Index: flexoentity/flexo_entity.py
===================================================================
--- flexoentity/flexo_entity.py	(revision ab1cc877e890cfbe90384115c7691e8d8c8a3be2)
+++ flexoentity/flexo_entity.py	(revision 045b8649f305ce4664e6f393e6da42083ee7509f)
@@ -96,4 +96,10 @@
 
     # ───────────────────────────────────────────────────────────────
+
+    @property
+    @abstractmethod
+    def text_seed(self) -> str:
+        """Canonicalized text used for ID generation."""
+        raise NotImplementedError("Subclasses must define text_seed property")
 
     def __post_init__(self):