The Kinsta MU (must use) plugin has been designed to work on our WordPress hosting platform. It handles things such as our full page caching technology and Kinsta’s CDN integration.

By default, the Kinsta MU plugin is installed on every site hosted by us and is available from the left-hand side of your WordPress admin dashboard. The plugin is required to ensure your site runs smoothly in our environment.

Installing the Kinsta MU Plugin

If you’ve migrated your site yourself or installed WordPress manually, you may not have installed the Kinsta MU plugin. We periodically install and update the plugin for every site at Kinsta that doesn’t use Composer or manage the entire wp-content directory or mu-plugins directory in Git. If you prefer or need to install the Kinsta MU plugin manually, you can do so by following one of the applicable methods below.

Installing Via SFTP

Step 1: Create mu-plugins Folder

Connect to your site via SFTP and create a folder called mu-plugins in your wp-content folder if it doesn’t already exist (finished path: /wp-content/mu-plugins/).

The mu-plugins folder in FTP.
The mu-plugins folder in FTP.

Step 2: Download and Unzip the Plugin

After ensuring the mu-plugins folder has been created, download the Kinsta MU plugin and unzip it.

Step 3: Upload to Site

Upload the kinsta-mu-plugins folder and kinsta-mu-plugins.php file to the /wp-content/mu-plugins/ directory.

Kinsta MU plugin folder and file in FTP.
Kinsta MU plugin folder and file in FTP.

This will install the plugin, and you can see it in your WordPress dashboard by logging in and going to Plugins > Must-Use.

Installing Via Composer

If your site is built with Bedrock or any boilerplate or framework that uses Composer, you’ll need to take some extra steps to install the Kinsta Must Use plugin on your site.

Step 1: Declare the Kinsta MU Plugin Package Repository

Begin by declaring the Kinsta MU plugin as a package repository in the repositories array in your composer.json file:


    {
      "type": "package",
      "package": {
        "name": "kinsta/kinsta-mu-plugins",
        "type": "wordpress-muplugin",
        "version": "2.3.7",
        "dist": {
          "url": "https://kinsta.com/kinsta-tools/kinsta-mu-plugins.zip",
          "type": "zip"
        }
      }
    }

Note: While you can technically set the version number to anything valid (because you’re installing the plugin from a specific zip file) this will need to be changed each time you need to update the plugin, so we recommend checking the version in the lastest download of the Kinsta MU plugin.

Step 2: Require the Kinsta MU Plugin

Next, run the following command in your site’s bedrock directory (or the directory where your composer.json file is located).

composer require kinsta/kinsta-mu-plugins

Or, add the Kinsta MU plugin to the require array in your composer.json file. Here’s an example require array from a Bedrock site after adding the Kinsta MU plugin:


"require": {
    "php": ">=7.4",
    "composer/installers": "^2.1",
    "vlucas/phpdotenv": "^5.4",
    "oscarotero/env": "^2.1",
    "roots/bedrock-autoloader": "^1.0",
    "roots/bedrock-disallow-indexing": "^2.0",
    "roots/wordpress": "5.9.3",
    "roots/wp-config": "1.0.0",
    "roots/wp-password-bcrypt": "1.1.0",
    "kinsta/kinsta-mu-plugins": "^2.3"
  },

Step 3: Fix the Path for Kinsta MU Plugin Assets

To fix the path to assets used by the MU plugin, add the following to your site’s configuration file (bedrock/config/application.php in Bedrock sites):

/**
 * Fix for Kinsta's CDN with Bedrock
 */
define('KINSTA_CDN_USERDIRS', 'app');

/**
 * Fix Kinsta MU Plugins URL path with Bedrock
 */
$mu_plugins_url = Config::get('WP_CONTENT_URL') . '/mu-plugins';
define('KINSTAMU_CUSTOM_MUPLUGIN_URL', "{$mu_plugins_url}/kinsta-mu-plugins");

Installing Via Git

If you use Git with your site, installing the Kinsta MU plugin depends on what parts of the site you manage with Git.

If you manage the entire wp-content directory or mu-plugins directory in your Git repo, you’ll need to download and install the plugin in your local repo, commit that change, then deploy it to your site. You can install the plugin locally by downloading it and placing plugin files in your site’s mu-plugins directory.

