Redth · Redth · Mar 11, 2026 · Mar 11, 2026
diff --git a/README.md b/README.md
@@ -292,6 +292,8 @@ auto-assigned by the broker (range 10223–10899), or configurable via `.mauidev
 | `/api/profiler/span` | POST | Publish manual span `{"kind":"ui.operation","name":"...","startTsUtc":"...","endTsUtc":"..."}` |
 | `/api/profiler/hotspots?kind=ui.operation&minDurationMs=16&limit=20` | GET | Aggregated slow-operation hotspots ordered by P95 duration |
 
+Profiler sample payloads also include `nativeMemoryKind` to disambiguate what `nativeMemoryBytes` means for that sample. Current values include `apple.phys-footprint`, `android.native-heap-allocated`, `windows.working-set`, and `process.working-set-minus-managed` when the collector falls back to process working set minus managed memory.
+
 ## Project Structure
 
 ```

diff --git a/src/MauiDevFlow.Agent.Core/Profiling/INativeFrameStatsProvider.cs b/src/MauiDevFlow.Agent.Core/Profiling/INativeFrameStatsProvider.cs
@@ -11,6 +11,7 @@ public sealed class NativeFrameStatsSnapshot
     public int JankFrameCount { get; set; }
     public int UiThreadStallCount { get; set; }
     public long? NativeMemoryBytes { get; set; }
+    public string? NativeMemoryKind { get; set; }
 }
 
 public interface INativeFrameStatsProvider : IDisposable

diff --git a/src/MauiDevFlow.Agent.Core/Profiling/ProfilerContracts.cs b/src/MauiDevFlow.Agent.Core/Profiling/ProfilerContracts.cs
@@ -20,6 +20,7 @@ public class ProfilerSample
     public int Gc1 { get; set; }
     public int Gc2 { get; set; }
     public long? NativeMemoryBytes { get; set; }
+    public string? NativeMemoryKind { get; set; }
     public double? CpuPercent { get; set; }
     public int? ThreadCount { get; set; }
     public int JankFrameCount { get; set; }

diff --git a/src/MauiDevFlow.Agent.Core/Profiling/RuntimeProfilerCollector.cs b/src/MauiDevFlow.Agent.Core/Profiling/RuntimeProfilerCollector.cs
@@ -133,7 +133,12 @@ public bool TryCollect(out ProfilerSample sample)
         sample.Gc0 = GC.CollectionCount(0);
         sample.Gc1 = GC.CollectionCount(1);
         sample.Gc2 = GC.CollectionCount(2);
-        sample.NativeMemoryBytes ??= TryReadNativeMemoryBytes(processSnapshotAvailable, sample.ManagedBytes);
+        if (!sample.NativeMemoryBytes.HasValue)
+        {
+            var nativeMemory = TryReadNativeMemory(processSnapshotAvailable, sample.ManagedBytes);
+            sample.NativeMemoryBytes = nativeMemory.Bytes;
+            sample.NativeMemoryKind = nativeMemory.Kind;
+        }
         sample.CpuPercent = cpuPercent;
         sample.ThreadCount = threadCount;
 
@@ -158,6 +163,7 @@ private ProfilerSample BuildFrameSample(DateTime now)
                 JankFrameCount = nativeSnapshot.JankFrameCount,
                 UiThreadStallCount = nativeSnapshot.UiThreadStallCount,
                 NativeMemoryBytes = nativeSnapshot.NativeMemoryBytes,
+                NativeMemoryKind = nativeSnapshot.NativeMemoryKind,
                 FrameSource = nativeSnapshot.Source,
                 FrameQuality = _nativeFrameStatsProvider.ProvidesExactFrameTimings
                     ? "native.exact"
@@ -255,26 +261,26 @@ ex is InvalidOperationException
         }
     }
 
-    private long? TryReadNativeMemoryBytes(bool processSnapshotAvailable, long managedBytes)
+    private (long? Bytes, string? Kind) TryReadNativeMemory(bool processSnapshotAvailable, long managedBytes)
     {
         if (!_capabilities.NativeMemorySupported || !processSnapshotAvailable)
-            return null;
+            return (null, null);
 
         try
         {
             var workingSetBytes = _process.WorkingSet64;
             if (workingSetBytes <= 0)
-                return null;
+                return (null, null);
 
-            return Math.Max(0L, workingSetBytes - managedBytes);
