diff --git a/item.php b/item.php
index 136e334..e1c34a9 100644
--- a/item.php
+++ b/item.php
@@ -2,7 +2,16 @@
 
 class Item implements JsonSerializable
 {
+
+    // TODO: create a persist() method that updates the line if the offset where
+    //       it originally existed in is given by 'ftell'. If it doesn't have an
+    //       ID, then try to find it in the file and if it doesn't exist, append
+    //
+    // TODO: Maybe implement tags as an associative array or somethign?
+    //
     // TODO: Change to id here in all occurrences
+    //
+
     private string $hash;
     private string $extension;
     private array $tags = [];
@@ -46,18 +55,20 @@ class Item implements JsonSerializable
             Json::error('Trying to upload illegal or non-existent file')->die();
 
         // --- INITIALIZE ---
-        $ret = new Item();
-        $ret->hash = hash_file('sha256', $from_path);
-        $ret->extensionFromUpload($php_file);
+        $item = new Item();
+        $item->hash = hash_file('sha256', $from_path);
+        $item->extensionFromUpload($php_file);
 
         // --- ACTUALLY GRAB FILE ---
-        $new_path = $ret->getPath();
+        $new_path = $item->getPath();
         if (file_exists($new_path))
             Json::error('File already exists')->die();
         if (!move_uploaded_file($from_path, $new_path))
             Json::error('Failed to move uploaded file')->die();
 
-        return $ret;
+        MediaDB::add($item);
+
+        return $item;
     }
 
     private function extensionFromTags()
@@ -69,6 +80,8 @@ class Item implements JsonSerializable
                 return;
             }
         }
+
+        Json::error('Detected file without file format tag')->die();
     }
 
     // Assumes is_uploaded_file has been done
@@ -83,8 +96,7 @@ class Item implements JsonSerializable
         // REVIEW: Maybe change it so it doesn't have to be separated like this but
         //         do somethign like ['mime/type', null] be equivalent to this?
         if (array_search($ext, ['webp', 'png', 'jpeg']) !== false) {
-            $this->extension = $ext;
-            return;
+            goto success;
         }
 
         // If it doesn't work, try to figure it out from the original extension
@@ -101,23 +113,34 @@ class Item implements JsonSerializable
             $ext  = pathinfo($name, PATHINFO_EXTENSION);
 
             if (array_search([$mime, $ext], $whitelist) !== false) {
-                $this->extension = $ext;
-                return;
+                goto success;
             }
         }
 
         Json::error('File mime-type and or extension not allowed.')->die();
+
+        success:
+        $this->extension = $ext;
+        $this->tags[] = 'format:' . $ext;
+
+        return;
     }
 
     public function getHash(): string
     {
         return $this->hash;
     }
+
     public function getExtension(): string
     {
         return $this->extension;
     }
 
+    public function getTags(): array
+    {
+        return $this->tags;
+    }
+
     public function getPath(bool $absolute = false): string
     {
         return sprintf(
diff --git a/main.php b/main.php
index 6340cf7..e2612e7 100644
--- a/main.php
+++ b/main.php
@@ -45,6 +45,7 @@ function get_item()
   return $item->getJson();
 }
 
+
 function post_item()
 {
   // The checks are performed internally
@@ -53,6 +54,7 @@ function post_item()
   return $item->getJson();
 };
 
+
 function get_search()
 {
   $query = $_GET['q'] ?? '';
diff --git a/mediadb.php b/mediadb.php
index 1ef9759..2b3476a 100644
--- a/mediadb.php
+++ b/mediadb.php
@@ -5,6 +5,11 @@ class MediaDB
     private $handler;
     private array $lines = [];
 
+    // TODO: create a persist() method that updates the line if the offset where
+    //       it originally existed in is given by 'ftell'. If it doesn't have
+    //       an ID, then try to find it in the file and if it doesn't exist,
+    //       append
+
     public function __construct()
     {
         // Just initialize the file handler
@@ -22,6 +27,22 @@ class MediaDB
         return $ret;
     }
 
+    public static function add(array|Item $item)
+    {
+        $file = fopen($GLOBALS['path_mediadb'], 'a+');
+        if ($file === false)
+            Json::error('Failed opening media DB for adding new Item')->die();
+
+        $line = $item->getHash() . ' ' . implode(' ', $item->getTags());
+
+        if (fwrite($file, $line) == false)
+            Json::error('Write operation failed on Item adding')->die();
+
+        fclose($file);
+
+        // The $this->list will be updated on trying to find new items
+    }
+
     public function map(callable $func)
     {
         // First read from what's already in memory
@@ -29,8 +50,8 @@ class MediaDB
             if ($func($i_line) === true) return;
         }
 
-        // If we run out, read from the file and append to array so the next lookup
-        // is fast
+        // If we run out, read from the file and append to array so the next
+        // lookup is fast
         while ($line = $this->getLine()) {
             $this->lines[] = $line;