diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index ae265ca..a0e9cbf 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -30,6 +30,12 @@
     min_sdk_version: "29",
 }
 
+filegroup {
+    name: "libgui_aidl",
+    srcs: ["aidl/**/*.aidl"],
+    path: "aidl/",
+}
+
 cc_library_shared {
     name: "libgui",
     vendor_available: false,
@@ -42,6 +48,7 @@
 
     srcs: [
         ":framework_native_aidl",
+        ":libgui_aidl",
         ":libgui_bufferqueue_sources",
 
         "BitTube.cpp",
@@ -74,6 +81,7 @@
         "SurfaceControl.cpp",
         "SurfaceComposerClient.cpp",
         "SyncFeatures.cpp",
+        "TransactionTracing.cpp",
         "view/Surface.cpp",
         "bufferqueue/1.0/B2HProducerListener.cpp",
         "bufferqueue/1.0/H2BGraphicBufferProducer.cpp",
@@ -145,6 +153,7 @@
     defaults: ["libgui_bufferqueue-defaults"],
 
     srcs: [
+        ":libgui_aidl",
         ":libgui_bufferqueue_sources",
     ],
 }
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 5b7d2c5..7a2f656 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -20,6 +20,8 @@
 #include <stdint.h>
 #include <sys/types.h>
 
+#include <android/gui/ITransactionTraceListener.h>
+
 #include <binder/Parcel.h>
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
@@ -1197,6 +1199,15 @@
 
         return reply.readInt32();
     }
+
+    virtual status_t addTransactionTraceListener(
+            const sp<gui::ITransactionTraceListener>& listener) {
+        Parcel data, reply;
+        SAFE_PARCEL(data.writeInterfaceToken, ISurfaceComposer::getInterfaceDescriptor());
+        SAFE_PARCEL(data.writeStrongBinder, IInterface::asBinder(listener));
+
+        return remote()->transact(BnSurfaceComposer::ADD_TRANSACTION_TRACE_LISTENER, data, &reply);
+    }
 };
 
 // Out-of-line virtual method definition to trigger vtable emission in this
@@ -2026,6 +2037,13 @@
             reply->writeInt32(result);
             return NO_ERROR;
         }
+        case ADD_TRANSACTION_TRACE_LISTENER: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            sp<gui::ITransactionTraceListener> listener;
+            SAFE_PARCEL(data.readStrongBinder, &listener);
+
+            return addTransactionTraceListener(listener);
+        }
         default: {
             return BBinder::onTransact(code, data, reply, flags);
         }
diff --git a/libs/gui/TransactionTracing.cpp b/libs/gui/TransactionTracing.cpp
new file mode 100644
index 0000000..eedc3df
--- /dev/null
+++ b/libs/gui/TransactionTracing.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "gui/TransactionTracing.h"
+#include "gui/ISurfaceComposer.h"
+
+#include <private/gui/ComposerService.h>
+
+namespace android {
+
+sp<TransactionTraceListener> TransactionTraceListener::sInstance = nullptr;
+std::mutex TransactionTraceListener::sMutex;
+
+TransactionTraceListener::TransactionTraceListener() {}
+
+sp<TransactionTraceListener> TransactionTraceListener::getInstance() {
+    const std::lock_guard<std::mutex> lock(sMutex);
+
+    if (sInstance == nullptr) {
+        sInstance = new TransactionTraceListener;
+
+        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+        sf->addTransactionTraceListener(sInstance);
+    }
+
+    return sInstance;
+}
+
+binder::Status TransactionTraceListener::onToggled(bool enabled) {
+    ALOGD("TransactionTraceListener: onToggled listener called");
+    mTracingEnabled = enabled;
+
+    return binder::Status::ok();
+}
+
+bool TransactionTraceListener::isTracingEnabled() {
+    return mTracingEnabled;
+}
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/gui/aidl/android/gui/ITransactionTraceListener.aidl b/libs/gui/aidl/android/gui/ITransactionTraceListener.aidl
new file mode 100644
index 0000000..5cd12fd
--- /dev/null
+++ b/libs/gui/aidl/android/gui/ITransactionTraceListener.aidl
@@ -0,0 +1,6 @@
+package android.gui;
+
+/** @hide */
+interface ITransactionTraceListener {
+   void onToggled(boolean enabled);
+}
\ No newline at end of file
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index 7c25b97..3627deb 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -22,6 +22,7 @@
 #include <binder/IBinder.h>
 #include <binder/IInterface.h>
 
