Lego
May 7, 2026 · View on GitHub
Automatic Certificates and HTTPS for everyone.
Lego
ACME client and library for Let's Encrypt and other ACME CAs written in Go.
lego is an independent, free, and open-source project, if you value it, consider supporting it! ❤️
Everybody thinks that the others will donate, but in the end, nobody does.
So if you think that lego is worth it, please consider donating.
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-ietf-acme-profiles-00: Profiles Extension
- Support draft-ietf-acme-dns-persist-01: Challenge for Persistent DNS TXT Record Validation
- Comes with more than 200 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
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.
If your DNS provider is not supported, please open an issue.