diff --git a/web/extensions/core/subflow.js b/web/extensions/core/subflow.js
index 2a3aa3947..cfa740b76 100644
--- a/web/extensions/core/subflow.js
+++ b/web/extensions/core/subflow.js
@@ -8,10 +8,21 @@ app.registerExtension({
     if (!node.widgets) return;
     if (node.widgets[0].name !== "subflow_name") return;
 
-    const refreshPins = (subflowNodes) => {
+    let outputSlots = []; // (int (node), int (slot))
+    let inputSlots = [];
+
+    const refreshPins = async (subflowName) => {
+      const subflowData = await api.getSubflow(subflowName);
+      if (!subflowData.subflow) return;
+
+      inputSlots = [];
+      outputSlots = [];
+
+      const subflowNodes = subflowData.subflow.nodes
+      updateSubflowPrompt(subflowData.subflow);
       // remove all existing pins
-      const numInputs = node.inputs.length;
-      const numOutputs = node.outputs.length;
+      const numInputs = node.inputs?.length ?? 0;
+      const numOutputs = node.outputs?.length ?? 0;
       for(let i = numInputs-1; i > -1; i--) {
         node.removeInput(i);
       }
@@ -22,33 +33,41 @@ app.registerExtension({
       for (const subflowNode of subflowNodes) {
         const exports = subflowNode.properties.exports;
         if (exports) {
+          let pinNum = 0;
           for (const inputRef of exports.inputs) {
             const input = subflowNode.inputs.find(q => q.name === inputRef);
             if (!input) continue;
             node.addInput(input.name, input.type);
+            inputSlots.push([subflowNode.id, pinNum]);
+            pinNum++;
           }
+          pinNum = 0;
           for (const outputRef of exports.outputs) {
             const output = subflowNode.outputs.find(q => q.name === outputRef);
             if (!output) continue;
             node.addOutput(output.name, output.type);
+            outputSlots.push([subflowNode.id, pinNum]);
+            pinNum++;
           }
         }
       }
     };
 
-    node.onConfigure = async function () {
-      const subflowData = await api.getSubflow(node.widgets[0].value);
-      if (subflowData.subflow) {
-        refreshPins(subflowData.subflow.nodes);
-      }
-		};
+    const updateSubflowPrompt = (subflow) => {
+      node.subflow = subflow;
+    };
 
-    node.widgets[0].callback = async function (subflowName) {
-      const subflowData = await api.getSubflow(subflowName);
-      if (subflowData.subflow) {
-        refreshPins(subflowData.subflow.nodes);
-      }
-		};
+    // node.onSerialize = () =>
+    node.onConfigure = () => refreshPins(node.widgets[0].value);
+    node.widgets[0].callback = (subflowName) => refreshPins(subflowName);
+
+    node.getExportedOutput = (slot) => {
+      return outputSlots[slot];
+    };
+
+    node.getExportedInput = (slot) => {
+      return inputSlots[slot];
+    };
 
   }
 });
diff --git a/web/lib/litegraph.core.js b/web/lib/litegraph.core.js
index df07cc220..b9fc9ed97 100644
--- a/web/lib/litegraph.core.js
+++ b/web/lib/litegraph.core.js
@@ -2618,6 +2618,9 @@
         if (this.shape) {
             o.shape = this.shape;
         }
+        if (this.subflow) {
+            o.subflow = this.subflow;
+        }
 
         if (this.onSerialize) {
             if (this.onSerialize(o)) {
diff --git a/web/scripts/app.js b/web/scripts/app.js
index 5b9e76580..92032608d 100644
--- a/web/scripts/app.js
+++ b/web/scripts/app.js
@@ -1467,15 +1467,21 @@ export class ComfyApp {
 		}
 	}
 
+	
+
+
 	/**
 	 * Converts the current graph workflow for sending to the API
 	 * @returns The workflow and node links
 	 */
-	async graphToPrompt() {
-		const workflow = this.graph.serialize();
+	async graphToPrompt(graph=this.graph) {
+		let subflowNodeIdOffset = graph.last_node_id;
+		const subflowIdMapping = {};
+		const workflow = graph.serialize();
 		const output = {};
+
 		// Process nodes in order of execution
-		for (const node of this.graph.computeExecutionOrder(false)) {
+		for (const node of graph.computeExecutionOrder(false)) {
 			const n = workflow.nodes.find((n) => n.id === node.id);
 
 			if (node.isVirtualNode) {
@@ -1491,6 +1497,28 @@ export class ComfyApp {
 				continue;
 			}
 
+			if (node.subflow) {
+				const subgraph = new LGraph();
+				subgraph.configure(node.subflow);
+				const subgraphPrompt = (await this.graphToPrompt(subgraph)).output;
+
+				// replace ids to not conflict with existing ids
+				for ( const [key, value] of Object.entries(subgraphPrompt) ) {
+					for ( const [inputKey, inputValue] of Object.entries(value.inputs) ) {
+						if (Array.isArray(inputValue)) {
+							value.inputs[inputKey][0] = String(Number(value.inputs[inputKey][0]) + subflowNodeIdOffset);
+						}
+					}
+					output[String(Number(key) + subflowNodeIdOffset)] = {
+						...value,
+						for_subflow: String(node.id) // keep reference of parent node
+					};
+				}
+				subflowIdMapping[node.id] = subflowNodeIdOffset;
+
+				subflowNodeIdOffset += Object.keys(node.subflow).length;
+			}
+
 			const inputs = {};
 			const widgets = node.widgets;
 
@@ -1504,6 +1532,17 @@ export class ComfyApp {
 				}
 			}
 
+			const getInputRef = (inputNode, inputSlot) => {
+				if (inputNode.type == "Subflow") {
+					// input should be mapped to inner node
+					const [ localOriginId, originSlot ] = inputNode.getExportedOutput(inputSlot);
+					const originId = subflowIdMapping[inputNode.id] + localOriginId;
+					return [String(originId), parseInt(originSlot)];
+				}
+
+				return [String(inputNode.id), parseInt(inputSlot)];
+			};
+
 			// Store all node links
 			for (let i in node.inputs) {
 				let parent = node.getInputNode(i);
@@ -1543,15 +1582,24 @@ export class ComfyApp {
 					}
 
 					if (link) {
-						inputs[node.inputs[i].name] = [String(link.origin_id), parseInt(link.origin_slot)];
+						if (node.type == "Subflow") {
+							// inner node's input should be used
+							const [ localTargetId, targetSlot ] = node.getExportedInput(link.target_slot);
+							const targetId = subflowIdMapping[node.id] + localTargetId;
+							output[ String(targetId) ].inputs[ node.inputs[targetSlot].name ] = getInputRef(parent, link.origin_slot);
+						}
+
+						inputs[node.inputs[i].name] = getInputRef(parent, link.origin_slot);
 					}
 				}
 			}
 
-			output[String(node.id)] = {
-				inputs,
-				class_type: node.comfyClass,
-			};
+			if (node.type != "Subflow") {
+				output[String(node.id)] = {
+					inputs,
+					class_type: node.comfyClass,
+				};
+			}
 		}
 
 		// Remove inputs connected to removed nodes