kapynDev Tools

Bun ditches Zig for Rust with help from Claude Fable 5, writes over a million lines of code in 11 days

Bun is a JavaScript runtime now fully rewritten in Rust using AI assistance. Claude Fable 5, an Anthropic model, played a significant role in generating over a million lines of code in just 11 days for this substantial rewrite. This shift to Rust, aided by advanced AI, aims to improve performance and maintainability for the Bun project, offering a more robust foundation for developers.

The Decoder·Jul 10, 2026

Opening Kapyn…