+            return (Math.Max(0L, workingSetBytes - managedBytes), "process.working-set-minus-managed");
         }
         catch (Exception ex) when (
             ex is InvalidOperationException
             || ex is NotSupportedException
             || ex is PlatformNotSupportedException)
         {
             _capabilities.NativeMemorySupported = false;
-            return null;
+            return (null, null);
         }
     }
 

diff --git a/src/MauiDevFlow.Agent/Profiling/NativeFrameStatsProviderFactory.cs b/src/MauiDevFlow.Agent/Profiling/NativeFrameStatsProviderFactory.cs
@@ -182,6 +182,9 @@ public bool TryCollect(out NativeFrameStatsSnapshot snapshot)
             return false;
 
         snapshot.NativeMemoryBytes = TryReadAndroidNativeMemoryBytes();
+        snapshot.NativeMemoryKind = snapshot.NativeMemoryBytes.HasValue
+            ? "android.native-heap-allocated"
+            : null;
         return true;
     }
 
@@ -278,6 +281,9 @@ public bool TryCollect(out NativeFrameStatsSnapshot snapshot)
             return false;
 
         snapshot.NativeMemoryBytes = TryReadAndroidNativeMemoryBytes();
+        snapshot.NativeMemoryKind = snapshot.NativeMemoryBytes.HasValue
+            ? "android.native-heap-allocated"
+            : null;
         return true;
     }
 
@@ -386,6 +392,9 @@ public bool TryCollect(out NativeFrameStatsSnapshot snapshot)
             return false;
 
         snapshot.NativeMemoryBytes = TryReadPhysFootprint();
+        snapshot.NativeMemoryKind = snapshot.NativeMemoryBytes.HasValue
+            ? "apple.phys-footprint"
+            : null;
         return true;
     }
 
@@ -527,6 +536,9 @@ public bool TryCollect(out NativeFrameStatsSnapshot snapshot)
             return false;
 
         snapshot.NativeMemoryBytes = TryReadResidentMemoryBytes();
+        snapshot.NativeMemoryKind = snapshot.NativeMemoryBytes.HasValue
+            ? "windows.working-set"
+            : null;
         return true;
     }
 

diff --git a/src/MauiDevFlow.Driver/AgentClient.cs b/src/MauiDevFlow.Driver/AgentClient.cs
@@ -464,6 +464,8 @@ public class ProfilerSample
     public int Gc2 { get; set; }
     [System.Text.Json.Serialization.JsonPropertyName("nativeMemoryBytes")]
     public long? NativeMemoryBytes { get; set; }
+    [System.Text.Json.Serialization.JsonPropertyName("nativeMemoryKind")]
+    public string? NativeMemoryKind { get; set; }
     [System.Text.Json.Serialization.JsonPropertyName("cpuPercent")]
     public double? CpuPercent { get; set; }
     [System.Text.Json.Serialization.JsonPropertyName("threadCount")]

diff --git a/tests/MauiDevFlow.Tests/ProfilerAgentClientTests.cs b/tests/MauiDevFlow.Tests/ProfilerAgentClientTests.cs
@@ -54,6 +54,7 @@ public async Task Profiler_StartStopAndPollFlow_WorksThroughAgentClient()
                           "worstFrameTimeMs": 48.2,
                           "managedBytes": 2048,
                           "nativeMemoryBytes": 8192,
+                          "nativeMemoryKind": "android.native-heap-allocated",
                           "gc0": 1,
                           "gc1": 0,
                           "gc2": 0,
@@ -130,6 +131,7 @@ public async Task Profiler_StartStopAndPollFlow_WorksThroughAgentClient()
         Assert.Equal("native.android.choreographer", batch.Samples[0].FrameSource);
         Assert.Equal(3, batch.Samples[0].JankFrameCount);
         Assert.Equal(8192, batch.Samples[0].NativeMemoryBytes);
+        Assert.Equal("android.native-heap-allocated", batch.Samples[0].NativeMemoryKind);
         Assert.Equal(1, batch.SampleCursor);
         Assert.Equal(1, batch.MarkerCursor);
         Assert.Equal(1, batch.SpanCursor);

diff --git a/tests/MauiDevFlow.Tests/ProfilerCoreTests.cs b/tests/MauiDevFlow.Tests/ProfilerCoreTests.cs
