diff --git a/soundtrigger/sthal_cli/Android.bp b/soundtrigger/sthal_cli/Android.bp
new file mode 100644
index 0000000..dafdfc3
--- /dev/null
+++ b/soundtrigger/sthal_cli/Android.bp
@@ -0,0 +1,8 @@
+java_binary {
+    name: "sthal_cli",
+    wrapper: "sthal_cli",
+    srcs: ["java/**/*.java"],
+    static_libs: [
+        "android.hardware.soundtrigger-V2.4-java",
+    ],
+}
diff --git a/soundtrigger/sthal_cli/OWNERS b/soundtrigger/sthal_cli/OWNERS
new file mode 100644
index 0000000..e21b66e
--- /dev/null
+++ b/soundtrigger/sthal_cli/OWNERS
@@ -0,0 +1 @@
+include /media/java/android/media/soundtrigger_middleware/OWNERS
diff --git a/soundtrigger/sthal_cli/java/android/hardware/soundtrigger/cli/SthalCli.java b/soundtrigger/sthal_cli/java/android/hardware/soundtrigger/cli/SthalCli.java
new file mode 100644
index 0000000..ebefd90
--- /dev/null
+++ b/soundtrigger/sthal_cli/java/android/hardware/soundtrigger/cli/SthalCli.java
@@ -0,0 +1,406 @@
+/*
+ * Copyright 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.
+ */
+package android.hardware.soundtrigger.cli;
+
+import android.hardware.soundtrigger.V2_0.PhraseRecognitionExtra;
+import android.hardware.soundtrigger.V2_0.RecognitionMode;
+import android.hardware.soundtrigger.V2_0.SoundModelType;
+import android.hardware.soundtrigger.V2_3.OptionalModelParameterRange;
+import android.hardware.soundtrigger.V2_4.ISoundTriggerHw;
+import android.hardware.soundtrigger.V2_4.ISoundTriggerHwCallback;
+import android.hardware.soundtrigger.V2_4.ISoundTriggerHwGlobalCallback;
+import android.os.HidlMemoryUtil;
+import android.os.HwBinder;
+import android.os.RemoteException;
+import android.os.SystemProperties;
+import java.util.Scanner;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * This is a quick-and-dirty sound trigger HAL console mock.
+ *
+ * It would only work on userdebug builds.
+ *
+ * When this app is started, it will initially:
+ * - Register a ISoundTriggerHw HAL with an instance name "mock".
+ * - Set a sysprop that tells SoundTriggerMiddlewareService to try to connect to the mock instance
+ * rather than the default one.
+ * - Reboot the real (default) HAL.
+ *
+ * In response to that, SoundTriggerMiddlewareService is going to connect to the mock HAL and resume
+ * normal operation.
+ *
+ * Our mock HAL will print to stdout every call it receives as well as expose a basic set of
+ * operations for sending event callbacks to the client. This allows us to simulate the frameworks
+ * behavior in response to different HAL behaviors.
+ */
+public class SthalCli {
+    private static SoundTriggerImpl mService;
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) {
+        try {
+            System.out.println("Registering mock STHAL");
+            HwBinder.setTrebleTestingOverride(true);
+            mService = new SoundTriggerImpl();
+            mService.registerAsService("mock");
+
+            System.out.println("Rebooting STHAL");
+            SystemProperties.set("debug.soundtrigger_middleware.use_mock_hal", "true");
+            SystemProperties.set("sys.audio.restart.hal", "1");
+
+            while (processCommand())
+                ;
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            cleanup();
+        }
+    }
+
+    private static void cleanup() {
+        System.out.println("Cleaning up.");
+        SystemProperties.set("debug.soundtrigger_middleware.use_mock_hal", "false");
+        HwBinder.setTrebleTestingOverride(false);
+    }
+
+    private static boolean processCommand() {
+        String line = scanner.nextLine();
+        String[] tokens = line.split("\\s+");
+        if (tokens.length < 1) {
+            return false;
+        }
+        switch (tokens[0]) {
+            case "q":
+                return false;
+
+            case "a":
+                mService.sendOnResourcesAvailable();
+                return true;
+
+            case "u":
+                mService.sendModelUnloaded(Integer.parseInt(tokens[1]));
+                return true;
+
+            case "r":
+                mService.sendRecognitionEvent(
+                        Integer.parseInt(tokens[1]), Integer.parseInt(tokens[2]));
+                return true;
+
+            case "p":
+                mService.sendPhraseRecognitionEvent(
+                        Integer.parseInt(tokens[1]), Integer.parseInt(tokens[2]));
+                return true;
+
+            case "d":
+                mService.dumpModels();
+                return true;
+
+            case "h":
+                System.out.print("Available commands:\n"
+                        + "h - help\n"
+                        + "q - quit\n"
+                        + "a - send onResourcesAvailable event\n"
+                        + "u <model> - send modelUnloaded event\n"
+                        + "r <model> <status> - send recognitionEvent\n"
+                        + "p <model> <status> - send phraseRecognitionEvent\n"
+                        + "d - dump models\n");
+
+            default:
+                return true;
+        }
+    }
+
+    private static class SoundTriggerImpl extends ISoundTriggerHw.Stub {
+        static class Model {
+            final ISoundTriggerHwCallback callback;
+            final SoundModel model;
+            final PhraseSoundModel phraseModel;
+            public android.hardware.soundtrigger.V2_3.RecognitionConfig config = null;
+
+            Model(ISoundTriggerHwCallback callback, SoundModel model) {
