Caddy is an extensible, cross-platform, open-source web server written in Go.
The name "Caddy" refers both to a helper for tedious tasks, and a way to organize multiple parts into a simplified system. At its core, Caddy is an extensible platform for deploying long-running services ("apps") using a single, unified configuration that can be updated on-line with a REST API. Official Caddy distributions ship with a set of standard modules which include HTTP server, TLS automation, and PKI apps. It is best known for its automatic HTTPS features.