diff --git a/swh/web/api/views/vault.py b/swh/web/api/views/vault.py
--- a/swh/web/api/views/vault.py
+++ b/swh/web/api/views/vault.py
@@ -100,10 +100,15 @@
     )
 
     res = _dispatch_cook_progress(request, "directory", obj_id)
-    res["fetch_url"] = reverse(
-        "api-1-vault-fetch-directory", url_args={"dir_id": dir_id}
-    )
-    return res
+
+    return {
+        "fetch_url": res["fetch_url"],
+        "obj_type": res["type"],
+        "progress_message": res["progress_msg"],
+        "id": res["task_id"],
+        "status": res["task_status"],
+        "obj_id": res["object_id"],
+    }
 
 
 @api_route(
diff --git a/swh/web/assets/src/bundles/vault/vault-ui.js b/swh/web/assets/src/bundles/vault/vault-ui.js
--- a/swh/web/assets/src/bundles/vault/vault-ui.js
+++ b/swh/web/assets/src/bundles/vault/vault-ui.js
@@ -193,7 +193,9 @@
       localStorage.setItem('swh-vault-cooking-tasks', JSON.stringify(vaultCookingTasks));
       checkVaultId = setTimeout(checkVaultCookingTasks, pollingInterval);
     })
-    .catch(() => {});
+    .catch(error => {
+      console.log('Error when fetching vault cooking tasks:', error);
+    });
 }
 
 export function removeCookingTaskInfo(tasksToRemove) {
diff --git a/swh/web/tests/api/views/test_vault.py b/swh/web/tests/api/views/test_vault.py
--- a/swh/web/tests/api/views/test_vault.py
+++ b/swh/web/tests/api/views/test_vault.py
@@ -36,11 +36,11 @@
         )
         stub_cook = {
             "fetch_url": fetch_url,
-            "obj_id": obj_id,
-            "obj_type": obj_type,
-            "progress_message": None,
-            "status": "done",
-            "task_uuid": "de75c902-5ee5-4739-996e-448376a93eff",
+            "type": obj_type,
+            "progress_msg": None,
+            "task_id": 1,
+            "task_status": "done",
+            "object_id": obj_id,
         }
         stub_fetch = b"content"
 
@@ -54,13 +54,17 @@
             query_params={"email": email},
         )
 
-        rv = check_api_post_responses(api_client, url, data=None, status_code=200)
-
-        stub_cook["fetch_url"] = rv.wsgi_request.build_absolute_uri(
-            stub_cook["fetch_url"]
-        )
+        expected_data = {
+            "fetch_url": fetch_url,
+            "obj_type": obj_type,
+            "progress_message": None,
+            "id": 1,
+            "status": "done",
+            "obj_id": obj_id,
+        }
 
-        assert rv.data == stub_cook
+        rv = check_api_post_responses(api_client, url, data=None, status_code=200)
+        assert rv.data == expected_data
         mock_archive.vault_cook.assert_called_with(
             obj_type, hashutil.hash_to_bytes(obj_id), email
         )