diff --git a/hwc3/ComposerClient.h b/hwc3/ComposerClient.h
new file mode 100644
index 0000000..bdf4b0a
--- /dev/null
+++ b/hwc3/ComposerClient.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2021 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 <aidl/android/hardware/graphics/common/DisplayDecorationSupport.h>
+#include <aidl/android/hardware/graphics/composer3/BnComposerClient.h>
+#include <utils/Mutex.h>
+
+#include <memory>
+
+using AidlPixelFormat = aidl::android::hardware::graphics::common::PixelFormat;
+using AidlNativeHandle = aidl::android::hardware::common::NativeHandle;
+
+namespace aidl::android::hardware::graphics::composer3::impl {
+
+class ComposerClient : public BnComposerClient {
+ public:
+  ComposerClient() = default;
+  ~ComposerClient() override;
+
+  // composer3 interface
+  ndk::ScopedAStatus createLayer(int64_t display, int32_t buffer_slot_count,
+                                 int64_t* layer) override;
+  ndk::ScopedAStatus createVirtualDisplay(int32_t width, int32_t height,
+                                          AidlPixelFormat format_hint,
+                                          int32_t output_buffer_slot_count,
+                                          VirtualDisplay* display) override;
+  ndk::ScopedAStatus destroyLayer(int64_t display, int64_t layer) override;
+  ndk::ScopedAStatus destroyVirtualDisplay(int64_t display) override;
+  ndk::ScopedAStatus executeCommands(
+      const std::vector<DisplayCommand>& commands,
+      std::vector<CommandResultPayload>* results) override;
+  ndk::ScopedAStatus getActiveConfig(int64_t display, int32_t* config) override;
+  ndk::ScopedAStatus getColorModes(
+      int64_t display, std::vector<ColorMode>* color_modes) override;
+  ndk::ScopedAStatus getDataspaceSaturationMatrix(
+      common::Dataspace dataspace, std::vector<float>* matrix) override;
+  ndk::ScopedAStatus getDisplayAttribute(int64_t display, int32_t config,
+                                         DisplayAttribute attribute,
+                                         int32_t* value) override;
+  ndk::ScopedAStatus getDisplayCapabilities(
+      int64_t display, std::vector<DisplayCapability>* caps) override;
+  ndk::ScopedAStatus getDisplayConfigs(int64_t display,
+                                       std::vector<int32_t>* configs) override;
+  ndk::ScopedAStatus getDisplayConnectionType(
+      int64_t display, DisplayConnectionType* type) override;
+  ndk::ScopedAStatus getDisplayIdentificationData(
+      int64_t display, DisplayIdentification* id) override;
+  ndk::ScopedAStatus getDisplayName(int64_t display,
+                                    std::string* name) override;
+  ndk::ScopedAStatus getDisplayVsyncPeriod(int64_t display,
+                                           int32_t* vsync_period) override;
+  ndk::ScopedAStatus getDisplayedContentSample(
+      int64_t display, int64_t max_frames, int64_t timestamp,
+      DisplayContentSample* samples) override;
+  ndk::ScopedAStatus getDisplayedContentSamplingAttributes(
+      int64_t display, DisplayContentSamplingAttributes* attrs) override;
+  ndk::ScopedAStatus getDisplayPhysicalOrientation(
+      int64_t display, common::Transform* orientation) override;
+  ndk::ScopedAStatus getHdrCapabilities(int64_t display,
+                                        HdrCapabilities* caps) override;
+  ndk::ScopedAStatus getMaxVirtualDisplayCount(int32_t* count) override;
+  ndk::ScopedAStatus getPerFrameMetadataKeys(
+      int64_t display, std::vector<PerFrameMetadataKey>* keys) override;
+  ndk::ScopedAStatus getReadbackBufferAttributes(
+      int64_t display, ReadbackBufferAttributes* attrs) override;
+  ndk::ScopedAStatus getReadbackBufferFence(
+      int64_t display, ndk::ScopedFileDescriptor* acquire_fence) override;
+  ndk::ScopedAStatus getRenderIntents(
+      int64_t display, ColorMode mode,
+      std::vector<RenderIntent>* intents) override;
+  ndk::ScopedAStatus getSupportedContentTypes(
+      int64_t display, std::vector<ContentType>* types) override;
+  ndk::ScopedAStatus getDisplayDecorationSupport(
+      int64_t display,
+      std::optional<common::DisplayDecorationSupport>* support) override;
+  ndk::ScopedAStatus registerCallback(
+      const std::shared_ptr<IComposerCallback>& callback) override;
+  ndk::ScopedAStatus setActiveConfig(int64_t display, int32_t config) override;
+  ndk::ScopedAStatus setActiveConfigWithConstraints(
+      int64_t display, int32_t config,
+      const VsyncPeriodChangeConstraints& constraints,
+      VsyncPeriodChangeTimeline* timeline) override;
+  ndk::ScopedAStatus setBootDisplayConfig(int64_t display,
+                                          int32_t config) override;
+  ndk::ScopedAStatus clearBootDisplayConfig(int64_t display) override;
+  ndk::ScopedAStatus getPreferredBootDisplayConfig(int64_t display,
+                                                   int32_t* config) override;
+  ndk::ScopedAStatus setAutoLowLatencyMode(int64_t display, bool on) override;
+  ndk::ScopedAStatus setClientTargetSlotCount(int64_t display,
+                                              int32_t count) override;
+  ndk::ScopedAStatus setColorMode(int64_t display, ColorMode mode,
+                                  RenderIntent intent) override;
+  ndk::ScopedAStatus setContentType(int64_t display, ContentType type) override;
+  ndk::ScopedAStatus setDisplayedContentSamplingEnabled(
+      int64_t display, bool enable, FormatColorComponent component_mask,
+      int64_t max_frames) override;
+  ndk::ScopedAStatus setPowerMode(int64_t display, PowerMode mode) override;
+  ndk::ScopedAStatus setReadbackBuffer(
+      int64_t display, const AidlNativeHandle& buffer,
+      const ndk::ScopedFileDescriptor& release_fence) override;
+  ndk::ScopedAStatus setVsyncEnabled(int64_t display, bool enabled) override;
+  ndk::ScopedAStatus setIdleTimerEnabled(int64_t display,
+                                         int32_t timeout) override;
+
+ protected:
+  ::ndk::SpAIBinder createBinder() override;
+};
+
+}  // namespace aidl::android::hardware::graphics::composer3::impl