mcpField
C
comfyui-node-migration

comfyui-node-migration

github.com/jtydhr88Development308108 installsUpdated 2w ago
Repository

About comfyui-node-migration

A migration guide skill for converting existing ComfyUI V1 nodes to the V3 API. It maps legacy node schemas, methods, inputs, outputs, and registration to V3 patterns, with examples and notes on common pitfalls.

Key features

  1. 01Map V1 properties to V3 schema fields
  2. 02Convert input types to typed V3 inputs
  3. 03Update execution and validation methods
  4. 04Replace tuple returns with NodeOutput
  5. 05Migrate node registration to ComfyExtension
  6. 06Review V3 behavior and migration pitfalls

Use cases

  1. 01Port a V1 custom node to the V3 API
  2. 02Convert node inputs and outputs during an upgrade
  3. 03Update execution, validation, and hidden-input access
  4. 04Check registration changes before migrating a node

Install

Copy the command and run it in a terminal.

$npx skills add https://github.com/jtydhr88/comfyui-custom-node-skills --skill comfyui-node-migration

After installing, type/comfyui-node-migrationin Claude Code to confirm it loaded.

Details

From the project README

ComfyUI V1 → V3 Migration Guide

Migrate existing V1 nodes to the modern V3 API. V3 uses classmethods, typed inputs/outputs, and ComfyExtension registration.

Migration Checklist

  1. Change base class to io.ComfyNode
  2. Replace INPUT_TYPES() with define_schema() returning io.Schema
  3. Rename execution function to execute and make it a @classmethod
  4. Replace return tuples with io.NodeOutput(...)
  5. Replace IS_CHANGED with fingerprint_inputs
  6. Replace VALIDATE_INPUTS with validate_inputs
  7. Convert check_lazy_status to @classmethod
  8. Replace NODE_CLASS_MAPPINGS with ComfyExtension + comfy_entrypoint()
  9. Access hidden inputs via cls.hidden instead of kwargs
  10. Remove __init__ methods (no instance state in V3)

Side-by-Side Comparison

V1 (Before)
import torch

class ImageInvertV1:
    CATEGORY = "image"
    FUNCTION = "invert"
    RETURN_TYPES = ("IMAGE",)
    RETURN_NAMES = ("image",)
    OUTPUT_TOOLTIPS = ("The inverted image",)
    DESCRIPTION = "Inverts image colors"

    @classmethod
    def INPUT_TYPES(s):
        return {
            "required": {
                "image": ("IMAGE",),
                "strength": ("FLOAT", {
                    "default": 1.0,
                    "min": 0.0,
                    "max": 1.0,
                    "step": 0.01,
                }),
            },
            "optional": {
                "mask": ("MASK",),
            },
            "hidden": {
                "unique_id": "UNIQUE_ID",
            },
        }

    @classmethod
    def IS_CHANGED(s, image, strength, mask=None, unique_id=None):
        return strength

    @classmethod
    def VALIDATE_INPUTS(s, image, strength, mask=None, unique_id=None):
        if strength < 0:
            return "Strength must be non-negative"
        return True

    def invert(self, image, strength, mask=None, unique_id=None):
        inverted = 1.0 - image
        result = image * (1 - strength) + inverted * strength
        if mask is not None:
            result = image * (1 - mask.unsqueeze(-1)) + result * mask.unsqueeze(-1)
        return (result,)

NODE_CLASS_MAPPINGS = {"ImageInvertV1": ImageInvertV1}
NODE_DISPLAY_NAME_MAPPINGS = {"ImageInvertV1": "Invert Image"}
V3 (After)
import torch
from typing_extensions import override
from comfy_api.latest import ComfyExtension, io

class ImageInvertV3(io.ComfyNode):
    @classmethod
    def define_schema(cls):
        return io.Schema(
            node_id="ImageInvertV3",
            display_name="Invert Image",
            description="Inverts image colors",
            category="image",
            inputs=[
                io.Image.Input("image"),
                io.Float.Input("strength", default=1.0, min=0.0, max=1.0, step=0.01),
                io.Mask.Input("mask", optional=True),
            ],
            outputs=[
                io.Image.Output("IMAGE", tooltip="The inverted image"),
            ],
            hidden=[io.Hidden.unique_id],
        )

