@@ -82,21 +82,21 @@ All primitive types (except `Map` and `Json`) have corresponding set types for s
 
 ### Nested Collection Types
 
-Feast supports 2-level nested collections, combining Array and Set types:
+Feast supports arbitrarily nested collections using a recursive `VALUE_LIST` / `VALUE_SET` design. The outer container determines the proto enum (`VALUE_LIST` for `Array(…)`, `VALUE_SET` for `Set(…)`), while the full inner type structure is persisted via a mandatory `feast:nested_inner_type` Field tag.
 
 | Feast Type | Python Type | ValueType | Description |
 |------------|-------------|-----------|-------------|
-| `Array(Array(T))` | `List[List[T]]` | `LIST_LIST` | List of lists |
-| `Array(Set(T))` | `List[List[T]]` | `LIST_SET` | List of sets (inner elements deduplicated) |
-| `Set(Array(T))` | `List[List[T]]` | `SET_LIST` | Set of lists |
-| `Set(Set(T))` | `List[List[T]]` | `SET_SET` | Set of sets (inner elements deduplicated) |
+| `Array(Array(T))` | `List[List[T]]` | `VALUE_LIST` | List of lists |
+| `Array(Set(T))` | `List[List[T]]` | `VALUE_LIST` | List of sets |
+| `Set(Array(T))` | `List[List[T]]` | `VALUE_SET` | Set of lists |
+| `Set(Set(T))` | `List[List[T]]` | `VALUE_SET` | Set of sets |
+| `Array(Array(Array(T)))` | `List[List[List[T]]]` | `VALUE_LIST` | 3-level nesting |
 
-Where `T` is any supported primitive type (Int32, Int64, Float32, Float64, String, Bytes, Bool, UnixTimestamp).
+Where `T` is any supported primitive type (Int32, Int64, Float32, Float64, String, Bytes, Bool, UnixTimestamp) or another nested collection type.
 
 **Notes:**
-- Nesting is limited to 2 levels. `Array(Array(Array(T)))` will raise a `ValueError`.
-- Inner type information is preserved via Field tags (`feast:nested_inner_type`) and restored during deserialization.
-- For `Array(Set(T))` and `Set(Set(T))`, inner collection elements are automatically deduplicated.
+- Nesting depth is **unlimited**. `Array(Array(Array(T)))`, `Set(Array(Set(T)))`, etc. are all supported.
+- Inner type information is preserved via Field tags (`feast:nested_inner_type`) and restored during deserialization. This tag is mandatory for nested collection types.
 - Empty inner collections (`[]`) are stored as empty proto values and round-trip as `None`. For example, `[[1, 2], [], [3]]` becomes `[[1, 2], None, [3]]` after a write-read cycle.
 
 ### Map Types
@@ -275,23 +275,20 @@ tag_ids = set(tag_list)  # {100, 200, 300}
 
 ### Nested Collection Type Usage Examples
 
-Nested collections allow storing multi-dimensional data:
+Nested collections allow storing multi-dimensional data with unlimited depth:
 
 ```python
 # List of lists — e.g., weekly score history per user
 weekly_scores = [[85.0, 90.5, 78.0], [92.0, 88.5], [95.0, 91.0, 87.5]]
 
 # List of sets — e.g., unique tags assigned per category
 unique_tags_per_category = [["python", "ml"], ["rust", "systems"], ["python", "web"]]
-# Inner sets are automatically deduplicated:
-# [["python", "ml"], ...] (duplicates within each inner set are removed)
 
-# Set of lists — e.g., distinct ordered sequences observed
-distinct_sequences = [[1, 2, 3], [4, 5], [1, 2, 3]]
+# 3-level nesting — e.g., multi-dimensional matrices
+Field(name="tensor", dtype=Array(Array(Array(Float64))))
 
-# Set of sets — e.g., distinct groups of unique items
-distinct_groups = [["a", "b"], ["c", "d"], ["a", "b"]]
-# Inner elements are deduplicated within each set
+# Mixed nesting
+Field(name="grouped_tags", dtype=Array(Set(Array(String))))
 ```
 
 **Limitation:** Empty inner collections round-trip as `None`:
 
@@ -57,10 +57,10 @@ message ValueType {
     JSON_LIST = 33;
     STRUCT = 34;
     STRUCT_LIST = 35;
-    LIST_LIST = 36;
-    LIST_SET = 37;
-    SET_LIST = 38;
-    SET_SET = 39;
+    // 36-39 were LIST_LIST, LIST_SET, SET_LIST, SET_SET (removed, replaced by VALUE_LIST/VALUE_SET)
+    reserved 36, 37, 38, 39;
+    VALUE_LIST = 40;
+    VALUE_SET = 41;
   }
 }
 
