diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 1a70468..7e7d24f 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.5.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.6.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/src/main/java/org/llschall/control/board/UiRestController.java b/src/main/java/org/llschall/control/board/UiRestController.java
index c91a800..ec76e76 100644
--- a/src/main/java/org/llschall/control/board/UiRestController.java
+++ b/src/main/java/org/llschall/control/board/UiRestController.java
@@ -4,12 +4,14 @@
 import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 
 @RestController
 @RequestMapping("/api")
 public class UiRestController {
     private final CounterViewModel viewModel;
+    private final AtomicInteger echoCallCount = new AtomicInteger(0);
 
     public UiRestController(CounterViewModel viewModel) {
         this.viewModel = viewModel;
@@ -43,6 +45,17 @@ public List<MeasurementDto> getMeasurements() {
         return toDtoList(viewModel.getAllMeasurements());
     }
 
+    @GetMapping("/echo")
+    public ResponseEntity<?> echo() {
+        int i = echoCallCount.incrementAndGet();
+        return ResponseEntity.ok(new EchoDto(i));
+    }
+
+    @GetMapping("/echo-count")
+    public ResponseEntity<?> getEchoCount() {
+        return ResponseEntity.ok(new EchoCountDto(echoCallCount.get()));
+    }
+
     private List<MeasurementDto> toDtoList(Iterable<Measurement> measurements) {
         return ((List<Measurement>) ((measurements instanceof List) ? measurements : toList(measurements)))
                 .stream()
@@ -51,32 +64,19 @@ private List<MeasurementDto> toDtoList(Iterable<Measurement> measurements) {
     }
 
     private List<Measurement> toList(Iterable<Measurement> iterable) {
-        return (List<Measurement>) ((List<?>)
-                java.util.stream.StreamSupport.stream(iterable.spliterator(), false).collect(Collectors.toList()));
+        return java.util.stream.StreamSupport.stream(iterable.spliterator(), false).collect(Collectors.toList());
     }
 
-    static class CounterDto {
-        public final int value;
-        public final String display;
-        public final boolean switchOn;
+    record CounterDto(int value, String display, boolean switchOn) {
+    }
 
-        public CounterDto(int value, String display, boolean switchOn) {
-            this.value = value;
-            this.display = display;
-            this.switchOn = switchOn;
-        }
+    record MeasurementDto(Long id, int value, String timestamp) {
     }
 
-    static class MeasurementDto {
-        public final Long id;
-        public final int value;
-        public final String timestamp;
+    record EchoDto(int count) {
+    }
 
-        public MeasurementDto(Long id, int value, String timestamp) {
-            this.id = id;
-            this.value = value;
-            this.timestamp = timestamp;
-        }
+    record EchoCountDto(int count) {
     }
 }
 
diff --git a/src/main/resources/static/index.html b/src/main/resources/static/index.html
index 9ea84ef..047ee17 100644
--- a/src/main/resources/static/index.html
+++ b/src/main/resources/static/index.html
@@ -21,6 +21,7 @@
     <button id="inc">Increment</button>
     <label>Led <input type="checkbox" id="led" /></label>
     <button id="refreshDb">Refresh DB</button>
+    <span id="echoCount">Echo Calls: 0</span>
   </div>
 
   <div id="chart"></div>
@@ -55,11 +56,19 @@ <h3>Measurements</h3>
       return res.json();
     }
 
+    async function fetchEchoCount() {
+      const res = await fetch('/api/echo-count');
+      return res.json();
+    }
+
     async function refreshUi() {
       const counter = await fetchCounter();
       document.getElementById('display').textContent = counter.display;
       document.getElementById('led').checked = counter.switchOn;
 
+      const echoCounter = await fetchEchoCount();
+      document.getElementById('echoCount').textContent = 'Echo Calls: ' + echoCounter.count;
+
       const measurements = await fetchMeasurements();
       const series = measurements.map((m, idx) => m.value);
       const x = measurements.map((m, idx) => idx);