Anthropic releases Claude Opus 5.5 at 40% lower cost with stricter safeguards

Anthropic released Claude Opus 5.5, which the company says matches Fable 5.1's performance at 40% lower cost and adds stricter safeguards against sandbox escapes and risky behaviors. The launch drew 778 points on Hacker News, where multiple users reported the model performed worse than expected and made more errors than prior versions despite unchanged usage patterns.

Anthropic releases Claude Opus 5.5 at 40% lower cost with stricter safeguards According to Anthropic, Claude Opus 5.5 achieves performance equivalent to Fable 5.1 at 40% lower cost and includes stricter safeguards against sandbox escapes and risky behaviors. The release received 778 points on Hacker News, though multiple users reported the model performed worse than expected and made more errors than prior versions despite unchanged usage patterns. Topics Sources - Official Read article https://www.anthropic.com/claude-opus-5-5 - Social HN thread https://news.ycombinator.com/item?id=49798699 This intelligence is sourced automatically from public sources across the web and synthesised by the Prefactor AI pipeline. Stories are reviewed before publication.