This example demonstrates how to create and use a custom MXCP plugin. The plugin provides various UDFs (User Defined Functions) that can be used in your SQL queries.

Overview

This plugin implements the Caesar cipher, a simple encryption technique where each letter in the plaintext is shifted by a fixed number of positions in the alphabet.

Project Structure

examples/plugin/
├── plugins/
│   └── my_plugin/
│       └── __init__.py    # Plugin implementation
├── tools/
│   └── decipher.yml       # Endpoint using the plugin
├── python/                # Directory for Python endpoints
├── sql/                   # Directory for SQL implementations
├── config.yml             # Example plugin configuration
├── mxcp-site.yml          # Project configuration
└── README.md

Configuration

1. User Configuration

The example includes two plugin configurations in config.yml:

rot1: Rotates letters by 1 position (A->B, B->C, etc.)
rot10: Rotates letters by 10 positions (A->K, B->L, etc.)

To use the plugin, register these configurations in your MXCP user config (~/.mxcp/config.yml):

mxcp: 1

projects:
  demo-plugin:
    profiles:
      dev:
        plugin:
          config:
            rot1:
              rotation: "1"
            rot10:
              rotation: "10"

Then in your mxcp-site.yml, you can reference one of these configurations:

mxcp: 1
project: demo-plugin
profile: dev
plugin:
  - name: str_secret
    module: my_plugin
    config: rot1
  - name: tricky
    module: my_plugin
    config: rot10

Running the MCP

To run the service using the example configuration:

Set the MXCP_CONFIG environment variable to point to the example's config file:
```
export MXCP_CONFIG=/path/to/examples/plugin/config.yml
```
Start the MXCP server:
```
mxcp serve
```

The service will now use the example configuration with both the simple (rot1) and tricky (rot10) Caesar cipher plugins.