diff --git a/php/chronotrack_api/fx_chronotrack_admin.php b/php/chronotrack_api/fx_chronotrack_admin.php
index 0cc5238..f9380e1 100644
--- a/php/chronotrack_api/fx_chronotrack_admin.php
+++ b/php/chronotrack_api/fx_chronotrack_admin.php
@@ -103,7 +103,7 @@ function fxChronotrackApiAdminRenderEventPage($intEveId, $strLangue = 'fr', $bln
 
     // Sync d’abord (usage courant) ; config repliable ensuite. MSIN-4328
     if ($arrConfig !== null && $blnEventLinked && $blnConfigured) {
-        fxChronotrackApiAdminRenderPushPanel($intEveId, $blnClosed);
+        fxChronotrackApiAdminRenderPushPanel($intEveId, $blnClosed, $arrConfig);
     }
 
     if ($arrConfig !== null && $blnEventLinked) {
@@ -244,7 +244,7 @@ function fxChronotrackApiAdminRenderRaceMapping($intEveId, $arrConfig, $strLangu
     echo '</div></div></div>';
 }
 
-function fxChronotrackApiAdminRenderPushPanel($intEveId, $blnClosed = false) {
+function fxChronotrackApiAdminRenderPushPanel($intEveId, $blnClosed = false, $arrConfig = null) {
     echo '<div class="card mb-4 border-primary" id="ct_api_push_card">';
     echo '<div class="card-header">Synchronisation ChronoTrack</div>';
     echo '<div class="card-body">';
@@ -252,7 +252,63 @@ function fxChronotrackApiAdminRenderPushPanel($intEveId, $blnClosed = false) {
         echo '<div class="alert alert-warning py-2 small mb-2">Événement fermé — envoi manuel encore possible.</div>';
     }
 
