Automatic Certificates and HTTPS for everyone.

Lego

Let’s Encrypt client and ACME library written in Go.

Features

• ACME v2 RFC 8555
  • Support RFC 8737: TLS Application‑Layer Protocol Negotiation (ALPN) Challenge Extension
  • Support RFC 8738: certificates for IP addresses
  • Support RFC 9773: Renewal Information (ARI) Extension
  • Support draft-aaron-acme-profiles-00: Profiles Extension
• Comes with about 150 DNS providers
• Register with CA
• Obtain certificates, both from scratch or with an existing CSR
• Renew certificates
• Revoke certificates
• Robust implementation of ACME challenges:
  • HTTP (http-01)
  • DNS (dns-01)
  • TLS (tls-alpn-01)
• SAN certificate support
• CNAME support by default
• Custom challenge solvers
• Certificate bundling
• OCSP helper function

Installation

How to install.

Usage

• as a CLI
• as a library

Documentation

Documentation is hosted live at https://go-acme.github.io/lego/.

DNS providers

Detailed documentation is available here.

If your DNS provider is not supported, please open an issue.