diff --git a/cameleer-server-core/src/main/java/com/cameleer/server/core/runtime/DirtyStateCalculator.java b/cameleer-server-core/src/main/java/com/cameleer/server/core/runtime/DirtyStateCalculator.java
index f9a32ad6..2fc24b53 100644
--- a/cameleer-server-core/src/main/java/com/cameleer/server/core/runtime/DirtyStateCalculator.java
+++ b/cameleer-server-core/src/main/java/com/cameleer/server/core/runtime/DirtyStateCalculator.java
@@ -51,7 +51,7 @@ public class DirtyStateCalculator {
         if (!(desired instanceof ObjectNode desiredObj) || !(deployed instanceof ObjectNode deployedObj)) {
             if (!Objects.equals(desired, deployed)) {
                 diffs.add(new DirtyStateResult.Difference(prefix,
-                        String.valueOf(desired), String.valueOf(deployed)));
+                        nodeToString(desired), nodeToString(deployed)));
             }
             return;
         }
@@ -61,10 +61,18 @@ public class DirtyStateCalculator {
         for (String key : keys) {
             JsonNode d = desiredObj.get(key);
             JsonNode p = deployedObj.get(key);
-            if (!Objects.equals(d, p)) {
-                diffs.add(new DirtyStateResult.Difference(prefix + "." + key,
-                        String.valueOf(d), String.valueOf(p)));
+            if (Objects.equals(d, p)) continue;
+            if (d instanceof ObjectNode && p instanceof ObjectNode) {
+                compareJson(prefix + "." + key, d, p, diffs);
+            } else {
+                diffs.add(new DirtyStateResult.Difference(prefix + "." + key, nodeToString(d), nodeToString(p)));
             }
         }
     }
+
+    private static String nodeToString(JsonNode n) {
+        if (n == null) return "(none)";
+        if (n.isValueNode()) return n.asText();
+        return n.toString();  // arrays/objects: compact JSON
+    }
 }
diff --git a/cameleer-server-core/src/test/java/com/cameleer/server/core/runtime/DirtyStateCalculatorTest.java b/cameleer-server-core/src/test/java/com/cameleer/server/core/runtime/DirtyStateCalculatorTest.java
index ba9ec733..bb57be38 100644
--- a/cameleer-server-core/src/test/java/com/cameleer/server/core/runtime/DirtyStateCalculatorTest.java
+++ b/cameleer-server-core/src/test/java/com/cameleer/server/core/runtime/DirtyStateCalculatorTest.java
@@ -88,4 +88,57 @@ class DirtyStateCalculatorTest {
         assertThat(result.differences()).extracting(DirtyStateResult.Difference::field)
                 .contains("containerConfig.memoryLimitMb");
     }
+
+    @Test
+    void nullAgentConfigInSnapshot_marksAgentConfigDiff() {
+        DirtyStateCalculator calc = new DirtyStateCalculator();
+        ApplicationConfig desired = new ApplicationConfig();
+        desired.setSamplingRate(1.0);
+        UUID jarId = UUID.randomUUID();
+        DeploymentConfigSnapshot snap = new DeploymentConfigSnapshot(jarId, null, Map.of());
+
+        DirtyStateResult result = calc.compute(jarId, desired, Map.of(), snap);
+
+        assertThat(result.dirty()).isTrue();
+        assertThat(result.differences()).extracting(DirtyStateResult.Difference::field)
+                .contains("agentConfig");
+    }
+
+    @Test
+    void nestedAgentField_reportsDeepPath() {
+        DirtyStateCalculator calc = new DirtyStateCalculator();
+
+        ApplicationConfig deployed = new ApplicationConfig();
+        deployed.setTracedProcessors(Map.of("proc-1", "DEBUG"));
+        ApplicationConfig desired = new ApplicationConfig();
+        desired.setTracedProcessors(Map.of("proc-1", "TRACE"));
+        UUID jarId = UUID.randomUUID();
+        DeploymentConfigSnapshot snap = new DeploymentConfigSnapshot(jarId, deployed, Map.of());
+
+        DirtyStateResult result = calc.compute(jarId, desired, Map.of(), snap);
+
+        assertThat(result.dirty()).isTrue();
+        assertThat(result.differences()).extracting(DirtyStateResult.Difference::field)
+                .contains("agentConfig.tracedProcessors.proc-1");
+    }
+
+    @Test
+    void stringField_differenceValueIsUnquoted() {
+        DirtyStateCalculator calc = new DirtyStateCalculator();
+
+        ApplicationConfig deployed = new ApplicationConfig();
+        deployed.setApplicationLogLevel("INFO");
+        ApplicationConfig desired = new ApplicationConfig();
+        desired.setApplicationLogLevel("DEBUG");
+        UUID jarId = UUID.randomUUID();
+        DeploymentConfigSnapshot snap = new DeploymentConfigSnapshot(jarId, deployed, Map.of());
+
+        DirtyStateResult result = calc.compute(jarId, desired, Map.of(), snap);
+
+        DirtyStateResult.Difference diff = result.differences().stream()
+                .filter(d -> d.field().equals("agentConfig.applicationLogLevel"))
+                .findFirst().orElseThrow();
+        assertThat(diff.staged()).isEqualTo("DEBUG");
+        assertThat(diff.deployed()).isEqualTo("INFO");
+    }
 }