-    // Zone employé : statut clair + actions d’abord. MSIN-4328
+    // MSIN-4328 — Phase A : config sync auto (exécutée plus tard par cron)
+    $blnAutoOn = (intval($arrConfig['auto_sync_enabled'] ?? 0) === 1);
+    $intAutoInterval = intval($arrConfig['auto_sync_interval_min'] ?? 15);
+    if (!in_array($intAutoInterval, array(1, 5, 15, 30, 60), true)) {
+        $intAutoInterval = 15;
+    }
+    $strUntilRaw = trim((string)($arrConfig['auto_sync_until'] ?? ''));
+    $strUntilLocal = '';
+    if ($strUntilRaw !== '' && $strUntilRaw !== '0000-00-00 00:00:00') {
+        $intUntilTs = strtotime($strUntilRaw);
+        if ($intUntilTs !== false) {
+            $strUntilLocal = date('Y-m-d\TH:i', $intUntilTs);
+        }
+    }
+
+    echo '<div class="ct-api-auto-wrap mb-3' . ($blnClosed ? ' ct-api-auto-wrap--disabled' : '') . '" id="ct_api_auto_wrap">';
+    echo '<div class="form-check mb-2">';
+    echo '<input class="form-check-input" type="checkbox" id="ct_api_auto_enabled" value="1"'
+        . ($blnAutoOn ? ' checked' : '') . ($blnClosed ? ' disabled' : '') . '>';
+    echo '<label class="form-check-label font-weight-bold" for="ct_api_auto_enabled">Mise à jour automatique</label>';
+    echo '</div>';
+    echo '<div class="form-row align-items-end" id="ct_api_auto_options">';
+    echo '<div class="form-group col-sm-4 mb-2 mb-sm-0">';
+    echo '<label class="small text-muted mb-1" for="ct_api_auto_interval">Fréquence</label>';
+    echo '<select class="form-control form-control-sm" id="ct_api_auto_interval"'
+        . ($blnClosed ? ' disabled' : '') . '>';
+    foreach (array(1 => 'Toutes les minutes', 5 => 'Toutes les 5 minutes', 15 => 'Toutes les 15 minutes',
+        30 => 'Toutes les 30 minutes', 60 => 'Toutes les heures') as $intMin => $strLabel) {
+        echo '<option value="' . $intMin . '"' . ($intAutoInterval === $intMin ? ' selected' : '') . '>'
+            . fxChronotrackApiAdminEsc($strLabel) . '</option>';
+    }
+    echo '</select></div>';
+    echo '<div class="form-group col-sm-5 mb-2 mb-sm-0">';
+    echo '<label class="small text-muted mb-1" for="ct_api_auto_until">Date et heure de fin</label>';
+    echo '<input type="datetime-local" class="form-control form-control-sm" id="ct_api_auto_until" value="'
+        . fxChronotrackApiAdminEsc($strUntilLocal) . '"' . ($blnClosed ? ' disabled' : '') . '>';
+    echo '</div>';
+    if (!$blnClosed) {
+        echo '<div class="form-group col-sm-3 mb-0">';
+        echo '<button type="button" class="btn btn-outline-primary btn-sm btn-block" id="ct_api_btn_auto_save">'
+            . 'Enregistrer</button>';
+        echo '</div>';
+    }
+    echo '</div>';
+    echo '<p class="small text-muted mb-0 mt-2" id="ct_api_auto_hint">';
+    if ($blnAutoOn && $strUntilRaw !== '') {
+        echo 'Config enregistrée — exécution serveur (cron) à brancher. Arrêt prévu : '
+            . fxChronotrackApiAdminEsc($strUntilRaw) . '.';
+    } else {
+        echo 'Quand c’est coché, le serveur (cron) poussera le différentiel à cet intervalle jusqu’à la date de fin. '
+            . 'Pas encore actif côté serveur.';
+    }
+    echo '</p>';
+    echo '<div id="ct_api_auto_msg" class="small mt-1"></div>';
+    echo '</div>';
+
+    // Zone employé : statut clair + actions
     echo '<div id="ct_api_push_status" class="ct-api-push-status mb-3">';
     echo '<div class="text-muted small">Cliquez <strong>Actualiser</strong> pour vérifier s’il y a des changements à envoyer.</div>';
     echo '</div>';
@@ -263,7 +319,7 @@ function fxChronotrackApiAdminRenderPushPanel($intEveId, $blnClosed = false) {
     echo '<button type="button" class="btn btn-primary btn-lg" id="ct_api_btn_push" disabled>';
     echo '<i class="fa fa-cloud-upload" aria-hidden="true"></i>&nbsp;Envoyer vers ChronoTrack</button>';
     echo '</div>';
-    echo '<p class="small text-muted mb-2">La sync automatique arrivera bientôt — pour l’instant, un clic suffit quand il y a du nouveau.</p>';
+    echo '<p class="small text-muted mb-2">Envoi manuel : uniquement les nouveaux / modifiés depuis le dernier push OK.</p>';
     echo '<div id="ct_api_push_result" class="small mb-3"></div>';
 
     // Détails / debug : sous les boutons, repliés par défaut
@@ -355,6 +411,13 @@ function fxChronotrackApiAdminRenderPageScript($intEveId, $arrConfig, $blnClosed
 }
 .ct-api-push-actions .btn-lg { font-size: 1.05rem; padding: 0.55rem 1.1rem; }
 #ct_api_push_details_card .card-header a { text-decoration: none; }
+.ct-api-auto-wrap {
+    padding: 12px 14px;
+    border-radius: 8px;
+    border: 1px dashed #adb5bd;
+    background: #fafbfc;
+}
+.ct-api-auto-wrap--disabled { opacity: 0.7; }
 </style>
 <?php fxChronotrackApiAdminRenderLoaderAssets($vDomaine); ?>
 <script>
@@ -1080,6 +1143,50 @@ function fxChronotrackApiAdminRenderPageScript($intEveId, $arrConfig, $blnClosed
             loadPushPreview(false);
         }
 
