Anthropic replaces git with in-house system Scion for agent-scale code

The new system, Scion, was designed specifically for agents that are always online, abandoning git’s decentralized, offline-first model. Instead, Scion uses a client-server architecture where the server handles commits, merges, and history queries, while clients maintain only sparse, on-demand working copies. This approach eliminates the need for large local repositories and allows for horizontal scaling without the maintenance burden of packfiles or internal mirrors.

Anthropic built Scion, along with a code review tool named Antique, in five months. The company notes that while few organizations face such extreme scale today, the pressure points identified are likely to become common as AI coding tools become more widespread. The shift highlights how developer infrastructure must evolve to support autonomous software development at machine speed.