"SoL-Pi: Recursively Scaling Auto-Research Loops for Efficient Agent Harness" This paper lets coding agents recursively optimize their own harness instead of hand-designing it. Across diverse coding environments, it discovers four mechanisms that compress context, observations, reading, and actions. The result is comparable performance with 44.7-49% less token traffic and roughly one-third lower API cost. https://alphaxiv.org/abs/2609.20519