There is!!

https://code.claude.com/docs/en/cli-reference#system-prompt-...

  --append-system-prompt
  --append-system-prompt-file
  --system-prompt
  --system-prompt-file

Can this script be made to work without patching the executable?

Might be worth extracting the system prompt and then patching it. TBH, that's what I was expecting when I saw the gist.

This might be more complex than I imagined. It seems Claude Code dynamically customizes the system prompt. They also update the system prompt with every version so outright replacing it will cause us to miss out on updates. Patching is probably the best solution.

https://github.com/Piebald-AI/claude-code-system-prompts

https://github.com/Piebald-AI/tweakcc

Interesting. So literally triggering any of these changes probably invalidates the cache as well…