#Anthropic

Claude Fable 5 is Anthropic's first Mythos-class model available to everyone — and it's not really a chat model anymore. It's an agent runtime. Here's what that actually means for people building on it.

Anthropic dropped Claude Opus 4.8 and the reactions split predictably: half the community raving about benchmark supremacy, the other half staring at their API bills. Both camps are right. At $25 per million output tokens — and thinking tokens that count twice — you can burn through serious budget before you realize what's happening. One documented case: 62 million tokens in 24 hours, hitting a $2,500 monthly cap overnight. That's the model doing exactly what you asked. Whether that's a feature or a problem depends entirely on how you're using it.

Anthropic's "Code with Claude" event had a specific energy — optimistic, a little breathless, and slightly unnerving if you've been writing code for a living for more than a decade. The head of Claude Code said it plainly: "The default isn't 'I'm going to prompt Claude' — the default is now 'I'm going to have Claude prompt itself.'" Most people in the room nodded along. Meanwhile, technical managers at Anthropic are already overloaded managing the volume of auto-generated code from their own internal tools. That's either ironic or clarifying, depending on how you look at it.