On Tuesday, June 9th, Anthropic officially launched Claude Fable 5, a public version of its closely-guarded Mythos model, which has been locked away in a digital panic room since April.
Anthropic was genuinely terrified of what it could do in the wrong hands, so they only let a tiny group of trusted partners touch it. But now? Anyone with an API key or an Enterprise plan can take it for a spin.
So what makes Fable 5 such a massive deal?
Think of the original Mythos as the secret, boss-level AI Anthropic kept behind a closed door. Fable 5 is what happens when they finally crack that door open for the rest of us, with some heavy-duty safety bumpers bolted onto the sides.
This model absolutely crushes software engineering, complex analysis, and visual tasks. The analytics firm Hex reported that it scored a mind-blowing 90% on a brutal benchmark for long, complex analytical work, completely beating every other model they tested.
Meanwhile, the team at Genspark said Fable easily beat every other model in their private evaluations, performing significantly better on things like UI design and game coding.
And if you love a good "vibe-coding" moment, platform Base44 noted in a statement that Fable is next-level at tool-calling and "one-shotting full apps" in a single go.
But that’s not all:
Researcher Ethan Mollick from the University of Pennsylvania put Fable through its paces and shared his findings on his Substack.
He confirmed that the model consistently outperformed every single public AI he has ever tested. To prove it, Fable managed to build multiple full, playable browser games from a single prompt in Claude Code.
We’re talking about a working Snake clone and, get this, a moody walking game inspired by Rainer Maria Rilke's poetry. I mean, a literal poetic video game from one text prompt. Whole development teams used to spend weeks doing stuff like this.
Now for the fine print:
Because this model is so powerful, Anthropic is acting like a total helicopter parent.
First, Fable 5 will absolutely refuse to help you with anything touching cybersecurity, biology, chemistry, or high-risk tech. If you try to ask it something shady, it will instantly ghost you and fall back to the lower-tier Claude Opus 4.8. Anthropic actually ran over 1,000 hours of jailbreak testing before launch, and they claim no universal workarounds were found.
Second, your privacy agreements just got a makeover. All traffic gets a mandatory 30-day data retention policy going forward, even for giant enterprises that previously had zero-retention contracts.
Third, the price tag is incredibly spicy. It costs $10 per million input tokens and $50 per million output tokens, which is exactly double what Opus 4.8 costs.
For the elite cyber-defenders out there, Anthropic is also deploying a hyper-exclusive version called Mythos 5 to organizations already approved for the advanced model.
The company explicitly promised they won’t use this elite tier's data for training. Instead, they are using it strictly to "defend against complex and novel attacks, including new jailbreaks," and to "identify and reduce false positives." Essentially, it's the ultimate digital shield.
How to get your hands on Fable 5: If you’re currently a subscriber on Pro, Max, Team, or seat-based Enterprise plans, you can access Fable 5 for free until June 22. After that, the free ride is over and your usage credits kick in.
And don’t forget to meet us on YouTube so you can get our full take on this later today!
