comfyui-frontend-extensions

1# ComfyUI v2 Frontend Extension API
2 
3The v2 extension API is the published npm package `@comfyorg/extension-api`. It
4replaces the legacy `app.registerExtension()` / `nodeType.prototype` monkey-patching
5model with a typed, tree-shakeable, import-based API.
6 
7> If you are converting an existing v1 extension, read
8> [`references/migrate-v1-to-v2.md`](references/migrate-v1-to-v2.md) for a
9> pattern-by-pattern mapping.
10 
11## Mental model
12 
13| v1 (legacy) | v2 (`@comfyorg/extension-api`) |
14|-------------|-------------------------------|
15| One giant `app.registerExtension({...})` call | One `defineX` per concern, each independently disposable |
16| `window.app` / `app.*` globals | Direct `import` from the package; no `window.app` at module-eval time |
17| `nodeType.prototype.onExecuted = ...` patching | `node.on('executed', fn)` on a `NodeHandle` |
18| Mutate `widget.value`, assign `widget.callback` | `widget.setValue(v)` / `widget.on('valueChange', fn)` |
19| `api.addEventListener('execution_start', fn)` | `execution.on('start', fn)` (typed namespaces) |
20| Manual `removeEventListener` bookkeeping | Every subscription returns `Unsubscribe`; every `defineX` returns `DisposableHandle` |
21 
22Core principles baked into the API:
23 
24- **Import, don't reach for globals.** `import { defineNode } from '@comfyorg/extension-api'`. No `window.app` dependency at module evaluation time.
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