Anthropic Launches Fable 5 (Mythos-Class Model) With Built-In Restrictions
7 videos · score: 10,211 · first seen Jun 12, 2026
Anthropic releases Fable 5, internally the restricted consumer-facing version of its frontier 'Mythos 5' model, alongside new usage-based billing. Videos cover the model's benchmark performance (Terminal Bench, SWEBench Pro), the surprisingly high token costs under the new billing scheme, and confusion over the built-in access restrictions and safeguards distinguishing Fable 5 from Mythos 5.
Mythos is here, it’s time to start tokenmaxxing
The Fable (Mythos) model is being removed from Claude Code Pro and Max tier subscriptions on June 23rd due to high compute costs, ending a limited-time offer where users could access up to $8,000 in inference for $200/month.
Fable is Mythos, and it is really good.
The creator announces a fresh rebranding of Fable as Mythos, praising it as really good and highlighting a new perspective on the game.
The weird situation with Fable
Anthropic's launch of Fable 5, a restricted Mythos-class model, has drawn criticism for its heavy limitations and US government-mandated safeguards, which many argue render it ineffective for developers.
Anthropic's Horrible New Restrictions
Anthropic's new Fable model faces criticism for restrictive access policies and poor performance, as it failed all 200 tasks on Program Bench, according to recent backlash.
Fable/Mythos Usage Is INSANE
The creator found that switching to usage-based billing led to unexpectedly high costs and rapidly maxed out two subscriptions, making it impractical for completing their task without significant additional spending.
What Is Fable 5?
The creator provides an in-depth review of Fable 5, a restricted version of Mythos 5 with added safeguards, revealing it outperforms the Opus series on key code benchmarks like Terminal Bench and SWEBench Pro, despite higher costs and lower token usage.
Fable 5 vs Mythos 5: The Basics
Enthropic has released Fable 5 and Mythos 5, with Mythos 5 being the production-ready AI model and Fable 5 incorporating additional security checks under the Project Glass Wing initiative.