@@ -100,10 +100,8 @@ message Value {
     StringList json_list_val = 33;
     Map struct_val = 34;
     MapList struct_list_val = 35;
-    RepeatedValue list_list_val = 36;
-    RepeatedValue list_set_val = 37;
-    RepeatedValue set_list_val = 38;
-    RepeatedValue set_set_val = 39;
+    RepeatedValue list_val = 40;
+    RepeatedValue set_val = 41;
   }
 }
 
 
@@ -171,13 +171,7 @@ def from_proto(cls, field_proto: FieldProto):
             dtype = Array(inner_struct)
             user_tags = {k: v for k, v in tags.items() if k not in internal_tags}
         elif (
-            value_type
-            in (
-                ValueType.LIST_LIST,
-                ValueType.LIST_SET,
-                ValueType.SET_LIST,
-                ValueType.SET_SET,
-            )
+            value_type in (ValueType.VALUE_LIST, ValueType.VALUE_SET)
             and NESTED_COLLECTION_INNER_TYPE_TAG in tags
         ):
             dtype = _str_to_feast_type(tags[NESTED_COLLECTION_INNER_TYPE_TAG])
 
@@ -96,7 +96,7 @@ def _proto_value_to_transport_value(proto_value: ValueProto) -> Any:
 
         # Nested collection types use feast_value_type_to_python_type
         # which handles recursive conversion of RepeatedValue protos.
-        if val_attr in ("list_list_val", "list_set_val", "set_list_val", "set_set_val"):
+        if val_attr in ("list_val", "set_val"):
             return feast_value_type_to_python_type(proto_value)
 
         # Map/Struct types are converted to Python dicts by
 
@@ -63,7 +63,7 @@ def to_json_object(printer: _Printer, message: ProtoMessage) -> JsonObject:
         # to JSON. The parse back result will be different from original message.
         if which is None or which == "null_val":
             return None
-        elif which in ("list_list_val", "list_set_val", "set_list_val", "set_set_val"):
+        elif which in ("list_val", "set_val"):
             # Nested collection: RepeatedValue containing Values
             repeated = getattr(message, which)
             value = [
@@ -96,13 +96,13 @@ def from_json_object(
                 # Nested collection (list of lists).
                 # Check any() to handle cases where the first element is None
                 # (empty inner collections round-trip through proto as None).
-                # Default to list_list_val since JSON transport loses the
+                # Default to list_val since JSON transport loses the
                 # outer/inner set distinction.
                 rv = RepeatedValue()
                 for inner in value:
                     inner_val = rv.val.add()
                     from_json_object(parser, inner, inner_val)
-                message.list_list_val.CopyFrom(rv)
+                message.list_val.CopyFrom(rv)
             elif isinstance(value[0], bool):
                 message.bool_list_val.val.extend(value)
             elif isinstance(value[0], str):
 
@@ -25,11 +25,11 @@ class Aggregation(google.protobuf.message.Message):
     NAME_FIELD_NUMBER: builtins.int
     column: builtins.str
     function: builtins.str
-    name: builtins.str
     @property
     def time_window(self) -> google.protobuf.duration_pb2.Duration: ...
     @property
     def slide_interval(self) -> google.protobuf.duration_pb2.Duration: ...
+    name: builtins.str
     def __init__(
         self,
         *,
 
@@ -118,14 +118,18 @@ class FeatureViewSpec(google.protobuf.message.Message):
         """
     @property
     def batch_source(self) -> feast.core.DataSource_pb2.DataSource:
-        """Batch/Offline DataSource where this view can retrieve offline feature data."""
+        """Batch/Offline DataSource where this view can retrieve offline feature data.
+        Optional: if not set, the feature view has no associated batch data source (e.g. purely derived views).
+        """
     online: builtins.bool
     """Whether these features should be served online or not
     This is also used to determine whether the features should be written to the online store
     """
     @property
     def stream_source(self) -> feast.core.DataSource_pb2.DataSource:
-        """Streaming DataSource from where this view can consume "online" feature data."""
+        """Streaming DataSource from where this view can consume "online" feature data.
+        Optional: only required for streaming feature views.
+        """
     description: builtins.str
     """Description of the feature view."""
     owner: builtins.str
 
