Claude Opus 5 Quietly Launched: Some Accounts See 'Opus 4.8' with Clear Output Gap

According to a tweet, Claude Opus 5 has already gone live for some accounts, served as 'Opus 4.8' in Claude Web and Claude Code. It knows things 4.8 doesn't, with a clear output gap, especially in frontend skills.

• Claude
• Opus 5
• モデル更新