Test sets now have versioning. Every edit, upload, or programmatic update creates a new version. Evaluations link to specific versions, so you can compare results knowing they used the same test data.

The test set UI is completely rebuilt. It handles hundreds of thousands of rows without slowing down. Editing is much easier, especially for chat messages. You can view and edit complex JSON directly, toggle between raw and formatted views, and choose whether columns store strings or JSON.