Article

AI The new coding leaderboard tests whether code can be merged, and Opus 5.5 still has of attempts fail

Beating AI Breaking news: Artificial Analysis has launched FrontierCode 1.1 coding leaderboard, focusing on evaluating whether AI code can meet open-source project maintainers’ merge standards. Claude Opus 5.5 scored 52.2%highest overall, but only 58%of attempts passed all hard checks, meaning more than still failed.

This benchmark was developed by Cognition together with maintainers of 36 open-source projects, with each task refined for more than 40 hours. It checks not only whether code runs, but also whether added tests can detect issues in the old code, whether unrelated files are modified arbitrarily, and whether existing functionality is broken. Artificial Analysis selected 100 of the more difficult private tasks, had all models use the same Agent framework, and ran each task 3 times. For 9 of the tasks, no evaluated model succeeded.

The cost gap is larger than the score gap.GPT-6.1 Sol scored 49.1%, only 5.5 percentage points below Opus, 3.1 but its average cost per task was only 0.81 USD, compared with 10.15 USD for the latter—a difference of more than 12 times. Xiaomi MiMo-V2.6-Pro led the open-source models with 45%, at a per-task cost of only 0.18 USD;DeepSeek V4.1 Flash and Kimi K3 both came in at 44%.

It is important to note that 52.2%is an overall score, not the actual PR merge rate. The benchmark used automated checks and reviews by the GPT-6 Luna model; tasks were not actually reviewed individually by maintainers. All models used a standardized Agent framework, which also means this ranking cannot directly represent the real-world performance of each company’s official coding tools.

Original link https://m.theblockbeats.info/flash/371531