Simon Willison used Claude Fable to fix critical bugs in sqlite-utils 4.0 for about $149.25

sqlite-utils 4.0rc2, mostly written by Claude Fable (for about $149.25)

Simon Willison had Claude Fable do a final review before shipping sqlite-utils 4.0 stable. The model found a data-loss bug where delete_where() never commits, silently rolling back all subsequent writes. The fix took 37 prompts, 34 commits across 30 files, costing $149.25. He then had GPT-5.5 cross-review the changes and found two more issues. The new release rewrites transaction docs: all writes auto-commit by default, and you only need to think about transactions when using db.atomic() or manual begin().

Why it matters: Simon Willison used Claude Fable for a pre-release review of sqlite-utils 4.0 and the model caught a silent data-loss bug. Full prompt count, commit count, and cost are disclosed — this is a first-person experiment, not a vendor case study. Not scored higher because it's a sin...