deploy/monitor.py probes /health, /mcp/rpc initialize, /scan x402 challenge,
and reads USDC.balanceOf(wallet) on Base mainnet via public RPC. Appends one
JSON line per run to data/monitor.jsonl and persists state to detect:
- service_down / ingest_stale / mcp_transport_broken / x402_misconfig
- FIRST_PAYMENT_RECEIVED (when wallet balance crosses 0)
- balance_changed (delta vs previous run)
Installed as aegis402-monitor.{service,timer} on the VPS with hardened
systemd sandbox (NoNewPrivileges, ProtectSystem=strict, ReadWritePaths
limited to data/). Timer active, first run green: cves=500, mcp=ok,
x402 challenge returns 402 with payTo=0x3D1F...4ff6, balance=0 USDC.
6df6b80a68