Anthropic releases another Claude model days after calling for AI slowdown

Anthropic has released Claude Sonnet 5.5, the second model in its Claude 5.5 family. The startup claims it runs more than 30% faster than Sonnet 5 and costs up to 30% less for most work. Anthropic unveiled Claude Opus 5.5 last week. The launches come days after CEO Dario Amodei called for a slowdown in AI development.