Developer warns of 'enshittification' for Bun following Anthropic acquisition

A developer who frequently utilises the high-performance JavaScript runtime Bun has expressed significant concern regarding its future under the stewardship of Anthropic. While acknowledging that Bun remains excellent software, the author warns that its integration into Anthropic's product layer coincides with a noticeable decline in the quality and reliability of the company's own tool, Claude Code. This deterioration has led the developer to actively migrate existing projects away from Bun to pnpm for package management.

The developer, who previously viewed the acquisition as a strategic win for the open-source community, now fears a trajectory of "enshittification" similar to that experienced by Claude Code. The author notes that while the announcement of the acquisition included reassuring details about Bun remaining open source and MIT-licensed, the subsequent performance of the product layer has eroded confidence. The core worry is that policies affecting the AI coding assistant could eventually impact the runtime itself as the two become further intertwined.

Specific grievances with Claude Code have fuelled this caution. The developer reports that the tool, which once felt like a robust agent capable of reading projects and executing focused edits, has become difficult to use over the last year. Issues include confusing billing practices, restrictions on third-party harnesses, and a general decline in reliability. These concerns were highlighted in an engineering postmortem released by Anthropic, which acknowledged internal product-layer issues such as reduced default reasoning effort and stale-session bugs.

A particular point of contention was the "OpenClaw" controversy, where reports emerged that simply having OpenClaw in a repository's git history could trigger billing anomalies or request refusals within Claude Code. The developer suggests this behaviour indicates a lack of careful testing regarding the code-level experience before changes are shipped. Consequently, the author argues that the product appears to be moving in the wrong direction, with more restrictions and surprise behaviours undermining user trust.

In response to these developments, the developer is now recommending pnpm for new JavaScript or TypeScript projects. While pnpm is identified as a popular package manager that does not attempt to replace Node.js or provide a full toolchain in a single binary, it offers the specific package management speed and monorepo functionality the author requires. The developer advises existing users to stick with Bun unless they have a specific reason to switch, but personally plans to abandon the runtime for their own work.

The situation leaves the developer in a position of uncertainty regarding the sustainability of Bun. Although Anthropic possesses the capital and distribution to support the tool, the author does not trust the current situation as much as they did prior to the acquisition. The hope remains that Bun can emerge stronger, but the fear is that the same policies leading to the collapse of Claude Code will eventually affect the runtime, making the developer hesitant to continue using it.