Fable 5.1, Anthropic's upgraded model for coding and long-running agentic work, launched yesterday and is now available in Ana.
The headline changes are cost and speed. Fable 5.1 runs about 25% cheaper than Fable 5 on typical workloads and up to 45% cheaper on agentic tasks, largely from a steep cut to cache-read pricing. It's also noticeably faster, and it holds up better on coding work than both Fable 5 and Opus 5.
For Ana, that means the model handling your deepest investigations and longest-running agents just got faster and meaningfully cheaper to run at scale.
Try it now by opening a new thread and selecting Fable 5.1 from the model picker.
Enabling Access
Fable 5.1 is available to all Ana users. To enable it for your organization, go to Settings > Models and toggle Enabled next to Fable 5.1.
Learn More
Full model configuration options are in our documentation.
