The author expresses skepticism about Bun's claimed rewrite in Rust, announced by Jarred Sumner on July 8, 2026. Sumner stated the rewrite took 11 days (May 3–14) at a cost of $165,000 in Anthropic API calls—roughly $15,000 per day—but this excludes CI/CD costs on Buildkite. Six weeks after the merge to main (as of July 27), no release tag exists; the last release was May 12. Open PRs from robobun (a proxy for Claude Code) surged from 1,277 to 2,475 in 18 days.

Merging all would take ~86 days of continuous pipeline runs. Anthropic employees are directly contributing, suggesting ongoing costs. The author argues the rewrite isn't truly "done" and questions whether the $165k figure is accurate, estimating true costs may approach $800k. They caution against accepting valuation-driven AI hype, noting Anthropic's C compiler and Cursor's Fast Render browser have seen no commits for months.