+                this.callback = callback;
+                this.model = model;
+                this.phraseModel = null;
+            }
+
+            Model(ISoundTriggerHwCallback callback, PhraseSoundModel model) {
+                this.callback = callback;
+                this.model = null;
+                this.phraseModel = model;
+            }
+        }
+
+        private ISoundTriggerHwGlobalCallback mGlobalCallback;
+        private final ConcurrentMap<Integer, Model> mLoadedModels = new ConcurrentHashMap<>();
+        private int mHandleCounter = 1;
+
+        public void dumpModels() {
+            mLoadedModels.forEach((handle, model) -> {
+                System.out.println("+++ Model " + handle);
+                System.out.println("    config = " + model.config);
+                android.hardware.soundtrigger.V2_3.RecognitionConfig recognitionConfig =
+                        model.config;
+                if (recognitionConfig != null) {
+                    System.out.println("    ACTIVE recognitionConfig = " + recognitionConfig);
+                } else {
+                    System.out.println("    INACTIVE");
+                }
+            });
+        }
+
+        public void sendOnResourcesAvailable() {
+            if (mGlobalCallback != null) {
+                try {
+                    mGlobalCallback.onResourcesAvailable();
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        public void sendRecognitionEvent(int modelHandle, int status) {
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null && model.config != null) {
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback.RecognitionEvent event =
+                        new android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback
+                                .RecognitionEvent();
+                event.header.model = modelHandle;
+                event.header.type = SoundModelType.GENERIC;
+                event.header.status = status;
+                event.header.captureSession = model.config.base.header.captureHandle;
+                event.header.captureAvailable = true;
+                event.header.audioConfig.channelMask = 16;
+                event.header.audioConfig.format = 1;
+                event.header.audioConfig.sampleRateHz = 16000;
+                event.data = HidlMemoryUtil.byteArrayToHidlMemory(new byte[0]);
+                try {
+                    model.callback.recognitionCallback_2_1(event, 0);
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+                model.config = null;
+            }
+        }
+
+        public void sendPhraseRecognitionEvent(int modelHandle, int status) {
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null && model.config != null) {
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback
+                        .PhraseRecognitionEvent event =
+                        new android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback
+                                .PhraseRecognitionEvent();
+                event.common.header.model = modelHandle;
+                event.common.header.type = SoundModelType.KEYPHRASE;
+                event.common.header.status = status;
+                event.common.header.captureSession = model.config.base.header.captureHandle;
+                event.common.header.captureAvailable = true;
+                event.common.header.audioConfig.channelMask = 16;
+                event.common.header.audioConfig.format = 1;
+                event.common.header.audioConfig.sampleRateHz = 16000;
+                event.common.data = HidlMemoryUtil.byteArrayToHidlMemory(new byte[0]);
+                if (!model.phraseModel.phrases.isEmpty()) {
+                    PhraseRecognitionExtra extra = new PhraseRecognitionExtra();
+                    extra.id = model.phraseModel.phrases.get(0).id;
+                    extra.confidenceLevel = 100;
+                    extra.recognitionModes = model.phraseModel.phrases.get(0).recognitionModes;
+                    event.phraseExtras.add(extra);
+                }
+                try {
+                    model.callback.phraseRecognitionCallback_2_1(event, 0);
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+                model.config = null;
+            }
+        }
+
+        public void sendModelUnloaded(int modelHandle) {
+            Model model = mLoadedModels.remove(modelHandle);
+            if (model != null) {
+                try {
+                    model.callback.modelUnloaded(modelHandle);
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        @Override
+        public void registerGlobalCallback(ISoundTriggerHwGlobalCallback callback) {
+            System.out.println("registerGlobalCallback()");
+            mGlobalCallback = callback;
+        }
+
+        @Override
+        public void loadSoundModel_2_4(SoundModel soundModel, ISoundTriggerHwCallback callback,
+                loadSoundModel_2_4Callback _hidl_cb) {
+            int handle = mHandleCounter++;
+            System.out.println(
+                    String.format("loadSoundModel_2_4(soundModel=%s) -> %d", soundModel, handle));
+            mLoadedModels.put(handle, new Model(callback, soundModel));
+            _hidl_cb.onValues(0, handle);
+        }
+
+        @Override
+        public void loadPhraseSoundModel_2_4(PhraseSoundModel soundModel,
+                ISoundTriggerHwCallback callback, loadPhraseSoundModel_2_4Callback _hidl_cb) {
