diff --git a/lbplanner/classes/enums/CAPABILITY.php b/lbplanner/classes/enums/CAPABILITY.php
index 4395de5c..ef195f00 100644
--- a/lbplanner/classes/enums/CAPABILITY.php
+++ b/lbplanner/classes/enums/CAPABILITY.php
@@ -60,8 +60,7 @@ class CAPABILITY extends Enum {
      * @return int the bitmappable flag
      * @link CAPABILITY_FLAG
      */
-    public static function to_capability(string $str): int {
-        $name = self::name_from($str);
-        return constant('CAPABILITY_FLAG::'.$name);
+    public static function to_flag(string $str): int {
+        return CAPABILITY_FLAG::get(self::name_from($str));
     }
 }
diff --git a/lbplanner/classes/enums/CAPABILITY_FLAG.php b/lbplanner/classes/enums/CAPABILITY_FLAG.php
index 6c3da573..88d06fe6 100644
--- a/lbplanner/classes/enums/CAPABILITY_FLAG.php
+++ b/lbplanner/classes/enums/CAPABILITY_FLAG.php
@@ -61,7 +61,6 @@ class CAPABILITY_FLAG extends Enum {
      * @link CAPABILITY
      */
     public static function to_capability(int $num): string {
-        $name = self::name_from($num);
-        return constant('CAPABILITY::'.$name);
+        return CAPABILITY::get(self::name_from($num));
     }
 }
diff --git a/lbplanner/classes/helpers/user_helper.php b/lbplanner/classes/helpers/user_helper.php
index 6daa68b5..c205a26f 100644
--- a/lbplanner/classes/helpers/user_helper.php
+++ b/lbplanner/classes/helpers/user_helper.php
@@ -16,15 +16,13 @@
 
 namespace local_lbplanner\helpers;
 
-use coding_exception;
 use context_system;
 use dml_exception;
 use moodle_exception;
 use stdClass;
-use user_picture;
 use core_user;
 
-use local_lbplanner\enums\{CAPABILITY, CAPABILITY_FLAG};
+use local_lbplanner\enums\CAPABILITY;
 use local_lbplanner\model\user;
 
 /**
@@ -51,7 +49,13 @@ class user_helper {
      */
     public static function check_access(int $userid): bool {
         global $USER;
-        return ((int) $USER->id) === $userid;
+
+        if (((int) $USER->id) === $userid) {
+            return true;
+        } else {
+            $context = context_system::instance();
+            return has_capability(CAPABILITY::ADMIN, $context, $USER->id);
+        }
     }
 
     /**
@@ -69,64 +73,6 @@ public static function assert_access(int $userid): void {
         }
     }
 
-    /**
-     * Checks if the given user is an admin.
-     *
-     * @param int $userid The id of the user to check.
-     *
-     * @return bool True if the given user is an admin, false otherwise.
-     * @throws coding_exception
-     * @throws dml_exception
-     */
-    public static function is_admin(int $userid): bool {
-        $context = context_system::instance();
-        return has_capability(CAPABILITY::ADMIN, $context, $userid, false);
-    }
-
-    /**
-     * Gives back a bitmask which represents the capabilities of the given user.
-     * 0 = no capabilities
-     * 1 = admin
-     * 2 = manager
-     * 3 = admin + manager
-     * 4 = teacher
-     * 5 = admin + teacher
-     * 6 = manager + teacher
-     * 7 = admin + manager + teacher
-     * 8 = student
-     * 9 = admin + student
-     * 10 = manager + student
-     * 11 = admin + manager + student
-     * 12 = teacher + student
-     * 13 = admin + teacher + student
-     * 14 = manager + teacher + student
-     * 15 = admin + manager + teacher + student
-     *
-     *
-     * @param int $userid The id of the user to check access for.
-     *
-     * @return int The capabilities of the given user.
-     * @throws coding_exception
-     * @throws dml_exception
-     */
-    public static function get_user_capability_bitmask(int $userid): int {
-        $capabilities = 0;
-        $context = context_system::instance();
-        if (has_capability(CAPABILITY::ADMIN, $context, $userid, false)) {
-            $capabilities += CAPABILITY_FLAG::ADMIN;
-        }
-        if (has_capability(CAPABILITY::MANAGER, $context, $userid, false)) {
-            $capabilities += CAPABILITY_FLAG::MANAGER;
-        }
-        if (has_capability(CAPABILITY::TEACHER, $context, $userid, false)) {
-            $capabilities += CAPABILITY_FLAG::TEACHER;
-        }
-        if (has_capability(CAPABILITY::STUDENT, $context, $userid, false)) {
-            $capabilities += CAPABILITY_FLAG::STUDENT;
-        }
-        return $capabilities;
-    }
-
     /**
      * Checks if the given user exists in the LB_PLANNER_USER database.
      *
diff --git a/lbplanner/classes/model/user.php b/lbplanner/classes/model/user.php
index 09643eb2..aef941d6 100644
--- a/lbplanner/classes/model/user.php
+++ b/lbplanner/classes/model/user.php
@@ -26,8 +26,11 @@
 namespace local_lbplanner\model;
 
