On the device you want to enroll, install Node.js then run the agent:

# 1. Copy agent.js to the device
# 2. Run enrollment
node agent.js --enroll

# 3. Start the daemon (add to startup/cron for persistence)
node agent.js --start

# Or run in background with pm2:
npm install -g pm2
pm2 start agent.js -- --start
pm2 startup && pm2 save

The agent stores its credentials at ~/.mdm/agent.json. Keep this file protected (chmod 600 is set automatically).