Claude Code Migrates To Bun

San FranciscoClaude Code has run on Bun-in-Rust since June.

Developer Simon Willison found strings inside the CLI pointing to a Rust port of Bun, cutting startup time 10% on Linux.

The unreleased Bun 1.4 rewrite remains in canary while millions of Claude Code installs run it in production.

Sources: Hacker News