Separate ComfyNodeV3 into an internal base class and one that only has the functions defined that a developer cares about overriding, reference ComfyNodeInternal in execution.py/server.py instead of ComfyNodeV3 to make the code not bound to a particular version of v3 schema (once placed on api)

comfy_api/internal/__init__.py

@@ -1,6 +1,10 @@
-class ComfyNodeInternal:
+from abc import ABC, abstractmethod
+
+class ComfyNodeInternal(ABC):
     """Class that all V3-based APIs inherit from for ComfyNode.
 
     This is intended to only be referenced within execution.py, as it has to handle all V3 APIs going forward."""
+    @classmethod
+    @abstractmethod
+    def GET_NODE_INFO_V1(cls):
         ...
-

comfy_api/v3/helpers.py

@@ -1,10 +1,16 @@
 from typing import Callable, Optional
 
 
-def first_real_override(cls: type, name: str, *, base: type) -> Optional[Callable]:
+def first_real_override(cls: type, name: str, *, base: type=None) -> Optional[Callable]:
     """Return the *callable* override of `name` visible on `cls`, or None if every
     implementation up to (and including) `base` is the placeholder defined on `base`.
+
+    If base is not provided, it will assume cls has a GET_BASE_CLASS
     """
+    if base is None:
+        if not hasattr(cls, "GET_BASE_CLASS"):
+            raise ValueError("base is required if cls does not have a GET_BASE_CLASS; is this a valid ComfyNode subclass?")
+        base = cls.GET_BASE_CLASS()
     base_attr = getattr(base, name, None)
     if base_attr is None:
         return None

comfy_api/v3/io.py

@@ -6,11 +6,12 @@ from collections import Counter
 from dataclasses import asdict, dataclass
 from enum import Enum
 from typing import Any, Callable, Literal, TypedDict, TypeVar
+from comfy_api.v3.helpers import first_real_override
 
 # used for type hinting
 import torch
 from spandrel import ImageModelDescriptor
-from typing_extensions import NotRequired
+from typing_extensions import NotRequired, final
 
 from comfy.clip_vision import ClipVisionModel
 from comfy.clip_vision import Output as ClipVisionOutput_
@@ -1244,8 +1245,9 @@ def add_to_dict_v3(io: InputV3 | OutputV3, d: dict):
     d[io.id] = (io.get_io_type(), io.as_dict())
 
 
-class ComfyNodeV3(ComfyNodeInternal):
+
-    """Common base class for all V3 nodes."""
+class _ComfyNodeBaseInternal(ComfyNodeInternal):
+    """Common base class for storing internal methods and properties; DO NOT USE for defining nodes."""
 
     RELATIVE_PYTHON_MODULE = None
     SCHEMA = None
@@ -1264,6 +1266,7 @@ class ComfyNodeV3(ComfyNodeInternal):
     @classmethod
     @abstractmethod
     def execute(cls, **kwargs) -> NodeOutput:
+        """Override this function with one that performs node's actions."""
         raise NotImplementedError
 
     @classmethod
@@ -1292,28 +1295,28 @@ class ComfyNodeV3(ComfyNodeInternal):
         """
         return [name for name in kwargs if kwargs[name] is None]
 
-    @classmethod
-    def GET_SERIALIZERS(cls) -> list[Serializer]:
-        return []
-
-    @classmethod
-    def GET_NODE_INFO_V3(cls) -> dict[str, Any]:
-        schema = cls.GET_SCHEMA()
-        info = schema.get_v3_info(cls)
-        return asdict(info)
-
     def __init__(self):
         self.local_state: NodeStateLocal = None
         self.local_resources: ResourcesLocal = None
         self.__class__.VALIDATE_CLASS()
 
+    @classmethod
+    def GET_SERIALIZERS(cls) -> list[Serializer]:
+        return []
+
+    @classmethod
+    def GET_BASE_CLASS(cls):
+        return _ComfyNodeBaseInternal
+
+    @final
     @classmethod
     def VALIDATE_CLASS(cls):
-        if not callable(cls.define_schema):
+        if first_real_override(cls, "define_schema") is None:
             raise Exception(f"No define_schema function was defined for node class {cls.__name__}.")
-        if not callable(cls.execute):
+        if first_real_override(cls, "execute") is None:
             raise Exception(f"No execute function was defined for node class {cls.__name__}.")
 
