diff --git a/meshroom/core/attribute.py b/meshroom/core/attribute.py
index 86b39fc6..0c9bb563 100644
--- a/meshroom/core/attribute.py
+++ b/meshroom/core/attribute.py
@@ -62,6 +62,7 @@ class Attribute(BaseObject):
         self._value = copy.copy(attributeDesc.value)
         self._label = attributeDesc.label
         self._enabled = True
+        self._validValue = True
 
         # invalidation value for output attributes
         self._invalidationValue = ""
@@ -147,6 +148,24 @@ class Attribute(BaseObject):
         """ Value for which the attribute should be ignored during the UID computation. """
         return self.attributeDesc.uidIgnoreValue
 
+    def getValidValue(self):
+        """
+        Get the status of _validValue:
+            - If it is a function, execute it and return the result
+            - Otherwise, simply return its value
+        """
+        if isinstance(self.desc.validValue, types.FunctionType):
+            try:
+                return self.desc.validValue(self.node)
+            except Exception:
+                return True
+        return self._validValue
+
+    def setValidValue(self, value):
+        if self._validValue == value:
+            return
+        self._validValue = value
+
     def _get_value(self):
         if self.isLink:
             return self.getLinkParam().value
@@ -338,6 +357,8 @@ class Attribute(BaseObject):
     enabledChanged = Signal()
     enabled = Property(bool, getEnabled, setEnabled, notify=enabledChanged)
     uidIgnoreValue = Property(Variant, getUidIgnoreValue, constant=True)
+    validValueChanged = Signal()
+    validValue = Property(bool, getValidValue, setValidValue, notify=validValueChanged)
 
 
 def raiseIfLink(func):
diff --git a/meshroom/core/desc.py b/meshroom/core/desc.py
index d62c0c21..05d9478a 100644
--- a/meshroom/core/desc.py
+++ b/meshroom/core/desc.py
@@ -14,7 +14,8 @@ class Attribute(BaseObject):
     """
     """
 
-    def __init__(self, name, label, description, value, advanced, semantic, uid, group, enabled, uidIgnoreValue=None):
+    def __init__(self, name, label, description, value, advanced, semantic, uid, group, enabled, uidIgnoreValue=None,
+                 validValue=True, errorMessage=""):
         super(Attribute, self).__init__()
         self._name = name
         self._label = label
@@ -26,6 +27,8 @@ class Attribute(BaseObject):
         self._enabled = enabled
         self._semantic = semantic
         self._uidIgnoreValue = uidIgnoreValue
+        self._validValue = validValue
+        self._errorMessage = errorMessage
 
     name = Property(str, lambda self: self._name, constant=True)
     label = Property(str, lambda self: self._label, constant=True)
@@ -37,6 +40,8 @@ class Attribute(BaseObject):
     enabled = Property(Variant, lambda self: self._enabled, constant=True)
     semantic = Property(str, lambda self: self._semantic, constant=True)
     uidIgnoreValue = Property(Variant, lambda self: self._uidIgnoreValue, constant=True)
+    validValue = Property(Variant, lambda self: self._validValue, constant=True)
+    errorMessage = Property(str, lambda self: self._errorMessage, constant=True)
     type = Property(str, lambda self: self.__class__.__name__, constant=True)
 
     def validateValue(self, value):
@@ -205,9 +210,9 @@ class GroupAttribute(Attribute):
 class Param(Attribute):
     """
     """
-    def __init__(self, name, label, description, value, uid, group, advanced, semantic, enabled, uidIgnoreValue=None):
+    def __init__(self, name, label, description, value, uid, group, advanced, semantic, enabled, uidIgnoreValue=None, validValue=True, errorMessage=""):
         super(Param, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled,
-            uidIgnoreValue=uidIgnoreValue)
+            uidIgnoreValue=uidIgnoreValue, validValue=validValue, errorMessage=errorMessage)
 
 
 class File(Attribute):
@@ -253,9 +258,10 @@ class BoolParam(Param):
 class IntParam(Param):
     """
     """
-    def __init__(self, name, label, description, value, range, uid, group='allParams', advanced=False, semantic='', enabled=True):
+    def __init__(self, name, label, description, value, range, uid, group='allParams', advanced=False, semantic='', enabled=True, validValue=True, errorMessage=""):
         self._range = range
-        super(IntParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled)
+        super(IntParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled,
+            validValue=validValue, errorMessage=errorMessage)
 
     def validateValue(self, value):
         # handle unsigned int values that are translated to int by shiboken and may overflow
@@ -275,9 +281,10 @@ class IntParam(Param):
 class FloatParam(Param):
     """
     """
-    def __init__(self, name, label, description, value, range, uid, group='allParams', advanced=False, semantic='', enabled=True):
+    def __init__(self, name, label, description, value, range, uid, group='allParams', advanced=False, semantic='', enabled=True, validValue=True, errorMessage=""):
         self._range = range
-        super(FloatParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled)
+        super(FloatParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled,
+            validValue=validValue, errorMessage=errorMessage)
 
     def validateValue(self, value):
         try:
@@ -334,9 +341,9 @@ class ChoiceParam(Param):
 class StringParam(Param):
     """
     """
-    def __init__(self, name, label, description, value, uid, group='allParams', advanced=False, semantic='', enabled=True, uidIgnoreValue=None):
+    def __init__(self, name, label, description, value, uid, group='allParams', advanced=False, semantic='', enabled=True, uidIgnoreValue=None, validValue=True, errorMessage=""):
         super(StringParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled,
-            uidIgnoreValue=uidIgnoreValue)
+            uidIgnoreValue=uidIgnoreValue, validValue=validValue, errorMessage=errorMessage)
 
     def validateValue(self, value):
         if not isinstance(value, str):