Anthropic PBC is rushing to address the inadvertent release of internal source code behind Claude Code, an AI-powered assistant that has become a key moneymaker for the company.

The entire source code for Anthropic’s Claude Code command line interface application (not the models themselves) has been leaked and disseminated, apparently due to a serious internal error. The leak gives competitors and armchair enthusiasts a detailed blueprint for how Claude Code works—a significant setback for a company that has seen explosive user growth and industry impact over the past several months.

Anthropic, the company behind the AI coding assistant, said it was fixing a problem blocking users.