Anthropic replaces Git with Scion, its in-house source control, as merges pass 30,000 a day

Anthropic says it built Scion, an in-house version control system that replaced Git for its monorepo, after daily code merges grew from 2,500 in May 2026 to over 30,000 in September. Seven engineers built Scion and the Antique code review tool in five months; Scion is not being open-sourced.