ARTFEED — Contemporary Art Intelligence

S-Bus: HTTP Middleware for LLM Agent Concurrency Control

ai-technology · 2026-05-25

S-Bus is an HTTP middleware aimed at managing concurrency in multi-agent LLM systems that utilize mutable state. It features a server-side DeliveryLog, which reconstructs each agent's read set at the time of commitment based on observed HTTP GET requests. This mechanism facilitates Observable-Read Isolation (ORI), effectively mitigating structural race conditions in dedicated-shard architectures. The system offers three key advancements: a DeliveryLog mechanism with formal verification through TLAPS, TLC, and Dafny; empirical safety equivalence with PostgreSQL 17 SERIALIZABLE and Redis 7 WATCH/MULTI, achieving zero Type-I corruptions across 884,110 commit attempts; and a formal proof of ORI properties. The research is published on arXiv with ID 2605.17076.

Key facts

  • S-Bus addresses concurrency control for LLM agents sharing mutable state over HTTP.
  • Agents cannot be modified to declare read sets.
  • Central mechanism is a server-side DeliveryLog.
  • DeliveryLog reconstructs each agent's read set at commit time from observed HTTP GET traffic.
  • Provides Observable-Read Isolation (ORI), a partial causal consistency property.
  • ORI prevents Structural Race Conditions in dedicated-shard topologies.
  • Three contributions: DeliveryLog with mechanized evidence, empirical safety parity, and formal proofs.
  • Empirical testing: zero Type-I corruptions across 884,110 commit attempts (427,308 under active contention).

Entities

Institutions

  • arXiv

Sources