acme.sh

acme.sh at a glance

acme.sh is a popular, dependency-light shell client for obtaining and renewing free ACME (Let's Encrypt and other CA) TLS certificates, widely used to automate HTTPS. acme.sh ships regular releases plus fixes; keeping it current maintains compatibility with ACME services and picks up security fixes.

For admins acme.sh usually runs as an automated renewal task. The main risks are operational: a broken or lapsed renewal means expired certificates and outage, so monitor and test renewals. Keep acme.sh current so it stays compatible with ACME protocol and CA API changes. Because it can install certificates and reload services, and stores account keys and DNS-API credentials for DNS-01 validation, protect its configuration and those secrets. After updates, verify a renewal succeeds and services pick up the new certificate. It can self-upgrade. Alternatives include Certbot and built-in ACME in Caddy/Traefik; keep whichever you use current. Patchletter surfaces new acme.sh releases.