Anthropic Amin built a model too risky to release

Hey folks, Keshav here. Ben is at AI Engineer this week, so I’m covering the intro.

A mis-timed blog last week leaked Anthropic’s next model - Claude Mythos. Well, it is real and has massive improvements on benchmarks over Opus 4.6:

• 53.4% → 77.8% on SWE-bench Pro

but we are not getting access to it anytime soon. Why? because it is really good at finding and exploiting software vulnerabilities. On Firefox exploit generation, Opus managed 2 working exploits out of hundreds of attempts. Mythos hit 181.

It found many-decades-old bugs in critical software projects like OpenBSD (27-year-old bug), FFmpeg (16-year-old bug) and more.

Instead of releasing it publicly, Anthropic is giving 12 companies access to a preview version of Mythos under “Project Glasswing” to find vulnerabilities in critical software. Anthropic is committing $100M in model usage credits and $4M in donations to open-source security orgs under this project.

Theo made a video on this, and I like his point: “Mythos is to Opus what Opus is to Sonnet.”

I tweeted a list of companies that Meta has acquired in the past year without anything to show for it, and soon after, Meta released details about their latest model - Muse Spark. At a glance, it sits somewhere between Sonnet 4.6 and Opus 4.6. Not usable yet: API access is coming, and there are promises about open-source too (rip llama).

Many people are dunking on Meta for its not-so-frontier model release after spending billions and a year of silence, but I think it’s a good step ahead. Plus, have you used Instagram search over the past couple of months? It’s gotten really good courtesy of AI.

As always, good recap from Ethan Mollick on the state of frontier models: Google, OpenAI and Anthropic lead, Meta joins the pack for now while xAI has fallen off, and the best Chinese models are still 7-9 months behind.

ps: Factory’s desktop app is now out of beta. It comes with a cloud computer, the ability to use other apps on your device, and, of course, the ability to run and manage multiple Droid sessions easily.

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Headlines

• Claude Managed Agents - You can use Claude’s developer console to build and deploy agents and let anthropic handle the infra for it, vs building it yourself. For example, Notion is using managed agents to build a “delegate tasks to Claude” feature. (Anthropic’s engineering blog on building this).