diff --git a/frontend/app/components/model-types/ModelTypeForm.vue b/frontend/app/components/model-types/ModelTypeForm.vue
index 83c365c..25987ab 100644
--- a/frontend/app/components/model-types/ModelTypeForm.vue
+++ b/frontend/app/components/model-types/ModelTypeForm.vue
@@ -194,15 +194,16 @@ const form = reactive<ModelTypePayload & { referenceFormula?: string | null }>({
 })
 
 const formulaBuilderCustomFields = computed(() => {
+  let fields: any[] = []
   if (form.category === 'PIECE') {
-    const fields = pieceStructure.value?.customFields
-    return Array.isArray(fields) ? fields : []
+    const raw = pieceStructure.value?.customFields
+    fields = Array.isArray(raw) ? raw : []
   }
-  if (form.category === 'COMPONENT') {
-    const fields = componentStructure.value?.customFields
-    return Array.isArray(fields) ? fields : []
+  else if (form.category === 'COMPONENT') {
+    const raw = componentStructure.value?.customFields
+    fields = Array.isArray(raw) ? raw : []
   }
-  return []
+  return fields.filter((f: any) => !f.machineContextOnly)
 })
 
 const extractFormulaFields = (formula: string | null | undefined): string[] => {
diff --git a/frontend/app/composables/useComponentCreate.ts b/frontend/app/composables/useComponentCreate.ts
index cfd3d92..499c2fe 100644
--- a/frontend/app/composables/useComponentCreate.ts
+++ b/frontend/app/composables/useComponentCreate.ts
@@ -151,6 +151,7 @@ export function useComponentCreate() {
     values: computed(() => []),
     entityType: 'composant',
     entityId: createdComponentId,
+    context: 'standalone',
   })
 
   const structureHasRequirements = computed(() =>
diff --git a/frontend/app/composables/useComponentEdit.ts b/frontend/app/composables/useComponentEdit.ts
index f24db16..104d4f8 100644
--- a/frontend/app/composables/useComponentEdit.ts
+++ b/frontend/app/composables/useComponentEdit.ts
@@ -209,6 +209,7 @@ export function useComponentEdit(componentId: string) {
     values: computed(() => component.value?.customFieldValues ?? []),
     entityType: 'composant',
     entityId: computed(() => component.value?.id ?? null),
+    context: 'standalone',
     onValueCreated: (newValue) => {
       if (component.value && Array.isArray(component.value.customFieldValues)) {
         component.value.customFieldValues.push(newValue)
@@ -556,6 +557,7 @@ export function useComponentEdit(componentId: string) {
     originalConstructeurLinks,
     constructeurIdsFromForm,
     customFieldInputs,
+    requiredCustomFieldsFilled,
     historyFieldLabels,
 
     // Computed
diff --git a/frontend/app/composables/usePieceEdit.ts b/frontend/app/composables/usePieceEdit.ts
index b5ad95b..5b49d1c 100644
--- a/frontend/app/composables/usePieceEdit.ts
+++ b/frontend/app/composables/usePieceEdit.ts
@@ -99,6 +99,7 @@ export function usePieceEdit(pieceId: string) {
     values: computed(() => piece.value?.customFieldValues ?? []),
     entityType: 'piece',
     entityId: computed(() => piece.value?.id ?? null),
+    context: 'standalone',
     onValueCreated: (newValue) => {
       if (piece.value && Array.isArray(piece.value.customFieldValues)) {
         piece.value.customFieldValues.push(newValue)
@@ -435,6 +436,7 @@ export function usePieceEdit(pieceId: string) {
     constructeurIdsFromForm,
     productSelections,
     customFieldInputs,
+    requiredCustomFieldsFilled,
     canEdit,
 
