diff --git a/packages/types/src/api.ts b/packages/types/src/api.ts
index b8d28dc429..6fb181b573 100644
--- a/packages/types/src/api.ts
+++ b/packages/types/src/api.ts
@@ -5,7 +5,7 @@ import type { RooCodeSettings } from "./global-settings.js"
 import type { ProviderSettingsEntry, ProviderSettings } from "./provider-settings.js"
 import type { ClineMessage, TokenUsage } from "./message.js"
 import type { ToolUsage, ToolName } from "./tool.js"
-import type { IpcMessage, IpcServerEvents } from "./ipc.js"
+import type { IpcMessage, IpcServerEvents, IsSubtask } from "./ipc.js"
 
 // TODO: Make sure this matches `RooCodeEvents` from `@roo-code/types`.
 export interface RooCodeAPIEvents {
@@ -18,7 +18,7 @@ export interface RooCodeAPIEvents {
 	taskAskResponded: [taskId: string]
 	taskAborted: [taskId: string]
 	taskSpawned: [parentTaskId: string, childTaskId: string]
-	taskCompleted: [taskId: string, tokenUsage: TokenUsage, toolUsage: ToolUsage]
+	taskCompleted: [taskId: string, tokenUsage: TokenUsage, toolUsage: ToolUsage, isSubtask: IsSubtask]
 	taskTokenUsageUpdated: [taskId: string, tokenUsage: TokenUsage]
 	taskToolFailed: [taskId: string, toolName: ToolName, error: string]
 }
diff --git a/packages/types/src/ipc.ts b/packages/types/src/ipc.ts
index db3fa2ab29..28accde9de 100644
--- a/packages/types/src/ipc.ts
+++ b/packages/types/src/ipc.ts
@@ -4,6 +4,14 @@ import { clineMessageSchema, tokenUsageSchema } from "./message.js"
 import { toolNamesSchema, toolUsageSchema } from "./tool.js"
 import { rooCodeSettingsSchema } from "./global-settings.js"
 
+/**
+ * isSubtaskSchema
+ */
+export const isSubtaskSchema = z.object({
+	isSubtask: z.boolean(),
+})
+export type IsSubtask = z.infer<typeof isSubtaskSchema>
+
 /**
  * RooCodeEvent
  */
@@ -41,7 +49,7 @@ export const rooCodeEventsSchema = z.object({
 	[RooCodeEventName.TaskAskResponded]: z.tuple([z.string()]),
 	[RooCodeEventName.TaskAborted]: z.tuple([z.string()]),
 	[RooCodeEventName.TaskSpawned]: z.tuple([z.string(), z.string()]),
-	[RooCodeEventName.TaskCompleted]: z.tuple([z.string(), tokenUsageSchema, toolUsageSchema]),
+	[RooCodeEventName.TaskCompleted]: z.tuple([z.string(), tokenUsageSchema, toolUsageSchema, isSubtaskSchema]),
 	[RooCodeEventName.TaskTokenUsageUpdated]: z.tuple([z.string(), tokenUsageSchema]),
 	[RooCodeEventName.TaskToolFailed]: z.tuple([z.string(), toolNamesSchema, z.string()]),
 })
diff --git a/src/extension/api.ts b/src/extension/api.ts
index e4cab41d29..b378c5800c 100644
--- a/src/extension/api.ts
+++ b/src/extension/api.ts
@@ -218,7 +218,11 @@ export class API extends EventEmitter<RooCodeEvents> implements RooCodeAPI {
 			})
 
 			cline.on("taskCompleted", async (_, tokenUsage, toolUsage) => {
-				this.emit(RooCodeEventName.TaskCompleted, cline.taskId, tokenUsage, toolUsage)
+				let isSubtask = false
+				if (cline.rootTask != undefined) {
+					isSubtask = true
+				}
+				this.emit(RooCodeEventName.TaskCompleted, cline.taskId, tokenUsage, toolUsage, { isSubtask: isSubtask })
 				this.taskMap.delete(cline.taskId)
 
 				await this.fileLog(