Overview of WordPress multisite support on the Pantheon Platform.

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You're just about to configure your WordPress Site Network.

Our expectation at this point is that you have a new WordPress Site Network created for you by a Pantheon employee. If you do not yet have a WordPress Site Network, refer to the introduction page of this guide. When you visit the Dev environment's site URL, you should be redirected to WordPress' web-based installer.


Adjust placeholders in code snippets as needed throughout this guide. This includes placeholders such as <site> and <env> within Terminus commands, in addition to placeholders wrapped in <> brackets within larger code blocks.

Install the WordPress Site Network

Using Terminus is our recommended way to install a WordPress Site Network.

  1. Install the most recent release of Terminus:

    curl -O && php installer.phar install
  2. Generate a Machine Token, then authenticate Terminus:

    terminus auth:login --machine-token=<machine-token>
  3. Make sure the site's connection mode is set to SFTP:

    terminus connection:set <site>.dev sftp
  4. Use Terminus to execute the wp core multisite-install command (full documentation):


    The default behavior for this command is to create a Site Network with the subdirectory configuration. To create your network with the subdomain configuration, add the --subdomains flag.

    terminus wp <site>.<env> -- core multisite-install --url=<url> --title=<site-title> --admin_user=<username> --admin_email=<email>

    When you install a new WordPress Site Network, you should see a success notice similar to this:

    terminus wp -- core multisite-install --title="Site Networks" --admin_user=aghost
    Admin password: abcdefgnotarealpassword
    Created single site database tables.
    Set up multisite database tables.
    Added multisite constants to 'wp-config.php'.
    Success: Network installed. Dont forget to set up rewrite rules.

Et voila! Your WordPress Site Network is now installed.

Configure the WordPress Site Network

The wp core multisite-install command we ran in the previous section modifies the wp-config.php file. One of those modifications sets the DOMAIN_CURRENT_SITE constant, which fixes your WordPress Site Network to a specific URL.

In order for things to run smoothly on Pantheon, we need to adjust the configuration so that the DOMAIN_CURRENT_SITE constant is defined conditionally based on the given environment:

  1. Navigate to Code in the Dev tab of your Site Dashboard.

  2. Click Connect with SFTP to access the credentials for connecting to your preferred SFTP client.

  3. Click Open SFTP client, and enter your User Dashboard password when prompted.

    If you run into issues, please refer to Pantheon's SFTP documentation.

  4. Open the code folder in your SFTP client, and download your site's wp-config.php file.

  5. Locate the configuration added by WP-CLI, and comment out the line that sets DOMAIN_CURRENT_SITE. For example:

    define( 'WP_ALLOW_MULTISITE', true );
    define( 'MULTISITE', true );
    define( 'SUBDOMAIN_INSTALL', false );
    $base = '/';
    # define( 'DOMAIN_CURRENT_SITE', '' );
    define( 'PATH_CURRENT_SITE', '/' );
    define( 'SITE_ID_CURRENT_SITE', 1 );
    define( 'BLOG_ID_CURRENT_SITE', 1 );
  6. Add the following code block to your wp-config.php file, under the lines mentioned in the previous step:

     * Define DOMAIN_CURRENT_SITE conditionally.
    if ( ! empty( $_ENV['PANTHEON_ENVIRONMENT'] ) ) {
      switch( $_ENV['PANTHEON_ENVIRONMENT'] ) {
        case 'live':
          // Value should be the primary domain for the Site Network.
          define( 'DOMAIN_CURRENT_SITE', 'live-<site>' );
          // Once you map a domain to Live, you can change DOMAIN_CURRENT_SITE
          // define( 'DOMAIN_CURRENT_SITE', '' );
        case 'test':
          define( 'DOMAIN_CURRENT_SITE', 'test-<site>' );
        case 'dev':
          define( 'DOMAIN_CURRENT_SITE', 'dev-<site>' );
          # Catch-all to accommodate default naming for multi-dev environments.

    The astute programmer will notice the test and dev cases are redundant. Feel free to remove if you don't intend to add custom domains to those environments. Generally, the key idea is that you're conditionally defining the DOMAIN_CURRENT_SITE constant based on the current Pantheon environment (Dev, Test, Live or Multidev).

  7. Save your changes and upload the wp-config.php file to Pantheon's Dev environment once edits are complete.


A warning may appear in the WordPress dashboard that you need to update your .htaccess file. Since Pantheon used Nginx and your site is already pre-configured for multisite by your Account Manager, you can ignore this warning.

Developing the Site Network

Congratulations on setting up your first WordPress Site Network. You are on your way to glory! When logged in to the WordPress Dashboard, you'll see a new My Sites menu item in the toolbar:

Enabling the network

You will have one site — go ahead and create another if you'd like. If you chose to use WordPress Site Networks with subdirectories, you'll be able to access the site right away. If you chose to use subdomains, you'll need to map a custom hostname to the environment before you can access the new environment.

Spend some additional time exploring the WordPress Network Dashboard to become familiar with the variety of additional settings you now have. Take a look at what options are available for each site you create, how to manage users across WordPress Multisite, and the grab bag of network settings.

Once you're ready to move on, the next section covers using a WordPress Site Network with the Pantheon Workflow.