@@ -4,7 +4,7 @@ isort:skip_file
 """
 import builtins
 import collections.abc
-import feast.protos.feast.types.Value_pb2
+import feast.types.Value_pb2
 import google.protobuf.descriptor
 import google.protobuf.internal.containers
 import google.protobuf.message
@@ -42,12 +42,12 @@ class PushRequest(google.protobuf.message.Message):
         VALUE_FIELD_NUMBER: builtins.int
         key: builtins.str
         @property
-        def value(self) -> feast.protos.feast.types.Value_pb2.Value: ...
+        def value(self) -> feast.types.Value_pb2.Value: ...
         def __init__(
             self,
             *,
             key: builtins.str = ...,
-            value: feast.protos.feast.types.Value_pb2.Value | None = ...,
+            value: feast.types.Value_pb2.Value | None = ...,
         ) -> None: ...
         def HasField(self, field_name: typing_extensions.Literal["value", b"value"]) -> builtins.bool: ...
         def ClearField(self, field_name: typing_extensions.Literal["key", b"key", "value", b"value"]) -> None: ...
@@ -63,15 +63,15 @@ class PushRequest(google.protobuf.message.Message):
     allow_registry_cache: builtins.bool
     to: builtins.str
     @property
-    def typed_features(self) -> google.protobuf.internal.containers.MessageMap[builtins.str, feast.protos.feast.types.Value_pb2.Value]: ...
+    def typed_features(self) -> google.protobuf.internal.containers.MessageMap[builtins.str, feast.types.Value_pb2.Value]: ...
     def __init__(
         self,
         *,
         features: collections.abc.Mapping[builtins.str, builtins.str] | None = ...,
         stream_feature_view: builtins.str = ...,
         allow_registry_cache: builtins.bool = ...,
         to: builtins.str = ...,
-        typed_features: collections.abc.Mapping[builtins.str, feast.protos.feast.types.Value_pb2.Value] | None = ...,
+        typed_features: collections.abc.Mapping[builtins.str, feast.types.Value_pb2.Value] | None = ...,
     ) -> None: ...
     def ClearField(self, field_name: typing_extensions.Literal["allow_registry_cache", b"allow_registry_cache", "features", b"features", "stream_feature_view", b"stream_feature_view", "to", b"to", "typed_features", b"typed_features"]) -> None: ...
 
@@ -116,12 +116,12 @@ class WriteToOnlineStoreRequest(google.protobuf.message.Message):
         VALUE_FIELD_NUMBER: builtins.int
         key: builtins.str
         @property
-        def value(self) -> feast.protos.feast.types.Value_pb2.Value: ...
+        def value(self) -> feast.types.Value_pb2.Value: ...
         def __init__(
             self,
             *,
             key: builtins.str = ...,
-            value: feast.protos.feast.types.Value_pb2.Value | None = ...,
+            value: feast.types.Value_pb2.Value | None = ...,
         ) -> None: ...
         def HasField(self, field_name: typing_extensions.Literal["value", b"value"]) -> builtins.bool: ...
         def ClearField(self, field_name: typing_extensions.Literal["key", b"key", "value", b"value"]) -> None: ...
@@ -135,14 +135,14 @@ class WriteToOnlineStoreRequest(google.protobuf.message.Message):
     feature_view_name: builtins.str
     allow_registry_cache: builtins.bool
     @property
-    def typed_features(self) -> google.protobuf.internal.containers.MessageMap[builtins.str, feast.protos.feast.types.Value_pb2.Value]: ...
+    def typed_features(self) -> google.protobuf.internal.containers.MessageMap[builtins.str, feast.types.Value_pb2.Value]: ...
     def __init__(
         self,
         *,
         features: collections.abc.Mapping[builtins.str, builtins.str] | None = ...,
         feature_view_name: builtins.str = ...,
         allow_registry_cache: builtins.bool = ...,
-        typed_features: collections.abc.Mapping[builtins.str, feast.protos.feast.types.Value_pb2.Value] | None = ...,
+        typed_features: collections.abc.Mapping[builtins.str, feast.types.Value_pb2.Value] | None = ...,
     ) -> None: ...
     def ClearField(self, field_name: typing_extensions.Literal["allow_registry_cache", b"allow_registry_cache", "feature_view_name", b"feature_view_name", "features", b"features", "typed_features", b"typed_features"]) -> None: ...