Anthropic Replaces Git With Its Own System, Scion: 7 Engineers and Claude in 5 Months

Seven engineers, five months, and Claude as an active co-author. That is the formula reported by the Chinese outlet Jiqizhixin: Anthropic wrote the Scion version control system from scratch for internal use and replaced Git with it. Git has been the developer standard for about 20 years. Along with Scion, the team built the Antique code review tool and several related systems. The report has few technical details so far, but the scale of the task alone says a lot.

What we know about the project

According to the outlet, a small group of seven engineers worked on the system. Claude was deeply involved in development rather than just suggesting code. Anthropic started with a clean slate: this is not a fork of Git or a layer on top of it, but its own system for storing and tracking changes to source code. The rest of the tooling, including review, was built around it.

• Team: 7 engineers and Claude
• Timeline: 5 months, built from scratch
• Scion: an internal source control system
• Antique: a code review tool that works together with Scion
• What was replaced: Git, the industry standard for about 20 years
• Status: internal use; the source does not mention a public release

Why big companies move away from Git

Git was created for distributed work on the Linux kernel, and in that role it long ago became a universal tool. But on very large monorepos and under a huge flow of changes, it hits its limits. Google has run for decades on its own system, Piper, Meta develops Sapling, and Microsoft once built VFS for Git. Anthropic now joins this list, with one unusual twist: according to the report, a significant part of the work was done by its own AI.

The source does not name the reasons for leaving Git. One plausible hypothesis: when agents also write and edit code, the load on the version control and review systems grows. Many parallel branches, small commits and merge requests appear, and tools designed for humans start to slow down. This is an assumption, not a confirmed fact.

What is still missing

The report rests on a single source, and the text provided contains no confirmation from Anthropic itself. It is unknown how Scion and Antique are built, whether they are compatible with Git at the level of formats and commands, or what repository sizes they can handle. It is not disclosed what share of the code Claude wrote or how the engineers verified the result. The word "replacement" also applies only to the company's internal infrastructure. The industry still runs on Git, and there is no indication that Scion will go beyond Anthropic.

What teams should take from this

Nobody needs to throw Git out. It is more useful to look at your own development process with agents and measure three things: the share of changes proposed by agents, average review time, and the frequency of merge conflicts. If review has become a bottleneck, the problem most likely lies in the process, and it is too early to change the version control system because of it.

The second takeaway concerns scale. Infrastructure projects of this class used to require dozens of people and years of work. If the figures are accurate, a small team with strong expertise and an AI agent can finish in five months. But this is Anthropic's team, which knows Claude's capabilities better than anyone. Anyone repeating this path should do so only with an honest estimate of maintenance costs: a homegrown version control system then needs support for years. It makes sense to wait for technical details from Anthropic and then compare.