Ph.D. thesis · 2026
Agentic Harnesses for ARC-AGI-3
Agentic Harnesses for ARC-AGI-3
TL;DR. ARC-AGI-3 drops an agent into interactive grid games with hidden mechanics, sparse rewards, and a tight interaction budget. The open secret of the benchmark is that the harness — the scaffold of tools, memory, and control logic around the LLM — matters as much as the model. ARC-SCOPE is a testbed that finally lets you compare harnesses fairly: same environments, same representations, same token / wall-clock budgets.
Within it we compared reactive analyzers, multi-agent orchestrators, and executable-world-model agents, and built DISH — a deterministic information-state harness that maintains a programmatic world model, verifies it against observed transitions, and plans through it with a thin event-driven controller, designed for sub-30B models.
The result is a capability–efficiency split: the strongest frontier-style baseline tops out at 36/37 levels, while DISH clears 28–31 levels at roughly half the tokens per level (≈20M vs. ≈43M). Everything runs on vLLM with FP8, from a single-GPU Qwen-27B up to GLM on an 8×H200 node.