Anthropic的最新模型Opus 5.5于周二发布，据该公司称，该模型在编码和知识工作性能方面树立了新的最先进水平。Opus是Anthropic旗下Claude三档产品线中能力最强、价格最高的一档；Sonnet位于中间档位，而Haiku则是最快且最便宜的。值得注意的是，Anthropic表示，该版本在许多基准测试中超越了更大的Fable模型，并在多项非正式任务中取得了成功，而Fable未能完成这些任务。

新模型的价格也较前代产品大幅降低。Opus 5.5的输出令牌收费为每百万令牌20美元，而前一代产品的价格为25美元。其他指标也有类似的价格下调。该模型的运行速度也更快，反映出服务该模型所需的整体计算量有所下降。

新版本还对Opus的沟通方式进行了重大调整，Opus 5.5较少使用行话，更倾向于将重要信息放在消息的开头。

此次发布距离7月24日推出Opus 5仅过去了两个月。根据公告，产品线中下一档的Sonnet 5.5和Haiku 5.5将在“未来几周内”发布，并带来类似的性能提升。

Anthropic表示，Opus 5.5在生物学和网络安全性方面的能力与Mythos相当，因此其发布需遵守与该公司Fable模型相同的安全保障措施。这些措施限制了模型被用于发现编译程序中的漏洞或开发可识别的生物武器等任务的程度。

Opus 5.5是Anthropic自首席执行官Dario Amodei采纳放缓前沿发展速度的呼吁以来的首次模型发布，他故意放慢AI能力的进步速度，以匹配对齐技术的进展速率。

“我已确信，充分应对风险需要更加谨慎，”Amodei在本月早些时候的一篇帖子中写道，“这不仅意味着投资于风险预防，还要控制能力发展的速度，以便风险预防有时间跟上。”

Opus 5.5的安全训练与其前代产品大致相似，包括由METR和Frontier Design等外部组织进行的对齐测试和发布前评估。但Anthropic强调，更先进的训练和评估系统已为未来模型准备就绪，包括改进的安全性和监控系统。

“随着AI能力不断增强，公共政策应在确保人们依赖的系统安全方面发挥更大作用。这种能力的建设需要时间，我们已开始搭建支持它的基础设施，”博客文章写道，“我们预计很快将分享更多关于这些努力的细节。”

Anthropic’s newest model, Opus 5.5, was released on Tuesday , setting a new state-of-the-art in coding and knowledge work performance, according to the company. Opus is the most capable and expensive tier in Anthropic’s three-tier Claude lineup; Sonnet sits in the middle, while Haiku is the fastest and cheapest. Notably, Anthropic says, the release outpaces the larger Fable model in many benchmarks and succeeded in a number of informal tasks that Fable failed to complete.

The new model is also significantly cheaper than its predecessor. Output tokens will be charged at $20 per million tokens for Opus 5.5, compared to $25 for the previous model. Other metrics have similar price drops. The model is also faster to run, reflecting an overall drop in the compute required to serve it.

The new version also makes significant changes to how Opus communicates, with the Opus 5.5 less likely to use jargon and more likely to put important information at the start of its messages.

The launch comes just two months after the release of Opus 5 on July 24 . According to the announcement, Sonnet 5.5 and Haiku 5.5, which are the next tiers in the lineup, will be released “in the coming weeks,” with similar performance improvements.

Anthropic says that Opus 5.5 is comparable to Mythos in its biology and cybersecurity capabilities, so its release is subject to the same safeguards as the company’s Fable model. Those safeguards limit how much the models can be used to discover exploits in compiled programs or developing recognizable biological weapons , among other tasks.

Opus 5.5 is Anthropic’s first model release since CEO Dario Amodei embraced calls to pace the frontier, deliberately slowing down progress on AI capabilities to match the rate of progress on alignment.

“I have become convinced that fully addressing the risks requires even more prudence,” Amodei wrote in a post earlier this month , “not just investing in risk prevention, but pacing the rate of capabilities advancement so that risk prevention has time to keep up.”

Opus 5.5’s safety training was broadly similar to its predecessors, with alignment testing and pre-release evaluation by outside organizations like METR and Frontier Design. But Anthropic emphasized that more advanced training and evaluation systems were already being prepared for future models, including improved security and monitoring systems.

“As AI becomes more capable, public policy should play a larger role in making sure the systems people rely on are safe. That capacity takes time to build, and we’ve started to put the infrastructure in place to support it,” the blog post reads. “We expect to share more details on these efforts soon.”