X-Request-ID header. They do not require authentication and are not rate-limited.
GET /health
200 when this server can serve requests, 503{"status": "unhealthy"} when it cannot.
GET /livez
200 as long as the process is up and answering.GET /readyz
200{"ready": true} only when the billing store is reachable; 503 {"ready": false, "reason": "..."} otherwise. /health stays 200 through a short billing-store outage (balances are served from the last known value and settled afterwards), so use /readyz when you want to drain traffic from a server that cannot bill.