ComfyUI/web/extensions/logging.js.example

import { app } from "../scripts/app.js";

const ext = {
	name: "Example.LoggingExtension",
	async init(app) {
		// Any initial setup to run as soon as the page loads
		console.log("[logging]", "extension init");
	},
	async setup(app) {
		// Any setup to run after the app is created
		console.log("[logging]", "extension setup");
	},
	async addCustomNodeDefs(defs, app) {
		// Add custom node definitions
		// These definitions will be configured and registered automatically
		// defs is a lookup core nodes, add yours into this
		console.log("[logging]", "add custom node definitions", "current nodes:", Object.keys(defs));
	},
	async getCustomWidgets(app) {
		// Return custom widget types
		// See ComfyWidgets for widget examples
		console.log("[logging]", "provide custom widgets");
	},
	async beforeRegisterNodeDef(nodeType, nodeData, app) {
		// Run custom logic before a node definition is registered with the graph
		console.log("[logging]", "before register node: ", nodeType, nodeData);

		// This fires for every node definition so only log once
		delete ext.beforeRegisterNodeDef;
	},
	async registerCustomNodes(app) {
		// Register any custom node implementations here allowing for more flexability than a custom node def
		console.log("[logging]", "register custom nodes");
	},
	loadedGraphNode(node, app) {
		// Fires for each node when loading/dragging/etc a workflow json or png
		// If you break something in the backend and want to patch workflows in the frontend
		// This is the place to do this
		console.log("[logging]", "loaded graph node: ", node);

		// This fires for every node on each load so only log once
		delete ext.loadedGraphNode;
	},
	nodeCreated(node, app) {
		// Fires every time a node is constructed
		// You can modify widgets/add handlers/etc here
		console.log("[logging]", "node created: ", node);

		// This fires for every node so only log once
		delete ext.nodeCreated;
	}
};

app.registerExtension(ext);