Anthropic Acquires Bun to Accelerate Claude Code Development

Anthropic has acquired Bun, a high-performance JavaScript runtime, to accelerate the development and infrastructure of Claude Code. This acquisition follows Claude Code reaching a $1 billion run-rate revenue milestone in November 2025, just six months after its public release in May 2025.

Claude Code Revenue and Enterprise Adoption

Claude Code has transitioned from an internal engineering experiment to a critical tool for major enterprises. Within six months of becoming generally available, the tool reached a $1 billion run-rate revenue milestone. Current enterprise users include Netflix, Spotify, KPMG, L’Oreal, and Salesforce.

The Role of Bun in AI-Led Software Engineering

Bun is an all-in-one toolkit that combines a runtime, package manager, bundler, and test runner. It is designed for speed and performance in JavaScript and TypeScript development, making it essential infrastructure for AI-led software engineering.

Key metrics for Bun include:

• Over 7 million monthly downloads.
• More than 82,000 stars on GitHub.
• Adoption by companies such as Midjourney and Lovable to increase productivity.

Integration and Future Impact on Claude Code

Anthropic and Bun have been close partners for several months, a collaboration that directly enabled the launch of Claude Code’s native installer. The acquisition aims to bring Bun's technical excellence in rethinking the JavaScript toolchain from first principles into Anthropic.

For users of Claude Code, the acquisition is expected to result in:

• Faster performance.
• Improved stability.
• New capabilities integrated into the developer workflow.

Open Source Commitment and Strategy

Bun will remain open source and MIT-licensed. Anthropic intends to continue investing in Bun as a runtime, bundler, package manager, and test runner for the broader JavaScript and TypeScript developer community.

"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."

This acquisition aligns with Anthropic's strategic approach to bolstering technical excellence and reinforcing its position as a leader in enterprise AI.