+#include <android/gui/ITransactionTraceListener.h>
 #include <gui/IScreenCaptureListener.h>
 #include <gui/ITransactionCompletedListener.h>
 
@@ -486,6 +487,12 @@
      */
     virtual status_t setFrameTimelineVsync(const sp<IGraphicBufferProducer>& surface,
                                            int64_t frameTimelineVsyncId) = 0;
+
+    /*
+     * Adds a TransactionTraceListener to listen for transaction tracing state updates.
+     */
+    virtual status_t addTransactionTraceListener(
+            const sp<gui::ITransactionTraceListener>& listener) = 0;
 };
 
 // ----------------------------------------------------------------------------
@@ -546,6 +553,7 @@
         SET_FRAME_RATE,
         ACQUIRE_FRAME_RATE_FLEXIBILITY_TOKEN,
         SET_FRAME_TIMELINE_VSYNC,
+        ADD_TRANSACTION_TRACE_LISTENER,
         // Always append new enum to the end.
     };
 
diff --git a/libs/gui/include/gui/TransactionTracing.h b/libs/gui/include/gui/TransactionTracing.h
new file mode 100644
index 0000000..9efba47
--- /dev/null
+++ b/libs/gui/include/gui/TransactionTracing.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <android/gui/BnTransactionTraceListener.h>
+#include <utils/Mutex.h>
+
+namespace android {
+
+class TransactionTraceListener : public gui::BnTransactionTraceListener {
+    static std::mutex sMutex;
+    static sp<TransactionTraceListener> sInstance;
+
+    TransactionTraceListener();
+
+public:
+    static sp<TransactionTraceListener> getInstance();
+
+    binder::Status onToggled(bool enabled) override;
+
+    bool isTracingEnabled();
+
+private:
+    bool mTracingEnabled = false;
+};
+
+} // namespace android
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 2508ebd..b8b8e4f 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -677,8 +677,7 @@
     NewFrameEventsEntry mNewFrameEntryOverride = { 0, 0, 0, nullptr };
 };
 
-
-class FakeSurfaceComposer : public ISurfaceComposer{
+class FakeSurfaceComposer : public ISurfaceComposer {
 public:
     ~FakeSurfaceComposer() override {}
 
@@ -878,6 +877,11 @@
         return NO_ERROR;
     }
 
+    status_t addTransactionTraceListener(
+            const sp<gui::ITransactionTraceListener>& /*listener*/) override {
+        return NO_ERROR;
+    }
+
 protected:
     IBinder* onAsBinder() override { return nullptr; }
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index e860dff..4b91da8 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4885,6 +4885,7 @@
             }
             return OK;
         }
+        case ADD_TRANSACTION_TRACE_LISTENER:
         case CAPTURE_DISPLAY_BY_ID: {
             IPCThreadState* ipc = IPCThreadState::self();
             const int uid = ipc->getCallingUid();
@@ -6230,6 +6231,17 @@
     }));
 }
 
+status_t SurfaceFlinger::addTransactionTraceListener(
+        const sp<gui::ITransactionTraceListener>& listener) {
+    if (!listener) {
+        return BAD_VALUE;
+    }
+
+    mInterceptor->addTransactionTraceListener(listener);
+
+    return NO_ERROR;
+}
+
 } // namespace android
 
 #if defined(__gl_h_)
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 5cd9dea..d6a75c3 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -596,6 +596,9 @@
     status_t setFrameTimelineVsync(const sp<IGraphicBufferProducer>& surface,
                                    int64_t frameTimelineVsyncId) override;
 
+    status_t addTransactionTraceListener(
+            const sp<gui::ITransactionTraceListener>& listener) override;
+
     // Implements IBinder::DeathRecipient.
     void binderDied(const wp<IBinder>& who) override;
 
diff --git a/services/surfaceflinger/SurfaceInterceptor.cpp b/services/surfaceflinger/SurfaceInterceptor.cpp
index d6b5338..9d705e5 100644
--- a/services/surfaceflinger/SurfaceInterceptor.cpp
+++ b/services/surfaceflinger/SurfaceInterceptor.cpp
@@ -45,9 +45,22 @@
 {
 }
 
