvotes127 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf code
abstractLarge language model (LLM) routing distributes inference work across different models, advancing the cost-quality Pareto frontier of LLM serving. While coarse-grained routing at the session or query level has been widely adopted in production systems, recent algorithmic work shows that fine-grained token-level routing can yield substantial efficiency and quality gains. However, efficiently serving token-level routed inference poses significant challenges to existing systems. Built on single-LLM assumptions, current systems suffer from severe step desynchronization and frequent batch admission delays under token-level routing, and they also impose high implementation complexity on developers. To address these challenges, we design TokenRouter, an efficient and developer-friendly serving system for token-level routed LLM inference. TokenRouter follows the principle of request-centric programming, model-centric execution: developers describe routing logic from the perspective of a single request, while the runtime launches a subserver for each LLM and dispatches requests asynchronously. Each subserver employs a delayed-batching scheduler, whose optimal hyperparameters are derived from a mathematical throughput model of the system. Across diverse routing algorithms, workloads, and model pairs, TokenRouter achieves 2.01-64.15x higher decoding throughput than existing systems, substantially advancing the serving efficiency of token-level LLM routing. Our code is available at https://github.com/thu-nics/TokenRouter.

cite

@misc{fu2026tokenrouter,
  title={TokenRouter: Efficient Serving System for Token-Level LLM Routing},
  author={Tianyu Fu and Tengxuan Liu and Ruoxi Wang and Yixin Dong and Yi Ge and Yichen You and Yu Wang},
  year={2026},
  eprint={2610.12242},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2610.12242}
}