[losvedir]

In what ways does Anthropic use Bun? I know it's used as the "runtime" for Claude Code, but rather than porting a million lines of Zig to Rust, why not just port Claude Code to rust and not need to bundle a JS runtime at all? Does Anthropic use Bun otherwise? Maybe for JS execution tool calls in Claude responses?

[atonse]

I’ve wondered the same. Especially because codex is written in rust.

Why not just port Claude code over.

But my guess is that maybe it doesn’t have as robust a test suite?

This might embolden them to do it…

[rane]

It's extremely difficult to have a robust test suite for a TUI app like Claude Code. Hence regressions keep showing up in every update.

[KronisLV]

> But my guess is that maybe it doesn’t have as robust a test suite?

Not sure about what's going on over there, but over the last year Claude Code has gotten way better, I sure hope that they're working on a good enough test suite to avoid a crapload of regressions (and pave way for more refactoring, should they need it).

[atonse]

Things improved tremendously the first month after they acquired Bun. People like Jared (bun creator) worked relentlessly on the performance bottlenecks, and posted details on X as he worked through them. I remember just launching claude code used to take multiple seconds, and within a month it went down to instant.