diff --git a/blocks/classes/external/fetch_addable_blocks.php b/blocks/classes/external/fetch_addable_blocks.php
new file mode 100644
index 00000000000..3e14ae55eab
--- /dev/null
+++ b/blocks/classes/external/fetch_addable_blocks.php
@@ -0,0 +1,118 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This is the external method used for fetching the addable blocks in a given page.
+ *
+ * @package    core_block
+ * @since      Moodle 3.11
+ * @copyright  2020 Mihail Geshoski <mihail@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core_block\external;
+
+defined('MOODLE_INTERNAL') || die();
+
+global $CFG;
+require_once($CFG->libdir . '/externallib.php');
+
+use external_api;
+use external_function_parameters;
+use external_multiple_structure;
+use external_single_structure;
+use external_value;
+
+/**
+ * This is the external method used for fetching the addable blocks in a given page.
+ *
+ * @copyright  2020 Mihail Geshoski <mihail@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class fetch_addable_blocks extends external_api {
+
+    /**
+     * Describes the parameters for execute.
+     *
+     * @return external_function_parameters
+     */
+    public static function execute_parameters(): external_function_parameters {
+        return new external_function_parameters(
+            [
+                'pagecontextid' => new external_value(PARAM_INT, 'The context ID of the page.'),
+                'pagetype' => new external_value(PARAM_ALPHAEXT, 'The type of the page.'),
+                'pagelayout' => new external_value(PARAM_ALPHA, 'The layout of the page.')
+            ]
+        );
+    }
+
+    /**
+     * Fetch the addable blocks in a given page.
+     *
+     * @param int $pagecontextid The context ID of the page
+     * @param string $pagetype The type of the page
+     * @param string $pagelayout The layout of the page
+     * @return array The blocks list
+     */
+    public static function execute(int $pagecontextid, string $pagetype, string $pagelayout): array {
+        global $PAGE;
+
+        $params = self::validate_parameters(self::execute_parameters(),
+            [
+                'pagecontextid' => $pagecontextid,
+                'pagetype' => $pagetype,
+                'pagelayout' => $pagelayout
+            ]
+        );
+
+        $context = \context::instance_by_id($params['pagecontextid']);
+        // Validate the context. This will also set the context in $PAGE.
+        self::validate_context($context);
+
+        // We need to manually set the page layout and page type.
+        $PAGE->set_pagelayout($params['pagelayout']);
+        $PAGE->set_pagetype($params['pagetype']);
+        // Firstly, we need to load all currently existing page blocks to later determine which blocks are addable.
+        $PAGE->blocks->load_blocks(false);
+        $PAGE->blocks->create_all_block_instances();
+
+        $addableblocks = $PAGE->blocks->get_addable_blocks();
+
+        return array_map(function($block) {
+            return [
+                'name' => $block->name,
+                'title' => get_string('pluginname', "block_{$block->name}")
+            ];
+        }, $addableblocks);
+    }
+
+    /**
+     * Describes the execute return value.
+     *
+     * @return external_multiple_structure
+     */
+    public static function execute_returns(): external_multiple_structure {
+        return new external_multiple_structure(
+            new external_single_structure(
+                [
+                    'name' => new external_value(PARAM_PLUGIN, 'The name of the block.'),
+                    'title' => new external_value(PARAM_RAW, 'The title of the block.'),
+                ]
+            ),
+            'List of addable blocks in a given page.'
+        );
+    }
+}
diff --git a/lib/db/services.php b/lib/db/services.php
index ef653f097c3..815404feace 100644
--- a/lib/db/services.php
+++ b/lib/db/services.php
@@ -2609,6 +2609,16 @@ $functions = array(
         'services'      => array(MOODLE_OFFICIAL_MOBILE_SERVICE),
     ),
 
+    'core_block_fetch_addable_blocks' => array(
+        'classname'     => 'core_block\external\fetch_addable_blocks',
+        'methodname'    => 'execute',
+        'description'   => 'Returns all addable blocks in a given page.',
+        'type'          => 'read',
+        'capabilities'  => 'moodle/site:manageblocks',
+        'ajax'          => true,
+        'services'      => array(MOODLE_OFFICIAL_MOBILE_SERVICE),
+    ),
+
     // Filters functions.
     'core_filters_get_available_in_context' => array(
         'classname'   => 'core_filters\external',
diff --git a/version.php b/version.php
index 99e6aaeeb6a..024d93e883b 100644
--- a/version.php
+++ b/version.php
@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2021052500.44;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2021052500.45;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.
 $release  = '4.0dev (Build: 20201127)'; // Human-friendly version name