diff --git a/bluetooth/audio/2.1/IBluetoothAudioProvider.hal b/bluetooth/audio/2.1/IBluetoothAudioProvider.hal
new file mode 100644
index 0000000..c462b9e
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+++ b/bluetooth/audio/2.1/IBluetoothAudioProvider.hal
@@ -0,0 +1,62 @@
+/*
+ * 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.
+ */
+
+package android.hardware.bluetooth.audio@2.1;
+
+import @2.0::IBluetoothAudioProvider;
+import @2.0::IBluetoothAudioPort;
+import @2.0::Status;
+
+/**
+ * HAL interface from the Bluetooth stack to the Audio HAL
+ *
+ * The Bluetooth stack calls methods in this interface to start and end audio
+ * sessions and sends callback events to the Audio HAL.
+ *
+ * Note: For HIDL APIs with a "generates" statement, the callback parameter used
+ * for return value must be invoked synchronously before the API call returns.
+ */
+interface IBluetoothAudioProvider extends @2.0::IBluetoothAudioProvider {
+
+    /**
+     * This method indicates that the Bluetooth stack is ready to stream audio.
+     * It registers an instance of IBluetoothAudioPort with and provides the
+     * current negotiated codec to the Audio HAL. After this method is called,
+     * the Audio HAL can invoke IBluetoothAudioPort.startStream().
+     *
+     * Note: endSession() must be called to unregister this IBluetoothAudioPort
+     *
+     * @param hostIf An instance of IBluetoothAudioPort for stream control
+     * @param audioConfig The audio configuration negotiated with the remote
+     *    device. The PCM parameters are set if software based encoding,
+     *    otherwise the correct codec configuration is used for hardware
+     *    encoding.
+     *
+     * @return status One of the following
+     *    SUCCESS if this IBluetoothAudioPort was successfully registered with
+     *        the Audio HAL
+     *    UNSUPPORTED_CODEC_CONFIGURATION if the Audio HAL cannot register this
+     *        IBluetoothAudioPort with the given codec configuration
+     *    FAILURE if the Audio HAL cannot register this IBluetoothAudioPort for
+     *        any other reason
+     * @return dataMQ The fast message queue for audio data from/to this
+     *    provider. Audio data will be in PCM format as specified by the
+     *    audioConfig.pcmConfig parameter. Invalid if streaming is offloaded
+     *    from/to hardware or on failure.
+     */
+    startSession_2_1(IBluetoothAudioPort hostIf, AudioConfiguration audioConfig)
+                generates (Status status, fmq_sync<uint8_t> dataMQ);
+};