+    @final
     @classmethod
     def EXECUTE_NORMALIZED(cls, *args, **kwargs) -> NodeOutput:
         to_return = cls.execute(*args, **kwargs)
@@ -1330,6 +1333,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         else:
             raise Exception(f"Invalid return type from node: {type(to_return)}")
 
+    @final
     @classmethod
     def PREPARE_CLASS_CLONE(cls, hidden_inputs: dict) -> type[ComfyNodeV3]:
         """Creates clone of real node class to prevent monkey-patching."""
@@ -1339,10 +1343,24 @@ class ComfyNodeV3(ComfyNodeInternal):
         type_clone.hidden = HiddenHolder.from_dict(hidden_inputs)
         return type_clone
 
+    @final
+    @classmethod
+    def GET_NODE_INFO_V3(cls) -> dict[str, Any]:
+        schema = cls.GET_SCHEMA()
+        info = schema.get_v3_info(cls)
+        return asdict(info)
     #############################################
     # V1 Backwards Compatibility code
     #--------------------------------------------
+    @final
+    @classmethod
+    def GET_NODE_INFO_V1(cls) -> dict[str, Any]:
+        schema = cls.GET_SCHEMA()
+        info = schema.get_v1_info(cls)
+        return asdict(info)
+
     _DESCRIPTION = None
+    @final
     @classproperty
     def DESCRIPTION(cls):  # noqa
         if cls._DESCRIPTION is None:
@@ -1350,6 +1368,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._DESCRIPTION
 
     _CATEGORY = None
+    @final
     @classproperty
     def CATEGORY(cls):  # noqa
         if cls._CATEGORY is None:
@@ -1357,6 +1376,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._CATEGORY
 
     _EXPERIMENTAL = None
+    @final
     @classproperty
     def EXPERIMENTAL(cls):  # noqa
         if cls._EXPERIMENTAL is None:
@@ -1364,6 +1384,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._EXPERIMENTAL
 
     _DEPRECATED = None
+    @final
     @classproperty
     def DEPRECATED(cls):  # noqa
         if cls._DEPRECATED is None:
@@ -1371,6 +1392,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._DEPRECATED
 
     _API_NODE = None
+    @final
     @classproperty
     def API_NODE(cls):  # noqa
         if cls._API_NODE is None:
@@ -1378,6 +1400,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._API_NODE
 
     _OUTPUT_NODE = None
+    @final
     @classproperty
     def OUTPUT_NODE(cls):  # noqa
         if cls._OUTPUT_NODE is None:
@@ -1385,6 +1408,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._OUTPUT_NODE
 
     _INPUT_IS_LIST = None
+    @final
     @classproperty
     def INPUT_IS_LIST(cls):  # noqa
         if cls._INPUT_IS_LIST is None:
@@ -1392,6 +1416,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._INPUT_IS_LIST
     _OUTPUT_IS_LIST = None
 
+    @final
     @classproperty
     def OUTPUT_IS_LIST(cls):  # noqa
         if cls._OUTPUT_IS_LIST is None:
@@ -1399,6 +1424,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._OUTPUT_IS_LIST
 
     _RETURN_TYPES = None
+    @final
     @classproperty
     def RETURN_TYPES(cls):  # noqa
         if cls._RETURN_TYPES is None:
@@ -1406,6 +1432,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._RETURN_TYPES
 
     _RETURN_NAMES = None
+    @final
     @classproperty
     def RETURN_NAMES(cls):  # noqa
         if cls._RETURN_NAMES is None:
@@ -1413,6 +1440,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._RETURN_NAMES
 
