diff --git a/classes/tag.php b/classes/tag.php
index f58c4bd..d61219d 100644
--- a/classes/tag.php
+++ b/classes/tag.php
@@ -32,7 +32,150 @@
  */
 class tag extends referable {
 
+    /**
+     * @var \stdClass
+     */
+    protected $tag = null;
+
+
+    /**
+     * Constructor.
+     *
+     * @param int|\stdClass $tag
+     * @return void
+     */
+    public function __construct($tag) {
+        global $DB;
+        if (is_scalar($tag)) {
+            $tag = $DB->get_record('local_qtracker_tag', array('id' => $tag), '*', MUST_EXIST);
+            if (!$tag) {
+                throw new \moodle_exception('errorunexistingmodel', 'analytics', '', $tag);
+            }
+        }
+        $this->tag = $tag;
+    }
+
+
+    /**
+     * Returns the tag id.
+     *
+     * @return int
+     */
     public function get_id() {
-        return null;
+        return $this->tag->id;
+    }
+
+
+    /**
+     * Returns the tag name.
+     *
+     * @return string
+     */
+    public function get_name() {
+        return $this->tag->name;
+    }
+
+
+    /**
+     * Returns the tag color.
+     *
+     * @return string
+     */
+    public function get_color() {
+        return $this->tag->color;
+    }
+
+
+    /**
+     * Returns a plain \stdClass with the tag data.
+     *
+     * @return \stdClass
+     */
+    public function get_tag_obj() {
+        return $this->tag;
+    }
+
+
+    /**
+     * Loads and returns tag with id $tagid
+     *
+     * @param int $tagid
+     * @return tag|null
+     */
+    public static function load(int $tagid) {
+        global $DB;
+        $tagobj = $DB->get_record('local_qtracker_tag', ['id' => $tagid]);
+        if ($tagobj === false) {
+            return null;
+        }
+        return new tag($tagobj);
+    }
+
+
+    /**
+     * Creates a new tag.
+     *
+     * @param string $name
+     * @param string $color
+     *
+     * @return tag
+     */
+    public static function create($name, $color) {
+        global $DB;
+
+        $tagobj = new \stdClass();
+        $tagobj->name = $name;
+        $tagobj->color = $color;
+
+        $id = $DB->insert_record('local_qtracker_tag', $tagobj);
+
+        $tagobj->id = $id;
+
+        return new tag($tagobj);
+    }
+
+
+    /**
+     * Sets the name of the tag.
+     *
+     * @param string $name
+     */
+    public function set_name($name) {
+        global $DB;
+        $this->tag->name = $name;
+        $DB->update_record('local_qtracker_tag', $this->tag);
+    }
+
+
+    /**
+     * Sets the color of the tag.
+     *
+     * @param string $color
+     */
+    public function set_color($color) {
+        global $DB;
+        $this->tag->color = $color;
+        $DB->update_record('local_qtracker_tag', $this->tag);
+    }
+
+
+    /**
+     * Deletes the tag and all its references.
+     *
+     * @return void
+     */
+    public function delete() {
+        global $DB;
+
+        $outrefs = $this->get_outgoing_references();
+        foreach ($outrefs as $outref) {
+            $outref->delete();
+        }
+        $inrefs = $this->get_incoming_references();
+        foreach ($inrefs as $inref) {
+            $inref->delete();
+        }
+
+        return $DB->delete_records('local_qtracker_tag', array('id' => $this->get_id()));
     }
 }