diff --git a/extensions/codex/src/app-server/client.test.ts b/extensions/codex/src/app-server/client.test.ts
index 50097cc2edf..68a7f64ce4a 100644
--- a/extensions/codex/src/app-server/client.test.ts
+++ b/extensions/codex/src/app-server/client.test.ts
@@ -1,6 +1,6 @@
 import { EventEmitter } from "node:events";
 import { PassThrough } from "node:stream";
-import { embeddedAgentLog } from "openclaw/plugin-sdk/agent-harness-runtime";
+import { embeddedAgentLog, OPENCLAW_VERSION } from "openclaw/plugin-sdk/agent-harness-runtime";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import {
   __testing,
@@ -57,14 +57,25 @@ describe("CodexAppServerClient", () => {
 
     harness.process.stdout.write('{"token":"secret-value"} trailing\n');
 
-    await vi.waitFor(() =>
-      expect(warn).toHaveBeenCalledWith(
-        "failed to parse codex app-server message",
-        expect.objectContaining({
-          consoleMessage: expect.stringContaining("<redacted>"),
-          linePreview: '{"token":"<redacted>"} trailing',
-        }),
-      ),
+    await vi.waitFor(() => expect(warn).toHaveBeenCalledTimes(1));
+    expect(warn.mock.calls[0]?.[0]).toBe("failed to parse codex app-server message");
+    const metadata = warn.mock.calls[0]?.[1] as
+      | {
+          error?: unknown;
+          errorMessage?: string;
+          fragmentCount?: number;
+          linePreview?: string;
+          consoleMessage?: string;
+        }
+      | undefined;
+    expect(metadata?.error).toBeInstanceOf(SyntaxError);
+    expect(metadata?.errorMessage).toBe(
+      "Unexpected non-whitespace character after JSON at position 25 (line 1 column 26)",
+    );
+    expect(metadata?.fragmentCount).toBe(1);
+    expect(metadata?.linePreview).toBe('{"token":"<redacted>"} trailing');
+    expect(metadata?.consoleMessage).toBe(
+      'failed to parse codex app-server message: preview="{\\"token\\":\\"<redacted>\\"} trailing"',
     );
     expect(JSON.stringify(warn.mock.calls)).not.toContain("secret-value");
   });
@@ -157,13 +168,17 @@ describe("CodexAppServerClient", () => {
     });
 
     await expect(initializing).resolves.toBeUndefined();
-    expect(outbound).toMatchObject({
+    expect(outbound).toStrictEqual({
+      id: outbound.id,
       method: "initialize",
       params: {
         clientInfo: {
           name: "openclaw",
           title: "OpenClaw",
-          version: expect.any(String),
+          version: OPENCLAW_VERSION,
+        },
+        capabilities: {
+          experimentalApi: true,
         },
       },
     });
@@ -433,14 +448,11 @@ describe("CodexAppServerClient", () => {
         ],
       },
     });
-    expect(warn).toHaveBeenCalledWith(
-      "codex app-server server request timed out",
-      expect.objectContaining({
-        id: "srv-timeout",
-        method: "item/tool/call",
-        timeoutMs: __testing.CODEX_DYNAMIC_TOOL_SERVER_REQUEST_TIMEOUT_MS,
-      }),
-    );
+    expect(warn).toHaveBeenCalledWith("codex app-server server request timed out", {
+      id: "srv-timeout",
+      method: "item/tool/call",
+      timeoutMs: __testing.CODEX_DYNAMIC_TOOL_SERVER_REQUEST_TIMEOUT_MS,
+    });
   });
 
   it("fails closed for unhandled native app-server approvals", async () => {