Synced Report About 90% of Claude Code’s own codebase has now been written by Claude. Code writing switched to AI, and the volume of changes surged accordingly: from June to September, the number of PRs merged into the codebase more than doubled. Across Anthropic, the number of changes merged into the main codebase each day rose from about 2,500 in May to more than 30,000 in September. Can humans still read through all this code? If even code review is han