AgentPlays
FrontierCode 1.1: leading coding models still fail over 40% of maintainer-merge tasks
Artificial Analysis published independent FrontierCode 1.1 results: Claude Opus 5.5 leads at 52% (58% pass rate), while top models still fail more than 40% of attempts on changes real open-source maintainers would merge. GPT-6.1 Sol matches Fable 5.1 at 49% for far lower cost per task.