 use coding_exception;
+use context_system;
 use external_single_structure;
 use external_value;
+use local_lbplanner\enums\CAPABILITY;
+use local_lbplanner\enums\CAPABILITY_FLAG;
 use local_lbplanner\helpers\plan_helper;
 use local_lbplanner\helpers\user_helper;
 use user_picture;
@@ -81,6 +84,11 @@ class user {
      */
     private ?int $planid;
 
+    /**
+     * @var ?int $capabilitybitmask the cached user capability bitmask
+     */
+    private ?int $capabilitybitmask;
+
     /**
      * Constructs a new course
      * @param int $lbpid ID of the lb planner user
@@ -107,6 +115,7 @@ public function __construct(
         $this->set_displaytaskcount($displaytaskcount);
         $this->planid = null;
         $this->pfp = null;
+        $this->capabilitybitmask = null;
 
         if ($mdlid === (int) $USER->id) {
             $this->mdluser = $USER;
@@ -240,6 +249,24 @@ public function get_pfp(): string {
         return $this->pfp;
     }
 
+    /**
+     * gets the user's capability bitmask
+     * @return int
+     */
+    public function get_capabilitybitmask(): int {
+        if ($this->capabilitybitmask === null) {
+            $context = context_system::instance();
+            $this->capabilitybitmask = 0;
+            foreach (CAPABILITY::cases() as $case) {
+                if (has_capability($case->value, $context, $this->mdlid, false)) {
+                    $this->capabilitybitmask |= CAPABILITY::to_flag($case->value);
+                }
+            }
+        }
+
+        return $this->capabilitybitmask;
+    }
+
     /**
      * Prepares data for the DB endpoint.
      * doesn't set ID if it's 0
@@ -269,14 +296,21 @@ public function prepare_for_db(): object {
      */
     public function prepare_for_api_short(): array {
         $mdluser = $this->get_mdluser();
-        return [
+        $capabilitybm = $this->get_capabilitybitmask();
+
+        $data = [
             'userid' => $this->mdlid,
             'username' => $mdluser->username,
             'firstname' => $mdluser->firstname,
             'lastname' => $mdluser->lastname,
             'profileimageurl' => $this->get_pfp(),
-            'vintage' => $mdluser->address,
         ];
+
+        if ($capabilitybm & CAPABILITY_FLAG::STUDENT) {
+            $data['vintage'] = $mdluser->address;
+        }
+
+        return $data;
     }
 
     /**
@@ -292,7 +326,7 @@ public static function api_structure_short(): external_single_structure {
                 'firstname' => new external_value(PARAM_TEXT, 'The firstname of the user'),
                 'lastname' => new external_value(PARAM_TEXT, 'The lastname of the user'),
                 'profileimageurl' => new external_value(PARAM_URL, 'The url of the profile image'),
-                'vintage' => new external_value(PARAM_TEXT, 'The vintage of the user'),
+                'vintage' => new external_value(PARAM_TEXT, 'The vintage of the user', VALUE_DEFAULT),
             ]
         );
     }
@@ -303,21 +337,17 @@ public static function api_structure_short(): external_single_structure {
      * @return array a full representation of this user and its data
      */
     public function prepare_for_api(): array {
-        $mdluser = $this->get_mdluser();
-        return [
-            'userid' => $mdluser->id,
-            'username' => $mdluser->username,
-            'firstname' => $mdluser->firstname,
-            'lastname' => $mdluser->lastname,
-            'theme' => $this->theme,
-            'lang' => $this->lang,
-            'profileimageurl' => $this->get_pfp(),
-            'planid' => $this->get_planid(),
-            'colorblindness' => $this->colorblindness,
-            'displaytaskcount' => $this->displaytaskcount,
-            'capabilities' => user_helper::get_user_capability_bitmask($this->mdlid),
-            'vintage' => $mdluser->address,
-        ];
+        return array_merge(
+            $this->prepare_for_api_short(),
+            [
+                'theme' => $this->theme,
+                'lang' => $this->lang,
+                'planid' => $this->get_planid(),
+                'colorblindness' => $this->colorblindness,
+                'displaytaskcount' => $this->displaytaskcount,
+                'capabilities' => $this->get_capabilitybitmask(),
+            ]
+        );
     }
 