@@ -30,6 +30,7 @@ public void ProfilerBatch_SerializesAndDeserializes()
                     WorstFrameTimeMs = 31.2,
                     ManagedBytes = 123_456,
                     NativeMemoryBytes = 654_321,
+                    NativeMemoryKind = "android.native-heap-allocated",
                     Gc0 = 10,
                     Gc1 = 4,
                     Gc2 = 1,
@@ -79,6 +80,7 @@ public void ProfilerBatch_SerializesAndDeserializes()
         Assert.Equal(4, parsed.SpanCursor);
         Assert.Equal(123_456, parsed.Samples[0].ManagedBytes);
         Assert.Equal(654_321, parsed.Samples[0].NativeMemoryBytes);
+        Assert.Equal("android.native-heap-allocated", parsed.Samples[0].NativeMemoryKind);
         Assert.Equal("native.android.choreographer", parsed.Samples[0].FrameSource);
         Assert.Equal(2, parsed.Samples[0].JankFrameCount);
     }
@@ -175,6 +177,10 @@ public void RuntimeProfilerCollector_CollectsRuntimeMetrics()
         Assert.StartsWith("estimated", sample1.FrameQuality);
         Assert.True(sample1.Fps > 0);
         Assert.True(sample1.FrameTimeMsP95 > 0);
+        if (sample1.NativeMemoryBytes.HasValue)
+            Assert.Equal("process.working-set-minus-managed", sample1.NativeMemoryKind);
+        else
+            Assert.Null(sample1.NativeMemoryKind);
         Assert.True(sample2.TsUtc > sample1.TsUtc);
     }
 
@@ -213,6 +219,30 @@ public void RuntimeProfilerCollector_WhenNativeProviderStartFails_CleansUpAndFal
         Assert.False(capabilities.UiThreadStallSupported);
     }
 
+    [Fact]
+    public void RuntimeProfilerCollector_PropagatesNativeMemoryKindFromProvider()
+    {
+        var provider = new SnapshotNativeProvider(new NativeFrameStatsSnapshot
+        {
+            Source = "native.test",
+            Fps = 60,
+            FrameTimeMsP50 = 16.7,
+            FrameTimeMsP95 = 20.5,
+            WorstFrameTimeMs = 24.1,
+            NativeMemoryBytes = 42_000,
+            NativeMemoryKind = "apple.phys-footprint"
+        });
+        var collector = new RuntimeProfilerCollector(provider);
+
+        collector.Start(100);
+        var collected = collector.TryCollect(out var sample);
+        collector.Stop();
+
+        Assert.True(collected);
+        Assert.Equal(42_000, sample.NativeMemoryBytes);
+        Assert.Equal("apple.phys-footprint", sample.NativeMemoryKind);
+    }
+
     [Fact]
     public void ProfilerContractModels_StayAlignedWithDriverModels()
     {
@@ -351,4 +381,40 @@ public void Dispose()
         {
         }
     }
+
+    private sealed class SnapshotNativeProvider(NativeFrameStatsSnapshot snapshotToReturn) : INativeFrameStatsProvider
+    {
+        public bool IsSupported => true;
+        public bool ProvidesExactFrameTimings => true;
+        public string Source => snapshotToReturn.Source;
+
+        public void Start()
+        {
+        }
+
+        public void Stop()
+        {
+        }
+
+        public bool TryCollect(out NativeFrameStatsSnapshot snapshot)
+        {
+            snapshot = new NativeFrameStatsSnapshot
+            {
+                Source = snapshotToReturn.Source,
+                Fps = snapshotToReturn.Fps,
+                FrameTimeMsP50 = snapshotToReturn.FrameTimeMsP50,
+                FrameTimeMsP95 = snapshotToReturn.FrameTimeMsP95,
+                WorstFrameTimeMs = snapshotToReturn.WorstFrameTimeMs,
+                JankFrameCount = snapshotToReturn.JankFrameCount,
+                UiThreadStallCount = snapshotToReturn.UiThreadStallCount,
+                NativeMemoryBytes = snapshotToReturn.NativeMemoryBytes,
+                NativeMemoryKind = snapshotToReturn.NativeMemoryKind
+            };
+            return true;
+        }
+
+        public void Dispose()
+        {
+        }
+    }
 }