Health And Readiness

Use this page to probe service liveness, readiness, and metrics without confusing local and hosted deployment behavior.

Who This Is For

• operators wiring load balancers and uptime checks
• developers debugging startup and database readiness
• teams scraping Prometheus-compatible metrics

When To Use This

Use this page when you need to decide which probe endpoint belongs in which operational context.

How It Works

System endpoints:

• GET /health
• GET /healthz
• GET /readyz
• GET /metrics

Semantics:

• /health is the hosted-safe liveness alias
• /healthz is the standard liveness probe for local and self-hosted compatibility
• /readyz returns 200 when ready and 503 when not ready
• /metrics returns Prometheus text

Hosted guidance:

• prefer /health for Cloud Run-facing external liveness
• keep /healthz for local and self-hosted tooling

Example

curl https://api.licensekit.dev/health
curl https://api.licensekit.dev/readyz
curl https://api.licensekit.dev/metrics

Readiness responses always use a JSON envelope, even on 503.

Common Mistakes

• using /readyz as if it were a liveness check
• expecting /metrics to return a JSON envelope
• assuming /healthz is the preferred external hosted probe path

Related Pages

• Cloud Run
• Self-Hosting
• API Reference