> This is a library showing you how to train your own Claude Code end-to-end.

What does it even mean?

Claude Code is a so called "harness" - a thing that builds a context for LLMs, calls LLMs, executes tool calls etc. It uses various Anthropic models under the hood.

It can also use other models AFAIK.

It cannot be "trained".

Sorry if this comment sounds nitpicky, I'm just annoyed by the imprecise use of terminology.

I see what you mean, but I disagree. I expect that Claude Code is backed by a separate post-train of Claude base which has been trained using the Claude Code harness and toolset.

It is possible of course, but I see no reason to believe it.

fwiw, other models seem to / are reported to struggle much more with using claude code compared with codex / opencode / pi etc.

that being said, there are other potential explanations

Yeah it should really be about post-training a model for tool-use.