Problem: MCP client won't start (Brave MCP WinError 2 / npx didn't run) —— Trove problem library

What you will run into

After configuring an MCP client (e.g. Brave Search MCP), deepcode mcp reports WinError 2 / command not found; npx didn't run. The client config is fine - the launch environment is the problem.

Why this happens

The MCP client starts via the npx/Node environment:

WinError 2 is Windows' "file not found" — the MCP config is fine; deepcode failed to find npx.exe when spawning the child process.

PATH in GUI/service environments often differs from the terminal (some service environments do not even inherit the user PATH), so npx works in your terminal while the client fails with WinError 2 on startup.

A second hidden gotcha: npx downloads the package on first run — that is a network operation, and a timeout also counts as "start failed". So manually run npx -y <package> once first, which separates the "network problem" and "config problem" variables.

Step by step

1. Confirm Node/npx works — Required

npx --version

Command not found -> install Node first and confirm PATH.

2. Manually run npx once to pre-download — Required

npx -y <mcp-package>

Pull the package down first, then configure it into deepcode, to avoid a first-start timeout after configuring.

3. Windows: PATH and cmd permissions — Required

Configure service-type MCPs with full paths; on Windows watch cmd execution permissions.

How to confirm it works

The MCP client starts normally (expected shape):

deepcode mcp
-> MCP service starts/handshakes normally (no more WinError 2)

npx --version prints a version normally.

Other environments

Symptom

After configuring an MCP client (e.g. Brave Search MCP), deepcode mcp reports WinError 2 / command not found; npx didn't run.

Cause

The MCP client starts via the npx/Node environment; Node not in PATH, or an npx first-download timeout, both fail the start.

Solution

1. Confirm Node/npx works: npx --version.
2. Manually run npx once to pre-download (npx -y <mcp-package>), then configure it into deepcode.
3. On Windows watch PATH and cmd permissions; configure service-type MCPs with full paths.