comfy-runtime 0.1.0

Minimal ComfyUI runtime for deploying custom nodes as microservices

comfy-runtime

Minimal ComfyUI Runtime for Custom Nodes

comfy-runtime is a minimal Python runtime for loading and executing ComfyUI nodes outside the full ComfyUI app. It is designed for packaging custom nodes into scripts, workers, and microservices. It is not a server, not a UI, and not a workflow engine.

Installation

pip install comfy-runtime
# Optional: built-in extra nodes
pip install comfy-builtin-nodes

Quick Start

import comfy_runtime

# Configure model paths (optional — has defaults)
comfy_runtime.configure(
    models_dir="/path/to/models",
    output_dir="/path/to/output",
)

# Execute a built-in node
result = comfy_runtime.execute_node(
    "EmptyLatentImage",
    width=512, height=512, batch_size=1,
)
latent = result[0]
print(f"Latent shape: {latent['samples'].shape}")

# Load extra nodes from a file
comfy_runtime.load_nodes_from_path("/path/to/my_custom_node.py")

# List all registered nodes
print(comfy_runtime.list_nodes())

# Get node info
info = comfy_runtime.get_node_info("EmptyLatentImage")
print(info["input_types"])

API Reference

configure(models_dir, output_dir, input_dir, temp_dir, vram_mode, device)

Configures runtime directories and device flags. This must be called before importing comfy.model_management.

execute_node(class_type, **kwargs) -> tuple

Runs one registered node and returns its output tuple. Handles both V1 and V3 node styles transparently.

create_node_instance(class_type) -> object

Creates a reusable instance of a registered node class. Useful for stateful nodes.

register_node(class_type, node_cls, display_name)

Registers a node class manually under a given class type.

load_nodes_from_path(path) -> list[str]

Loads nodes from a .py file or a directory of Python files. Supports both V1 mapping based nodes and V3 entrypoint based nodes.

list_nodes() -> list[str]

Returns all registered node class names.

get_node_info(class_type) -> dict

Returns public metadata for a node, including input types, return types, category, and execution method.

unregister_node(class_type)

Removes a registered node from the runtime registry.

get_config() -> dict

Returns the current runtime configuration.

Exceptions

• NodeNotFoundError
• NodeExecutionError

Microservice Example

# Example: wrapping a node with FastAPI
from fastapi import FastAPI
import comfy_runtime

app = FastAPI()
comfy_runtime.configure(models_dir="/data/models", output_dir="/data/output")

@app.post("/generate")
def generate(width: int = 512, height: int = 512):
    result = comfy_runtime.execute_node(
        "EmptyLatentImage", width=width, height=height, batch_size=1,
    )
    return {"shape": list(result[0]["samples"].shape)}

Memory Management

from comfy.model_management import soft_empty_cache, cleanup_models
soft_empty_cache()  # Free unused VRAM

Limitations

• Single-node execution only, no workflow graph
• Single-process only, no interrupt signaling across processes
• No built-in HTTP server, wrap it with FastAPI or gRPC yourself
• configure() must be called before importing model_management

License

GPL-3.0, same as ComfyUI