Summary
On September 1, 2026, Cursor made Claude Fable 5.1 available in the editor, calling it the most capable model it has run on CursorBench 3.2 with a 73.4% score at max effort, ahead of Grok 4.6 (70.8%) and Fable 5 (70.5%). Cursor highlighted the model's ability to verify its own work and carry difficult coding tasks from start to finish.
What changed
Cursor integrated Claude Fable 5.1 as a selectable model and published CursorBench 3.2 results showing it leading at 73.4% at max effort.
Why it matters
For a priority coding-tool vendor, first-day support of a new frontier model plus a public benchmark shapes which model developers reach for on hard, long-horizon tasks. It reinforces the pattern of coding platforms racing to expose the strongest model on day one while steering routine work to cheaper in-house models like Composer 2.5.
Evidence excerpt
Claude Fable 5.1 is now available in Cursor! It's the most capable model we've run on CursorBench 3.2, scoring 73.4% at max effort. We found it especially skilled at verifying its own work.