# Reference Plugins

This guide outlines the architecture and standard conventions for reference plugins in Cacti.

The Reference Plugin(s) are generic plugins that implement key pieces of the
Plugin Architecture.

They are broken down into several separate plugins, each covering different
portions of the [Hook API Reference](Plugin-Hook-API-Ref.md)

## Standard Files

The following files should be included in every plugin

* CHANGELOG
* INFO
* LICENSE
* index.php
* README.md
* setup.php

In general, the index.php file example below should be included in every plugin
directory as it prevents remote file browsing of your Cacti site.

```php
<?php

/*
 +-------------------------------------------------------------------------+
 | Copyright (C) 2004-2026 The Cacti Group                                 |
 |                                                                         |
 | This program is free software; you can redistribute it and/or           |
 | modify it under the terms of the GNU General Public License             |
 | as published by the Free Software Foundation; either version 2          |
 | of the License, or (at your option) any later version.                  |
 |                                                                         |
 | This program is distributed in the hope that it will be useful,         |
 | but WITHOUT ANY WARRANTY; without even the implied warranty of          |
 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           |
 | GNU General Public License for more details.                            |
 +-------------------------------------------------------------------------+
 | Cacti: The Complete RRDtool-based Graphing Solution                     |
 +-------------------------------------------------------------------------+
 | This code is designed, written, and maintained by the Cacti Group. See  |
 | about.php and/or the AUTHORS file for specific developer information.   |
 +-------------------------------------------------------------------------+
 | https://www.cacti.net/                                                   |
 +-------------------------------------------------------------------------+
*/

header("Location:../index.php");

?>
```

## File Structure

All plugin files should reside under their own respective plugin directory.  The
example below is for a plugin called 'myplugin'.

```console
myplugin/
    images/
        myimage.png
        index.php
    lib/
        index.php
        functions.php
    include/
        index.php
        settings.php
    CHANGELOG
    INFO
    LICENSE
    README.md
    index.php
    setup.php
```

## Contents of Files

The four core sub-directories included in your plugin should be docs, images,
lib, and include.  As previously mentioned, each of these directories should
include an index.php that points to it's parent directory index.php.  This way
we prevent people from randomly browsing the contents of our web site.

The two main files required for every plugin are the INFO and the setup.php
file.  Without these two files, the plugin directory will not be recognized as a
valid plugin and will be skipped.

The INFO file is formatted as Microsoft standard INI file.  It contains
information about the plugin including its version, author, dependencies,
functions, and minimum version of Cacti and other plugins required.  Below, you
can see a reference INFO file for the myplugin plugin.

```console
[info]
name = mplugin
version = 1.0
longname = My First Plugin
author = Depeche Mode
email = somewhere@outthere.com
homepage = http://www.outthere.com
compat = 1.2
requires = thold monitor
capabilities = online_view:1, online_mgmt:1, offline_view:0, offline_mgmt:0, remote_collect:0
```

The setup file includes key plugin functions that allow the plugin to be
installed, uninstalled, upgraded, etc.  Those core functions include:

```php
<?php
function plugin_myplugin_install() {
}

function plugin_myplugin_uninstall() {
}

function plugin_myplugin_check_config() {
}

function plugin_myplugin_upgrade() {
}

function plugin_myplugin_version() {
}

?>
```

Without these core functions, in your setup.php, your plugin will not fully
operate.  We will document those functions and what they should include as we
continue to document the plugin design principals.

Any core plugin functions should always be placed in the lib/functions.php file,
and settings should go into the include/settings.php file.  The plugin
architecture allows hooks to be defined that reach into the include/settings.php
file.  Having those hooks point to the include version of the file will keep
Cacti page loads fast.  Including too much in the setup.php slows Cacti and
should be avoided.

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Copyright (c) 2004-2026 The Cacti Group