People loved Fable 5 because it inferred intent better than any other model by a considerable margin. Sure, it was also the most capable model, but it's ability to just 'get' what you wanted, was unparalleled.
brainstorming with Opus 4.8 or GPT 5.5 is measurably worse than just thinking by myself
with Fable that was not the case
Fable was a helpful contributor, with deep understanding of the entire project
but with other LLMs, I just feel myself drowning in brain fog
I’ve had a number of conversations with folks inside and outside government about the current situation with Anthropic, and here is what I believe to be true:
— As we know, Anthropic publicly released its Mythos class models earlier this week under the commercial name Fable.
— Fable is Mythos with guardrails. But if those guardrails fail, then you’ve exposed Mythos and its advanced cyber capabilities to people who shouldn’t have them. (Keep in mind that Anthropic itself widely promoted the idea that Mythos was a cyberweapon and needed to be regulated as such. They asked for government regulation of Mythos and championed the guardrails on Fable. If there is a vulnerability — big or small — it is Anthropic’s responsibility to patch.)
— A highly credible trusted partner of both Anthropic and the USG who was testing Fable came forward with a jailbreak of those guardrails. The Admin asked Dario to fix the jailbreak or de-deploy the model. Dario refused.
— In their blog post, Anthropic defended its decision by saying the jailbreak isn’t serious. That is not what the trusted partner and the USG believe; nor is that kind of minimizing language consistent with Anthropic’s brand as the AI safety company. It’s difficult to fathom how they could claim a jailbreak allowing operability of a cyber weapon could be defined as not “serious.”
— In the past, Anthropic has always said that safety must be top priority and taken super seriously. In this case, Anthropic prioritized the continued offering of the consumer model over safety.
— In reaction, the Admin issued the export control. The Admin did this reluctantly. It’s been very surprised that Anthropic hasn’t wanted to cooperate with a reasonable safety request (ie fixing the jailbreak issue). Anthropic’s reaction is very much at odds with their branding and ethos as a safe AI research community.
— The Admin’s hope now is that Anthropic remediates the safety issue, the export control is lifted, and Fable goes back into general release. The Admin wants all of this to happen as soon as possible. It is frankly bewildered that Anthropic hasn’t wanted to comply with safety requests that it previously said were its highest priority.
— Those trying to misdirect and tie this action to the prior DoW/Anthropic issues are wrong. The Admin values Anthropic’s technical capabilities and feels that this issue, while serious, should be easily resolved. The ball is in Anthropic’s court.
For anyone wondering what this means:
- Anthropic (and potentially future OpenAI, Google, xAI) models that cost billions to develop will make 0 revenue outside the US
- a big double digit percentage of Anthropic (and potentially OpenAI, Google, xAI) workforce can no longer work there, because they are foreigners and are not allowed to use those models
So Trump just made frontier model development effectively unprofitable and tremendously slowed down Anthropic (and potentially others in the future)
He's handing China the win on a gold platter.
*potentially: if the same restrictions are imposed on other frontier labs and models
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Fable has just released 30 minutes of gameplay, showcasing:
- Date, marry, start a family, or even divorce NPCs
- Your decisions shape the entire game
- Unique NPC system, they react based on your actions
Getting the most out of Claude Fable 5, Anthropic’s powerful new model, you need to maximize your ambition:
It’s built for full task delegation—you leave it looping for hours or overnight and come back to a finished product. If you want to get the most out of it, you need to relearn what software engineering is and how to step away to let the model do its work.
That’s why I invited @mikeyk, head of Anthropic Labs, on @every’s AI & I. Mike’s been using Mythos-class models for a few months now internally at Anthropic, and he’s learned a ton of new tricks to make its increased powers work for him.
And, as a co-founder of Instagram, he can reflect on how software engineering has changed over the last 15 years and what it means going forward.
We get into:
- Why the right workflow for Fable 5 is overnight delegation, not back-and-forth iteration—Mike ends his workday by briefing the model, then wakes up to a completed task. When a remote service went down mid-task, Fable 5 wrote a workaround, documented it, and forged ahead
- The gap between what’s in your head and what exists in the world is closing fast—given access to Fable 5 and a set of internal MCPs, an Anthropic recruiter described the experience as, "The first time in my life where I feel like the thing that's in my head and the thing that exists in the world are right next to each other. I can just do it."
- Software engineering isn’t dead, but the role has been reinvented—the PM/eng split is blurring, and the better engineers Mike talks to are holding two feelings at once: loss for the craft and shock at what’s now possible
- Verification is the new bottleneck—Mike gives Fable video captures of its own work so it can catch animation glitches that screenshots would miss
This is a must-watch for anyone building software and trying to figure out their role now that the models can handle so much.
Watch below!
Timestamps
Introduction: 00:00:03
How Fable completely reshaped Mike's workflow: 00:01:48
When to use Sonnet versus Fable: 00:04:48
What the media tracker Mike built over a weekend reveals about agent-native architecture: 00:10:06
The cost to build has collapsed: 00:15:00
Is software engineering over?: 00:19:03
How Anthropic's engineering teams work today: 00:21:48
The mechanics of verification: 00:38:39
Dynamic workflows: 00:47:24
What people should use the model to build: 00:44:39
The best in the world operate off pure intuition. You can only read so much. You can only think so much. Ask anyone who is the best of the best in their field how they do it and they can't give an answer.
They are not being humble or secretive. They themselves do not know. Magnus always talks about how he is a poor chess player by theory standards, but he just has one-in-a-billion intuition for middle and endgames.
The best traders in the world are not the smartest, they don't have the best models. They somehow just know where to allocate capital. Same for best researchers, best designers, best athletes, etc.
Of course, this does not mean that they do not work hard. Really, most of this intuition *comes from* the hours in the dark where they themselves were in the dark; learning to traverse the idea-tree independently. To gain the intuition, you need both hours and blessings.
"No amount of money poured into physics could have ever gotten you Special Relativity, only an Einstein daydreaming at a Swiss patent shop" - @iamgingertrash