Bun joins Anthropic - Claude Code hits $1B milestone
Dec 3, 2025
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Anthropic has made its first-ever acquisition: Bun, the all-in-one JavaScript/TypeScript toolkit. The announcement comes alongside news that Claude Code has reached $1 billion in run-rate revenue, just six months after becoming publicly available.
Why Bun?
Bun is more than a Node.js alternative. It’s a complete JavaScript toolchain in a single executable: runtime, package manager, bundler, and test runner. With 7 million monthly downloads and 82,000 GitHub stars, it’s become a favorite among developers who want fast, streamlined tooling.
Anthropic sees Bun as the infrastructure foundation for Claude Code, Claude Agent SDK, and future AI coding products. The acquisition is about speed and stability for their coding agents.
“Bun represents exactly the kind of technical excellence we want to bring into Anthropic. Jarred and his team rethought the entire JavaScript toolchain from first principles while remaining focused on real use cases.” — Mike Krieger, CPO of Anthropic
What stays the same
Bun will remain open source and MIT-licensed. Anthropic has committed to continuing investment in making it the runtime, bundler, package manager, and test runner of choice for JavaScript and TypeScript developers.
The bigger picture
Claude Code is now used by enterprises like Netflix, Spotify, and Salesforce. The $1B milestone signals that AI-assisted coding has moved from experiment to production-grade tooling at scale.
This acquisition suggests Anthropic is thinking beyond just the model layer—they’re building the full stack for AI-native development.