+void SurfaceInterceptor::addTransactionTraceListener(
+        const sp<gui::ITransactionTraceListener>& listener) {
+    sp<IBinder> asBinder = IInterface::asBinder(listener);
+
+    std::scoped_lock lock(mListenersMutex);
+
+    asBinder->linkToDeath(this);
+
+    listener->onToggled(mEnabled); // notifies of current state
+
+    mTraceToggledListeners.emplace(asBinder, listener);
+}
+
 void SurfaceInterceptor::binderDied(const wp<IBinder>& who) {
-    // TODO: Implement
-    (void)who;
+    std::scoped_lock lock(mListenersMutex);
+    mTraceToggledListeners.erase(who);
 }
 
 void SurfaceInterceptor::enable(const SortedVector<sp<Layer>>& layers,
@@ -57,8 +70,14 @@
         return;
     }
     ATRACE_CALL();
+    {
+        std::scoped_lock lock(mListenersMutex);
+        for (const auto& [_, listener] : mTraceToggledListeners) {
+            listener->onToggled(true);
+        }
+    }
     mEnabled = true;
-    std::lock_guard<std::mutex> protoGuard(mTraceMutex);
+    std::scoped_lock<std::mutex> protoGuard(mTraceMutex);
     saveExistingDisplaysLocked(displays);
     saveExistingSurfacesLocked(layers);
 }
@@ -68,8 +87,14 @@
         return;
     }
     ATRACE_CALL();
-    std::lock_guard<std::mutex> protoGuard(mTraceMutex);
+    {
+        std::scoped_lock lock(mListenersMutex);
+        for (const auto& [_, listener] : mTraceToggledListeners) {
+            listener->onToggled(false);
+        }
+    }
     mEnabled = false;
+    std::scoped_lock<std::mutex> protoGuard(mTraceMutex);
     status_t err(writeProtoFileLocked());
     ALOGE_IF(err == PERMISSION_DENIED, "Could not save the proto file! Permission denied");
     ALOGE_IF(err == NOT_ENOUGH_DATA, "Could not save the proto file! There are missing fields");
diff --git a/services/surfaceflinger/SurfaceInterceptor.h b/services/surfaceflinger/SurfaceInterceptor.h
index 62cc717..4908bae 100644
--- a/services/surfaceflinger/SurfaceInterceptor.h
+++ b/services/surfaceflinger/SurfaceInterceptor.h
@@ -60,6 +60,8 @@
     virtual void disable() = 0;
     virtual bool isEnabled() = 0;
 
+    virtual void addTransactionTraceListener(
+            const sp<gui::ITransactionTraceListener>& listener) = 0;
     virtual void binderDied(const wp<IBinder>& who) = 0;
 
     // Intercept display and surface transactions
@@ -99,6 +101,7 @@
     void disable() override;
     bool isEnabled() override;
 
+    void addTransactionTraceListener(const sp<gui::ITransactionTraceListener>& listener) override;
     void binderDied(const wp<IBinder>& who) override;
 
     // Intercept display and surface transactions
@@ -199,6 +202,9 @@
     std::mutex mTraceMutex {};
     Trace mTrace {};
     SurfaceFlinger* const mFlinger;
+    std::mutex mListenersMutex;
+    std::map<wp<IBinder>, sp<gui::ITransactionTraceListener>> mTraceToggledListeners
+            GUARDED_BY(mListenersMutex);
 };
 
 } // namespace impl
diff --git a/services/surfaceflinger/tests/unittests/mock/MockSurfaceInterceptor.h b/services/surfaceflinger/tests/unittests/mock/MockSurfaceInterceptor.h
index 2f3f524..e2c8a65 100644
--- a/services/surfaceflinger/tests/unittests/mock/MockSurfaceInterceptor.h
+++ b/services/surfaceflinger/tests/unittests/mock/MockSurfaceInterceptor.h
@@ -33,6 +33,7 @@
                       const DefaultKeyedVector<wp<IBinder>, DisplayDeviceState>&));
     MOCK_METHOD0(disable, void());
     MOCK_METHOD0(isEnabled, bool());
+    MOCK_METHOD1(addTransactionTraceListener, void(const sp<gui::ITransactionTraceListener>&));
     MOCK_METHOD1(binderDied, void(const wp<IBinder>&));
     MOCK_METHOD6(saveTransaction,
                  void(const Vector<ComposerState>&,