     /**
@@ -339,7 +369,7 @@ public static function api_structure(): external_single_structure {
                 'colorblindness' => new external_value(PARAM_TEXT, 'The colorblindness of the user'),
                 'displaytaskcount' => new external_value(PARAM_INT, 'If the user has the taskcount-enabled 1-yes 0-no'),
                 'capabilities' => new external_value(PARAM_INT, 'The capabilities of the user represented as a bitmask value'),
-                'vintage' => new external_value(PARAM_TEXT, 'The vintage of the user'),
+                'vintage' => new external_value(PARAM_TEXT, 'The vintage of the user', VALUE_DEFAULT),
             ]
         );
     }
diff --git a/lbplanner/classes/polyfill/Enum.php b/lbplanner/classes/polyfill/Enum.php
index dde1b238..3a429f91 100644
--- a/lbplanner/classes/polyfill/Enum.php
+++ b/lbplanner/classes/polyfill/Enum.php
@@ -40,7 +40,7 @@ class Enum {
      * @return ?EnumCase the matching enum case or null if not found and $try==true
      * @throws ValueError if not found and $try==false
      */
-    private static function find(mixed $value, bool $try): ?EnumCase {
+    private static function find($value, bool $try): ?EnumCase {
         foreach (static::cases() as $case) {
             if ($case->value === $value) {
                 return $case;
@@ -53,12 +53,32 @@ private static function find(mixed $value, bool $try): ?EnumCase {
             throw new ValueError("value {$value} cannot be represented as a value in enum ".static::class);
         }
     }
+    /**
+     * tries to match the passed value to one of the enum values
+     * @param string $name the value to be matched
+     * @param bool $try whether to return null (true) or throw an error (false) if not found
+     * @return ?EnumCase the matching enum case or null if not found and $try==true
+     * @throws ValueError if not found and $try==false
+     */
+    private static function find_from_name(string $name, bool $try): ?EnumCase {
+        foreach (static::cases() as $case) {
+            if ($case->name === $name) {
+                return $case;
+            }
+        }
+
+        if ($try) {
+            return null;
+        } else {
+            throw new ValueError("name {$name} doesn't exist in ".static::class);
+        }
+    }
     /**
      * tries to match the passed value to one of the enum values
      * @param mixed $value the value to be matched
      * @return mixed either the matching enum value or null if not found
      */
-    public static function try_from(mixed $value): mixed {
+    public static function try_from($value) {
         // TODO: replace with nullsafe operator in php8.
         $case = static::find($value, true);
         if (is_null($case)) {
@@ -73,16 +93,15 @@ public static function try_from(mixed $value): mixed {
      * @return mixed the matching enum value
      * @throws ValueError if not found
      */
-    public static function from(mixed $value): mixed {
+    public static function from($value) {
         return static::find($value, false)->value;
     }
     /**
      * tries to match the passed value to one of the enum values
      * @param mixed $value the value to be matched
-     * @return string the matching enum case name
-     * @throws mixed either the matching enum case name or null if not found
+     * @return ?string either the matching enum case name or null if not found
      */
-    public static function try_name_from(mixed $value): ?string {
+    public static function try_name_from($value): ?string {
         // TODO: replace with nullsafe operator in php8.
         $case = static::find($value, true);
         if (is_null($case)) {
@@ -97,9 +116,26 @@ public static function try_name_from(mixed $value): ?string {
      * @return string the matching enum case name
      * @throws ValueError if not found
      */
-    public static function name_from(mixed $value): string {
+    public static function name_from($value): string {
         return static::find($value, false)->name;
     }
+    /**
+     * tries to get a value based on the name
+     * @param string $name the name to look for
+     * @return mixed the matching enum case value
+     * @throws ValueError if not found
+     */
+    public static function get(string $name) {
+        return static::find_from_name($name, false)->value;
+    }
+    /**
+     * tries to get a value based on the name
+     * @param string $name the name to look for
+     * @return ?mixed either the matching enum case value or null if not found
+     */
+    public static function try_get(string $name) {
+        return static::find_from_name($name, false)->value;
+    }
     /**
      * Returns an array of all the cases that exist in this enum
      *
diff --git a/lbplanner/services/user/delete_user.php b/lbplanner/services/user/delete_user.php
index ca062be8..d89756ff 100644
--- a/lbplanner/services/user/delete_user.php
+++ b/lbplanner/services/user/delete_user.php
@@ -59,13 +59,11 @@ public static function delete_user_parameters(): external_function_parameters {
      * @throws moodle_exception
      */
     public static function delete_user($userid) {
-        global $DB, $USER;
+        global $DB;
 
         self::validate_parameters(self::delete_user_parameters(), ['userid' => $userid]);
 
-        if (!user_helper::is_admin($USER->id)) {
-            user_helper::assert_access($userid);
-        }
+        user_helper::assert_access($userid);
 
         // Check if User is in user table.
         if (!$DB->record_exists(user_helper::LB_PLANNER_USER_TABLE, ['userid' => $userid])) {