Artificial intelligence company Anthropic has just announced that it is acquiring Bun. The acquisition took place on December 2, 2025, at a time when its Claude Code tool is enjoying tremendous success. Claude is described as the most intelligent and capable artificial intelligence model for developers, startups, and large enterprises. Claude Code introduces a new way to build software using agents, transforming the entire software development process. In November, the tool reached an important milestone: just six months after becoming publicly available, it achieved $1 billion in annual revenue (approximately CZK 23.5 billion). And now comes the acquisition of Bun, which is expected to accelerate everything even further.
Bun is a tool that is transforming speed and performance in modern programming. It was founded by Jarred Sumner in 2021 and is much faster than its main competitors. It serves as an all-in-one toolkit—including a runtime (an environment for running code), package manager, bundler, and testing tool. It has become a key component of AI-assisted software development because it allows developers to build and test applications at unprecedented speed.
For those who use Claude Code, this acquisition means better performance, greater reliability, and new features. Anthropic promises that together they will make Bun an even better tool for all developers working with JavaScript (a language for web applications) and TypeScript (its extended version). At the same time, they will integrate these improvements directly into Claude Code to make the entire development process smoother.
Previous Collaboration Between Claude Code and Bun
Claude Code became publicly available in May 2025. It began as an internal experiment at Anthropic but quickly evolved into an important tool for many leading companies around the world. These include Netflix, Spotify, KPMG, L’Oreal, and Salesforce. Bun played a key role in scaling Claude Code’s infrastructure during this growth. Anthropic and Bun had already been working together for several months, and this collaboration helped the Claude Code team quickly turn its ideas into reality. It directly contributed to the recent launch of the native installer for Claude Code.
Mike Krieger, Chief Product Officer at Anthropic, said: "Bun represents exactly the kind of technical excellence we want to bring to Anthropic. Jarred and his team have rethought the entire JavaScript toolchain from the ground up, focusing on real-world needs. Claude Code reached $1 billion in annual revenue in just 6 months. Bringing the Bun team into Anthropic will allow us to build the infrastructure that will strengthen this momentum and keep pace with the rapid growth in artificial intelligence usage."
Why Is Bun So Popular?
As the use of artificial intelligence in software development grows, the underlying infrastructure is becoming increasingly important. Bun has proven to be an essential tool—it has more than 7 million downloads per month, has earned over 82,000 stars on GitHub (a code-sharing platform), and is used by companies such as Midjourney and Lovable to increase the speed and productivity of their teams.
The decision to acquire Bun fits into Anthropic’s strategy, which focuses on acquisitions that strengthen technical capabilities, reinforce its position as a leader in enterprise artificial intelligence, and, most importantly, align with its principles and goals. Bun will help build the foundation for the next generation of software. Together, they will make Claude the platform of choice for developers and those who rely on artificial intelligence for critical work.
Bun will remain open source under the MIT license, and Anthropic will continue to invest in its development as the primary runtime, bundler, package manager, and testing tool for JavaScript and TypeScript.