If you do not maintain a copy of the Kinsta MU plugin in your Git repo, we’ll automatically install the Kinsta MU plugin for you or you can use SFTP to install it manually.

Kinsta MU Plugin Settings

The Kinsta MU plugin is set to work harmoniously with WordPress and our infrastructure. On most sites, it won’t need any modifications. The plugin enables automatic clearing of cache on important parts of your site when you make updates to your page and post content.

Kinsta Cache plugin in the WordPress dashboard.
Kinsta Cache plugin in the WordPress dashboard.

Manually Clearing Cache

You can also manually clear the cache on your WordPress site with the following methods.

  1. Press the Clear All Caches button on the Kinsta Cache plugin page in your WordPress dashboard.
  2. Press the Clear Caches link on the WordPress admin toolbar.
  3. Clear cache in MyKinsta.
  4. Running wp kinsta cache purge in the command line.
Clear cache in the WordPress dashboard.
Clear cache in the WordPress dashboard.

Adding Custom Caching URLs

We already purge single pages and key pages such as the home page immediately and impose a minimal throttle time on archive pages. This ensures high availability at all times. However, depending on how your site’s configuration, additional caching rules might be needed. You can add custom paths to purge whenever your site is updated.

1. Add Single Path Custom URL

If you need cache cleared on an exact URL (post or page), you can enter this as a single path rule on the Kinsta Cache plugin page in your WordPress dashboard. Example: https://yourdomain.com/important-page

Custom URL single path in Kinsta Cache.
Custom URL single path in Kinsta Cache.

2. Add Group Path Custom URL

The group path purges all the URLs which start with that specific URL. This can be especially useful if you have a custom post type and need the cache cleared on it and the posts underneath it. For example, if you add https://yourdomain.com/custom-post-type/ as a group path URL, then it will purge the cache on the following:

https://yourdomain.com/custom-post-type/
https://yourdomain.com/custom-post-type/post-1
https://yourdomain.com/custom-post-type/post-2
https://yourdomain.com/custom-post-type/post-3
Custom URL group path in Kinsta Cache.
Custom URL group path in Kinsta Cache.

Additional Notes

You aren’t allowed to add only “/” as a path, as this would trigger a clear of the full site’s cache with a post/page update. Purging all pages would take a significant toll on server resources, especially during high load times and frequent publishing schedules. This could also degrade the performance of your site for visitors as it would have to re-cache everything.

If you have clients and prefer they not see any Kinsta branding, you can also white label the plugin.

Updating the Kinsta MU Plugin

If your site doesn’t use Composer or Git, we’ll automatically update the Kinsta MU plugin for you periodically. There’s nothing more you need to do to keep the plugin updated.

Updating Via SFTP

If you need to update the plugin manually (perhaps you restored an older backup or an update didn’t go as planned), you can use SFTP to manually update the Kinsta MU plugin.

  1. Download the Kinsta MU plugin and unzip it.
  2. Upload the kinsta-mu-plugins folder and kinsta-mu-plugins.php file to the /wp-content/mu-plugins/ directory and overwrite the existing files when prompted by your SFTP client.
  3. This will overwrite the old plugin files with the new ones to update the plugin to the latest version.

Updating Via Composer

  1. Update the version number in the Kinsta MU plugin repository declaration in your composer.json file: 
        {
      "type": "package",
      "package": {
        "name": "kinsta/kinsta-mu-plugins",
        "type": "wordpress-muplugin",
        "version": "2.3.7",
        "dist": {
          "url": "https://kinsta.com/kinsta-tools/kinsta-mu-plugins.zip",
          "type": "zip"
        }
      }
    }
  2. Run composer update kinsta/kinsta-mu-plugins in your site’s bedrock directory (or the directory where your composer.json file is located).

Updating Via Git

If you use Git with your site, the process of updating the plugin depends on what parts of the site you manage with Git.

If you manage the entire wp-content directory or mu-plugins directory in your Git repo, you’ll need to update the plugin in your local repo, commit that change, then deploy it to your site. You can update locally by downloading the plugin and overwriting the existing plugin files in your repo.

If you do not maintain a copy of the Kinsta MU plugin in your Git repo, we’ll automatically update the Kinsta MU plugin for you; there’s nothing more you’ll need to do.