Post by @mattpaige68

Comment: "FABLE" for the full breakdown. Three months ago Anthropic basically said this class of model was too dangerous to hand out. Only a handful of vetted orgs could touch it, under a program called Glasswing. Today they shipped a public version. It's called Fable 5. Same underlying model as Mythos, but wrapped in new safeguards that block the high-risk cyber and bio stuff and route those requests down to Opus 4.8 instead. Mythos 5 itself still went to the vetted partners who already had access. Fable 5 is the one the rest of us get. So what changed in 90 days? Not the model. The guardrails. That's the actual story here. The capability was always there. Anthropic just decided they finally trusted the fence around it enough to open the gate. Early data says ~95% of Fable sessions run start to finish without ever falling back to Opus. It's strong at coding, knowledge work, and long-horizon tasks where it has to remember what it's doing across a lot of steps. Heads up on price though. It's the most expensive thing they've released. $10 per million input tokens, $50 per million output. Roughly double an Opus model. Comment: "FABLE" for the full breakdown. #mythos #claudefable #fable5 #anthropic