npx Troubleshooting

This guide covers npx and Node.js specific issues when running the WhoisXML API MCP Server. Using npx eliminates most installation and dependency management issues, but can still encounter environment-specific challenges.

Quick Resolution

Most npx and Node.js issues can be resolved by:

  1. Using npx (recommended): npx -y @whoisxmlapidotcom/mcp-whoisxmlapi --help
  2. Checking Node.js version: node --version (should be 22+ LTS)
  3. Updating npm if needed: npm install -g npm@latest
  4. Clearing npm cache: npm cache clean --force

Package Execution Issues

Package Not Found or Download Failures

Symptoms:

  • "Package '@whoisxmlapidotcom/mcp-whoisxmlapi' not found"
  • npx hangs or times out during download
  • Network or registry errors during package fetch

Diagnosis:

# Check npm configuration
npm config list
npm config get registry

# Test npm connectivity
npm ping

# Check Node.js and npm versions
node --version
npm --version

Solutions:

  1. Use npx with force flag (recommended):

    # Force fresh download
npx --yes @whoisxmlapidotcom/mcp-whoisxmlapi --help

# With -y flag for non-interactive
npx -y @whoisxmlapidotcom/mcp-whoisxmlapi --help

  2. Clear npm cache:

    npm cache clean --force
npm cache verify

  3. Check network connectivity:

    # Test registry access
curl -I https://registry.npmjs.org/

# Check for proxy settings
npm config get proxy
npm config get https-proxy

Node.js Version Compatibility

Symptoms:

  • "Unsupported engine" errors
  • Package fails to run after installation
  • Runtime errors related to Node.js features

Diagnosis:

# Check Node.js version
node --version

# Check npm version
npm --version

# Check package requirements
npm view @whoisxmlapidotcom/mcp-whoisxmlapi engines

Solutions:

  1. Update Node.js:

    # Download and install from nodejs.org
# Visit: https://nodejs.org/ and download the LTS version

  2. Check minimum requirements:

    # WhoisXML API MCP Server requires Node.js 22+ LTS
node --version  # Should show v22.0.0 or higher

  3. Verify Node.js version:

    # Ensure you have Node.js 22+ LTS
node --version  # Should show v22.0.0 or higher

# Test npx works correctly
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

Execution and Runtime Issues

Package Execution Issues

Symptoms:

  • Binary starts but crashes immediately
  • "Module not found" errors
  • Runtime errors during execution

Diagnosis:

# Test package directly with npx
npx @whoisxmlapidotcom/mcp-whoisxmlapi --version
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

# Check for npm/Node.js issues
npm doctor
node --version
npm --version

Solutions:

  1. Use npx with fresh download:

    npx --yes @whoisxmlapidotcom/mcp-whoisxmlapi --help

  2. Clear npm cache:

    npm cache clean --force
npm cache verify

  3. Try specific version:

    # Run specific version with npx
npx @whoisxmlapidotcom/mcp-whoisxmlapi@latest --help

# Check available versions
npm view @whoisxmlapidotcom/mcp-whoisxmlapi versions --json

Configuration Issues

Environment Variables Not Working

Symptoms:

  • "API key token environment variable is required"
  • Environment variables not being read
  • Configuration not taking effect

Diagnosis:

# Check environment variables
echo $WHOISXMLAPI_TOKEN
env | grep WHOISXMLAPI

# Test with explicit environment
WHOISXMLAPI_TOKEN=test-token npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

Solutions:

  1. Set environment variables correctly:

    # For current session
export WHOISXMLAPI_TOKEN="your-token-here"

# For permanent (add to ~/.bashrc or ~/.zshrc)
echo 'export WHOISXMLAPI_TOKEN="your-token-here"' >> ~/.bashrc
source ~/.bashrc

  2. Use client configuration:

    {
  "mcpServers": {
    "whoisxmlapi": {
      "command": "npx",
      "args": ["-y", "@whoisxmlapidotcom/mcp-whoisxmlapi"],
      "env": {
        "WHOISXMLAPI_TOKEN": "your-token-here"
      }
    }
  }
}

  3. Test environment passing:

    # Verify environment is passed correctly
WHOISXMLAPI_TOKEN=test npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

MCP Client Integration Issues

Symptoms:

  • MCP client doesn't recognize the npx-configured server
  • Configuration syntax errors
  • Server starts but tools don't appear

Diagnosis:

# Test server independently
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

# Check JSON configuration syntax
python -m json.tool your-config.json
# or
jq . your-config.json

Solutions:

  1. Use npx in MCP configuration (recommended):
    {
  "mcpServers": {
    "whoisxmlapi": {
      "command": "npx",
      "args": ["-y", "@whoisxmlapidotcom/mcp-whoisxmlapi"],
      "env": {
        "WHOISXMLAPI_TOKEN": "your-token-here"
      }
    }
  }
}

Network and Proxy Issues

Corporate Network Problems

Symptoms:

