What happened
Scott Chacon, co-founder of GitHub and GitButler, used AI agents to rewrite Git in Rust, creating "Grit." This new library-based, memory-safe implementation passes over 99% of Git's 42,000+ test suite. The project, costing an estimated $10-15k in tokens across Claude and Cursor models, generated over 360,000 lines of Rust code, demonstrating agentic capabilities for complex software re-engineering. Grit is released under an MIT licence, diverging from Git's GPL.
Why it matters
This re-implementation offers platform engineers a pure-Rust, embeddable Git core, enabling new use cases like WASM builds for edge functions or custom Git servers. Procurement teams should note the estimated $10-15k token cost for this complex rewrite, highlighting the significant operational expenditure for agent-driven development. The MIT licence also removes previous GPL linking constraints, potentially broadening adoption for tools like GitButler and Jujutsu.
