EACCES: Permission Denied Error

Run your app on a high port and use Nginx as a reverse proxy on port 80/443.

# Run app on port 3000 instead of 80
PORT=3000 node app.js

# Nginx reverse proxy to forward port 80 to 3000
server {
  listen 80;
  location / {
    proxy_pass http://localhost:3000;
  }
}

Configure npm to use a local directory for global packages instead of /usr.

# Option 1: Change npm prefix
mkdir ~/.npm-global
npm config set prefix "~/.npm-global"
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc

# Option 2: Use nvm (recommended)
# nvm manages Node.js without sudo

Use chmod to grant appropriate file permissions.

# Make file readable and writable by owner
chmod 644 file.txt

# Make directory executable (traversable)
chmod 755 directory

# Change ownership
sudo chown -R $(whoami) /path/to/project