  • npx package download fails with network errors
  • Registry timeouts
  • SSL/TLS certificate errors

Diagnosis:

# Check npm configuration
npm config list
npm config get proxy
npm config get https-proxy
npm config get registry

# Test connectivity
npm ping
curl -I https://registry.npmjs.org/

Solutions:

  1. Configure proxy:

    npm config set proxy http://proxy.company.com:8080
npm config set https-proxy http://proxy.company.com:8080

  2. Configure registry:

    # Use HTTP registry if HTTPS fails
npm config set registry http://registry.npmjs.org/

# Or use company registry
npm config set registry http://npm.company.com/

  3. Bypass SSL issues (not recommended for production):

    npm config set strict-ssl false

  4. Use different network:

    # Try from different network/location
# or use mobile hotspot

Package Registry Issues

Symptoms:

  • "Package not found" despite package existing
  • Slow download speeds
  • Registry connection errors

Solutions:

  1. Clear npm cache:

    npm cache clean --force
npm cache verify

  2. Try different registry:

    # Set different registry temporarily
npm config set registry https://registry.npmjs.org/
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

Platform-Specific Issues

Windows Issues

PowerShell execution policy:

# Check execution policy
Get-ExecutionPolicy

# Set execution policy (as Administrator)
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

PowerShell profile setup (if needed):

# Create PowerShell profile if needed
if (!(Test-Path -Path $profile)) {
  New-Item -ItemType File -Path $profile -Force
}

Node.js installation:

# Use Chocolatey
choco install nodejs

# Or use Windows installer from nodejs.org

macOS Issues

Homebrew conflicts:

# Check Homebrew Node.js
brew list | grep node

# Uninstall Homebrew Node.js if conflicting
brew uninstall node

# Install Node.js from official installer
# Visit: https://nodejs.org/ and download the LTS version

Linux Issues

Package manager conflicts:

# Remove system Node.js
sudo apt remove nodejs npm  # Ubuntu/Debian
sudo yum remove nodejs npm   # CentOS/RHEL

# Install via NodeSource
curl -fsSL https://deb.nodesource.com/setup_lts.x | sudo -E bash -
sudo apt-get install -y nodejs

User permissions:

# Add user to appropriate groups
sudo usermod -aG admin $USER
newgrp admin

Debugging and Diagnostics

Comprehensive Health Check

# System information
node --version
npm --version
npm config list
npm doctor

# Package availability
npm view @whoisxmlapidotcom/mcp-whoisxmlapi

# Test execution with npx
npx @whoisxmlapidotcom/mcp-whoisxmlapi --version
WHOISXMLAPI_TOKEN=test npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

Verbose Debugging

# Run npx with debug output
DEBUG=* npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

# Test with verbose npm output
npm --loglevel silly view @whoisxmlapidotcom/mcp-whoisxmlapi

# Clear cache with verbose output
npm cache clean --force --loglevel silly

Clean Cache Reset

# Complete cache cleanup (npx will download fresh)
npm cache clean --force
rm -rf ~/.npm/_npx
npm cache verify

# Test with fresh download
npx --yes @whoisxmlapidotcom/mcp-whoisxmlapi --help

Prevention and Best Practices

Environment Setup

  1. Regular maintenance:

    # Update npm if needed
npm install -g npm@latest

# Clean cache periodically
npm cache clean --force

  2. Use npx for testing:

    # Always test with npx first
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help

Configuration Best Practices

  1. Use npx in MCP configurations (recommended):

    {
  "command": "npx",
  "args": ["-y", "@whoisxmlapidotcom/mcp-whoisxmlapi"]
}

  2. Environment variable management:

    # Use shell profiles for permanent variables
echo 'export WHOISXMLAPI_TOKEN="your-token"' >> ~/.bashrc
source ~/.bashrc

  3. Version specification with npx:

    # Run specific version with npx (no installation needed)
npx @whoisxmlapidotcom/mcp-whoisxmlapi@1.2.3 --help

# Use in MCP configuration
"args": ["-y", "@whoisxmlapidotcom/mcp-whoisxmlapi@1.2.3"]

Getting Help

Collecting Debug Information

When seeking help, provide:

# System information
node --version
npm --version
npm config list
npm doctor

# Package information
npm view @whoisxmlapidotcom/mcp-whoisxmlapi

# Test npx execution
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help 2>&1 | tee npx-debug.log

Common Commands Reference

# Execution methods (npx only)
npx -y @whoisxmlapidotcom/mcp-whoisxmlapi --help
npx --yes @whoisxmlapidotcom/mcp-whoisxmlapi@latest
npx @whoisxmlapidotcom/mcp-whoisxmlapi@1.2.3

# Debugging and diagnostics
npm cache clean --force
npm doctor
npm config list
npm view @whoisxmlapidotcom/mcp-whoisxmlapi

# Test execution
npx @whoisxmlapidotcom/mcp-whoisxmlapi --version
npx @whoisxmlapidotcom/mcp-whoisxmlapi --help
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