June 1, 2026

Anthropic discloses Claude wrote 80%+ of its production code in May

Anthropic's Recursive Self-Improvement post reports that over 80% of production code merged in May 2026 was authored by Claude, engineers merge ~8x more code per day than the 2024 baseline, and Claude Mythos Preview delivered a ~52x speedup on selected model-training code. The first measurable corporate disclosure of recursive self-improvement.