diff --git a/init.php b/init.php
index 188c7e0..02d43c4 100644
--- a/init.php
+++ b/init.php
@@ -13,13 +13,103 @@ class Elfeed_Sync extends Plugin {
 	function init($host) {
 		$this->host = $host;
 
-		$this->host->add_api_method("kek", $this);
+		$this->host->add_api_method("setFeedsTree", $this);
+	}
+
+	function createCategoriesTree($tree, $feed_categories = null, $current_cat = null) {
+		if ($feed_categories === null) {
+			$feed_categories = ORM::for_table('ttrss_feed_categories')
+				->select_many('id', 'title', 'order_id', 'parent_cat')
+				->where('owner_uid', $_SESSION['uid'])
+				->order_by_asc('order_id')
+				->order_by_asc('title')
+				->find_many();
+		}
+		$categories = array();
+		$feeds = array();
+		foreach ($tree as $datum) {
+			if (array_key_exists("group", $datum)) {
+				$existing_cat = null;
+				$title = $datum["group"]["name"];
+				foreach ($feed_categories as $cat) {
+					if ($cat->title === $title  && $cat->parent_cat === $current_cat) {
+						$existing_cat = $cat->id;
+						break;
+					}
+				}
+				if (!$existing_cat) {
+					$existing_cat = rand(-10000000, -1);
+				}
+				array_push($categories, array("id" => $existing_cat, "title" => $title, "parent_id" => $current_cat));
+				list($child_categories, $child_feeds) = $this->createCategoriesTree(
+					$datum["group"]["children"],
+					$feed_categories,
+					$existing_cat
+				);
+				$categories = array_merge($categories, $child_categories);
+				$feeds = array_merge($feeds, $child_feeds);
+			} else if (array_key_exists("feed", $datum)) {
+				$url = $datum["feed"]["url"];
+				$title = $datum["feed"]["title"];
+				$tags = $datum["feed"]["tags"];
+				array_push($feeds, array("url" => $url, "title" => $title, "tags" => $tags, "cat" => $current_cat));
+			}
+		}
+		return array($categories, $feeds);
+	}
+
+	function mergeCategoriesTree($categories, $feeds) {
+		$enable_cats = get_pref(Prefs::ENABLE_FEED_CATS);
+		$cat_ids = array();
+		if ($enable_cats) {
+			foreach($categories as $cat_data) {
+				if ($cat_data["id"] >= 0) {
+					$cat_ids[$cat_data["id"]] = $cat_data["id"];
+				} else {
+					$cat = ORM::for_table('ttrss_feed_categories')->create();
+					$parent_cat = $cat_ids[$cat_data["parent_id"]] ?? $cat_data["parent_id"] ?? null;
+					$cat->set([
+						'owner_uid' => $_SESSION['uid'],
+						'parent_cat' => $parent_cat,
+						'order_id' => 0,
+						'title' => $cat_data['title']
+					]);
+					$cat->save();
+					$cat_ids[$cat_data["id"]] = $cat->id;
+				}
+			}
+		}
+		$results = array();
+		foreach($feeds as $feed_datum) {
+			$cat_id = $cat_ids[$feed_datum["cat"]];
+			$rc = Feeds::_subscribe($feed_datum["url"], $cat_id);
+			if ($rc["code"] === 0 || $rc["code"] === 1) {
+				$feed = ORM::for_table('ttrss_feeds')
+					->where('id', $rc["feed_id"])
+					->where('owner_uid', $_SESSION['uid'])
+					->find_one();
+				$feed->set([
+					'title' => $feed_datum['title'],
+					'cat_id' => $cat_id
+				]);
+				$feed->save();
+				$results[$feed_datum["url"]] = $feed->id;
+			} else {
+				$results[$feed_datum["url"]] = null;
+			}
+		}
+		return $results;
 	}
 
 	/**
 	 * Our own API.
 	 */
-	function kek() {
-		return array(API::STATUS_OK, array("ok" => true));
+	function setFeedsTree() {
+		$tree = $_REQUEST["tree"];
+
+		list($categories, $feeds) = $this->createCategoriesTree($tree);
+		$subscribed = $this->mergeCategoriesTree($categories, $feeds);
+
+		return array(API::STATUS_OK, array('subscribed' => $subscribed));
 	}
 }