I didn’t see this one coming. I think the key sentence from the announcement is this:

As an all-in-one toolkit—combining runtime, package manager, bundler, and test runner—it’s become essential infrastructure for AI-led software engineering, helping developers build and test applications at unprecedented velocity.

Rust has become my favorite language to build in with Claude Code, and the reason why is because the superb toolchain creates a tight feedback loop for agentic iteration.

Typescript/Javascript’s toolchain has always been an absolute nightmare and Bun was created, in part, to address that. A tight feedback loop means Claude Code arrives at solutions faster with fewer tokens burned. Strategically, if Anthropic can more tightly integrate Bun into their products, it means improved user experience and reduced variable costs.