Introduction

What is Cadmin?

Cadmin is a multi-server manager for Caddy. It allows you to manage virtual hosts, TLS certificates and reverse proxy configurations across multiple Caddy servers from a centralized web interface.

Hub / Agent Architecture

Cadmin is built on a hub/agent architecture:

                        +---------------------------+
                        |           Hub             |
                        |  (Backend API + Frontend) |
                        |       SQLite DB           |
                        +-----+----------+----------+
                              |          |
                   HTTPS      |          |      HTTPS
                 (Bearer)     |          |    (Bearer)
                              v          v
                  +-----------+--+  +----+-----------+
                  |   Agent A    |  |   Agent B      |
                  |  Server 1    |  |  Server 2      |
                  |  +--------+  |  |  +--------+   |
                  |  | Caddy  |  |  |  | Caddy  |   |
                  |  +--------+  |  |  +--------+   |
                  +--------------+  +----------------+

• Hub: central server hosting the backend API (Hono + SQLite), the React frontend and the database. It is the entry point for all users.
• Agent: lightweight service deployed on each server running a Caddy instance. The agent receives commands from the hub (config reload, log reading) and forwards them to the Caddy admin API.

Communication between the hub and agents uses HTTP with Bearer token authentication.

Who is Cadmin for?

Cadmin is designed for system administrators and DevOps engineers who manage multiple Caddy servers and want to:

• Centralize virtual host and reverse proxy management
• Keep a modification history (changelog with diff)
• View access logs from a single interface
• Manage users and access control