Bun Acquired by Anthropic for Claude Code | Generated by AI

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Question: Was Bun.js acquired by Anthropic?

Answer:

Yes, Bun was officially acquired by Anthropic, announced on December 2, 2025. This was Anthropic’s first-ever acquisition.

What is Bun?

Bun, founded by Jarred Sumner in 2021, emerged as a popular alternative to Node.js, offering developers an all-in-one solution that combines runtime, package management, bundling, and testing. Known for its speed and lightweight architecture, the toolkit has accumulated more than 83,000 stars on GitHub since its July 2022 debut.

Why Did Anthropic Acquire Bun?

Claude Code ships as a Bun executable. Since becoming generally available in May 2025, Claude Code has grown from 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.

Anthropic’s first acquisition is a JavaScript runtime. They’re betting that the winning AI company will be the one most deeply embedded in how software gets built, not the one with the best chat UI.

What Happens to Bun After Acquisition?

Anthropic said Bun “will remain open source and MIT-licensed” and that its development for general use by JavaScript and TypeScript developers will continue.

The same team continues working on Bun full-time, and they now get access to the resources of the world’s premier AI lab instead of a small VC-backed startup. Bun’s roadmap will continue to focus on high-performance JavaScript tooling, Node.js compatibility, and replacing Node.js as the default server-side runtime for JavaScript.

Key Context: Claude Code’s Growth

Claude Code surpassed a $1 billion annualized revenue run rate just six months after its public debut in May 2025, making the acquisition a strategic move to compound that momentum.

Potential Concerns

There could be friction ahead, as Bun’s native code is written in Zig — a language whose inventor Andrew Kelley has a “strict no LLM/No AI policy” in the official code of conduct for Zig contributors. Many acquisitions begin with those involved stating that nothing will change, but this rarely proves to be the case a few years later.

In summary: Yes, Bun was acquired by Anthropic in December 2025 to power Claude Code and future AI developer tools, while remaining open source and MIT-licensed.

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