I am developing a registration system that will connect our main database from a php website with the database of wordpress.

I would like to use the following functions.

<?php wp_insert_user( $userdata ); ?>    
<?php wp_update_user( $userdata ); ?>
<?php add_user_meta( $user_id, $meta_key, $meta_value, $unique ); ?>
<?php update_user_meta( $user_id, $meta_key, $meta_value, $prev_value ); ?>

So far I added the following code to my php file which is located in the root directory of my wordpress installation.

//$output variable is set by $_GET
$result = getURLparams($output);

function getURLparams($data){
    parse_str($data, $result);

function getMethod($result){

function registerUser($data){   
    $userdata = array(
    'user_pass'     =>  $data['password'],
    'user_login'    =>  $data['email'],
    'user_email'    =>  $data['email'], 
    'first_name'    =>  $data['fname'],
    'last_name'     =>  $data['lname']

    $user_id = wp_insert_user( $userdata ) ;

    //On success add meta keys
    if( !is_wp_error($user_id) ) {
        add_user_meta( $user_id, 'telephone', $data['tel'], true );
        add_user_meta( $user_id, 'university', $data['uni_id'], true );
        add_user_meta( $user_id, 'enrollment_year', $data['admission_year'], true);     
        echo '300';


So far the error I get is Call to undefined function wp_insert_user()

What is my mistake?


1 Answer 1


You need to make the functions available, they are located in wp-includes/user.php. So load the user.php via require e.g. like this:

require( ABSPATH . WPINC . '/user.php' );

But keep in mind, if you need to do that and load wp-load.php manually, then you likely have not done it right. Meaning, you should aim for a solution that is integrated into the WordPress process, so that no manual stuff like that is necessary.

  • Hi ialocin, I added user.php however it kept asking for more files to be added. is there a line or a require file that adds all the functions of wordpress? Some suggest wp-blog-header.php which seems to be old.
    – Onisiforos
    May 1, 2015 at 19:58
  • @Onisiforos wp-load.php itself is quite far-reaching. The difference in contrast to wp-blog-header.php is minimal, just look at the files. I don't know a one-liner, because I haven't done this in years, since it - as stated - isn't a very good solution. And mostly it is not a must to do it taht way, so I don't. I guess you probably have to trickle-down all the dependencies/files needed. May 2, 2015 at 14:22
  • is it a good idea if I make file in my page template in my theme?
    – Onisiforos
    May 3, 2015 at 9:49

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