Quick answer
Change the MCP launch command from npx to cmd and place /c and npx at the beginning of the argument list. Keep all original package arguments after them.
The exact error
SPAWN ERROR: ENOENT spawn npx ENOENTDo not use this guide for a merely similar message. The workaround is scoped to this signature and the environments below.
Match your environment
- Claude Code 2.1.139 report
- Windows 10 and 11
- Bare npx plugin commands
What to do
- 01
Confirm NPX works in the same terminal
If this fails, repair Node/PATH before editing Claude configuration.
npx --version - 02
Wrap the command with cmd.exe
Replace a bare npx command with the Windows command processor. Preserve the package name and original arguments.
{ "command": "cmd", "args": ["/c", "npx", "-y", "<mcp-package>"] } - 03
Restart Claude Code
Fully restart the client, then check the MCP list. The reporter confirmed six official plugin MCPs connected after this edit.
- 04
Recheck after plugin updates
Updating an official plugin can overwrite generated MCP configuration. If the error returns, inspect the command again.
What likely happened
The native Windows launcher tried to spawn the NPX shim directly and failed to resolve it as an executable. cmd.exe /c lets Windows resolve the command shim in the normal shell path.
First-hand sources
Source links support the environment and workaround claims above. An issue being closed does not by itself mean a fix shipped.