AI startup Anthropic today announced the acquisition of Bun, the developer toolkit company. The move is designed to immediately boost the performance and stability of Anthropic's code-generation product, Claude Code, which has already reached a significant milestone.
This acquisition formalizes a partnership that Anthropic has been utilizing for months. Bun’s technology has been critical in scaling the infrastructure behind Claude Code and supporting its native installer launch.
The goal now is to integrate Bun founder Jarred Sumner and his team to solidify the foundation for future AI software development.
What Anthropic Bought
Bun, founded by Jarred Sumner in 2021, is an all-in-one JavaScript and TypeScript toolkit. It packages the code runtime, package manager, bundler, and test runner into one system. Bun’s key value is speed and optimized developer experience.
- Product Impact: Anthropic is bringing Bun’s technical team and IP in-house to make Claude Code faster and more reliable for enterprise users.
- The Path: This deal moves Anthropic into the developer tooling space, signaling a strategic intent to control the low-level infrastructure for its AI coding agents.
- Commitment: Anthropic confirmed Bun will remain open source and MIT-licensed. The investment will continue development to make it a preferred tool for JavaScript/TypeScript builders, while ensuring it serves as the stable engine for Claude's AI-driven workflows.
The Business Context
The deal comes as Anthropic’s focused push into enterprise coding proves highly effective.
- Revenue Milestone: Claude Code, which became generally available in May 2025, hit an annualized revenue run rate of $1 billion in November. This growth was achieved in just six months since its public launch.
- User Adoption: Large enterprises including Netflix, Spotify, and Salesforce have adopted the coding agent.
- Financial Backdrop: The acquisition follows major investment announcements, including commitments from Microsoft and Nvidia that total up to $15 billion in investment for Anthropic. This funding is fueling rapid expansion across Anthropic's operations, including a $30 billion commitment to utilize Microsoft's cloud services.
Anthropic leadership stated that Bun will be "instrumental in helping us build the infrastructure for the next generation of software."
The company, recently valued at $183 billion, continues to move aggressively to compete in the enterprise AI market. The financial terms of the Bun acquisition were not disclosed.
