Anthropic has acquired Bun, one of the fastest JavaScript runtimes, and is keeping it MIT licensed to strengthen open, AI-driven developer tools and agentic workflows.
Anthropic has made a rare move in the AI industry by acquiring Bun while pledging to keep the high-performance JavaScript runtime fully open source under the MIT licence. The decision ensures that the global developer community continues to access, contribute to, and innovate with one of the fastest runtimes available, preserving transparency, preventing lock-in, and strengthening Bun’s open development model.
The acquisition positions Bun as core infrastructure for Anthropic’s AI-powered coding ecosystem, forming the foundation for tools such as Claude Code, the Claude Agent SDK, and emerging autonomous developer agents. By keeping Bun open, Anthropic is building an open foundation for next-generation AI tools rather than enclosing a strategically valuable runtime.
Bun’s integration is expected to significantly enhance the efficiency, scalability, and reliability of Anthropic’s AI-driven coding workflows. Its lightweight architecture, ultra-fast execution, and ability to produce single-file executables align perfectly with the needs of high-intensity AI workloads. Predictable performance and broad JavaScript compatibility make Bun particularly suited to autonomous agents that write, test, and deploy code.
With Anthropic’s investment, Bun becomes a cornerstone for automated software pipelines and agent-based development. The company aims to evolve Bun to handle higher loads, more complex orchestration requirements, and increasingly sophisticated AI coding tasks.
The acquisition also reflects a shared vision between Bun’s founder and Anthropic: pushing the boundaries of agentic systems, reducing repetitive developer work, and enabling more advanced autonomous software creation.
