diff --git a/audio/aidl/default/extension/Android.bp b/audio/aidl/default/extension/Android.bp
new file mode 100644
index 0000000..4e5d352
--- /dev/null
+++ b/audio/aidl/default/extension/Android.bp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "hardware_interfaces_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["hardware_interfaces_license"],
+}
+
+cc_library_shared {
+    name: "libextensioneffect",
+    defaults: [
+        "aidlaudioeffectservice_defaults",
+        "latest_android_media_audio_common_types_ndk_shared",
+        "latest_android_hardware_audio_effect_ndk_shared",
+    ],
+    srcs: [
+        "ExtensionEffect.cpp",
+        ":effectCommonFile",
+    ],
+    relative_install_path: "soundfx",
+    visibility: [
+        "//hardware/interfaces/audio/aidl/default",
+    ],
+}
diff --git a/audio/aidl/default/extension/ExtensionEffect.cpp b/audio/aidl/default/extension/ExtensionEffect.cpp
new file mode 100644
index 0000000..d2e3ccd
--- /dev/null
+++ b/audio/aidl/default/extension/ExtensionEffect.cpp
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2023 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 <algorithm>
+#include <cstddef>
+#include <memory>
+#include <unordered_set>
+
+#define LOG_TAG "AHAL_ExtensionEffect"
+#include <Utils.h>
+#include <aidl/android/hardware/audio/effect/DefaultExtension.h>
+#include <android-base/logging.h>
+#include <fmq/AidlMessageQueue.h>
+
+#include "ExtensionEffect.h"
+
+using aidl::android::hardware::audio::effect::DefaultExtension;
+using aidl::android::hardware::audio::effect::Descriptor;
+using aidl::android::hardware::audio::effect::ExtensionEffect;
+using aidl::android::hardware::audio::effect::IEffect;
+using aidl::android::hardware::audio::effect::kExtensionEffectImplUUID;
+using aidl::android::hardware::audio::effect::kExtensionEffectTypeUUID;
+using aidl::android::hardware::audio::effect::Range;
+using aidl::android::hardware::audio::effect::VendorExtension;
+using aidl::android::media::audio::common::AudioUuid;
+
+extern "C" binder_exception_t createEffect(const AudioUuid* in_impl_uuid,
+                                           std::shared_ptr<IEffect>* instanceSpp) {
+    if (!in_impl_uuid || *in_impl_uuid != kExtensionEffectImplUUID) {
+        LOG(ERROR) << __func__ << "uuid not supported";
+        return EX_ILLEGAL_ARGUMENT;
+    }
+    if (instanceSpp) {
+        *instanceSpp = ndk::SharedRefBase::make<ExtensionEffect>();
+        LOG(DEBUG) << __func__ << " instance " << instanceSpp->get() << " created";
+        return EX_NONE;
+    } else {
+        LOG(ERROR) << __func__ << " invalid input parameter!";
+        return EX_ILLEGAL_ARGUMENT;
+    }
+}
+
+extern "C" binder_exception_t queryEffect(const AudioUuid* in_impl_uuid, Descriptor* _aidl_return) {
+    if (!in_impl_uuid || *in_impl_uuid != kExtensionEffectImplUUID) {
+        LOG(ERROR) << __func__ << "uuid not supported";
+        return EX_ILLEGAL_ARGUMENT;
+    }
+    *_aidl_return = ExtensionEffect::kDescriptor;
+    return EX_NONE;
+}
+
+namespace aidl::android::hardware::audio::effect {
+
+const std::string ExtensionEffect::kEffectName = "ExtensionEffectExample";
+
+const Descriptor ExtensionEffect::kDescriptor = {
+        .common = {.id = {.type = kExtensionEffectTypeUUID,
+                          .uuid = kExtensionEffectImplUUID,
+                          .proxy = std::nullopt},
+                   .name = ExtensionEffect::kEffectName,
+                   .implementor = "The Android Open Source Project"}};
+
+ndk::ScopedAStatus ExtensionEffect::getDescriptor(Descriptor* _aidl_return) {
+    LOG(DEBUG) << __func__ << kDescriptor.toString();
+    *_aidl_return = kDescriptor;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ExtensionEffect::setParameterSpecific(const Parameter::Specific& specific) {
+    RETURN_IF(Parameter::Specific::vendorEffect != specific.getTag(), EX_ILLEGAL_ARGUMENT,
+              "EffectNotSupported");
+    RETURN_IF(!mContext, EX_NULL_POINTER, "nullContext");
+
+    auto& vendorEffect = specific.get<Parameter::Specific::vendorEffect>();
+    std::optional<DefaultExtension> defaultExt;
+    RETURN_IF(STATUS_OK != vendorEffect.extension.getParcelable(&defaultExt), EX_ILLEGAL_ARGUMENT,
