diff --git a/tests/routes/canvas-agent-operations.test.ts b/tests/routes/canvas-agent-operations.test.ts
index d16fac32f..d4a1dcccd 100644
--- a/tests/routes/canvas-agent-operations.test.ts
+++ b/tests/routes/canvas-agent-operations.test.ts
@@ -10,6 +10,7 @@ import {
 } from "@/lib/canvas/agent-mutations";
 import type { CanvasAgentFeatureFlags } from "@/lib/canvas/agent-feature-flags";
 import { handleCanvasAgentOperationRouteRequest } from "@/lib/canvas/agent-operation-route";
+import type { CanvasOperationPlan } from "@/types/canvas/agent-protocol";
 
 const projectId = "11111111-1111-4111-8111-111111111111";
 const enabledRouteFeatures: CanvasAgentFeatureFlags = {
@@ -513,6 +514,77 @@ test.describe("canvas agent operation mutation contract", () => {
     ).toThrow(/媒体来源节点不存在/);
   });
 
+  test("creates agent slot nodes with stable metadata and idempotency", () => {
+    const canvasData = {
+      ...getCanvasData([]),
+      viewport: { x: -120, y: -80, zoom: 2, width: 1000, height: 700 },
+    };
+    const plan: CanvasOperationPlan = {
+      version: 1 as const,
+      operationId: "op-create-video-slot",
+      operation: "create_agent_slot" as const,
+      projectId,
+      targetPosition: { x: 240, y: 180 },
+      slot: {
+        slotType: "video" as const,
+        label: "视频结果槽",
+        aspectRatio: "16:9",
+        fillPolicy: "append-version" as const,
+        acceptedSources: ["text", "image", "annotation"],
+      },
+      metadata: {
+        messageId: "assistant-message-1",
+        chatId: "chat-1",
+        prompt: "创建一个视频槽位",
+      },
+    };
+
+    const first = applyCanvasOperationPlanToCanvasData({
+      canvasData,
+      plan,
+    });
+    const createdSlotId = first.createdNodeIds[0];
+    const createdSlot = getResultNodes(first.canvasData).find(
+      (node) => node.id === createdSlotId
+    );
+
+    expect(createdSlot).toMatchObject({
+      type: "agent-slot",
+      position: { x: 240, y: 180 },
+      size: { width: 360, height: 220 },
+      data: {
+        slotType: "video",
+        label: "视频结果槽",
+        status: "empty",
+        aspectRatio: "16:9",
+        fillPolicy: "append-version",
+        acceptedSources: ["text", "image", "annotation"],
+        filledNodeIds: [],
+        metadata: {
+          createdByAgent: true,
+          canvasAgentOperationId: "op-create-video-slot",
+          canvasAgentOperation: "create_agent_slot",
+          messageId: "assistant-message-1",
+          chatId: "chat-1",
+          prompt: "创建一个视频槽位",
+        },
+      },
+    });
+    expect((first.canvasData as { selectedNodeIds?: string[] }).selectedNodeIds).toEqual([
+      createdSlotId,
+    ]);
+
+    const retry = applyCanvasOperationPlanToCanvasData({
+      canvasData: first.canvasData,
+      plan,
+    });
+
+    expect(retry.createdNodeIds).toEqual(first.createdNodeIds);
+    expect(getResultNodes(retry.canvasData)).toHaveLength(
+      getResultNodes(first.canvasData).length
+    );
+  });
+
   test("fills an agent slot and returns media item node mappings", () => {
     const slot = buildAgentSlotNode();
     const result = applyCanvasOperationPlanToCanvasData({