diff --git a/parser/object_model.py b/parser/object_model.py
index 56dccd8..fbe7611 100644
--- a/parser/object_model.py
+++ b/parser/object_model.py
@@ -212,9 +212,19 @@ def _ooname(fn_name: str, cls: str) -> str:
 
 def _oo_excluded(fn: dict, role: str) -> bool:
     """True for functions classified to a class that are internal machinery,
-    not user OO methods: aggregate transition helpers, and comparators with no
-    SQL function (qsort / bound / min / max sort helpers)."""
+    not user OO methods: functions the catalog marks internal (the ``_p`` peeks,
+    the bbox / skiplist plumbing, ``*_in`` / ``*_out``), aggregate transition
+    helpers, and comparators with no SQL function (qsort / bound / min / max sort
+    helpers).
+
+    The internal-API check is the load-bearing one for a binding that generates
+    its object layer from ``classes[*].methods``: without it that list mixes the
+    public surface with functions a binding cannot call, so every binding would
+    re-derive the split. The catalog carries ``api`` per function, so the method
+    carries the exclusion and a binding keeps only ``not m['ooExclude']``."""
     name = fn["name"]
+    if fn.get("api") != "public":
+        return True
     if any(name.endswith(s) for s in _OONAME_EXCLUDE_SUFFIXES):
         return True
     if role == "predicate" and not fn.get("sqlfn"):
diff --git a/tests/test_object_model.py b/tests/test_object_model.py
index a8c5683..60dd7aa 100644
--- a/tests/test_object_model.py
+++ b/tests/test_object_model.py
@@ -156,6 +156,19 @@ def test_classification(self):
         self.assertIsNone(ftc["add_int_int"]["class"])
         self.assertIn("no-prefix-match", ftc["add_int_int"]["reason"])
 
+    def test_internal_api_methods_are_excluded(self):
+        # A function the catalog marks internal is classified to its class (so
+        # the reverse index stays complete) but flagged ooExclude, so a binding
+        # generating from classes[*].methods keeps only the public surface.
+        idl = attach_object_model({"functions": [
+            {"name": "temporal_num_instants", "api": "public"},
+            {"name": "temporal_inst_n", "api": "internal"},
+        ]}, MODEL, None)
+        meths = {m["backing"]: m
+                 for m in idl["objectModel"]["classes"]["Temporal"]["methods"]}
+        self.assertNotIn("ooExclude", meths["temporal_num_instants"])
+        self.assertTrue(meths["temporal_inst_n"].get("ooExclude"))
+
     def test_tree_derived(self):
         om = self._attach(["temporal_merge"])["objectModel"]
         lat = om["lattice"]