+        function syncAutoOptionsState() {
+            var blnOn = $('#ct_api_auto_enabled').is(':checked');
+            $('#ct_api_auto_interval, #ct_api_auto_until').prop('disabled', blnClosed || !blnOn);
+        }
+        syncAutoOptionsState();
+        $('#ct_api_auto_enabled').on('change', syncAutoOptionsState);
+
+        $('#ct_api_btn_auto_save').on('click', function () {
+            var $btn = $(this);
+            var $msg = $('#ct_api_auto_msg');
+            var $hint = $('#ct_api_auto_hint');
+            var blnOn = $('#ct_api_auto_enabled').is(':checked');
+            $btn.prop('disabled', true);
+            $msg.removeClass('text-success text-danger').text('Enregistrement…');
+            $.post(strAjaxUrl, {
+                a: 'sync_auto_save',
+                eve_id: intEveId,
+                enabled: blnOn ? 1 : 0,
+                interval_min: $('#ct_api_auto_interval').val(),
+                until: $('#ct_api_auto_until').val()
+            }, function (res) {
+                if (rejectIfSessionLost(res)) {
+                    return;
+                }
+                if (!res || res.state !== 'ok') {
+                    $msg.addClass('text-danger').text((res && res.message) ? res.message : 'Erreur');
+                    return;
+                }
+                $msg.addClass('text-success').text(res.message || 'Enregistré');
+                if (res.auto_sync) {
+                    if (res.auto_sync.enabled && res.auto_sync.until) {
+                        $hint.text('Config enregistrée — exécution serveur (cron) à brancher. Arrêt prévu : '
+                            + res.auto_sync.until + '.');
+                    } else {
+                        $hint.text('Sync auto désactivée. Le cron (phase B) ne traitera pas cet événement.');
+                    }
+                }
+            }, 'json').fail(function () {
+                $msg.addClass('text-danger').text('Erreur réseau');
+            }).always(function () {
+                $btn.prop('disabled', false);
+            });
+        });
+
         $('#ct_api_btn_push_refresh').on('click', function () {
             loadPushPreview(true);
             $('#ct_api_push_result').empty();
diff --git a/php/chronotrack_api/fx_chronotrack_config.php b/php/chronotrack_api/fx_chronotrack_config.php
index b8c5f92..19ed628 100644
--- a/php/chronotrack_api/fx_chronotrack_config.php
+++ b/php/chronotrack_api/fx_chronotrack_config.php
@@ -135,6 +135,79 @@ function fxChronotrackApiConfigSetLastPush($intEveId, $intOkCount) {
     return (bool)$objDatabase->fxQuery($sql);
 }
 