    @classmethod
    def fingerprint_inputs(cls, image, strength, mask=None):
        return strength

    @classmethod
    def validate_inputs(cls, image, strength, mask=None):
        if strength < 0:
            return "Strength must be non-negative"
        return True

    @classmethod
    def execute(cls, image, strength, mask=None):
        node_id = cls.hidden.unique_id  # access hidden via cls.hidden

        inverted = 1.0 - image
        result = image * (1 - strength) + inverted * strength
        if mask is not None:
            result = image * (1 - mask.unsqueeze(-1)) + result * mask.unsqueeze(-1)
        return io.NodeOutput(result)


class MyExtension(ComfyExtension):
    @override
    async def get_node_list(self) -> list[type[io.ComfyNode]]:
        return [ImageInvertV3]

async def comfy_entrypoint() -> MyExtension:
    return MyExtension()

Property Mapping

V1 PropertyV3 Equivalent
CATEGORY = "image"io.Schema(category="image")
FUNCTION = "my_func"Always execute (fixed name)
RETURN_TYPES = ("IMAGE",)outputs=[io.Image.Output()]
RETURN_NAMES = ("image",)outputs=[io.Image.Output(display_name="image")]
OUTPUT_TOOLTIPS = ("tip",)outputs=[io.Image.Output(tooltip="tip")]
OUTPUT_NODE = Trueio.Schema(is_output_node=True)
DEPRECATED = Trueio.Schema(is_deprecated=True)
EXPERIMENTAL = Trueio.Schema(is_experimental=True)
API_NODE = Trueio.Schema(is_api_node=True)
NOT_IDEMPOTENT = Trueio.Schema(not_idempotent=True)
DESCRIPTION = "..."io.Schema(description="...")
SEARCH_ALIASES = [...]io.Schema(search_aliases=[...])
INPUT_IS_LIST = Trueio.Schema(is_input_list=True)
OUTPUT_IS_LIST = (True,)io.Image.Output(is_output_list=True)
DEV_ONLY = Trueio.Schema(is_dev_only=True)
ESSENTIALS_CATEGORY = "Basic"io.Schema(essentials_category="Basic")

