Anthropic ditches Git for its own version control system Scion

Anthropic, a US AI company, has dropped the widely used version control system Git and switched to its in-house system Scion, moving most source code management to servers.

The switch came as code changes surged: in May, Anthropic merged about 2,500 code changes a day, and by September that number passed 30,000, more than Git could handle. Scion uses only one two-hundredth of the CPU and memory Git needs, and code checkout now takes seconds instead of minutes.

Scion runs commits, merges, rebases, and file history lookups on the server, while the client only tracks local edits, manages files, and keeps a small cache. Since most of Anthropic's clients are AI agents that stay online all the time, Git's offline support offers little benefit.

This setup cuts local storage and syncing costs, but it relies on custom code review, search, and CI tools, so other companies can hardly copy it.