After running `npm install -g @anthropic-ai/claude-code`, a developer opens a new terminal window and finds the `claude` command is not found. What is the most likely cause?
Answer: The npm global binary directory is not included in the system PATH
When npm installs a package globally, it places the binary in a directory such as ~/.npm-global/bin or /usr/local/bin depending on the npm configuration. If that directory is not in the shell PATH, the command will not be found in new terminal sessions. Node version incompatibility would cause the install itself to fail or produce errors. The API key is required at runtime, not at install time. Homebrew is one installation option but npm global install is fully supported.