diff --git a/public/api/_db.php b/public/api/_db.php
index 708ff5c..8848260 100755
--- a/public/api/_db.php
+++ b/public/api/_db.php
@@ -2,9 +2,13 @@
 try {
     require_once __DIR__ . '/../../tools/db.php';
     $pdo = tools_build_pdo();
-} catch (PDOException $e) {
+} catch (Throwable $e) {
     http_response_code(500);
-    header('Content-Type: application/json');
-    echo json_encode(['error' => 'DB connection failed']);
+    header('Content-Type: application/json; charset=utf-8');
+    $payload = ['error' => 'DB connection failed'];
+    if (getenv('APP_DEBUG') === '1') {
+        $payload['detail'] = $e->getMessage();
+    }
+    echo json_encode($payload, JSON_UNESCAPED_UNICODE);
     exit;
 }
diff --git a/tools/db.php b/tools/db.php
index 2a61402..7cac6f8 100644
--- a/tools/db.php
+++ b/tools/db.php
@@ -2,6 +2,15 @@
 function tools_build_pdo(): PDO
 {
     $cfg = require __DIR__ . '/../src/config.php';
+    if (!is_array($cfg)) {
+        throw new RuntimeException('DB config did not return an array.');
+    }
+    $required = ['db_host', 'db_name', 'db_user', 'db_pass', 'db_charset'];
+    foreach ($required as $key) {
+        if (!array_key_exists($key, $cfg)) {
+            throw new RuntimeException('Missing DB config key: ' . $key);
+        }
+    }
     $dsn = "mysql:host={$cfg['db_host']};dbname={$cfg['db_name']};charset={$cfg['db_charset']}";
     $options = [
         PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,