The way I figure it, a Claude subscription today at $200 buys about $2,000 worth of Fable before the promo window closes. If you’re building, it’s absolutely worth buying a second subscription.
The window is real and it’s short. Anthropic’s launch note says Fable 5 is included on Pro, Max, Team and seat-based Enterprise plans “from today through June 22” at no extra cost, and that on the API the same model runs $10 per million input tokens and $50 per million output. That gap, between tokens priced at the plan and the same tokens priced at the meter, is where the $2,000 lives.
Get Fable to do the big stuff, though. Don’t squander tokens on having it draft an email. Have it build a dream.
The big stuff is where this model earns its price. Anthropic’s own examples aren’t small. Stripe reported that Fable 5 “compressed months of engineering into days”, including a codebase-wide migration across 50 million lines of Ruby that the model did in a day and that would otherwise have taken a whole team over two months. Anthropic also says the longer and more complex the task, the larger Fable’s lead over its other models. An email is a job for a model that costs a fraction as much. A migration is a dream.
Security audits are big stuff too, and here Anthropic’s design deserves a word before you run one. The company says Mythos-class models “excel at discovering and exploiting software vulnerabilities”, which is exactly why you want one reading your code, and also why Fable carries classifiers that hand certain requests to a different model. In Anthropic’s words: “When Fable’s classifiers detect a request related to cybersecurity, biology and chemistry, or distillation, the response is automatically handled by Claude Opus 4.8 instead.” TechCrunch reports that Anthropic’s early data has at least 95% of Fable sessions running entirely on the model’s own responses, so the hand-off is rare overall. A security audit may well count as a cybersecurity request, though, so some of those answers could come from Opus 4.8 rather than Fable.
I must have sent out five notes to friends already today telling them to do a security audit with Fable.