+            int handle = mHandleCounter++;
+            System.out.println(String.format(
+                    "loadPhraseSoundModel_2_4(soundModel=%s) -> %d", soundModel, handle));
+            mLoadedModels.put(handle, new Model(callback, soundModel));
+            _hidl_cb.onValues(0, handle);
+        }
+
+        @Override
+        public int startRecognition_2_4(
+                int modelHandle, android.hardware.soundtrigger.V2_3.RecognitionConfig config) {
+            System.out.println(String.format("startRecognition_2_4(modelHandle=%d)", modelHandle));
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null) {
+                model.config = config;
+            }
+            return 0;
+        }
+
+        @Override
+        public void getProperties_2_3(getProperties_2_3Callback _hidl_cb) {
+            System.out.println("getProperties_2_3()");
+            android.hardware.soundtrigger.V2_3.Properties properties =
+                    new android.hardware.soundtrigger.V2_3.Properties();
+            properties.base.implementor = "Android";
+            properties.base.description = "Mock STHAL";
+            properties.base.maxSoundModels = 2;
+            properties.base.maxKeyPhrases = 1;
+            properties.base.recognitionModes =
+                    RecognitionMode.VOICE_TRIGGER | RecognitionMode.GENERIC_TRIGGER;
+            _hidl_cb.onValues(0, properties);
+        }
+
+        @Override
+        public void queryParameter(
+                int modelHandle, int modelParam, queryParameterCallback _hidl_cb) {
+            _hidl_cb.onValues(0, new OptionalModelParameterRange());
+        }
+
+        @Override
+        public int getModelState(int modelHandle) {
+            System.out.println(String.format("getModelState(modelHandle=%d)", modelHandle));
+            return 0;
+        }
+
+        @Override
+        public int unloadSoundModel(int modelHandle) {
+            System.out.println(String.format("unloadSoundModel(modelHandle=%d)", modelHandle));
+            return 0;
+        }
+
+        @Override
+        public int stopRecognition(int modelHandle) {
+            System.out.println(String.format("stopRecognition(modelHandle=%d)", modelHandle));
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null) {
+                model.config = null;
+            }
+            return 0;
+        }
+
+        @Override
+        public void debug(android.os.NativeHandle fd, java.util.ArrayList<String> options) {
+            if (!options.isEmpty()) {
+                switch (options.get(0)) {
+                    case "reboot":
+                        System.out.println("Received a reboot request. Exiting.");
+                        cleanup();
+                        System.exit(1);
+                }
+            }
+        }
+
+        ////////////////////////////////////////////////////////////////////////////////////////////
+        // Everything below is not implemented and not expected to be called.
+
+        @Override
+        public int startRecognition_2_3(
+                int modelHandle, android.hardware.soundtrigger.V2_3.RecognitionConfig config) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int setParameter(int modelHandle, int modelParam, int value) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void getParameter(int modelHandle, int modelParam, getParameterCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadSoundModel_2_1(SoundModel soundModel,
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback callback, int cookie,
+                loadSoundModel_2_1Callback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadPhraseSoundModel_2_1(PhraseSoundModel soundModel,
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback callback, int cookie,
+                loadPhraseSoundModel_2_1Callback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int startRecognition_2_1(int modelHandle, RecognitionConfig config,
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback callback, int cookie) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void getProperties(getPropertiesCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadSoundModel(
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHw.SoundModel soundModel,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHwCallback callback, int cookie,
+                loadSoundModelCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadPhraseSoundModel(
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHw.PhraseSoundModel soundModel,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHwCallback callback, int cookie,
+                loadPhraseSoundModelCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int startRecognition(int modelHandle,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHw.RecognitionConfig config,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHwCallback callback, int cookie) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int stopAllRecognitions() {
+            throw new UnsupportedOperationException();
+        }
+    }
+}
\ No newline at end of file
diff --git a/soundtrigger/sthal_cli/sthal_cli b/soundtrigger/sthal_cli/sthal_cli
new file mode 100644
index 0000000..9fc6779
--- /dev/null
+++ b/soundtrigger/sthal_cli/sthal_cli
@@ -0,0 +1,7 @@
+#!/system/bin/sh
+# Script to start "sthal_cli" on the device
+#
+base=/system
+export CLASSPATH=$base/framework/sthal_cli.jar
+exec app_process $base/bin android.hardware.soundtrigger.cli.SthalCli "$@"
+