diff --git a/lib/Alchemy/Phrasea/Controller/Api/V3/V3MonitorDataController.php b/lib/Alchemy/Phrasea/Controller/Api/V3/V3MonitorDataController.php
new file mode 100644
index 00000000000..cefcca7cf2d
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Controller/Api/V3/V3MonitorDataController.php
@@ -0,0 +1,97 @@
+<?php
+
+namespace Alchemy\Phrasea\Controller\Api\V3;
+
+use Alchemy\Phrasea\Application\Helper\DispatcherAware;
+use Alchemy\Phrasea\Application\Helper\JsonBodyAware;
+use Alchemy\Phrasea\Controller\Api\InstanceIdAware;
+use Alchemy\Phrasea\Controller\Api\Result;
+use Alchemy\Phrasea\Controller\Controller;
+use Alchemy\Phrasea\Controller\Exception;
+use Alchemy\Phrasea\Utilities\Stopwatch;
+use PDO;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+class V3MonitorDataController extends Controller
+{
+    use JsonBodyAware;
+    use DispatcherAware;
+    use InstanceIdAware;
+
+    /**
+     * monitor infos for app
+     *
+     * @param  Request $request
+     *
+     * @return Response
+     */
+    private function unitToMultiplier(string $unit)
+    {
+        static $map = ['o', 'ko', 'mo', 'go'];
+        if(($i = array_search(strtolower($unit), $map)) === false) {
+            return false;
+        }
+        return 1 << ($i * 10);
+    }
+
+    public function indexAction(Request $request)
+    {
+        $stopwatch = new Stopwatch("controller");
+        $ret = [
+            'databoxes' => []
+        ];
+        $matches = [];
+        if(preg_match("/^(\\d+)\\s*(ko|mo|go)?$/i", $request->get('blocksize', '1'), $matches) !== 1) {
+            throw new Exception("bad 'blocksize' parameter");
+        }
+        $matches[] = 'o';   // if no unit, force
+        $blocksize = (int)($matches[1]) * $this->unitToMultiplier($matches[2]);
+
+        $sql = "SELECT COALESCE(r.`coll_id`, '?') AS `coll_id`,
+                    COALESCE(c.`asciiname`, CONCAT('_',r.`coll_id`), '?') AS `asciiname`, s.`name`,
+                    SUM(1) AS n, SUM(s.`size`) AS `size`, SUM(CEIL(s.`size` / " . $blocksize . ") * " . $blocksize . ") AS `disksize`
+                    FROM `subdef` AS s LEFT JOIN `record` AS r ON r.`record_id`=s.`record_id` 
+                    LEFT JOIN `coll` AS c ON r.`coll_id`=c.`coll_id`
+                GROUP BY r.`coll_id`, s.`name`;";
+
+        foreach($this->app->getDataboxes() as $databox) {
+            $collections = [];
+            $subdefs = [];
+            $stmt = $databox->get_connection()->prepare($sql);
+            $stmt->execute();
+            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
+                if(!array_key_exists($row['coll_id'], $collections)) {
+                    $collections[$row['coll_id']] = [
+                        'coll_id' => $row['coll_id'],
+                        'name' => $row['asciiname'],
+                        'subdefs' => []
+                    ];
+                }
+                $collections[$row['coll_id']]['subdefs'][$row['name']] = [
+                    'count' => $row['n'],
+                    'size' => $row['size'],
+                    'disksize' => $row['disksize']
+                ];
+                if(!array_key_exists($row['name'], $subdefs)) {
+                    $subdefs[$row['name']] = [
+                        'count' => 0,
+                        'size' => 0,
+                        'disksize' => 0
+                    ];
+                }
+                $subdefs[$row['name']]['count'] += $row['n'];
+                $subdefs[$row['name']]['size'] += $row['size'];
+                $subdefs[$row['name']]['disksize'] += $row['disksize'];
+            }
+            $ret['databoxes'][$databox->get_sbas_id()] = [
+                'sbas_id' => $databox->get_sbas_id(),
+                'viewname' => $databox->get_viewname(),
+                'collections' => $collections,
+                'subdefs' => $subdefs
+            ];
+        }
+        return Result::create($request, $ret)->createResponse([$stopwatch]);
+    }
+
+}
diff --git a/lib/Alchemy/Phrasea/ControllerProvider/Api/V3.php b/lib/Alchemy/Phrasea/ControllerProvider/Api/V3.php
index dafff86a2f0..5bc6b69ad0a 100644
--- a/lib/Alchemy/Phrasea/ControllerProvider/Api/V3.php
+++ b/lib/Alchemy/Phrasea/ControllerProvider/Api/V3.php
@@ -5,6 +5,7 @@
 use Alchemy\Phrasea\Application as PhraseaApplication;
 use Alchemy\Phrasea\Controller\Api\V1Controller;
 use Alchemy\Phrasea\Controller\Api\V3\V3Controller;
+use Alchemy\Phrasea\Controller\Api\V3\V3MonitorDataController;
 use Alchemy\Phrasea\Controller\Api\V3\V3RecordController;
 use Alchemy\Phrasea\Controller\Api\V3\V3ResultHelpers;
 use Alchemy\Phrasea\Controller\Api\V3\V3SearchController;
@@ -50,6 +51,9 @@ public function register(Application $app)
                 ->setInstanceId($app['conf'])
                 ;
         });
+        $app['controller.api.v3.monitorData'] = $app->share(function (PhraseaApplication $app) {
+            return (new V3MonitorDataController($app));
+        });
         $app['controller.api.v3.searchraw'] = $app->share(function (PhraseaApplication $app) {
             return (new V3SearchRawController($app));
         });
@@ -96,6 +100,13 @@ public function connect(Application $app)
             ->assert('record_id', '\d+')
             ->value('must_be_story', true);
 
+        /**
+         * @uses V3MonitorDataController::indexAction()
+         */
+        $controllers->get('/monitor/data/', 'controller.api.v3.monitorData:indexAction')
+            ->before('controller.api.v1:ensureAdmin')
+        ;
+
         /**
          * @uses V3SearchController::helloAction()
          */