diff --git a/adapters/feishu/__tests__/streaming-card.test.ts b/adapters/feishu/__tests__/streaming-card.test.ts
index fbb090ae..2cec35df 100644
--- a/adapters/feishu/__tests__/streaming-card.test.ts
+++ b/adapters/feishu/__tests__/streaming-card.test.ts
@@ -246,6 +246,31 @@ describe('StreamingCard: ensureCreated (fallback 降级路径)', () => {
     expect(sc._getMessageId()).toBe('om_fb2')
   })
 
+  it('reply 发送失败后降级 create 时复用同一个 uuid 避免重复消息', async () => {
+    const { client, calls } = makeMockClient({
+      'card.create': { code: 0, data: { card_id: 'ck' } },
+      'im.message.reply': () => {
+        throw Object.assign(new Error('reply failed after send'), { code: 231003 })
+      },
+      'im.message.create': { data: { message_id: 'om_fb_after_reply' } },
+    })
+    const sc = new StreamingCard({
+      larkClient: client,
+      chatId: 'c',
+      replyToMessageId: 'om_parent',
+    })
+
+    await sc.ensureCreated()
+
+    const replyCall = calls.find((c) => c.api === 'im.message.reply')
+    const fallbackCreate = calls.find((c) => c.api === 'im.message.create')
+    expect(replyCall).toBeDefined()
+    expect(fallbackCreate).toBeDefined()
+    expect(typeof replyCall!.args.data.uuid).toBe('string')
+    expect(replyCall!.args.data.uuid.length).toBeGreaterThan(0)
+    expect(fallbackCreate!.args.data.uuid).toBe(replyCall!.args.data.uuid)
+  })
+
   it('降级发送也失败 → aborted + throw', async () => {
     const { client } = makeMockClient({
       'card.create': { code: 99991672 },
diff --git a/adapters/feishu/cardkit.ts b/adapters/feishu/cardkit.ts
index 4a343331..bb9eda9d 100644
--- a/adapters/feishu/cardkit.ts
+++ b/adapters/feishu/cardkit.ts
@@ -189,6 +189,7 @@ export async function sendCardAsMessage(
   chatId: string,
   cardId: string,
   replyToMessageId?: string,
+  uuid?: string,
 ): Promise<string> {
   const content = JSON.stringify({
     type: 'card',
@@ -199,7 +200,7 @@ export async function sendCardAsMessage(
     const resp = await withImCardRequestTimeout('im.message.reply', () =>
       client.im.message.reply({
         path: { message_id: replyToMessageId },
-        data: { content, msg_type: 'interactive' },
+        data: { content, msg_type: 'interactive', uuid },
       }),
     )
     const messageId = resp.data?.message_id
@@ -221,6 +222,7 @@ export async function sendCardAsMessage(
         receive_id: chatId,
         msg_type: 'interactive',
         content,
+        uuid,
       },
     }),
   )
diff --git a/adapters/feishu/streaming-card.ts b/adapters/feishu/streaming-card.ts
index 233a4435..16b1b90f 100644
--- a/adapters/feishu/streaming-card.ts
+++ b/adapters/feishu/streaming-card.ts
@@ -13,6 +13,7 @@
  */
 
 import type * as Lark from '@larksuiteoapi/node-sdk'
+import { randomUUID } from 'node:crypto'
 import { FlushController, THROTTLE } from './flush-controller.js'
 import {
   createCardEntity,
@@ -152,6 +153,8 @@ export class StreamingCard {
   private cardId: string | null = null
   /** IM message_id。始终应该有值（否则连 patch 也做不了）。 */
   private messageId: string | null = null
+  /** Same idempotency key for the first IM send and any create fallback. */
+  private readonly outboundMessageUuid = randomUUID()
   /** CardKit cardElement.content() 单调递增序列号。 */
   private sequence = 0
   /** CardKit 流式还在工作。230099 或连续 N 次未知错误之后置为 false，
@@ -198,6 +201,7 @@ export class StreamingCard {
         this.deps.chatId,
         cardId,
         this.deps.replyToMessageId,
+        this.outboundMessageUuid,
       )
       this.cardId = cardId
       this.messageId = messageId
@@ -219,6 +223,7 @@ export class StreamingCard {
               receive_id: this.deps.chatId,
               msg_type: 'interactive',
               content: JSON.stringify(buildRenderedCard(' ')),
+              uuid: this.outboundMessageUuid,
             },
           }),
         )