Anthropic acquires Bun as Claude Code reaches $1B milestone

Claude is the world’s smartest and most capable AI model for developers, startups, and enterprises. Claude Code represents a new era of agentic coding, fundamentally changing how teams build software. In November, Claude Code achieved a significant milestone: just six months after becoming available to the public, it reached $1 billion in run-rate revenue. And today we’re announcing that Anthropic is acquiring Bun—a breakthrough JavaScript runtime—to further accelerate Claude Code.

Bun is redefining speed and performance for modern software engineering and development. Founded by Jarred Sumner in 2021, Bun is dramatically faster than the leading competition. As an all-in-one toolkit—combining runtime, package manager, bundler, and test runner—it's become essential infrastructure for AI-led software engineering, helping developers build and test applications at unprecedented velocity.

Bun has improved the JavaScript and TypeScript developer experience by optimizing for reliability, speed, and delight. For those using Claude Code, this acquisition means faster performance, improved stability, and new capabilities. Together, we’ll keep making Bun the best JavaScript runtime for all developers, while building even better workflows into Claude Code.

Since becoming generally available in May 2025, Claude Code has grown from its origins as an internal engineering experiment into a critical tool for many of the world’s category-leading enterprises, including Netflix, Spotify, KPMG, L’Oreal, and Salesforce—and Bun has been key in helping scale its infrastructure throughout that evolution. 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.

"Bun represents exactly the kind of technical excellence we want to bring into Anthropic," said Mike Krieger, Chief Product Officer of Anthropic. "Jarred and his team rethought the entire JavaScript toolchain from first principles while remaining focused on real use cases. Claude Code reached $1 billion in run-rate revenue in only 6 months, and bringing the Bun team into Anthropic means we can build the infrastructure to compound that momentum and keep pace with the exponential growth in AI adoption."

As developers increasingly build with AI, the underlying infrastructure matters more than ever—and Bun has emerged as an essential tool. Bun gets more than 7 million monthly downloads, has earned over 82,000 stars on GitHub, and has been adopted by companies like Midjourney and Lovable to increase speed and productivity.

The decision to acquire Bun is in line with our strategic, disciplined approach to acquisitions: we will continue to pursue opportunities that bolster our technical excellence, reinforce our strength as the leader in enterprise AI, and most importantly, align with our principles and mission. 

Bun will be instrumental in helping us build the infrastructure for the next generation of software. Together, we will continue to make Claude the platform of choice for coders and anyone who relies on AI for important work. Bun will remain open source and MIT-licensed, and we will continue to invest in making it the runtime, bundler, package manager, and test runner of choice for JavaScript and TypeScript developers.

If you’re interested in joining Anthropic’s engineering team, visit our careers page.