Anthropic’s Fable 5.1 Gets Better, Up to 45% Cheaper #
Anthropic released Fable 5.1 and Mythos 5.1, claiming sharper performance for agentic coding and scientific research. Fable 5.1 doubles its predecessor’s Terminal-Bench-Science score and improves agentic coding by more than 30 percent.
Fable 5.1 is estimated to cost 25 percent less than Fable 5 for typical workloads billed by token. For long autonomous runs with many tool calls, costs can fall by up to 45 percent, with Anthropic attributing the reduction in part to lower cache-read pricing.
TechCrunch reports that Fable 5.1 also includes changes meant to reduce token costs and false-positive restrictions from the model’s safeguards.
Why it matters: Customers running long autonomous coding or research tasks can get more than 30 percent better agentic-coding performance while paying up to 45 percent less than with Fable 5.
Key Takeaways
- Fable 5.1 doubles its predecessor’s Terminal-Bench-Science score.
- Anthropic estimates 25 percent lower costs for typical workloads billed by token, citing reduced cache-read pricing.
- TechCrunch reports changes to Fable 5.1’s safeguards meant to reduce false-positive restrictions.