No, has not killed git. It stopped using it for its own monorepo, the huge repository that holds almost all its code, and replaced it with Scion, a version control system it built in five months. itself says Scion is not a replacement for git for most people. The interesting part is why: when AI agents write the code, the thing that jams is no longer writing it, it is everything that comes after.
explains it on its engineering blog, in “Redesigning source control at Anthropic”, published on October 13.
What git is, in two lines
Git is the version control tool almost everyone who writes code uses. It records every change to the code, who made it and when, and lets you go back or combine several people’s work. Every git copy is complete: anyone can work offline with the full history on their computer. Platforms like GitHub and GitLab are built on top of git.
What happened at Anthropic
summed it up on X:
> “In May, we merged around 2,500 code changes per day. In September, we merged more than 30,000 per day. As a result, we became bottlenecked by developer infrastructure built for human (rather than agent) scale.” > > Anthropic (@AnthropicAI) on X
uses , its own model, to write software far more than almost any other company. According to the post, the history of the main branch alone is almost 100 GB and a compressed working copy is over 25 GB. For CI alone, the automated tests that run on every change, they do on the order of 25 million code checkouts a day. If every one of those checkouts cloned the whole repository with git, it would come to over 600 PB a day. That is ’s estimate to show the scale, not real traffic. At their peak they ran several hundred internal git mirrors to keep up.
Spanish developer and educator midudev put it like this (our translation below):
> «¡Anthropic crea su propio Git! Desde septiembre fusionan más de 30.000 cambios de código al día. ¡Y git era un cuello de botella! Su solución: crear en solo 5 meses su propio sistema de control de versiones, pensado para agentes de IA en lugar de humanos» > > Miguel Ángel Durán (@midudev) on X
“Anthropic builds its own Git! Since September they merge more than 30,000 code changes a day, and git was a bottleneck. Their fix: build their own version control system in just 5 months, designed for AI agents instead of humans.”
How Scion works
The core idea is simple. Git gives every computer a full copy because it assumes you will work offline. Almost all of ’s clients are agents and automated jobs that are always online. So in Scion the server does the heavy lifting (history, who changed each line, merges) and each client only downloads the files it actually reads.
According to , Scion’s infrastructure needs 200 times less CPU and memory than the internal git mirrors they ran before. Code checkouts for CI and research take seconds instead of minutes, and CI, the automatic testing of code, gained 25% of CPU capacity.
A team of seven people built Scion and also Antique, their code review tool, in those five months. They also built code search and a permissions system that can protect individual folders, with writing much of the code. The engineers say they now review the intent of each change instead of reading every line.
What is still true about git
is clear: Scion is not a replacement for git for general use and only makes sense for truly enormous monorepos, with tens of thousands of engineers or swarms of agents. has not announced any plan to release it, and says adopting it would mean changing the whole development lifecycle. Instead it wants to share what it learned so some of the ideas reach git, and to work with GitHub, GitLab and the open source community. If your company uses git, it is still the right tool.
The warning for your business
expects this kind of problem to become common at other companies over the next 6 to 12 months. That is a forecast, not a launch date. Your company will not merge 30,000 changes a day, but the pattern repeats on a small scale. Once you start using Code or other agents to write code, code comes out faster and the jam moves somewhere else: slow tests, a growing pile of reviews, deployments nobody automated, permissions nobody checks.
So it pays to look at your infrastructure before it becomes the bottleneck. That is what our €200 Technical Audit is for: analysis and an improvement report for your website or app. If you would rather talk first, get in touch.