Chatrix

This plugin can be used in two distinct ways:

1. By adding a block to a page through the block editor
2. By selecting pages in which a popup will be displayed. You configure this through Settings -> Chatrix.

Yes. Instead of configuring the popup through Settings -> Chatrix, you can configure it through code, by using the chatrix_instances filter:

// functions.php

add_filter( 'chatrix_instances', function ( array $default_instances ) {
    // The key is an instance_id, the value array is the config for that instance.
    // Set 'pages' to an array of the ids of the pages which should show chatrix.
    // You can also set 'pages' to 'all' which results in that instance always being used.
    // Only one instance can be shown on a given page.
    return array(
        'foo' => array(
            'homeserver' => 'https://foo.com',
            'room_id'    => '!id:foo.com',
            'pages'      => 'all',
        ),
        'bar' => array(
            'homeserver' => 'https://bar.com',
            'room_id'    => '!id:bar.com',
            'pages'      => array(1, 2, 3),
        ),
    );
} );

The plugin will respect the login methods configured on the Matrix homeserver. For example, if the homeserver has both password and SSO login enabled, both options will be available to the user.

In light of the plan for Matrix to replace their user management with Open ID Connect (OIDC), we recommend to use a Single-Sign On (SSO) flow by configuring Open ID Connect login on Synapse and use the OpenID Connect Server WordPress plugin.

The flow will then be as follows: When logging into your homeserver, it will redirect you to your own WordPress login page and ask you to authorize the login by the click of a button, and then relay your information to the homeserver. You’ll be redirected back to your WordPress page and Chatrix will receive the login information and you can start chatting.

Later, when Matrix makes the switch to OIDC, you are already prepared and can continue to use this setup.