HarnessPro - GPT-5.5 Codex - ProgramBench: leaderboard

HarnessPro (2026): label-free harness development, GPT-5.5 Codex execution setup. Official held-out evaluations; baseline GPT-5.5 high effort, GLM-5.2 max for Terminal-Bench/SWE and high for ProgramBench. HarnessPro evolves effort dynamically; Lite/Medium/Heavy are optimization cost weights, not fixed provider reasoning settings. ProgramBench uses macro-averaged within-task test pass fraction. Each method remains a distinct model-plus-harness system; cost, timing and standard deviations are not capability scores. Pass Rate (%); higher is better.

Metric: Pass Rate (%). Source: arxiv.org. Saturation forecast: Rough model projection: around 2026. 10 models tracked.

Top models

#ModelScoreOverall rank
1HarnessPro Study GPT-5.5 Codex - HarnessPro-Heavy objective system69.6
2HarnessPro Study GPT-5.5 Codex - RHO objective system68.8
3HarnessPro Study GPT-5.5 Codex - Dynamic Cheatsheet objective system68.5
4HarnessPro Study GPT-5.5 Codex - RHO+Iteration objective system68.3
5HarnessPro Study GPT-5.5 Codex - HarnessPro-Medium objective system67.9
6HarnessPro Study GPT-5.5 Codex - Sleep-time Compute objective system67.7
7HarnessPro Study GPT-5.5 Codex - Balance objective system65.7
8HarnessPro Study GPT-5.5 Codex - HarnessPro-Lite objective system64.3
9HarnessPro Study GPT-5.5 Codex - ReasoningBank objective system62.5
10HarnessPro Study GPT-5.5 Codex - Vanilla objective system60.3

Interactive version: theaggregate.ai/benchmark?slug=harnesspro-gpt-5-5-codex-programbench · How It Works · Data refreshed daily, snapshot 2026-10-21.