diff --git a/admin/tool/mobile/classes/api.php b/admin/tool/mobile/classes/api.php
index 4841569c3de..160c4f0bdfe 100644
--- a/admin/tool/mobile/classes/api.php
+++ b/admin/tool/mobile/classes/api.php
@@ -151,6 +151,11 @@ class api {
             'tool_mobile_disabledfeatures' => get_config('tool_mobile', 'disabledfeatures'),
             'country' => clean_param($CFG->country, PARAM_NOTAGS),
             'agedigitalconsentverification' => \core_auth\digital_consent::is_age_digital_consent_verification_enabled(),
+            'autolang' => $CFG->autolang,
+            'lang' => clean_param($CFG->lang, PARAM_LANG),  // Avoid breaking WS because of incorrect package langs.
+            'langmenu' => $CFG->langmenu,
+            'langlist' => $CFG->langlist,
+            'locale' => $CFG->locale,
         );
 
         $typeoflogin = get_config('tool_mobile', 'typeoflogin');
diff --git a/admin/tool/mobile/classes/external.php b/admin/tool/mobile/classes/external.php
index 65a5ccf1ad8..eb2bf6723cb 100644
--- a/admin/tool/mobile/classes/external.php
+++ b/admin/tool/mobile/classes/external.php
@@ -168,6 +168,11 @@ class external extends external_api {
                     (only if age verification is enabled).', VALUE_OPTIONAL),
                 'supportemail' => new external_value(PARAM_EMAIL, 'Site support contact email
                     (only if age verification is enabled).', VALUE_OPTIONAL),
+                'autolang' => new external_value(PARAM_INT, 'Whether to detect default language from browser setting.'),
+                'lang' => new external_value(PARAM_LANG, 'Default language for the site.'),
+                'langmenu' => new external_value(PARAM_INT, 'Whether the language menu should be displayed.'),
+                'langlist' => new external_value(PARAM_RAW, 'Languages on language menu.'),
+                'locale' => new external_value(PARAM_RAW, 'Sitewide locale.'),
                 'warnings' => new external_warnings(),
             )
         );
diff --git a/admin/tool/mobile/tests/externallib_test.php b/admin/tool/mobile/tests/externallib_test.php
index 19483ee6739..e61657c5515 100644
--- a/admin/tool/mobile/tests/externallib_test.php
+++ b/admin/tool/mobile/tests/externallib_test.php
@@ -88,6 +88,11 @@ class tool_mobile_external_testcase extends externallib_advanced_testcase {
             'launchurl' => "$CFG->wwwroot/$CFG->admin/tool/mobile/launch.php",
             'country' => $CFG->country,
             'agedigitalconsentverification' => \core_auth\digital_consent::is_age_digital_consent_verification_enabled(),
+            'autolang' => $CFG->autolang,
+            'lang' => $CFG->lang,
+            'langmenu' => $CFG->langmenu,
+            'langlist' => $CFG->langlist,
+            'locale' => $CFG->locale,
             'warnings' => array()
         );
         $this->assertEquals($expected, $result);
@@ -101,6 +106,8 @@ class tool_mobile_external_testcase extends externallib_advanced_testcase {
         set_config('logocompact', 'mock.png', 'core_admin');
         set_config('forgottenpasswordurl', 'mailto:fake@email.zy'); // Test old hack.
         set_config('agedigitalconsentverification', 1);
+        set_config('autolang', 1);
+        set_config('lang', 'a_b');  // Set invalid lang.
 
         list($authinstructions, $notusedformat) = external_format_text($authinstructions, FORMAT_MOODLE, $context->id);
         $expected['registerauth'] = 'email';
@@ -110,6 +117,8 @@ class tool_mobile_external_testcase extends externallib_advanced_testcase {
         $expected['agedigitalconsentverification'] = true;
         $expected['supportname'] = $CFG->supportname;
         $expected['supportemail'] = $CFG->supportemail;
+        $expected['autolang'] = '1';
+        $expected['lang'] = ''; // Expect empty because it was set to an invalid lang.
 
         if ($logourl = $OUTPUT->get_logo_url()) {
             $expected['logourl'] = $logourl->out(false);