diff --git a/api/index.php b/api/index.php
index 63fdd73..d757ca7 100644
--- a/api/index.php
+++ b/api/index.php
@@ -1012,6 +1012,18 @@ try {
         case 'recipe_tags_update':
             recipeTagsUpdate($db);
             break;
+        case 'custom_units_list':
+            customUnitsList($db);
+            break;
+        case 'custom_units_add':
+            customUnitsAdd($db);
+            break;
+        case 'custom_units_remove':
+            customUnitsRemove($db);
+            break;
+        case 'custom_units_update':
+            customUnitsUpdate($db);
+            break;
         case 'recipes_list':
             recipesList($db);
             break;
@@ -12494,12 +12506,99 @@ function recipeTagsUpdate(PDO $db): void {
         return;
     }
 
-    $stmt = $db->prepare("UPDATE recipe_tags SET label = ?, icon = ? WHERE key = ?");
+   $stmt = $db->prepare("UPDATE recipe_tags SET label = ?, icon = ? WHERE key = ?");
     $stmt->execute([$label, $icon ?: '🏷️', $key]);
 
     echo json_encode(['success' => true]);
 }
 
+function customUnitsList(PDO $db): void {
+    $rows = $db->query("SELECT id, key, label, icon, base_unit, factor, sort_order FROM custom_units ORDER BY sort_order ASC, id ASC")->fetchAll();
+    echo json_encode(['success' => true, 'units' => $rows]);
+}
+
+function customUnitsAdd(PDO $db): void {
+    $input = json_decode(file_get_contents('php://input'), true) ?? [];
+    $key      = trim($input['key'] ?? '');
+    $label    = trim($input['label'] ?? '');
+    $icon     = trim($input['icon'] ?? '📏');
+    $baseUnit = trim($input['base_unit'] ?? '');
+    $factor   = (float)($input['factor'] ?? 1);
+
+    if ($label === '' || $key === '' || !in_array($baseUnit, ['pz', 'g', 'ml'], true) || $factor <= 0) {
+        echo json_encode(['success' => false, 'error' => 'key, label, base_unit (pz/g/ml) et factor (>0) requis']);
+        return;
+    }
+
+    $key = mb_strtolower($key);
+    $key = preg_replace('/[^a-z0-9]+/u', '_', $key);
+    $key = trim($key, '_');
+    if ($key === '' || in_array($key, ['pz', 'g', 'ml', 'conf'], true)) {
+        echo json_encode(['success' => false, 'error' => 'clé invalide ou réservée']);
+        return;
+    }
+
+    $stmt = $db->prepare("SELECT id FROM custom_units WHERE key = ?");
+    $stmt->execute([$key]);
+    if ($stmt->fetch()) {
+        echo json_encode(['success' => false, 'error' => 'unit already exists']);
+        return;
+    }
+
+    $maxOrder = (int)$db->query("SELECT COALESCE(MAX(sort_order), 0) FROM custom_units")->fetchColumn();
+
+    $stmt = $db->prepare("INSERT INTO custom_units (key, label, icon, base_unit, factor, sort_order) VALUES (?, ?, ?, ?, ?, ?)");
+    $stmt->execute([$key, $label, $icon, $baseUnit, $factor, $maxOrder + 1]);
+
+    echo json_encode(['success' => true, 'key' => $key]);
+}
+
+function customUnitsRemove(PDO $db): void {
+    $input = json_decode(file_get_contents('php://input'), true) ?? [];
+    $key = trim($input['key'] ?? '');
+
+    if ($key === '') {
+        echo json_encode(['success' => false, 'error' => 'key required']);
+        return;
+    }
+
+    $stmt = $db->prepare("SELECT COUNT(*) FROM products WHERE display_unit_key = ?");
+    $stmt->execute([$key]);
+    if ((int)$stmt->fetchColumn() > 0) {
+        echo json_encode(['success' => false, 'error' => 'unit still used by a product']);
+        return;
+    }
+
+    $db->prepare("DELETE FROM custom_units WHERE key = ?")->execute([$key]);
+    echo json_encode(['success' => true]);
+}
+
+function customUnitsUpdate(PDO $db): void {
+    $input = json_decode(file_get_contents('php://input'), true) ?? [];
+    $key      = trim($input['key'] ?? '');
+    $label    = trim($input['label'] ?? '');
+    $icon     = trim($input['icon'] ?? '');
+    $baseUnit = trim($input['base_unit'] ?? '');
+    $factor   = (float)($input['factor'] ?? 0);
+
+    if ($key === '' || $label === '' || !in_array($baseUnit, ['pz', 'g', 'ml'], true) || $factor <= 0) {
+        echo json_encode(['success' => false, 'error' => 'champs invalides']);
+        return;
+    }
+
+    $stmt = $db->prepare("SELECT id FROM custom_units WHERE key = ?");
+    $stmt->execute([$key]);
+    if (!$stmt->fetch()) {
+        echo json_encode(['success' => false, 'error' => 'unit not found']);
+        return;
+    }
+
+    $stmt = $db->prepare("UPDATE custom_units SET label = ?, icon = ?, base_unit = ?, factor = ? WHERE key = ?");
+    $stmt->execute([$label, $icon ?: '📏', $baseUnit, $factor, $key]);
+
+    echo json_encode(['success' => true]);
+}
+
 // ===== SHARED APP DATA FUNCTIONS =====
 
 function appSettingsGet(PDO $db): void {