     // Computed
diff --git a/frontend/app/pages/pieces/create.vue b/frontend/app/pages/pieces/create.vue
index 9013a2d..c0780f8 100644
--- a/frontend/app/pages/pieces/create.vue
+++ b/frontend/app/pages/pieces/create.vue
@@ -218,6 +218,9 @@
                 </p>
               </header>
               <CustomFieldInputGrid :fields="customFieldInputs" :disabled="!canEdit || submitting" />
+              <p v-if="hasRequiredCustomFields && !requiredCustomFieldsFilled" class="text-xs text-warning">
+                Certains champs personnalisés sont obligatoires. Veuillez les renseigner avant de valider.
+              </p>
             </div>
             <EmptyState
               v-else
@@ -237,6 +240,9 @@
             Créer la pièce
           </button>
         </div>
+        <p v-if="selectedType && hasRequiredCustomFields && !requiredCustomFieldsFilled" class="text-xs text-error text-right">
+          Merci de renseigner tous les champs personnalisés obligatoires avant de créer la pièce.
+        </p>
       </div>
     </section>
   </main>
@@ -311,7 +317,9 @@ const { fields: customFieldInputs, requiredFilled: requiredCustomFieldsFilled, s
   values: [] as any[],
   entityType: 'piece' as CustomFieldEntityType,
   entityId: createdEntityId,
+  context: 'standalone',
 })
+const hasRequiredCustomFields = computed(() => customFieldInputs.value.some(f => f.required))
 const selectedDocuments = ref<File[]>([])
 const uploadingDocuments = ref(false)
 
diff --git a/frontend/app/pages/product/[id]/index.vue b/frontend/app/pages/product/[id]/index.vue
index 2099ae1..1ba844c 100644
--- a/frontend/app/pages/product/[id]/index.vue
+++ b/frontend/app/pages/product/[id]/index.vue
@@ -274,6 +274,9 @@
                   </header>
                   <template v-if="isEditMode">
                     <CustomFieldInputGrid :fields="customFieldInputs" :disabled="!canEdit || saving" />
+                    <p v-if="hasRequiredCustomFields && !requiredCustomFieldsFilled" class="text-xs text-warning">
+                      Certains champs personnalisés sont obligatoires. Veuillez les renseigner avant de valider.
+                    </p>
                   </template>
                   <template v-else>
                     <div class="grid grid-cols-1 gap-4 md:grid-cols-2">
@@ -338,7 +341,7 @@
               Enregistrer les modifications
             </button>
           </div>
-          <p v-if="isEditMode && product && !requiredCustomFieldsFilled" class="text-xs text-error text-right">
+          <p v-if="isEditMode && hasRequiredCustomFields && !requiredCustomFieldsFilled" class="text-xs text-error text-right">
             Merci de renseigner tous les champs personnalisés obligatoires.
           </p>
         </div>
@@ -409,6 +412,7 @@ const {
   values: cfValues,
   entityType: 'product' as CustomFieldEntityType,
   entityId,
+  context: 'standalone',
 })
 const loading = ref(true)
 const saving = ref(false)
@@ -446,7 +450,7 @@ const editionForm = reactive({
   supplierPrice: '' as string,
 })
 
-// requiredCustomFieldsFilled comes from useCustomFieldInputs composable
+const hasRequiredCustomFields = computed(() => customFieldInputs.value.some(f => f.required))
 
 const canSubmit = computed(() =>
   Boolean(canEdit.value && product.value && editionForm.name.trim().length >= 2 && requiredCustomFieldsFilled.value && !saving.value),
diff --git a/frontend/app/pages/product/create.vue b/frontend/app/pages/product/create.vue
index 3fe0b47..c3e678e 100644
--- a/frontend/app/pages/product/create.vue
+++ b/frontend/app/pages/product/create.vue
@@ -158,6 +158,9 @@
                 </p>
               </header>
               <CustomFieldInputGrid :fields="customFieldInputs" :disabled="!canEdit || submitting" />
+              <p v-if="hasRequiredCustomFields && !requiredCustomFieldsFilled" class="text-xs text-warning">
+                Certains champs personnalisés sont obligatoires. Veuillez les renseigner avant de valider.
+              </p>
             </div>
             <EmptyState
               v-else
@@ -177,7 +180,7 @@
             Créer le produit
           </button>
         </div>
-        <p v-if="selectedType && !requiredCustomFieldsFilled" class="text-xs text-error text-right">
+        <p v-if="selectedType && hasRequiredCustomFields && !requiredCustomFieldsFilled" class="text-xs text-error text-right">
           Merci de renseigner tous les champs personnalisés obligatoires.
         </p>
       </div>
@@ -241,7 +244,9 @@ const { fields: customFieldInputs, requiredFilled: requiredCustomFieldsFilled, s
   values: [] as any[],
   entityType: 'product' as CustomFieldEntityType,
   entityId: createdEntityId,
+  context: 'standalone',
 })
+const hasRequiredCustomFields = computed(() => customFieldInputs.value.some(f => f.required))
 
 const productTypeList = computed<ProductCatalogType[]>(() =>
   (productTypes.value || []) as ProductCatalogType[],