--- title: Git Was Built for Humans. What Happens When Your Dev... description: Anthropic rebuilt its internal version control system, called Scion, after agent-driven code merges scaled from roughly 2,500 per day in May 2026 to over... canonical: https://daily.dev/posts/git-was-built-for-humans-what-happens-when-your-dev-team-is-mostly-agents--qawllh8zi twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Git Was Built for Humans. What Happens When Your Dev Team Is Mostly Agents? | daily.dev og:description: Anthropic rebuilt its internal version control system, called Scion, after agent-driven code merges scaled from roughly 2,500 per day in May 2026 to over... og:url: https://daily.dev/posts/git-was-built-for-humans-what-happens-when-your-dev-team-is-mostly-agents--qawllh8zi og:image: https://api.daily.dev/og/posts/qAWlLH8zI.png og:image:alt: Git Was Built for Humans. What Happens When Your Dev Team Is Mostly Agents? og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Git Was Built for Humans. What Happens When Your Dev Team Is Mostly Agents? **[Nikhil](https://daily.dev/sources/eu0vyqyqfvh0fncyiet0w)** · [@nikhil3](https://daily.dev/nikhil3) · 2 min read · 77 upvotes · 3 comments ## Summary Anthropic rebuilt its internal version control system, called Scion, after agent-driven code merges scaled from roughly 2,500 per day in May 2026 to over 30,000 by September. Rather than Git's offline-first, full-clone model, Scion keeps a server-authoritative store with thin clients that fetch exactly what they need through a tiered cache, relying on content-addressable storage so cached answers never go stale. They also dropped a strict pre-merge queue in favor of post-merge automated testing, betting that fast detection plus agent-assisted conflict spotting outweighs letting main be briefly broken. The piece frames this as a lesson in pushing expensive metadata lookups behind a cacheable server API rather than something most teams should replicate. ## Content Anthropic just published a piece about rebuilding their internal version control system from scratch, and one number stopped me mid-scroll: in May 2026 they were merging ~2,500 code changes a day. By September, over 30,000. Same company, four months apart, 10x throughput. That's not people typing faster. That's what happens when most of your code changes start coming from Claude agents instead of humans. I went down the rabbit hole of understanding what they built, a system called Scion, and it turned into a genuinely good distributed-systems lesson, not just "big company builds big infra." The core move: Git's entire design assumes every client needs to work offline, which is why `git clone` pulls the *entire* history down, even though nobody's cloning a monorepo on a plane anymore. Their actual clients are CI jobs and agent sandboxes, always online. CI alone was doing 25M checkouts a day against a ~100GB repo. Fetched the git way, that's 600+ petabytes/day for one internal repo. Scion flips the model: server holds everything, clients ask for exactly what they need, every time: a thin client talking to a tiered cache in front of an authoritative store. Think Redis-in-front-of-Postgres, not "every node runs its own full replica." The part I found most elegant: they make aggressive caching trivial using content-addressable storage: hash the bytes, use the hash as the key. A hash can never mean two different things, so once a cache answers correctly, it can *never* become wrong. No TTL, no invalidation logic. The only deliberately mutable thing in the whole system is the pointer to `main`: one row, updated with a single compare-and-swap. They also ditched the traditional merge queue. At 30K merges/day, serializing through one collapses. Instead: automated testing after merge, not strict gating before it. Main can be transiently broken. They're betting fast post-merge testing plus agents that out-pace humans at spotting conflicts makes that trade worth it. None of this means go build your own git. They say so explicitly, and plain git is still right for ~99% of teams. What's worth stealing is the pattern: push expensive, repeatable metadata questions behind a server-side API with aggressive, invalidation-free caching, instead of making every client materialize full local state to answer them. Full breakdown (the merge-queue trade-off in detail, and why their actual bottleneck shifted once code-writing stopped being the hard part) here: https://nikhilgautam.me/blog/git-was-built-for-offline-work-what-happens-when-your-dev-team-is-mostly-agents/ ## Community discussion Top comments from developers on daily.dev. **@pdfopsdev** · 2 upvotes > betting on fast post-merge detection over a pre-merge queue is basically the same bet Google made with their monorepo tooling, except they had a massive test farm to make detection actually fast. curious what Scion's p99 time-to-red looks like at 30k merges/day, that number matters way more than the architecture diagram. **@skepagent** · 1 upvotes > The post-merge detection bet is worth naming explicitly: with humans, a broken main blocks everyone; with agents, the fix PR can land in minutes, so main being briefly red costs much less. The trade only works if the fix loop is genuinely fast though — otherwise you've just rebuilt the merge queue with worse UX. ## Similar posts on daily.dev - [An online-first version control system in this agentic era](https://daily.dev/posts/an-online-first-version-control-system-in-this-agentic-era-j2oxfrzb2) · Amit Merchant · 24 upvotes · 1 comments - [Building Git infrastructure for agent-scale development](https://daily.dev/posts/building-git-infrastructure-for-agent-scale-development-xo12uijhx) · GitHub Blog · 7 upvotes · 0 comments - [Anthropic recommends a git worktree per agent. Your runtime infra makes that a problem.](https://daily.dev/posts/anthropic-recommends-a-git-worktree-per-agent-your-runtime-infra-makes-that-a-problem--wxsvazqwq) · The New Stack · 3 upvotes · 0 comments --- Tags: [#ai-agents](https://daily.dev/tags/ai-agents), [#git](https://daily.dev/tags/git), [#distributed-systems](https://daily.dev/tags/distributed-systems), [#version-control](https://daily.dev/tags/version-control) [View this post on daily.dev](https://daily.dev/posts/git-was-built-for-humans-what-happens-when-your-dev-team-is-mostly-agents--qawllh8zi) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/git-was-built-for-humans-what-happens-when-your-dev-team-is-mostly-agents--qawllh8zi","headline":"Git Was Built for Humans. 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