Claude Fable 5 and Mythos 5 are here.
Same model, two names. What sets them apart isn’t capability, but guardrails.
Fable 5 is available to everyone. Mythos 5 remains restricted to Project Glasswing partners, with some safeguards removed in specific domains.
The detail that matters for developers: this isn’t a model that burns through tokens. Quite the opposite.
On a spreadsheet benchmark suite, it outperforms Opus 4.8 at every effort level, using fewer turns and completing tasks 25–30% faster.
It’s included at no extra cost for Pro, Max, Team, and Enterprise users until June 22. After that, it switches to usage-based pricing.
They’re giving you the most powerful model they’ve ever released… for two weeks. Enjoy it while it lasts—on June 23, the free ride is over.
Definitely worth testing properly before forming an opinion. 🧐
Original post : Claude Fable 5 and Claude Mythos 5
Jatniel
Senior freelance PHP developer. Symfony, Laravel, PrestaShop.
Web applications, REST APIs, and e-commerce.
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