Install @anthropic-ai/claude-code using Nix npm

I was installing claude-code via Nix, but new releases take 2-3 days to appear in the nixpkgs-unstable branch. I want to use npm directly instead. By default, npm installs global packages to the immutable Nix store, causing npm install -g fails.

Based on this article, the solution is straightforward: configure npm to use a writable prefix directory. The required Nix configuration is (commit):

home.file = {
  ".npmrc".text = "prefix=~/.npm-global";
};

home.sessionPath = [
  "$HOME/.npm-global/bin"
];

Now I can install claude-code using npm:

npm install -g @anthropic-ai/claude-code

The version today is:

$ claude --version
1.0.72 (Claude Code)