diff --git a/CHANGELOG.md b/CHANGELOG.md
index 85fb7152..ac50b266 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,11 +16,13 @@ All notable changes to this project will be documented in this file.
   Previously, arbitrary file names were silently accepted and ignored ([#1027]).
 - Bump `stackable-operator` to 0.111.1 ([#1027], [#1028]).
 - Internal operator refactoring: introduce dereference() and validate() steps in the reconciler ([#1034]).
+- test: Bump vector-aggregator to 0.55.0, replace /graphql call with gRPC call ([#1038]).
 
 [#1020]: https://github.com/stackabletech/zookeeper-operator/pull/1020
 [#1027]: https://github.com/stackabletech/zookeeper-operator/pull/1027
 [#1028]: https://github.com/stackabletech/zookeeper-operator/pull/1028
 [#1034]: https://github.com/stackabletech/zookeeper-operator/pull/1034
+[#1038]: https://github.com/stackabletech/zookeeper-operator/pull/1038
 
 ## [26.3.0] - 2026-03-16
 
diff --git a/tests/templates/kuttl/logging/05-install-zookeeper-vector-aggregator.yaml b/tests/templates/kuttl/logging/05-install-zookeeper-vector-aggregator.yaml
index 21592583..55ce3cbd 100644
--- a/tests/templates/kuttl/logging/05-install-zookeeper-vector-aggregator.yaml
+++ b/tests/templates/kuttl/logging/05-install-zookeeper-vector-aggregator.yaml
@@ -5,7 +5,7 @@ commands:
   - script: >-
       helm install zookeeper-vector-aggregator vector
       --namespace $NAMESPACE
-      --version 0.49.0
+      --version 0.52.0 `# app version 0.55.0`
       --repo https://helm.vector.dev
       --values zookeeper-vector-aggregator-values.yaml
 ---
diff --git a/tests/templates/kuttl/logging/test_log_aggregation.py b/tests/templates/kuttl/logging/test_log_aggregation.py
index b21ac47e..c76786ab 100755
--- a/tests/templates/kuttl/logging/test_log_aggregation.py
+++ b/tests/templates/kuttl/logging/test_log_aggregation.py
@@ -1,48 +1,44 @@
-#!/usr/bin/env python3
-import requests
+import json
+import subprocess
 
 
 def check_sent_events():
-    response = requests.post(
-        'http://zookeeper-vector-aggregator:8686/graphql',
-        json={
-            'query': """
-                {
-                    transforms(first:100) {
-                        nodes {
-                            componentId
-                            metrics {
-                                sentEventsTotal {
-                                    sentEventsTotal
-                                }
-                            }
-                        }
-                    }
-                }
-            """
-        }
+    response = subprocess.run(
+        [
+            "grpcurl",
+            "-plaintext",
+            "-d",
+            '{"limit": 100}',
+            "zookeeper-vector-aggregator:8686",
+            "vector.observability.v1.ObservabilityService/GetComponents",
+        ],
+        capture_output=True,
+        text=True,
+        check=True,  # Raise a CalledProcessError if non-zero return
+        timeout=20,  # seconds
     )
+    result = json.loads(response.stdout)
+    components = result.get("components", [])
+    transforms = [
+        c for c in components if c.get("componentType") == "COMPONENT_TYPE_TRANSFORM"
+    ]
 
-    assert response.status_code == 200, \
-        'Cannot access the API of the vector aggregator.'
+    assert len(transforms) > 0, "No transform components found"
 
-    result = response.json()
-
-    transforms = result['data']['transforms']['nodes']
     for transform in transforms:
-        sentEvents = transform['metrics']['sentEventsTotal']
-        componentId = transform['componentId']
+        sentEvents = transform["metrics"]["sentEventsTotal"]
+        componentId = transform["componentId"]
 
-        if componentId == 'filteredInvalidEvents':
-            assert sentEvents is None or \
-                   sentEvents['sentEventsTotal'] == 0, \
-                   'Invalid log events were sent.'
+        if componentId == "filteredInvalidEvents":
+            assert sentEvents is None or int(sentEvents) == 0, (
+                "Invalid log events were sent."
+            )
         else:
-            assert sentEvents is not None and \
-                   sentEvents['sentEventsTotal'] > 0, \
-                   f'No events were sent in "{componentId}".'
+            assert sentEvents is not None and int(sentEvents) > 0, (
+                f'No events were sent in "{componentId}".'
+            )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     check_sent_events()
-    print('Test successful!')
+    print("Test successful!")