What is the problem?
终端报 npm: command not found 或 'npm' 不是内部或外部命令，几乎都是 Node.js 没装好、PATH 没配、或装了 nvm 没激活。给出 macOS/Linux/Windows 的真实检查和修复命令。
Quick solution
Treat this as a Node.js errors troubleshooting issue. First confirm the environment, inputs, permissions, logs, and delivery boundary. Then use the linked deep guide for the full checklist before changing production code or promising a result.
Read the deep guideDetailed steps
- 两个都报 not found → Node 根本没装（见 ①）
- `node -v` 有、`npm -v` 没有 → 少见，重装 Node 即可
- 刚装完就报 → 多半是 PATH 或终端没重开（见 ②③）
- 先**完全关掉终端重新打开**（PATH 改动对已开的终端不生效）——这一步能解决一大半。
- 还不行，确认安装目录在 PATH 里：macOS/Linux 看 `echo $PATH`；Windows 在「系统环境变量」里确认有 Node 的路径。
- 别随便复制网上"一键修复 PATH"的脚本去改系统环境变量，先看懂它改什么。
Commands or code
node -v
npm -vRisk notes
Confirm the real project environment, account permissions, platform rules, and output quality before delivery. Do not ship AI-generated changes without human review, and do not claim indexing, income, deployment success, or ranking improvements without measured evidence.