feat: show root orchestration cost tally for subtasks

webview-ui/src/components/chat/ChatView.tsx

@@ -505,7 +505,15 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 				text: currentTaskItem.id,
 			})
 		}
-	}, [taskTs, currentTaskItem?.id, currentTaskItem?.childIds])
+		// When viewing a subtask, also request aggregated costs for the root orchestration task
+		const rootId = currentTaskItem?.rootTaskId
+		if (taskTs && rootId && rootId !== currentTaskItem?.id) {
+			vscode.postMessage({
+				type: "getTaskWithAggregatedCosts",
+				text: rootId,
+			})
+		}
+	}, [taskTs, currentTaskItem?.id, currentTaskItem?.childIds, currentTaskItem?.rootTaskId])
 
 	useEffect(() => {
 		if (isHidden) {
@@ -1563,6 +1571,13 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 							)
 						}
 						parentTaskId={currentTaskItem?.parentTaskId}
+						rootOrchestrationCost={
+							currentTaskItem?.rootTaskId &&
+							currentTaskItem.rootTaskId !== currentTaskItem.id &&
+							aggregatedCostsMap.has(currentTaskItem.rootTaskId)
+								? aggregatedCostsMap.get(currentTaskItem.rootTaskId)!.totalCost
+								: undefined
+						}
 						costBreakdown={
 							currentTaskItem?.id && aggregatedCostsMap.has(currentTaskItem.id)
 								? getCostBreakdownIfNeeded(aggregatedCostsMap.get(currentTaskItem.id)!, {

webview-ui/src/components/chat/TaskHeader.tsx

@@ -36,6 +36,7 @@ export interface TaskHeaderProps {
 	aggregatedCost?: number
 	hasSubtasks?: boolean
 	parentTaskId?: string
+	rootOrchestrationCost?: number
 	costBreakdown?: string
 	contextTokens: number
 	buttonsDisabled: boolean
@@ -53,6 +54,7 @@ const TaskHeader = ({
 	aggregatedCost,
 	hasSubtasks,
 	parentTaskId,
+	rootOrchestrationCost,
 	costBreakdown,
 	contextTokens,
 	buttonsDisabled,
@@ -315,6 +317,25 @@ const TaskHeader = ({
 									</StandardTooltip>
 								</>
 							)}
+							{typeof rootOrchestrationCost === "number" && rootOrchestrationCost > 0 && (
+								<>
+									<span>·</span>
+									<StandardTooltip
+										content={
+											<div>
+												{t("chat:costs.orchestrationTotal", {
+													cost: rootOrchestrationCost.toFixed(2),
+												})}
+											</div>
+										}
+										side="top"
+										sideOffset={8}>
+										<span className="text-vscode-descriptionForeground">
+											{t("chat:costs.orchestrationLabel")}: ${rootOrchestrationCost.toFixed(2)}
+										</span>
+									</StandardTooltip>
+								</>
+							)}
 						</div>
 					</div>
 				)}
@@ -447,6 +468,28 @@ const TaskHeader = ({
 										</tr>
 									)}
 
+									{typeof rootOrchestrationCost === "number" && rootOrchestrationCost > 0 && (
+										<tr>
+											<th className="font-medium text-left align-top w-1 whitespace-nowrap pr-3 h-[24px]">
+												{t("chat:costs.orchestrationLabel")}
+											</th>
+											<td className="font-light align-top">
+												<StandardTooltip
+													content={
+														<div>
+															{t("chat:costs.orchestrationTotal", {
+																cost: rootOrchestrationCost.toFixed(2),
+															})}
+														</div>
+													}
+													side="top"
+													sideOffset={8}>
+													<span>${rootOrchestrationCost.toFixed(2)}</span>
+												</StandardTooltip>
+											</td>
+										</tr>
+									)}
+
 									{/* Size display */}
 									{!!currentTaskItem?.size && currentTaskItem.size > 0 && (
 										<tr>

webview-ui/src/components/chat/__tests__/TaskHeader.spec.tsx

@@ -470,4 +470,26 @@ describe("TaskHeader", () => {
 			expect(screen.getByText("0%")).toBeInTheDocument()
 		})
 	})
+
+	describe("Root orchestration cost", () => {
+		it("should display orchestration cost when rootOrchestrationCost is provided and > 0", () => {
+			renderTaskHeader({ rootOrchestrationCost: 1.5 })
+			expect(screen.getByText("chat:costs.orchestrationLabel: $1.50")).toBeInTheDocument()
+		})
+
+		it("should not display orchestration cost when rootOrchestrationCost is undefined", () => {
+			renderTaskHeader({ rootOrchestrationCost: undefined })
+			expect(screen.queryByText(/chat:costs.orchestrationLabel/)).not.toBeInTheDocument()
+		})
+
+		it("should not display orchestration cost when rootOrchestrationCost is 0", () => {
+			renderTaskHeader({ rootOrchestrationCost: 0 })
+			expect(screen.queryByText(/chat:costs.orchestrationLabel/)).not.toBeInTheDocument()
+		})
+
+		it("should display orchestration cost tooltip with correct text", () => {
+			renderTaskHeader({ rootOrchestrationCost: 2.75 })
+			expect(screen.getByText("chat:costs.orchestrationLabel: $2.75")).toBeInTheDocument()
+		})
+	})
 })

webview-ui/src/i18n/locales/en/chat.json

@@ -389,7 +389,9 @@
 	"costs": {
 		"totalWithSubtasks": "Total Cost (including subtasks): ${{cost}}",
 		"total": "Total Cost: ${{cost}}",
-		"includesSubtasks": "Includes subtask costs"
+		"includesSubtasks": "Includes subtask costs",
+		"orchestrationLabel": "Orchestration",
+		"orchestrationTotal": "Full orchestration cost (all tasks): ${{cost}}"
 	},
 	"codeblock": {
 		"tooltips": {