Show HN: Comfy Nodekit – build/serialize ComfyUI workflows in Python

13 hours ago 1

Utilities for working with ComfyUI node graphs from Python. The project provides typed wrappers around ComfyUI nodes, lightweight graph primitives, and helpers for exporting a workflow back to the JSON format that the ComfyUI API expects.

  • Typed Node and Edge models (Pydantic) for tracking dependencies and serialising graphs.
  • A generated nodes.py module that mirrors the ComfyUI node catalogue with Python callables.
  • Tooling (nodes_to_py.py) to regenerate those bindings directly from a running ComfyUI server.
  • Example workflow builder scaffolding that shows how to stitch nodes into higher-level pipelines.
  • Python 3.12+
  • requests and pydantic (installed automatically when the package is installed)
  • Access to a running ComfyUI server when regenerating node bindings
uv add comfy_nodekit # pip install comfy_nodekit

Generate node bindings (required before usage)

Before using the factory functions, generate nodes.py from your running ComfyUI:

uv run python -m comfy_nodekit.nodes_to_py http://127.0.0.1:8188/ # or: just run

If you omit the URL, it defaults to http://127.0.0.1:8188/. This writes nodes.py based on the server's /object_info. Re-run whenever your ComfyUI nodes change.

You can also generate from a local JSON schema (previously fetched from /object_info):

# From default server (same as before) uv run python -m comfy_nodekit.nodes_to_py # From a specific server and write to a custom path uv run python -m comfy_nodekit.nodes_to_py http://127.0.0.1:8188/ ./nodes.py # From a local JSON file and write to a custom path uv run python -m comfy_nodekit.nodes_to_py ./object_info.json ./nodes.py

Create nodes the same way you would wire a ComfyUI graph. Each factory function from nodes.py returns a typed Edge that keeps track of its originating node. When you are ready to export the workflow, grab the source_node of your terminal edge and call build_json_workflow().

from comfy_nodekit.models import Edge from comfy_nodekit.nodes import ( CheckpointLoaderSimple, CLIPTextEncode, EmptyLatentImage, KSampler, VAEDecode, ) # Load base models model, clip, vae = CheckpointLoaderSimple("juggernautXL_v9Rdphoto2Lightning.safetensors") # Encode prompts positive = CLIPTextEncode(text="a cinematic portrait of an astronaut", clip=clip) negative = CLIPTextEncode(text="", clip=clip) # Create latents and sample latent = EmptyLatentImage(width=1024, height=1024, batch_size=1) sampled = KSampler( model=model, seed=42, steps=20, cfg=7.5, sampler_name="euler", scheduler="normal", positive=positive, negative=negative, latent_image=latent, denoise=1.0, ) decoded = VAEDecode(samples=sampled, vae=vae) # Export to ComfyUI JSON format workflow = decoded.source_node.build_json_workflow() # Optionally: print or send to a ComfyUI server import json print(json.dumps(workflow, indent=2))
  • The generator downloads the node schema, sanitises type names, and rewrites nodes.py with updated classes and helper functions.
  • The just recipe just run wraps the generation command if you prefer using just.

Thanks to ComfyScript for inspiration and prior art.

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