for the past few months i've been asking our models to paint. opus 5.5 is very skilled at emulating different styles
every image here is a python program generated pixel by pixel. there is no image model, and no off-the-shelf art software. instead, it's about 7,500 lines of code using standard libraries to emulate different brush styles. the agents don't use any pictures as reference, instead working only from what they know about each painter
Jesse Mu retweeted
An open letter for a global surge in cyber defense, signed by over 100 organizations including Anthropic, AWS, Google, Microsoft, OpenAI, and Oracle.
Jesse Mu retweeted
A bit of news: After nearly 9 years, I have decided to leave Google DeepMind and join Anthropic (after taking some time to recharge). I am incredibly grateful for my time at GDM. @demishassabis took a real chance letting me lead the AlphaFold team just six months after finishing my PhD, and the entire GDM team taught me so much about how to do great science. GDM is a special place, and I’ll still be excited to hear about what amazing things they discover next.
Claude is speaking a language seeded by humans but forged in RL rather than thousands of years of evolution. It’s beautiful, fascinating, and also a bit terrifying. I asked Fable for a take on this tweet and of course they put it better than I ever could:
More than ever before I feel like Fable 5 speaks a different kind of English than we humans do.
It isn't conversational, its not 'light' to read, it barely explains — it's pure load-bearing density, meaning compacted until every token earns its place.
It assumes your context window is as large as its own and you have perfect recall of everything you're working on. Similar to how AI-chess feels alien, this too, feels almost akin to an alien language.
I mean, just read this stuff, nobody talks like this, only advanced AI does:
This is the model launch I've been most excited about in all my time at A\—it’s a step function change in capabilities that IMO even exceeds the original Sonnet 3.5 moment. We're simply running out of hard tasks to throw at this model.
we are getting spoiled with long-horizon coding benchmarks recently
here's another one: SWE-Marathon
Website: swe-marathon.org/
Paper: swe-marathon.org/swe-maratho…
Jesse Mu retweeted
Personal update: I've joined Anthropic. I think the next few years at the frontier of LLMs will be especially formative. I am very excited to join the team here and get back to R&D. I remain deeply passionate about education and plan to resume my work on it in time.
SOMEONE HOOK THIS MODEL UP TO OPENCLAW
Announcing Talkie: a new, open-weight historical LLM! We trained and finetuned a 13B model on a newly-curated dataset of only pre-1930 data. Try it below!
with @AlecRad and @status_effects 🧵
Jesse Mu retweeted
WolfSSL has extensive CI testing, fuzzing, static analysis tooling, their own internal AI-based static analysis tooling, code review, and spends thousands per month testing with Opus and other models. Despite all that, Mythos apparently found 8 CVEs missed by everything else.
Jesse Mu retweeted
A full-scale US Waymo rollout would cost ~700 full-time jobs in the funeral care industry (by saving around 35 thousand young American lives per year). Will no one think of (some of) the morticians!
Jesse Mu retweeted
Introducing Project Glasswing: an urgent initiative to help secure the world’s most critical software.
It’s powered by our newest frontier model, Claude Mythos Preview, which can find software vulnerabilities better than all but the most skilled humans.
anthropic.com/glasswing
protip for stanford undergrads: beware the classes with guest speaker lineups that read like AI coachella. you’re basically paying $5k to listen to a live podcast series.
instead I suggest learning by doing cs336.stanford.edu/
cs336 will kick your ass, but I can't think of a better way to get up to speed with the frontier of AI




































