diff --git a/src/agents/pi-embedded-runner/run/attempt.memory-flush-forwarding.test.ts b/src/agents/pi-embedded-runner/run/attempt.memory-flush-forwarding.test.ts
index 572788b4ad7..884ba9aea57 100644
--- a/src/agents/pi-embedded-runner/run/attempt.memory-flush-forwarding.test.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.memory-flush-forwarding.test.ts
@@ -5,6 +5,34 @@ import type { Api, Model } from "@mariozechner/pi-ai";
 import type { AuthStorage, ModelRegistry } from "@mariozechner/pi-coding-agent";
 import { describe, expect, it, vi } from "vitest";
 
+const MEMORY_RELATIVE_PATH = "memory/2026-03-24.md";
+
+function createAttemptParams(workspaceDir: string) {
+  return {
+    sessionId: "session-memory-flush",
+    sessionKey: "agent:main",
+    sessionFile: path.join(workspaceDir, "session.json"),
+    workspaceDir,
+    prompt: "flush durable notes",
+    timeoutMs: 30_000,
+    runId: "run-memory-flush",
+    provider: "openai",
+    modelId: "gpt-5.4",
+    model: {
+      api: "responses",
+      provider: "openai",
+      id: "gpt-5.4",
+      input: ["text"],
+      contextWindow: 128_000,
+    } as Model<Api>,
+    authStorage: {} as AuthStorage,
+    modelRegistry: {} as ModelRegistry,
+    thinkLevel: "off" as const,
+    trigger: "memory" as const,
+    memoryFlushWritePath: MEMORY_RELATIVE_PATH,
+  };
+}
+
 describe("runEmbeddedAttempt memory flush tool forwarding", () => {
   it("forwards memory trigger metadata into tool creation so append-only guards activate", async () => {
     vi.resetModules();
@@ -28,40 +56,61 @@ describe("runEmbeddedAttempt memory flush tool forwarding", () => {
 
       const { runEmbeddedAttempt } = await import("./attempt.js");
 
-      await expect(
-        runEmbeddedAttempt({
-          sessionId: "session-memory-flush",
-          sessionKey: "agent:main",
-          sessionFile: path.join(workspaceDir, "session.json"),
-          workspaceDir,
-          prompt: "flush durable notes",
-          timeoutMs: 30_000,
-          runId: "run-memory-flush",
-          provider: "openai",
-          modelId: "gpt-5.4",
-          model: {
-            api: "responses",
-            provider: "openai",
-            id: "gpt-5.4",
-            input: ["text"],
-            contextWindow: 128_000,
-          } as Model<Api>,
-          authStorage: {} as AuthStorage,
-          modelRegistry: {} as ModelRegistry,
-          thinkLevel: "off",
-          trigger: "memory",
-          memoryFlushWritePath: "memory/2026-03-24.md",
-        }),
-      ).rejects.toBe(stop);
+      await expect(runEmbeddedAttempt(createAttemptParams(workspaceDir))).rejects.toBe(stop);
 
       expect(capturedOptions).toHaveLength(1);
       expect(capturedOptions[0]).toMatchObject({
         trigger: "memory",
-        memoryFlushWritePath: "memory/2026-03-24.md",
+        memoryFlushWritePath: MEMORY_RELATIVE_PATH,
       });
     } finally {
       vi.doUnmock("../../pi-tools.js");
       await fs.rm(workspaceDir, { recursive: true, force: true });
     }
   });
+
+  it("keeps the forwarded memory flush write tool append-only", async () => {
+    vi.resetModules();
+
+    const workspaceDir = await fs.mkdtemp(
+      path.join(os.tmpdir(), "openclaw-attempt-memory-flush-append-"),
+    );
+    const memoryFile = path.join(workspaceDir, MEMORY_RELATIVE_PATH);
+    const stop = new Error("stop after append-only write check");
+    let appendOnlyWrite: Promise<unknown> | undefined;
+
+    try {
+      await fs.mkdir(path.dirname(memoryFile), { recursive: true });
+      await fs.writeFile(memoryFile, "seed", "utf-8");
+
+      vi.doMock("../../pi-tools.js", async () => {
+        const actual =
+          await vi.importActual<typeof import("../../pi-tools.js")>("../../pi-tools.js");
+        return {
+          ...actual,
+          createOpenClawCodingTools: vi.fn((options) => {
+            const tools = actual.createOpenClawCodingTools(options);
+            const writeTool = tools.find((tool) => tool.name === "write");
+            expect(writeTool).toBeDefined();
+
+            appendOnlyWrite = writeTool!.execute("call-memory-flush", {
+              path: MEMORY_RELATIVE_PATH,
+              content: "new durable note",
+            });
+
+            throw stop;
+          }),
+        };
+      });
+
+      const { runEmbeddedAttempt } = await import("./attempt.js");
+
+      await expect(runEmbeddedAttempt(createAttemptParams(workspaceDir))).rejects.toBe(stop);
+      await expect(appendOnlyWrite).resolves.toBeDefined();
+      await expect(fs.readFile(memoryFile, "utf-8")).resolves.toBe("seed\nnew durable note");
+    } finally {
+      vi.doUnmock("../../pi-tools.js");
+      await fs.rm(workspaceDir, { recursive: true, force: true });
+    }
+  });
 });