fix: diagnose naive identifiers on graph templates at create

hyperextract/utils/template_engine/parsers/identifiers.py

@@ -121,6 +121,14 @@ def validate_identifiers_fields(
     ):
         return
 
+    if not isinstance(identifiers, GraphIdentifiersSchema):
+        # Same diagnosis as the validator's HE-T003; without this the graph
+        # field checks below raise AttributeError on item_id-only identifiers.
+        raise ValueError(
+            f"{autotype} templates require identifiers.entity_id, "
+            "relation_id, and relation_members (not item_id)"
+        )
+
     entity_fields = declared_fields.get("entities", set())
     relation_fields = declared_fields.get("relations", set())
 

tests/template_engine/test_parser_identifiers.py

@@ -227,3 +227,30 @@ def test_undeclared_time_field_still_rejected(self):
                 "temporal_graph",
                 self._declared(["name"], ["source", "target"]),
             )
+
+
+class TestGraphTemplateWithNaiveIdentifiers:
+    """A graph-family template carrying item_id must fail with a diagnosis."""
+
+    def test_naive_identifiers_rejected_with_guidance(self):
+        from hyperextract.utils.template_engine.parsers.schemas import (
+            NaiveIdentifierSchema,
+        )
+
+        with pytest.raises(ValueError, match="not item_id"):
+            validate_identifiers_fields(
+                NaiveIdentifierSchema(item_id="name"),
+                "graph",
+                {"entities": {"name"}, "relations": {"source", "target"}},
+            )
+
+    def test_graph_identifiers_still_accepted(self):
+        validate_identifiers_fields(
+            GraphIdentifiersSchema(
+                entity_id="name",
+                relation_id="{source}|{target}",
+                relation_members={"source": "source", "target": "target"},
+            ),
+            "graph",
+            {"entities": {"name"}, "relations": {"source", "target"}},
+        )