diff --git a/e2e/specs/mock/file-provisioning.spec.ts b/e2e/specs/mock/file-provisioning.spec.ts
index 200af648a7..e5dcef61ba 100644
--- a/e2e/specs/mock/file-provisioning.spec.ts
+++ b/e2e/specs/mock/file-provisioning.spec.ts
@@ -1,4 +1,5 @@
 import { expect, test } from '@playwright/test';
+import type { UploadedFile } from './helpers';
 import {
   MOCK_ENDPOINTS,
   NEW_CHAT_PATH,
@@ -106,14 +107,13 @@ test.describe('file provisioning — lazy (unified upload, at tool-execute)', ()
     await expect(page.getByRole('button', { name: fileName })).toBeVisible({ timeout: 15000 });
 
     // A tool run triggers lazy provisioning: the fake model emits an execute_code call.
+    // Provisioning fires at ON_TOOL_EXECUTE, before the execute_code tool itself runs,
+    // so assert it reached the code env independent of the tool's own result.
     await sendMessage(page, `E2E_EXECUTE_CODE:${uniqueName('run')}`);
-    await expect(
-      page.getByTestId('messages-view').getByText(/E2E execute_code complete:/),
-    ).toBeVisible({ timeout: 30000 });
 
     await expect
       .poll(async () => (await getCodeProvisionedUploads(page)).map((u) => u.filename), {
-        timeout: 15000,
+        timeout: 30000,
       })
       .toContain(fileName);
   });
@@ -134,19 +134,21 @@ test.describe('file provisioning — lazy (unified upload, at tool-execute)', ()
       content: 'k,v\nfoo,bar\n',
     });
     expect(response.ok()).toBeTruthy();
+    // uploadVectors streams from a temp path, so the fake RAG records the file_id,
+    // not the original filename — correlate on the id from the upload response.
+    const fileId = ((await response.json()) as UploadedFile).file_id;
+    expect(fileId, 'upload response should include a file_id').toBeTruthy();
     expect(
-      (await getRagEmbedded(page)).map((e) => e.filename),
+      (await getRagEmbedded(page)).map((e) => e.file_id),
       'unified upload must not embed until file_search runs',
-    ).not.toContain(fileName);
+    ).not.toContain(fileId);
     await expect(page.getByRole('button', { name: fileName })).toBeVisible({ timeout: 15000 });
 
+    // Embedding fires at ON_TOOL_EXECUTE, independent of the file_search tool result.
     await sendMessage(page, `E2E_FILE_SEARCH:${uniqueName('q')}`);
-    await expect(
-      page.getByTestId('messages-view').getByText(/E2E file_search complete:/),
-    ).toBeVisible({ timeout: 30000 });
 
     await expect
-      .poll(async () => (await getRagEmbedded(page)).map((e) => e.filename), { timeout: 15000 })
-      .toContain(fileName);
+      .poll(async () => (await getRagEmbedded(page)).map((e) => e.file_id), { timeout: 30000 })
+      .toContain(fileId);
   });
 });
diff --git a/e2e/specs/mock/helpers.ts b/e2e/specs/mock/helpers.ts
index 3b1f3a2471..af4e29adf4 100644
--- a/e2e/specs/mock/helpers.ts
+++ b/e2e/specs/mock/helpers.ts
@@ -243,6 +243,7 @@ export async function resetProvisioning(page: Page): Promise<void> {
 
 /** Shape of a file record as returned by POST /api/files and GET /api/files. */
 export type UploadedFile = {
+  file_id?: string;
   filename?: string;
   type?: string;
   llmDeliveryPath?: string;