caddy-mcp

Overview

caddy-mcp is a server that provides a Model Context Protocol (MCP) interface for managing a Caddy server instance using the Caddy API. It exposes tools for retrieving, updating, and converting Caddy configurations (in JSON, Caddyfile, YAML, or Nginx formats) and for monitoring reverse proxy upstreams. The server can run over different transports: stdio, SSE, or HTTP stream.

Tools

• get_caddy_config - Get the current Caddy server configuration in JSON format
• update_caddy_config - Update the Caddy server configuration by providing a full JSON configuration
• convert_caddyfile_to_json - Convert a Caddyfile configuration to JSON format
• convert_nginx_to_json - Convert an Nginx configuration to Caddy JSON format
• convert_yaml_to_json - Convert a YAML configuration to Caddy JSON format
• upstream_proxy_statuses - Get the current status of configured reverse proxy upstreams as JSON

Build Steps

1. Prerequisites:

• Go 1.24+ installed (download)

2. Clone the repository:

git clone https://github.com/lum8rjack/caddy-mcp.git
   cd caddy-mcp

3. Build the server:

make
   # or
   go build -o caddy-mcp .

This will produce a caddy-mcp binary in the project root.

Running the MCP Server

You can run the server with different transports and ports:

./caddy-mcp -h
Usage of ./caddy-mcp:
  -port int
        Port to run the MCP server on (default 7000)
  -transport string
        The transport to use for the MCP server (stdio, sse, httpstream) (default "stdio")
  -url string
        The URL of the caddy server (default "http://127.0.0.1:2019")

Example MCP Settings:

{
    "mcpServers": {
        "caddy-mcp": {
            "command": "~/caddy-mcp",
            "args": ["-transport", "stdio", "-url", "http://127.0.0.1:2019"]
        }
    }
}

Caddyfile Example

A sample Caddyfile to test with that exposed the admin API:

{
    admin :2019
}

:8080 {
    respond "I am 8080"
}

:8081 {
    respond "I am 8081"
}

Adding Additional Caddy Modules

If you are using a custom-built version of Caddy with extra modules (for example, the Cloudflare DNS module), you need to add the corresponding Go module to your project. This ensures the MCP server can work with your custom Caddy build.

Steps:

1. **Add the module import to main.go:**

For example, to add the Cloudflare DNS module, add the following import (anywhere among the imports, typically with other Caddy modules):

import _ "github.com/caddy-dns/cloudflare"

2. Update dependencies:

Run:

go mod tidy

3. Rebuild the server:

make
   # or
   go build -o caddy-mcp .

This process can be repeated for any other Caddy modules you need. For a list of official and community modules, see the Caddy Modules Directory.