Git Rewritten in Rust Using AI Agents

What happened

GitHub co-founder Scott Chacon has pulled off something remarkable: using AI agents to rewrite all of Git from scratch in Rust. The project, called Grit, passes over 99% of Git's original 42,000-test suite, making it one of the most ambitious agent-driven software rewrites ever completed.

Why it matters

Chacon was inspired by Anthropic's experiment of unleashing a swarm of agents to write a C compiler. He applied the same approach to a problem he had been thinking about for 15 years: rebuilding Git as a linkable, reentrant Rust library rather than the Unix-style chain of commands that makes Git difficult to embed in long-running processes.

What's next

The result is a pure-Rust core library that can faithfully interact with Git repositories, paired with an independent CLI crate. Chacon warns Grit is not battle-tested yet and could corrupt data, but passing the entire C Git test suite from scratch is a striking demonstration of what AI agents can accomplish when pointed at well-defined, test-covered codebases.