diff --git a/src/auto-reply/reply/agent-runner.media-paths.test.ts b/src/auto-reply/reply/agent-runner.media-paths.test.ts
index 600a5ce4e5a..1cdce77351b 100644
--- a/src/auto-reply/reply/agent-runner.media-paths.test.ts
+++ b/src/auto-reply/reply/agent-runner.media-paths.test.ts
@@ -17,6 +17,7 @@ const enqueueFollowupRunMock = vi.fn();
 const scheduleFollowupDrainMock = vi.fn();
 const refreshQueuedFollowupSessionMock = vi.fn();
 const resolveOutboundAttachmentFromUrlMock = vi.fn();
+const createReplyMediaPathNormalizerRuntimeMock = vi.fn();
 
 vi.mock("../../agents/model-fallback.js", () => ({
   runWithModelFallback: (params: {
@@ -52,6 +53,18 @@ vi.mock("../../media/outbound-attachment.js", () => ({
     resolveOutboundAttachmentFromUrlMock(...args),
 }));
 
+// Spy on the .runtime import path used by agent-runner-execution.ts so we can assert
+// that the fix prevents a second normalizer from being created inside runAgentTurnWithFallback.
+vi.mock("./reply-media-paths.runtime.js", async (importOriginal) => {
+  const mod = await importOriginal<typeof import("./reply-media-paths.runtime.js")>();
+  return {
+    createReplyMediaPathNormalizer: (...args: Parameters<typeof mod.createReplyMediaPathNormalizer>) => {
+      createReplyMediaPathNormalizerRuntimeMock(...args);
+      return mod.createReplyMediaPathNormalizer(...args);
+    },
+  };
+});
+
 let runReplyAgent: typeof import("./agent-runner.js").runReplyAgent;
 
 describe("runReplyAgent media path normalization", () => {
@@ -73,6 +86,7 @@ describe("runReplyAgent media path normalization", () => {
     scheduleFollowupDrainMock.mockReset();
     refreshQueuedFollowupSessionMock.mockReset();
     resolveOutboundAttachmentFromUrlMock.mockReset();
+    createReplyMediaPathNormalizerRuntimeMock.mockReset();
     vi.stubEnv("OPENCLAW_TEST_FAST", "1");
     resolveOutboundAttachmentFromUrlMock.mockImplementation(async (mediaUrl: string) => ({
       path: path.join("/tmp/outbound-media", path.basename(mediaUrl)),
@@ -160,4 +174,69 @@ describe("runReplyAgent media path normalization", () => {
       }),
     );
   });
+
+  it("does not create a second normalizer inside runAgentTurnWithFallback when onBlockReply is provided", async () => {
+    // Regression test for openclaw/openclaw#68056.
+    // Before the fix, runAgentTurnWithFallback always called createReplyMediaPathNormalizer
+    // from reply-media-paths.runtime.js to build its own normalizer instance — separate from
+    // the one agent-runner.ts created and passed to buildReplyPayloads.  Two separate
+    // persistedMediaBySource caches meant the same source could be persisted twice (two UUID
+    // outbound files, two WhatsApp sends).
+    //
+    // After the fix, agent-runner.ts passes its normalizer into runAgentTurnWithFallback, so
+    // the .runtime import path is never called from inside that function.
+    runEmbeddedPiAgentMock.mockResolvedValue({
+      payloads: [],
+      meta: {
+        agentMeta: {
+          sessionId: "session",
+          provider: "anthropic",
+          model: "claude",
+        },
+      },
+    });
+
+    await runReplyAgent({
+      commandBody: "generate chart",
+      followupRun: createMockFollowupRun({
+        prompt: "generate chart",
+        run: {
+          agentId: "main",
+          agentDir: "/tmp/agent",
+          messageProvider: "whatsapp",
+          workspaceDir: "/tmp/workspace",
+        },
+      }) as unknown as FollowupRun,
+      queueKey: "main",
+      resolvedQueue: { mode: "interrupt" } as QueueSettings,
+      shouldSteer: false,
+      shouldFollowup: false,
+      isActive: false,
+      isStreaming: false,
+      typing: createMockTypingController(),
+      sessionCtx: {
+        Provider: "whatsapp",
+        Surface: "whatsapp",
+        To: "chat-1",
+        OriginatingTo: "chat-1",
+        AccountId: "default",
+        MessageSid: "msg-1",
+      } as unknown as TemplateContext,
+      defaultModel: "anthropic/claude",
+      resolvedVerboseLevel: "off",
+      isNewSession: false,
+      blockStreamingEnabled: false,
+      resolvedBlockStreamingBreak: "message_end",
+      shouldInjectGroupIntro: false,
+      typingMode: "instant",
+      opts: {
+        onBlockReply: vi.fn(),
+      },
+    });
+
+    // The .runtime import is only used by agent-runner-execution.ts.  After the fix,
+    // runAgentTurnWithFallback receives the normalizer from the caller and never
+    // calls createReplyMediaPathNormalizer itself.
+    expect(createReplyMediaPathNormalizerRuntimeMock).not.toHaveBeenCalled();
+  });
 });