Anthropic Migrates Internal Source Control from Git to Scion
Current overview (not historical)
Anthropic has finished migrating its internal source‑code management from Git to its own system, Scion. The seven‑person team completed the transition in five months, boosting daily merge volume from roughly 2,500 to over 30,000 merges while dramatically reducing Git traffic from 600 PB to negligible levels. Scion was designed to accommodate the heavy usage of Claude, Anthropic’s flagship model, which runs continuously. Because Claude is always online, the new system does not support offline operation, a trade‑off the team accepted to keep the platform responsive. The move reflects Anthropic’s broader effort to tailor infrastructure to its AI workloads, prioritizing low‑latency, high‑throughput code integration over the traditional Git workflow.
Written with AI from the reporting · updated 10/15/2026
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- 1Unclassified fact stationOct 13, 00:00recorded Oct 14, 22:22single sourcerevised
Anthropic 完成 Git 到 Scion 的迁移
Read original source ↗ Simon WillisonReplay this moment in the explorerEvidence & revisions · 1 source records
- Subject：
- anthropic
- Action：
- 完成自研 Scion 源代码系统的迁移
- Object：
- Git 源代码系统
- Occurred (fact side)：
- Oct 13, 00:00
- Published (valid side)：
- Oct 14, 07:00
- First seen (known side)：
- Oct 14, 22:22
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- Simon WillisonRelated fact: single sourceSource report revisedAnthropic builds custom source control system Scion to handle massive code change velocity
Report first recorded Oct 14, 22:22
Anthropic developed Scion, a custom source control alternative to Git, to manage a dramatic increase in code changes, rising from an average of 2,500 merged changes per day in May 2026 to over 30,000 per day by September. The new system was built by a seven-person team over five months, addressing issues like a 100 GB main branch history and reducing potential daily Git traffic from over 600 PB to a much lower level; Scion intentionally lacks offline support because Claude, a heavy user, is always online.
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