     _OUTPUT_TOOLTIPS = None
+    @final
     @classproperty
     def OUTPUT_TOOLTIPS(cls):  # noqa
         if cls._OUTPUT_TOOLTIPS is None:
@@ -1420,6 +1448,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         return cls._OUTPUT_TOOLTIPS
 
     _NOT_IDEMPOTENT = None
+    @final
     @classproperty
     def NOT_IDEMPOTENT(cls):  # noqa
         if cls._NOT_IDEMPOTENT is None:
@@ -1428,6 +1457,7 @@ class ComfyNodeV3(ComfyNodeInternal):
 
     FUNCTION = "EXECUTE_NORMALIZED"
 
+    @final
     @classmethod
     def INPUT_TYPES(cls, include_hidden=True, return_schema=False) -> dict[str, dict] | tuple[dict[str, dict], SchemaV3]:
         schema = cls.FINALIZE_SCHEMA()
@@ -1439,6 +1469,7 @@ class ComfyNodeV3(ComfyNodeInternal):
             return input, schema
         return input
 
+    @final
     @classmethod
     def FINALIZE_SCHEMA(cls):
         """Call define_schema and finalize it."""
@@ -1446,6 +1477,7 @@ class ComfyNodeV3(ComfyNodeInternal):
         schema.finalize()
         return schema
 
+    @final
     @classmethod
     def GET_SCHEMA(cls) -> SchemaV3:
         """Validate node class, finalize schema, validate schema, and set expected class properties."""
@@ -1487,16 +1519,58 @@ class ComfyNodeV3(ComfyNodeInternal):
             cls._OUTPUT_TOOLTIPS = output_tooltips
         cls.SCHEMA = schema
         return schema
-
-    @classmethod
-    def GET_NODE_INFO_V1(cls) -> dict[str, Any]:
-        schema = cls.GET_SCHEMA()
-        info = schema.get_v1_info(cls)
-        return asdict(info)
     #--------------------------------------------
     #############################################
 
 
+class ComfyNodeV3(_ComfyNodeBaseInternal):
+    """Common base class for all V3 nodes."""
+
+    @classmethod
+    @abstractmethod
+    def define_schema(cls) -> SchemaV3:
+        """Override this function with one that returns a SchemaV3 instance."""
+        raise NotImplementedError
+
+    @classmethod
+    @abstractmethod
+    def execute(cls, **kwargs) -> NodeOutput:
+        """Override this function with one that performs node's actions."""
+        raise NotImplementedError
+
+    @classmethod
+    def validate_inputs(cls, **kwargs) -> bool:
+        """Optionally, define this function to validate inputs; equivalent to V1's VALIDATE_INPUTS."""
+        raise NotImplementedError
+
+    @classmethod
+    def fingerprint_inputs(cls, **kwargs) -> Any:
+        """Optionally, define this function to fingerprint inputs; equivalent to V1's IS_CHANGED."""
+        raise NotImplementedError
+
+    @classmethod
+    def check_lazy_status(cls, **kwargs) -> list[str]:
+        """Optionally, define this function to return a list of input names that should be evaluated.
+
+        This basic mixin impl. requires all inputs.
+
+        :kwargs: All node inputs will be included here.  If the input is ``None``, it should be assumed that it has not yet been evaluated.  \
+            When using ``INPUT_IS_LIST = True``, unevaluated will instead be ``(None,)``.
+
+        Params should match the nodes execution ``FUNCTION`` (self, and all inputs by name).
+        Will be executed repeatedly until it returns an empty list, or all requested items were already evaluated (and sent as params).
+
+        Comfy Docs: https://docs.comfy.org/custom-nodes/backend/lazy_evaluation#defining-check-lazy-status
+        """
+        return [name for name in kwargs if kwargs[name] is None]
+
+    @final
+    @classmethod
+    def GET_BASE_CLASS(cls):
+        """DO NOT override this class. Will break things in execution.py."""
+        return ComfyNodeV3
+
+
 class NodeOutput:
     '''
     Standardized output of a node; can pass in any number of args and/or a UIOutput into 'ui' kwarg.

