Bun is great software.

I use it all the time. It is fast and practical, and the team ships constantly. It makes TypeScript a joy to work with in small scripts, apps, tests, and tooling. That is why this is frustrating. I want Bun to win. I want a serious Node.js alternative. I want faster installs, faster tests, better bundling, and less toolchain bloat.

But I am worried about Bun now.

Anthropic owns Bun

Anthropic acquired Bun in December 2025.

The announcement said everything I wanted to hear: Bun stays open source and MIT-licensed, the same team keeps working on it, and the roadmap keeps focusing on high-performance JavaScript tooling and Node.js compatibility.

It also said this:

Claude Code ships as a Bun executable to millions of users. If Bun breaks, Claude Code breaks. Anthropic has direct incentive to keep Bun excellent.

In December, that sounded reassuring. Anthropic had a huge product built on Bun. That meant Anthropic had a direct incentive to keep Bun fast, stable, and excellent.…