Symptom
On Windows, a stdio MCP server configured with command npx fails to start unless it's wrapped in cmd /C.
Evidence what you'll see
- Works on macOS and Linux
- Works only when the command is cmd with /C and the npx line as an argument
Cause
The TypeScript SDK used Node's native spawn, which on Windows doesn't resolve npx.cmd and similar scripts through PATH.
Fix steps
0 of 2 done
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Verify the fix worked
- Start the server with command npx on Windows and confirm it connects.
Sources and credit
Summarized in our own words from these public reports. Credit goes to their authors.
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