diff --git a/src/schema/TODO.md b/src/schema/TODO.md
index 65c4212..8cdcee8 100644
--- a/src/schema/TODO.md
+++ b/src/schema/TODO.md
@@ -20,6 +20,8 @@
   * cela pourrait servir pour générer automatiquement des tables SQL
   * ou pour modéliser un schéma FSV
 
+* support allowed_values
+
 * valeurs composite/computed
   * analyse / vérification de la valeur complète après calcul du résultat, si
     tous les résultats sont bons
diff --git a/src/schema/_assoc/AssocSchema.php b/src/schema/_assoc/AssocSchema.php
index 4b6b753..6c0156b 100644
--- a/src/schema/_assoc/AssocSchema.php
+++ b/src/schema/_assoc/AssocSchema.php
@@ -82,7 +82,15 @@ class AssocSchema extends Schema {
     # cf le code similaire dans AssocWrapper::__construct()
     $dontAnalyze = $value === null && $wrapper === null;
     if (!($wrapper instanceof AssocWrapper)) $wrapper = $this->newWrapper();
+
+    # le schéma peut contenir des paramètres par défaut
+    $nature = $this->definition[""];
+    foreach (array_keys(ref_schema::ASSOC_PARAMS_SCHEMA) as $key) {
+      $value = $nature[$key] ?? null;
+      if ($value !== null) $params[$key] = $value;
+    }
     if ($params !== null) $wrapper->resetParams($params);
+
     return $wrapper->reset($value, $valueKey, $dontAnalyze? ["analyze" => false]: null);
   }
 }
diff --git a/src/schema/_assoc/AssocWrapper.php b/src/schema/_assoc/AssocWrapper.php
index 71210d1..1c8f179 100644
--- a/src/schema/_assoc/AssocWrapper.php
+++ b/src/schema/_assoc/AssocWrapper.php
@@ -89,13 +89,13 @@ class AssocWrapper extends Wrapper {
    * @param AssocWrapper $wrapper
    */
   static function _analyze(WrapperContext $context, Wrapper $wrapper, ?array $params): int {
-    if ($context->ensureArray) {
+    if ($params["ensure_array"] ?? $context->ensureArray) {
       $valueKey = $context->valueKey;
       $array = $context->input->get($valueKey);
       if ($array === null) $context->input->set([], $valueKey);
     }
 
-    if ($context->ensureAssoc) {
+    if ($params["ensure_assoc"] ?? $context->ensureAssoc) {
       $context->input->ensureAssoc($context->schema->getKeys());
     }
 
@@ -113,7 +113,7 @@ class AssocWrapper extends Wrapper {
       }
     }
 
-    #XXX supprimer les clés "missing" ou "unavailable"
+    #XXX supprimer les clés "missing" ou "unavailable" sauf si $ensureKeys
     return $what;
   }
 
@@ -122,8 +122,8 @@ class AssocWrapper extends Wrapper {
    * @param AssocWrapper $wrapper
    */
   static function _normalize(WrapperContext $context, Wrapper $wrapper, ?array $params): bool {
-    $ensureKeys = $context->ensureKeys;
-    $ensureOrder = $context->ensureOrder;
+    $ensureKeys = $params["ensure_keys"] ?? $context->ensureKeys;
+    $ensureOrder = $params["ensure_order"] ?? $context->ensureOrder;
     if ($ensureKeys || $ensureOrder) {
       $schema = $context->schema;
       $keys = $schema->getKeys();
diff --git a/src/schema/_scalar/ScalarSchema.php b/src/schema/_scalar/ScalarSchema.php
index a9c2ad5..1a5dd8e 100644
--- a/src/schema/_scalar/ScalarSchema.php
+++ b/src/schema/_scalar/ScalarSchema.php
@@ -84,7 +84,15 @@ class ScalarSchema extends Schema {
     # cf le code similaire dans ScalarWrapper::__construct()
     $dontAnalyze = $value === null && $wrapper === null;
     if (!($wrapper instanceof ScalarWrapper)) $wrapper = $this->newWrapper();
+
+    # le schéma peut contenir des paramètres par défaut
+    $nature = $this->definition[""];
+    foreach (array_keys(ref_schema::SCALAR_PARAMS_SCHEMA) as $key) {
+      $value = $nature[$key] ?? null;
+      if ($value !== null) $params[$key] = $value;
+    }
     if ($params !== null) $wrapper->resetParams($params);
+
     return $wrapper->reset($value, $valueKey, $dontAnalyze? ["analyze" => false]: null);
   }
 }
diff --git a/tests/wip/schema/_assoc/AssocSchemaTest.php b/tests/wip/schema/_assoc/AssocSchemaTest.php
index cdd1567..cf5e9d4 100644
--- a/tests/wip/schema/_assoc/AssocSchemaTest.php
+++ b/tests/wip/schema/_assoc/AssocSchemaTest.php
@@ -13,9 +13,10 @@ class AssocSchemaTest extends TestCase {
       "assoc",
       "compute_func" => null,
       "validate_func" => null,
-      "ensure_array" => false,
-      "ensure_keys" => true,
-      "ensure_order" => true,
+      "ensure_array" => null,
+      "ensure_assoc" => null,
+      "ensure_keys" => null,
+      "ensure_order" => null,
     ],
     "schema" => null,
     "type" => [null],