Claude Code MCP spawn npx ENOENT Windows fix

Exact error

Match the message before using the fix

SPAWN ERROR: ENOENT spawn npx ENOENTFailed to connect

Quick answer

Start here

Configure the MCP server to launch through `cmd /c npx` on native Windows. The reporter verified this across six plugins. A direct edit inside a plugin cache can be overwritten by updates, so prefer a user-owned MCP definition or wrapper that you control.

Diagnosis

Why it happens

The native Windows process launcher fails to resolve the bare `npx` command in the affected plugin definitions.
Launching through the Windows command processor lets the `.cmd` shim resolve.

Safest first

Fixes, in order

Use cmd /c npx in a user-owned MCP definition

Applies when: Best match for native Windows and bare-npx plugin entries

The first-hand report connected Context7, Chrome DevTools, Azure, MongoDB, Desktop Commander, and Playwright after this change.

Back up the Claude MCP configuration.
Set the command to `cmd`.
Add `/c` and `npx` before the original package arguments.
Restart Claude Code and list MCP connections.

command: cmd
args: /c, npx, -y, <package-name>

Expected: The MCP server shows Connected instead of spawn npx ENOENT.

Use an explicit npx.cmd path

Applies when: Alternative when command lookup is restricted

An absolute path removes PATH ambiguity but must be updated if Node is moved.

Run `where.exe npx`.
Select the trusted npx.cmd installed with your Node distribution.
Use that exact path as the MCP command.
Restart Claude Code.

Expected: Claude starts the trusted npx.cmd shim directly.

Verification

Prove the fix worked

Run `where.exe npx` in the same user account.
Use Claude's MCP status/list command and confirm Connected.
Call one read-only tool from the server.

Escalation

If it still fails

Run the effective command manually and check whether the package exits with its own error.
Record Node, npm, Claude Code, Windows, and plugin versions.
Do not keep the only fix inside an auto-updated plugin cache.

Scope

Environment and version notes

The confirmed report covered Claude Code 2.1.139, Windows 10/11, and Node 20/22.
The issue was closed as stale/not planned, not as a documented shipped fix.
Sources rechecked August 20, 2026.

Evidence

Sources

Source labels describe the evidence available on the checked date. A closed issue is not automatically a shipped fix.

anthropics/claude-code #58510

First-hand six-plugin reproduction and cmd /c workaround.

Claude Code MCP documentation

Official MCP configuration guidance.

Microsoft cmd documentation

Official behavior of cmd /c.