+/**
+ * MSIN-4328 — fréquences autorisées (minutes), phase A.
+ */
+function fxChronotrackApiConfigAutoSyncIntervals() {
+    return array(1, 5, 15, 30, 60);
+}
+
+/**
+ * MSIN-4328 — enregistre la config sync auto (UI). Le cron (phase B) lira ces champs.
+ */
+function fxChronotrackApiConfigSaveAutoSync($intEveId, $blnEnabled, $intIntervalMin, $strUntil) {
+    global $objDatabase;
+
+    $intEveId = intval($intEveId);
+    $arrExisting = fxChronotrackApiConfigGet($intEveId);
+    if ($arrExisting === null) {
+        return array('state' => 'error', 'message' => 'Événement non lié à ChronoTrack');
+    }
+    if (($arrExisting['sync_status'] ?? '') === MSIN_API_CHRONOTRACK_SYNC_FERME) {
+        return array('state' => 'error', 'message' => 'Événement fermé — sync auto impossible.');
+    }
+
+    $blnEnabled = $blnEnabled ? 1 : 0;
+    $intIntervalMin = intval($intIntervalMin);
+    if (!in_array($intIntervalMin, fxChronotrackApiConfigAutoSyncIntervals(), true)) {
+        $intIntervalMin = 15;
+    }
+
+    $strUntilSql = 'NULL';
+    $strUntil = trim((string)$strUntil);
+    if ($strUntil !== '') {
+        // Accepte "YYYY-MM-DDTHH:MM" (input datetime-local) ou "YYYY-MM-DD HH:MM[:SS]"
+        $strUntilNorm = str_replace('T', ' ', $strUntil);
+        if (preg_match('/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}$/', $strUntilNorm)) {
+            $strUntilNorm .= ':00';
+        }
+        $intTs = strtotime($strUntilNorm);
+        if ($intTs === false) {
+            return array('state' => 'error', 'message' => 'Date / heure de fin invalide');
+        }
+        if ($blnEnabled && $intTs <= time()) {
+            return array('state' => 'error', 'message' => 'La date/heure de fin doit être dans le futur');
+        }
+        $strUntilSql = "'" . $objDatabase->fxEscape(date('Y-m-d H:i:s', $intTs)) . "'";
+    } elseif ($blnEnabled) {
+        return array('state' => 'error', 'message' => 'Indiquez une date et une heure de fin pour activer la sync auto');
+    }
+
+    $sql = "UPDATE api_chronotrack_config SET auto_sync_enabled = " . $blnEnabled
+        . ", auto_sync_interval_min = " . $intIntervalMin
+        . ", auto_sync_until = " . $strUntilSql
+        . ", updated_at = '" . fxGetDateTime() . "'"
+        . " WHERE eve_id = " . $intEveId;
+    if (!$objDatabase->fxQuery($sql)) {
+        return array('state' => 'error', 'message' => 'Erreur SQL enregistrement sync auto');
+    }
+
+    $arrFresh = fxChronotrackApiConfigGet($intEveId);
+    return array(
+        'state'   => 'ok',
+        'message' => $blnEnabled
+            ? ('Sync auto enregistrée (toutes les ' . $intIntervalMin . ' min jusqu’au '
+                . trim((string)($arrFresh['auto_sync_until'] ?? '')) . '). Le cron démarrera en phase B.')
+            : 'Sync auto désactivée.',
+        'auto_sync' => array(
+            'enabled'      => intval($arrFresh['auto_sync_enabled'] ?? 0) === 1,
+            'interval_min' => intval($arrFresh['auto_sync_interval_min'] ?? 15),
+            'until'        => ($arrFresh['auto_sync_until'] ?? null),
+            'last_run_at'  => ($arrFresh['last_auto_run_at'] ?? null),
+        ),
+    );
+}
+
 function fxChronotrackApiRaceMapGetForEvent($intEveId) {
     global $objDatabase;
 
