Bun is used as the runtime for Claude Code. Today it was acquired by Anthropic.

We’ve been a close partner of Bun for many months. Our collaboration has been central to the rapid execution of the Claude Code team, and it directly drove the recent launch of Claude Code’s native installer. We know the Bun team is building from the same vantage point that we do at Anthropic, with a focus on rethinking the developer experience and building innovative, useful products.

Congratulations to Jarred Sumner and the Bun team. Here he describes how the acquisition happened:

We’ve been prioritizing issues from the Claude Code team for several months now. I have so many ideas all the time and it’s really fun. Many of these ideas also help other AI coding products.

A few weeks ago, I went on a four hour walk with Boris from the Claude Code team. We talked about Bun. We talked about where AI coding is going. We talked about what it would look like for Bun’s team to join Anthropic. Then we did that about 3 more times over the next few weeks. Then I did that with many of their competitors. I think Anthropic is going to win.

I had the privilege to walk with Jarred a couple weeks ago during a rainy day at Apple Park. He’s very smart. I’m thrilled to hear he’s getting all the fuel needed to build great tools.