Peichun Hua

Accepted · HotNets 2026

Semantics Delivery Network: Rethinking Web Retrieval Infrastructure for LLM Agents

Peichun Hua, Yunming Xiao

Overview

Semantics Delivery Network (SemDN) proposes an origin-authorized edge layer that retrieves and delivers web content as task-relevant chunks for LLM agents. It addresses the gap between URL-based search and caching infrastructure and the short, useful passages agents consume across multi-step tasks.

Method

A client sends a semantic query to a nearby edge, which searches a hierarchical corpus and returns selected chunks. SemDN shares origin-authorized content acquisition and normalization, supports tenant-specific ranking, and caches normalized blocks, chunks, and index state. A coverage controller estimates when the corpus may be incomplete or stale and can trigger scoped discovery or refresh.

Comparison of today's search engine and URL-caching CDN path with SemDN's chunk-level search, caching, and coverage-aware delivery between agents and origins.
SemDN adds a semantics-aware delivery path for agent queries and returns relevant chunks rather than full pages. Figure 1 in the paper

Evaluation

In preliminary measurements on 100 live-web queries, agents consumed a median 7.1 KB of selected chunks while lightweight HTML retrieval processed 761 KB to obtain them (107×); full browser renders processed 18.1 MB. In trace-driven cache replays of Search-R1 over wiki-18, a 1.34 MB chunk cache served 73.8% of chunk requests and sent 13–41× fewer bytes to origin than a URL-object cache at equal capacity. On a fixed wiki-18 corpus across five QA sets, chunk-first retrieval with the same Qwen2.5-7B reader improved average F1 from 0.334 to 0.357 over page-first retrieval while delivering about 470× fewer bytes.

Selected preliminary measurements
MeasurePage or URL pathSemDN chunk path
Median content per live-web query761 KB lightweight HTML7.1 KB consumed chunks
Average answer F1 on five QA sets0.334 page-first0.357 chunk-first
Selected measurements from the paper's preliminary probes. The first row compares content processed with chunks consumed; the second holds the wiki-18 corpus and Qwen2.5-7B reader fixed. Measurements in the paper

Citation

@article{hua2026semantics,
    title={Semantics Delivery Network: Rethinking Web Retrieval Infrastructure for LLM Agents},
    author={Peichun Hua and Yunming Xiao},
    journal={CoRR},
    volume={abs/2609.22486},
    year={2026},
    url={https://arxiv.org/abs/2609.22486},
    doi={10.48550/arXiv.2609.22486},
    eprinttype={arXiv},
    eprint={2609.22486},
    primaryClass={cs.NI},
}