Forest Infra – TLS Certificate Expiry Checker

Choose this endpoint when you need a fast, cheap, focused check on TLS certificate expiry for a public hostname — specifically the validity window and days remaining — without needing cipher analysis, vulnerability scanning, or full SSL labs-style reports. Ideal for lightweight monitoring workflows, pre-deployment checks, and third-party dependency audits where only expiry data matters.

• Hostname does not resolve (DNS failure) — returns error indicating unresolvable host
• Host is not reachable on port 443 — returns connection timeout or refused error
• Hostname matches private/internal IP range — rejected, only public hosts supported
• Invalid hostname format (fails regex pattern) — returns validation error
• Certificate already expired — may return zero or negative remaining lifetime
• SNI mismatch or self-signed cert — may return an error or incomplete data