Is it Possible to Have Relationship Metabox Editable Only on One Side?

Hi,

Yes, it is possible. You can use the setting reciprocal when registering the relationship. If you set reciprocal for different object types (CPT) like your case, the connection meta box only shows on the from object type page.

Refer to the documentation https://docs.metabox.io/extensions/mb-relationships/#reciprocal-relationships

Hi,

You can use the field type select and add the attribute disabled to an object type to disable edit/add more connected objects. For example:

MB_Relationships_API::register( [
    'id'   => 'job-to-post',
    'from' => [
        'object_type'  => 'post',
        'post_type'    => 'job',
        'field' => [
            'type' => 'select',
            'disabled' => true //here
        ]    
    ],
    'to'   => [
        'object_type'  => 'post',
        'post_type'    => 'post',
        
    ],
] );

Read more on the documentation https://docs.metabox.io/extensions/mb-relationships/#syntax
https://docs.metabox.io/field-settings/

Hi,

The builder does not support options to customize the field settings. You need to use the code to get more control over field settings.

Hi,

You can export the relationship from the builder to get the PHP code, move it to the trash or delete it. Then add the code to the file functions.php in the theme/child theme folder.

The data is already saved into the database so don't worry it will be lost after deleting the relationship from the builder.

Refer to this documentation https://docs.metabox.io/extensions/meta-box-builder/#getting-php-code