Input Type Mapping

V1 InputV3 Input
("IMAGE",)io.Image.Input("id")
("MASK",)io.Mask.Input("id")
("LATENT",)io.Latent.Input("id")
("MODEL",)io.Model.Input("id")
("CLIP",)io.Clip.Input("id")
("VAE",)io.Vae.Input("id")
("CONDITIONING",)io.Conditioning.Input("id")
("INT", {"default": 0, ...})io.Int.Input("id", default=0, ...)
("FLOAT", {"default": 1.0, ...})io.Float.Input("id", default=1.0, ...)
("STRING", {"multiline": True})io.String.Input("id", multiline=True)
("BOOLEAN", {"default": True})io.Boolean.Input("id", default=True)
(["opt1", "opt2"],)io.Combo.Input("id", options=["opt1", "opt2"])
("CONTROL_NET",)io.ControlNet.Input("id")
("CLIP_VISION",)io.ClipVision.Input("id")
("CLIP_VISION_OUTPUT",)io.ClipVisionOutput.Input("id")
("STYLE_MODEL",)io.StyleModel.Input("id")
("GLIGEN",)io.Gligen.Input("id")
("UPSCALE_MODEL",)io.UpscaleModel.Input("id")
("AUDIO",)io.Audio.Input("id")
("VIDEO",)io.Video.Input("id")
("SAMPLER",)io.Sampler.Input("id")
("SIGMAS",)io.Sigmas.Input("id")
("NOISE",)io.Noise.Input("id")
("GUIDER",)io.Guider.Input("id")
("HOOKS",)io.Hooks.Input("id")
("LORA_MODEL",)io.LoraModel.Input("id")
("MESH",)io.Mesh.Input("id")
("VOXEL",)io.Voxel.Input("id")
("FILE_3D",)io.File3DAny.Input("id")
("FILE_3D_GLB",)io.File3DGLB.Input("id")
("SVG",)io.SVG.Input("id")
("COLOR",)io.Color.Input("id")
("BOUNDING_BOX",)io.BoundingBox.Input("id")
("CURVE",)io.Curve.Input("id")
("LATENT_UPSCALE_MODEL",)io.LatentUpscaleModel.Input("id")
("MODEL_PATCH",)io.ModelPatch.Input("id")
("HOOK_KEYFRAMES",)io.HookKeyframes.Input("id")
("AUDIO_ENCODER",)io.AudioEncoder.Input("id")
("AUDIO_ENCODER_OUTPUT",)io.AudioEncoderOutput.Input("id")
("TRACKS",)io.Tracks.Input("id")
("LOSS_MAP",)io.LossMap.Input("id")
("TIMESTEPS_RANGE",)io.TimestepsRange.Input("id")
("LATENT_OPERATION",)io.LatentOperation.Input("id")
("WEBCAM",)io.Webcam.Input("id")
("PHOTOMAKER",)io.Photomaker.Input("id")
("WAN_CAMERA_EMBEDDING",)io.WanCameraEmbedding.Input("id")
("LOAD_3D",)io.Load3D.Input("id")
("LOAD_3D_ANIMATION",)io.Load3DAnimation.Input("id")
("LOAD3D_CAMERA",)io.Load3DCamera.Input("id")
("FILE_3D_GLTF",)io.File3DGLTF.Input("id")
("FILE_3D_FBX",)io.File3DFBX.Input("id")
("FILE_3D_OBJ",)io.File3DOBJ.Input("id")
("FILE_3D_STL",)io.File3DSTL.Input("id")
("FILE_3D_USDZ",)io.File3DUSDZ.Input("id")
("FILE_3D_PLY",)io.File3DPLY.Input("id")
("FILE_3D_SPLAT",)io.File3DSPLAT.Input("id")
("FILE_3D_SPZ",)io.File3DSPZ.Input("id")
("FILE_3D_KSPLAT",)io.File3DKSPLAT.Input("id")
("FILE_3D_SPLAT_ANY",)io.File3DSplatAny.Input("id")
("FILE_3D_POINT_CLOUD_ANY",)io.File3DPointCloudAny.Input("id")
("SPLAT",)io.Splat.Input("id")
("LOAD3D_MODEL_INFO",)io.Load3DModelInfo.Input("id")
("BACKGROUND_REMOVAL",)io.BackgroundRemoval.Input("id")
("DICT",)io.Dict.Input("id")
("ARRAY",)io.Array.Input("id")
("COLORS",)io.Colors.Input("id")
("BOUNDING_BOXES",)io.BoundingBoxes.Input("id")
("RANGE",)io.Range.Input("id")
("HISTOGRAM",)io.Histogram.Input("id")
("POINT",)io.Point.Input("id")
("FACE_ANALYSIS",)io.FaceAnalysis.Input("id")
("BBOX",)io.BBOX.Input("id")
("SEGS",)io.SEGS.Input("id")
("IMAGECOMPARE",)io.ImageCompare.Input("id")
("LAYERS",)io.Layers.Input("id")
("COMPOSITOR",)io.Compositor.Input("id")
("CAMERA_INFO_STATE",)io.CameraInfoState.Input("id")
("VIDEO_EDIT",)io.VideoEdit.Input("id", features=["trim", "crop"])
("RESOLUTION_PREVIEW",)io.ResolutionPreview.Input("id")
("*",)io.AnyType.Input("id") or io.MultiType.Input("id", types=[...])