diff --git a/sql/MSIN-4328-chronotrack-auto-sync-config.sql b/sql/MSIN-4328-chronotrack-auto-sync-config.sql
new file mode 100644
index 0000000..7e5db52
--- /dev/null
+++ b/sql/MSIN-4328-chronotrack-auto-sync-config.sql
@@ -0,0 +1,57 @@
+-- MSIN-4328 — Config sync automatique (phase A : stockage + UI, pas encore de cron)
+-- Prérequis : sql/MSIN-4328-chronotrack-last-push-at.sql
+-- Idempotent.
+
+SET @db := DATABASE();
+
+SET @col_ase := (
+    SELECT COUNT(*) FROM information_schema.COLUMNS
+    WHERE TABLE_SCHEMA = @db AND TABLE_NAME = 'api_chronotrack_config' AND COLUMN_NAME = 'auto_sync_enabled'
+);
+SET @sql_ase := IF(
+    @col_ase = 0,
+    'ALTER TABLE api_chronotrack_config ADD COLUMN auto_sync_enabled TINYINT(1) NOT NULL DEFAULT 0 COMMENT ''MSIN-4328 — sync auto ON/OFF'' AFTER last_push_ok_count',
+    'SELECT ''auto_sync_enabled already exists'' AS note'
+);
+PREPARE stmt_ase FROM @sql_ase;
+EXECUTE stmt_ase;
+DEALLOCATE PREPARE stmt_ase;
+
+SET @col_asi := (
+    SELECT COUNT(*) FROM information_schema.COLUMNS
+    WHERE TABLE_SCHEMA = @db AND TABLE_NAME = 'api_chronotrack_config' AND COLUMN_NAME = 'auto_sync_interval_min'
+);
+SET @sql_asi := IF(
+    @col_asi = 0,
+    'ALTER TABLE api_chronotrack_config ADD COLUMN auto_sync_interval_min SMALLINT UNSIGNED NOT NULL DEFAULT 15 COMMENT ''MSIN-4328 — fréquence minutes'' AFTER auto_sync_enabled',
+    'SELECT ''auto_sync_interval_min already exists'' AS note'
+);
+PREPARE stmt_asi FROM @sql_asi;
+EXECUTE stmt_asi;
+DEALLOCATE PREPARE stmt_asi;
+
+SET @col_asu := (
+    SELECT COUNT(*) FROM information_schema.COLUMNS
+    WHERE TABLE_SCHEMA = @db AND TABLE_NAME = 'api_chronotrack_config' AND COLUMN_NAME = 'auto_sync_until'
+);
+SET @sql_asu := IF(
+    @col_asu = 0,
+    'ALTER TABLE api_chronotrack_config ADD COLUMN auto_sync_until DATETIME NULL DEFAULT NULL COMMENT ''MSIN-4328 — arrêt auto (date+heure)'' AFTER auto_sync_interval_min',
+    'SELECT ''auto_sync_until already exists'' AS note'
+);
+PREPARE stmt_asu FROM @sql_asu;
+EXECUTE stmt_asu;
+DEALLOCATE PREPARE stmt_asu;
+
+SET @col_lar := (
+    SELECT COUNT(*) FROM information_schema.COLUMNS
+    WHERE TABLE_SCHEMA = @db AND TABLE_NAME = 'api_chronotrack_config' AND COLUMN_NAME = 'last_auto_run_at'
+);
+SET @sql_lar := IF(
+    @col_lar = 0,
+    'ALTER TABLE api_chronotrack_config ADD COLUMN last_auto_run_at DATETIME NULL DEFAULT NULL COMMENT ''MSIN-4328 — dernier passage cron (phase B)'' AFTER auto_sync_until',
+    'SELECT ''last_auto_run_at already exists'' AS note'
+);
+PREPARE stmt_lar FROM @sql_lar;
+EXECUTE stmt_lar;
+DEALLOCATE PREPARE stmt_lar;
diff --git a/superadm/ajax_chronotrack_api.php b/superadm/ajax_chronotrack_api.php
index b2efd6a..28abdc9 100644
--- a/superadm/ajax_chronotrack_api.php
+++ b/superadm/ajax_chronotrack_api.php
@@ -131,6 +131,18 @@ switch ($strAction) {
         }
         break;
 
+    case 'sync_auto_save':
+        // MSIN-4328 — phase A : config only (cron phase B)
+        if ($intEveId <= 0) {
+            $tabRetour = array('state' => 'error', 'message' => 'eve_id manquant');
+            break;
+        }
+        $blnEnabled = (intval($_REQUEST['enabled'] ?? 0) === 1);
+        $intInterval = intval($_REQUEST['interval_min'] ?? 15);
+        $strUntil = trim((string)($_REQUEST['until'] ?? ''));
+        $tabRetour = fxChronotrackApiConfigSaveAutoSync($intEveId, $blnEnabled, $intInterval, $strUntil);
+        break;
+
     case 'sync_probe_push':
         if ($intEveId <= 0) {
             $tabRetour = array('state' => 'error', 'message' => 'eve_id manquant');