diff --git a/execution.py b/execution.py
index 47d58b9d..7063bd95 100644
--- a/execution.py
+++ b/execution.py
@@ -34,10 +34,12 @@ def get_input_data(inputs, class_def, unique_id, outputs={}, prompt={}, extra_da
         for x in h:
             if h[x] == "PROMPT":
                 input_data_all[x] = [prompt]
-            if h[x] == "EXTRA_PNGINFO":
+            elif h[x] == "EXTRA_PNGINFO":
                 input_data_all[x] = [extra_data.get('extra_pnginfo', None)]
-            if h[x] == "UNIQUE_ID":
+            elif h[x] == "UNIQUE_ID":
                 input_data_all[x] = [unique_id]
+            elif h[x] == "EXTRA_DATA":
+                input_data_all[x] = [extra_data.get(x, None)]
     return input_data_all
 
 def map_node_over_list(obj, input_data_all, func, allow_interrupt=False):
diff --git a/tests-ui/tests/extensions.test.js b/tests-ui/tests/extensions.test.js
index 159e5113..b854ead0 100644
--- a/tests-ui/tests/extensions.test.js
+++ b/tests-ui/tests/extensions.test.js
@@ -25,6 +25,7 @@ describe("extensions", () => {
 			nodeCreated: jest.fn(),
 			beforeConfigureGraph: jest.fn(),
 			afterConfigureGraph: jest.fn(),
+			// provideExtraData not testable without prompt.
 		};
 
 		const { app, ez, graph } = await start({
diff --git a/web/scripts/api.js b/web/scripts/api.js
index 8c8155be..10c7bd24 100644
--- a/web/scripts/api.js
+++ b/web/scripts/api.js
@@ -194,12 +194,14 @@ class ComfyApi extends EventTarget {
 	 *
 	 * @param {number} number The index at which to queue the prompt, passing -1 will insert the prompt at the front of the queue
 	 * @param {object} prompt The prompt data to queue
+	 * @param {object} extra_data extra data added to the prompt request
 	 */
-	async queuePrompt(number, { output, workflow }) {
+	async queuePrompt(number, { output, workflow }, extra_data) {
+		extra_data = { extra_pnginfo: { workflow }, ...extra_data }
 		const body = {
 			client_id: this.clientId,
 			prompt: output,
-			extra_data: { extra_pnginfo: { workflow } },
+			extra_data,
 		};
 
 		if (number === -1) {
diff --git a/web/scripts/app.js b/web/scripts/app.js
index a516be70..38e1e4cd 100644
--- a/web/scripts/app.js
+++ b/web/scripts/app.js
@@ -2119,7 +2119,9 @@ export class ComfyApp {
 					const p = await this.graphToPrompt();
 
 					try {
-						const res = await api.queuePrompt(number, p);
+						const extra_datas = await this.#invokeExtensionsAsync("provideExtraData");
+						const extra_data = Object.assign({}, ...extra_datas)
+						const res = await api.queuePrompt(number, p, extra_data);
 						this.lastNodeErrors = res.node_errors;
 						if (this.lastNodeErrors.length > 0) {
 							this.canvas.draw(true, true);
diff --git a/web/types/comfy.d.ts b/web/types/comfy.d.ts
index f7129b55..86695e9c 100644
--- a/web/types/comfy.d.ts
+++ b/web/types/comfy.d.ts
@@ -58,6 +58,11 @@ export interface ComfyExtension {
 	 * @param app The ComfyUI app instance
 	 */
 	nodeCreated(node: LGraphNode, app: ComfyApp);
+	/**
+	 * Allows the extension to add custom extra_data to the prompt queue
+	 * @param app The ComfyUI app instance
+	 */
+	provideExtraData(app: ComfyApp): Promise<unknown>;
 }
 
 export type ComfyObjectInfo = {