Method Migration

Execute Method
# V1: instance method with custom name
class V1Node:
    FUNCTION = "process"
    def process(self, image, value):
        return (result,)

# V3: classmethod named "execute", returns NodeOutput
class V3Node(io.ComfyNode):
    @classmethod
    def execute(cls, image, value):
        return io.NodeOutput(result)
IS_CHANGED → fingerprint_inputs
# V1
@classmethod
def IS_CHANGED(s, **kwargs):
    return float("NaN")  # always re-execute

# V3
@classmethod
def fingerprint_inputs(cls, **kwargs):
    import time
    return time.time()  # always re-execute
VALIDATE_INPUTS → validate_inputs
# V1
@classmethod
def VALIDATE_INPUTS(s, input_types=None, **kwargs):
    return True

# V3
@classmethod
def validate_inputs(cls, input_types=None, **kwargs):
    return True
check_lazy_status
# V1: instance method
def check_lazy_status(self, **kwargs):
    return ["input_name"]

# V3: classmethod
@classmethod
def check_lazy_status(cls, **kwargs):
    return ["input_name"]
Hidden Inputs
# V1: received as kwargs
def execute(self, image, unique_id=None, prompt=None):
    node_id = unique_id

# V3: accessed via cls.hidden
@classmethod
def execute(cls, image):
    node_id = cls.hidden.unique_id
    prompt = cls.hidden.prompt

Registration Migration

# V1
NODE_CLASS_MAPPINGS = {
    "Node1": Node1Class,
    "Node2": Node2Class,
}
NODE_DISPLAY_NAME_MAPPINGS = {
    "Node1": "Node One",
    "Node2": "Node Two",
}
WEB_DIRECTORY = "./js"

# V3
from typing_extensions import override
from comfy_api.latest import ComfyExtension, io

class MyExtension(ComfyExtension):
    @override
    async def get_node_list(self) -> list[type[io.ComfyNode]]:
        return [Node1Class, Node2Class]

    @override
    async def on_load(self):
        # Optional: initialization logic
        pass

async def comfy_entrypoint() -> MyExtension:
    return MyExtension()

# WEB_DIRECTORY still works the same way for JS extensions
WEB_DIRECTORY = "./js"

Output Node Migration

# V1
class V1SaveNode:
    RETURN_TYPES = ()
    OUTPUT_NODE = True
    FUNCTION = "save"

    def save(self, images, prefix):
        # ... save logic ...
        return {"ui": {"images": results}}

# V3
from comfy_api.latest import io, ui

class V3SaveNode(io.ComfyNode):
    @classmethod
    def define_schema(cls):
        return io.Schema(
            node_id="V3SaveNode",
            display_name="Save",
            category="image",
            is_output_node=True,
            inputs=[
                io.Image.Input("images"),
                io.String.Input("prefix", default="output"),
            ],
            outputs=[],
            hidden=[io.Hidden.prompt, io.Hidden.extra_pnginfo],
        )

    @classmethod
    def execute(cls, images, prefix):
        saved = ui.ImageSaveHelper.get_save_images_ui(images, prefix, cls=cls)
        return io.NodeOutput(ui=saved)

Key Gotchas

  1. No instance state: V3 execute is a classmethod. Don't store state on self. Use external storage if needed.
  2. Fixed method name: Always execute, never custom names.
  3. Hidden access changed: Use cls.hidden.prompt not function parameters.
  4. Return type changed: io.NodeOutput(val) not (val,).
  5. Optional inputs: Use =None default in execute params, not separate "optional" dict.
  6. Async support: V3 execute can be async def execute(cls, ...).

See Also

  • comfyui-node-basics - V3 node fundamentals
  • comfyui-node-packaging - Project structure
  • comfyui-node-lifecycle - Execution lifecycle differences

Comments

Markdown supported