James' Growth Diary

Jun 24, 2026 · Artificial Intelligence

Why Immutable Historical Context Is the Core of Hermes’ Prefix‑Caching Performance Design

The article explains how Hermes relies on prefix caching—keeping the system prompt unchanged throughout a session—to achieve 70‑80% cache‑hit rates, reduce token costs by up to 60%, and shape its architecture across agents, sub‑agents, and background review tasks.