execution.py

@@ -28,6 +28,7 @@ from comfy_execution.graph import (
 )
 from comfy_execution.graph_utils import GraphBuilder, is_link
 from comfy_execution.validation import validate_node_input
+from comfy_api.internal import ComfyNodeInternal
 from comfy_api.v3 import io, helpers
 
 
@@ -54,7 +55,7 @@ class IsChangedCache:
         class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
         has_is_changed = False
         is_changed_name = None
-        if issubclass(class_def, io.ComfyNodeV3) and helpers.first_real_override(class_def, "fingerprint_inputs", base=io.ComfyNodeV3) is not None:
+        if issubclass(class_def, ComfyNodeInternal) and helpers.first_real_override(class_def, "fingerprint_inputs") is not None:
             has_is_changed = True
             is_changed_name = "fingerprint_inputs"
         elif hasattr(class_def, "IS_CHANGED"):
@@ -127,7 +128,7 @@ class CacheSet:
         return result
 
 def get_input_data(inputs, class_def, unique_id, outputs=None, dynprompt=None, extra_data={}):
-    is_v3 = issubclass(class_def, io.ComfyNodeV3)
+    is_v3 = issubclass(class_def, ComfyNodeInternal)
     if is_v3:
         valid_inputs, schema = class_def.INPUT_TYPES(include_hidden=False, return_schema=True)
     else:
@@ -224,7 +225,7 @@ def _map_node_over_list(obj, input_data_all, func, allow_interrupt=False, execut
             if pre_execute_cb is not None and index is not None:
                 pre_execute_cb(index)
             # V3
-            if isinstance(obj, io.ComfyNodeV3) or (io.is_class(obj) and issubclass(obj, io.ComfyNodeV3)):
+            if isinstance(obj, ComfyNodeInternal) or (io.is_class(obj) and issubclass(obj, ComfyNodeInternal)):
                 # if is just a class, then assign no resources or state, just create clone
                 if io.is_class(obj):
                     type_obj = obj
@@ -411,8 +412,8 @@ def execute(server, dynprompt, caches, current_item, extra_data, executed, promp
                 obj = class_def()
                 caches.objects.set(unique_id, obj)
 
-            if issubclass(class_def, io.ComfyNodeV3):
+            if issubclass(class_def, ComfyNodeInternal):
-                lazy_status_present = helpers.first_real_override(class_def, "check_lazy_status", base=io.ComfyNodeV3) is not None
+                lazy_status_present = helpers.first_real_override(class_def, "check_lazy_status") is not None
             else:
                 lazy_status_present = getattr(obj, "check_lazy_status", None) is not None
             if lazy_status_present:
@@ -674,9 +675,9 @@ def validate_inputs(prompt, item, validated):
 
     validate_function_inputs = []
     validate_has_kwargs = False
-    if issubclass(obj_class, io.ComfyNodeV3):
+    if issubclass(obj_class, ComfyNodeInternal):
         validate_function_name = "validate_inputs"
-        validate_function = helpers.first_real_override(obj_class, validate_function_name, base=io.ComfyNodeV3)
+        validate_function = helpers.first_real_override(obj_class, validate_function_name)
     else:
         validate_function_name = "VALIDATE_INPUTS"
         validate_function = getattr(obj_class, validate_function_name, None)

server.py

@@ -29,7 +29,7 @@ import comfy.model_management
 import node_helpers
 from comfyui_version import __version__
 from app.frontend_management import FrontendManager
-from comfy_api.v3.io import ComfyNodeV3
+from comfy_api.internal import ComfyNodeInternal
 
 from app.user_manager import UserManager
 from app.model_manager import ModelFileManager
@@ -555,7 +555,7 @@ class PromptServer():
 
         def node_info(node_class):
             obj_class = nodes.NODE_CLASS_MAPPINGS[node_class]
-            if issubclass(obj_class, ComfyNodeV3):
+            if issubclass(obj_class, ComfyNodeInternal):
                 return obj_class.GET_NODE_INFO_V1()
             info = {}
             info['input'] = obj_class.INPUT_TYPES()