Simular's open-source Agent S4 evolves its own computer-use tools, lifting a 27B model past Opus 4.8
A meta-agent reads a task agent's trajectories and writes reusable interfaces (bulk spreadsheet edits, in-tab browser requests, app APIs), so Qwen3.8-27B hits 21.3% on OSWorld V2 versus 5.6% with fixed GUI tools and 20.6% for Claude Opus 4.8, at about $1.10 a task versus $72 (self-reported). Code is at simular-ai/Agent-S.