Automatically add members to all spaces

Do you use Fluent cart? Or Fluent Crm?Yess? That is the way you can set it up with tags or integration.

You have automation plugin? With fluent community integration? And how do you ad them now to your community? Can you tell me the flow?

Just a click away ;)

It's easy to do, have a look at the Developer Docs https://dev.fluentcommunity.co/guides/code-snippets

Use something like this (just add it to your Themes functions.php file or use FluentSnippet plugin)

add_action('user_register', function($userId) {
    if (!class_exists('\FluentCommunity\App\Functions\Utility')) {
        return;
    }

    $spaces = \FluentCommunity\App\Functions\Utility::getSpaces(false);

    foreach ($spaces as $space) {
        if (($space->status ?? '') === 'published' && ($space->type ?? '') === 'space') {
            \FluentCommunity\App\Services\Helper::addToSpace(
                $space->id,
                $userId,
                'member',
                'by_admin'
            );
        }
    }
}, 20, 1);

The Utility::getSpaces(false) returns all spaces including drafts, so you can use the status check to skip unpublished ones and only add users to Published Spaces. The by_admin flag means it's treated as an admin-initiated join rather than the user opting in themselves.

David Carton suggested the right approach.
FluentCRM (free version) is really the simplest solution — no hook needed, everything is done through the settings. Just create a tag in FluentCRM, then in FluentCommunity Settings → Access Management map that tag to each of your spaces. Any new member who receives the tag is automatically added.

Official doc: https://fluentcommunity.co/docs/access-management-through-fluentcrm-tags/