+              "getParcelableFailed");
+    RETURN_IF(!defaultExt.has_value(), EX_ILLEGAL_ARGUMENT, "parcelableNulld");
+    RETURN_IF(mContext->setParams(defaultExt->bytes) != RetCode::SUCCESS, EX_ILLEGAL_ARGUMENT,
+              "paramNotSupported");
+
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ExtensionEffect::getParameterSpecific(const Parameter::Id& id,
+                                                         Parameter::Specific* specific) {
+    auto tag = id.getTag();
+    RETURN_IF(Parameter::Id::vendorEffectTag != tag, EX_ILLEGAL_ARGUMENT, "wrongIdTag");
+    auto specificId = id.get<Parameter::Id::vendorEffectTag>();
+    VendorExtension extension;
+    DefaultExtension defaultExt;
+    defaultExt.bytes = mContext->getParams(specificId);
+    RETURN_IF(STATUS_OK != extension.extension.setParcelable(defaultExt), EX_ILLEGAL_ARGUMENT,
+              "setParcelableFailed");
+    specific->set<Parameter::Specific::vendorEffect>(extension);
+    return ndk::ScopedAStatus::ok();
+}
+
+std::shared_ptr<EffectContext> ExtensionEffect::createContext(const Parameter::Common& common) {
+    if (mContext) {
+        LOG(DEBUG) << __func__ << " context already exist";
+    } else {
+        mContext = std::make_shared<ExtensionEffectContext>(1 /* statusFmqDepth */, common);
+    }
+    return mContext;
+}
+
+std::shared_ptr<EffectContext> ExtensionEffect::getContext() {
+    return mContext;
+}
+
+RetCode ExtensionEffect::releaseContext() {
+    if (mContext) {
+        mContext.reset();
+    }
+    return RetCode::SUCCESS;
+}
+
+// Processing method running in EffectWorker thread.
+IEffect::Status ExtensionEffect::effectProcessImpl(float* in, float* out, int samples) {
+    // TODO: get data buffer and process.
+    LOG(DEBUG) << __func__ << " in " << in << " out " << out << " samples " << samples;
+    for (int i = 0; i < samples; i++) {
+        *out++ = *in++;
+    }
+    return {STATUS_OK, samples, samples};
+}
+
+}  // namespace aidl::android::hardware::audio::effect
diff --git a/audio/aidl/default/extension/ExtensionEffect.h b/audio/aidl/default/extension/ExtensionEffect.h
new file mode 100644
index 0000000..399fa83
--- /dev/null
+++ b/audio/aidl/default/extension/ExtensionEffect.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2023 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/audio/effect/BnEffect.h>
+#include <fmq/AidlMessageQueue.h>
+#include <memory>
+#include <vector>
+
+#include "effect-impl/EffectImpl.h"
+#include "effect-impl/EffectUUID.h"
+
+namespace aidl::android::hardware::audio::effect {
+
+class ExtensionEffectContext final : public EffectContext {
+  public:
+    ExtensionEffectContext(int statusDepth, const Parameter::Common& common)
+        : EffectContext(statusDepth, common) {
+        LOG(DEBUG) << __func__;
+    }
+
+    RetCode setParams(const std::vector<uint8_t>& params) {
+        mParams = params;
+        return RetCode::SUCCESS;
+    }
+    std::vector<uint8_t> getParams(int tag __unused) const { return mParams; }
+
+  private:
+    std::vector<uint8_t> mParams;
+};
+
+class ExtensionEffect final : public EffectImpl {
+  public:
+    static const std::string kEffectName;
+    static const Capability kCapability;
+    static const Descriptor kDescriptor;
+    ExtensionEffect() { LOG(DEBUG) << __func__; }
+    ~ExtensionEffect() {
+        cleanUp();
+        LOG(DEBUG) << __func__;
+    }
+
+    ndk::ScopedAStatus getDescriptor(Descriptor* _aidl_return) override;
+    ndk::ScopedAStatus setParameterSpecific(const Parameter::Specific& specific) override;
+    ndk::ScopedAStatus getParameterSpecific(const Parameter::Id& id,
+                                            Parameter::Specific* specific) override;
+
+    std::shared_ptr<EffectContext> createContext(const Parameter::Common& common) override;
+    std::shared_ptr<EffectContext> getContext() override;
+    RetCode releaseContext() override;
+
+    std::string getEffectName() override { return kEffectName; };
+    IEffect::Status effectProcessImpl(float* in, float* out, int samples) override;
+
+  private:
+    std::shared_ptr<ExtensionEffectContext> mContext;
+};
+}  // namespace aidl::android::hardware::audio::effect