Claude Fable 5.1 lands hard: faster, cheaper, and now running production agent workloads.

From the editor

The 5.1 release cycle is doing something interesting. Better benchmarks and lower costs are expected at this point, but the Agent Platform availability signals a real inflection: Anthropic is pushing Claude into long-running, high-stakes production workflows. Meanwhile, JetBrains data showing Claude Code as the dominant tool among 15,000 developers isn't a vanity metric, it's a moat forming in real time. The misalignment evals paper and transparency essay arrive exactly when you'd want them to, as the agentic surface area grows fastest.