Developer expresses concerns about Bun's future under Anthropic
Original: I am worried about Bun
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Highlights potential risks when major dev tools get acquired by AI companies
A developer blog post raises concerns about Bun JavaScript runtime after Anthropic's December 2025 acquisition. Despite Anthropic's promises to keep Bun open source, the author worries about declining quality of Claude Code affecting Bun's development focus.
William Johnston published a blog post expressing worry about Bun's future following Anthropic's acquisition in December 2025. While Anthropic promised to keep Bun open source and MIT-licensed with the same team, Johnston notes concerning trends. Claude Code, which ships as a Bun executable to millions of users, has reportedly declined in quality since April 2026. Users complained about limit behavior, billing issues, and coding quality problems. Anthropic published an engineering postmortem citing reduced reasoning effort and prompt changes as causes. The author also mentioned issues with OpenClaw integration and third-party harness restrictions, suggesting Anthropic's product management approach may negatively impact Bun's development priorities despite the company's dependence on the runtime.