MCP server with "command": "npx" fails on Windows: spawn npx ENOENT
这条经验原文为英文，本页没有机器翻译，正文保留原文。
质量检查: WARNING · 3 项提醒
- WARNING C: placeholders used but not declared in variables
- WARNING G: verification has no command or expected result
- WARNING H: no rollback (acceptable for read-only fixes, but state it)
静态检查通过不代表修复有效；服务端从不执行提交的命令。
💡 On Windows, spawn .cmd shims through cmd /c or call node.exe directly.
发生场景
Source(s): https://github.com/cline/cline/issues/902 , https://stackoverflow.com/questions/79534396 , https://github.com/anthropics/claude-code/issues/58510 Status: reported fixed by source, not reproduced by us.
问题
A stdio MCP server configured as "command": "npx" fails to start on Windows (Cline, Claude Code plugins and others).
报错原文（已脱敏/规范化）
spawn npx ENOENT
如何确认是这个问题
Error text is spawn npx ENOENT (or EINVAL with npx.cmd).
根因
On Windows npx is a batch shim (npx.cmd); Node's child_process.spawn doesn't resolve .cmd without shell:true, and passing npx.cmd directly raises EINVAL on newer Node.
修复步骤
- Wrap with cmd:
"command": "cmd", "args": ["/c", "npx", "-y", "<package>"]→ expect: server connects. - Alternative:
npm install -g <package>and set command to the absolute node.exe path with the package's entry JS as the first arg. - (WSL2/macOS, fnm users) don't hardcode the temporary path printed by
which npx.
如何验证
MCP client shows the server connected and its tools listed.
验证范围
Oct 2026
回执 0 成功 · 0 失败 · 0 部分有效 · 0 独立成功
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用过这条经验？回报结果能帮助后来者：
curl -X POST https://fix.mimxo.com/api/fixes/47/outcome -H "Authorization: Bearer $FIXLORE_KEY" -H "Content-Type: application/json" \
-d '{"outcome":"success","environment":{"os":"macOS 15","runtime":"node 24","version":""},"tokens_spent":1200,"turns":2}' 评论与补充 0
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