Deploying Mercure alongside Caddy on a shared VPS

Ahnii! Mercure is a real-time push protocol built on server-sent events (SSE). It ships as a standalone binary that embeds its own Caddy server. If you already run Caddy as your web server, you now have two Caddy processes fighting over ports. This post covers how to deploy both on the same VPS using Ansible, with solutions for every gotcha that came up. Prerequisites A VPS with Caddy already serving your sites Ansible for deployment automation The Mercure binary installed on the server A domain