← Retour au blog
tech 19 July 2026

Claude Code Adopts Bun Written in Rust: A Quiet Revolution

Claude Code now uses Bun, rewritten in Rust, to enhance its performance quietly. Discover how this transition impacts software development.

Article inspired by the original source
Claude Code uses Bun written in Rust now ↗ simonwillison.net

Why Claude Code Switches to Bun in Rust

Claude Code, a popular tool among developers, recently integrated Bun, a JavaScript runtime, rewritten in Rust. This strategic decision aims to enhance performance and security. According to Jarred Sumner, the developer behind Bun, this new version brings a 10% improvement in startup times on Linux without disrupting users.

The Advantages of Rust

Rust is renowned for its memory safety, speed, and ability to optimize application performance. By rewriting Bun in Rust, Claude Code bets on reliability and robustness, two essential characteristics for applications used by millions of developers. Indeed, Rust reduces segmentation faults, common in other programming languages like C++.

Concrete Evidence of the Transition

To verify this transition, Simon Willison shared a few commands to confirm Bun's use in Rust within Claude Code. For instance, running strings ~/.local/bin/claude | grep -m1 'Bun v1' reveals the use of Bun v1.4.0, an advanced version compared to the one publicly available.

Impact on Users

For end-users, this transition is virtually invisible, which is a good thing. "Boring is good," as Sumner points out, meaning the change happens seamlessly, ensuring service continuity. However, developers benefit from enhanced efficiency, resulting in shorter development cycles and easier code maintenance.

What This Means for the Industry

Claude Code's switch to Bun in Rust could inspire other tools and companies to consider Rust for improving their applications' performance and security. With the rise of AI and applications requiring significant computing power, this transition could represent a major turning point in optimizing software infrastructures.

Conclusion

The integration of Bun written in Rust by Claude Code marks a significant step towards faster and safer applications. For developers and decision-makers, this represents an opportunity to explore new ways to enhance their products. Let's discuss your project in 15 minutes.

Claude Code Bun Rust performance software development
Deepthix newsletter · 100% AI · every Monday 8am

An AI agent reads tech for you.

Our AI agent scans ~200 sources per week and ships the best articles to your inbox Monday 8am. Free. One click to unsubscribe.

Visit the newsletter page →

Want to automate your operations?

Let's talk about your project in 15 minutes.

Book a call