Anthropic Preps Opus 4.7 and Full-Stack AI Studio—While Sitting on Something Much Scarier

In brief

• Anthropic is preparing Claude Opus 4.7 and an AI design tool for websites and presentations
• Claude Mythos remains Anthropic's true frontier model, and the company won't release it publicly.
• The industry still can't reliably measure AI improvements, making claims about Opus 4.7's gains hard to verify.

Anthropic is gearing up to release Claude Opus 4.7 alongside a new AI-powered design tool that lets users build websites, presentations, and landing pages with plain English prompts—news that caused a dip in Adobe, Wix, and Figma shares on Monday, according to The Information.

The products could drop as soon as this week, a person with knowledge of the plans told The Information. The design tool targets developers and non-technical users alike, putting it on a collision course with startups like Gamma and Google's Stitch.

Anthropic did not respond to Decrypt’s request for comment.

Opus 4.7 isn't even Anthropic's most powerful model. That title belongs to Claude Mythos—a cybersecurity-focused beast the company is quietly handing to select security firms while keeping it away from the public.

The UK's AI Security Institute recently evaluated Mythos Preview and found it can autonomously execute sophisticated cyber attacks at rates no other model has matched. It became the first AI to complete "The Last Ones," a 32-step corporate network attack simulation that typically takes human red teams 20 hours. Mythos nailed it in three out of ten attempts, averaging 22 of 32 steps—compared to Opus 4.6's 16.

This matters beyond enterprise security. Measuring what AI can actually do has become an industry-wide headache. OpenAI recently called the leading coding benchmark "contaminated," yet models continue to be compared using those same tests. A separate ARC-AGI-3 evaluation saw Gemini score 0.37% and GPT-5.4 hit 0.26%—while humans got 100%. The result is a landscape where benchmarks are both contested and still used as evidence, making it difficult to contextualize claims about Opus 4.7’s gains until Anthropic releases a detailed model card.

The relationship between Opus and Mythos is closer than most realize. Anthropic builds its frontier models by fine-tuning atop the Opus line—the same backbone powering public Claude products gets stress-tested and hardened into Mythos. Opus 4.7 is the foundation that eventually gets the cybersecurity kung fu beaten into it.