diff --git a/graphics/composer/2.3/IComposerClient.hal b/graphics/composer/2.3/IComposerClient.hal
index e5ee3c5..cf78dea 100644
--- a/graphics/composer/2.3/IComposerClient.hal
+++ b/graphics/composer/2.3/IComposerClient.hal
@@ -20,6 +20,7 @@
 import android.hardware.graphics.common@1.1::PixelFormat;
 import android.hardware.graphics.common@1.2::ColorMode;
 import android.hardware.graphics.common@1.2::Dataspace;
+import android.hardware.graphics.common@1.2::Hdr;
 import android.hardware.graphics.composer@2.1::IComposerClient.Command;
 import @2.2::IComposerClient;
 import @2.1::Display;
@@ -27,7 +28,7 @@
 
 interface IComposerClient extends @2.2::IComposerClient {
 
-    // TODO: Move this enum to LLNDK after we decide where to put graphic types.
+    // Bug: Move this enum to LLNDK after we decide where to put graphic types.
     /**
      * Required capabilities which are supported by the display. The
      * particular set of supported capabilities for a given display may be
@@ -63,6 +64,48 @@
         DOZE = 2,
     };
 
+    //Bug: Move this enum to LLNDK after we decide where to put graphic types.
+    /**
+     * PerFrameMetadataKey
+     *
+     * A set of PerFrameMetadataKey pertains specifically to blob-formatted
+     * metadata (as opposed to float-valued metadata).
+     * The list of keys that represent blobs are:
+     * 1. HDR10_PLUS_SEI
+     */
+    enum PerFrameMetadataKey : @2.2::IComposerClient.PerFrameMetadataKey {
+        /**HDR10+ metadata
+         * Specifies a metadata blob adhering to
+         * the ST2094-40 SEI message spec, Version 1.0
+         */
+        HDR10_PLUS_SEI,
+    };
+
+    /**
+     * PerFrameMetadata
+     * This struct encapsulates float-valued
+     * metadata - key must not be in the list
+     * of keys representing blob-formatted metadata
+     * (see PerFrameMetadataKey)
+     */
+    struct PerFrameMetadata {
+        PerFrameMetadataKey key;
+        float value;
+    };
+
+    /**
+     * PerFrameMetadataBlob
+     * This struct encapsulates blob
+     * metadata - key must be one of the list of keys
+     * associated with blob-type metadata key
+     * and the blob must adhere to the format specified by
+     * that key (See PerFrameMetadataKey).
+     */
+    struct PerFrameMetadataBlob {
+        PerFrameMetadataKey key;
+        vec<uint8_t> blob;
+    };
+
     enum Command : @2.2::IComposerClient.Command {
         /**
          * SET_LAYER_COLOR_TRANSFORM has this pseudo prototype
@@ -106,6 +149,22 @@
          * @param matrix is a 4x4 transform matrix (16 floats) as described above.
          */
         SET_LAYER_COLOR_TRANSFORM = 0x40d << @2.1::IComposerClient.Command:OPCODE_SHIFT,
+
+        /* SET_LAYER_PER_FRAME_METADATA_BLOBS has this pseudo prototype
+         *
+         *   setLayerPerFrameMetadataBlobs(Display display, Layer layer,
+         *                                   vec<PerFrameMetadataBlob> metadata);
+         *
+         *   This command sends metadata that may be used for tone-mapping the
+         *   associated layer.  The metadata structure follows a {key, blob}
+         *   format (see the PerFrameMetadataBlob struct).  All keys must be
+         *   returned by a prior call to getPerFrameMetadataKeys and must
+         *   be part of the list of keys associated with blob-type metadata
+         *   (see PerFrameMetadataKey).
+         *
+         *   This method may be called every frame.
+         */
+        SET_LAYER_PER_FRAME_METADATA_BLOBS = 0x304 << @2.1::IComposerClient.Command:OPCODE_SHIFT,
     };
 
     /**
@@ -399,4 +458,43 @@
     getDisplayCapabilities(Display display)
               generates (Error error,
                          vec<DisplayCapability> capabilities);
+
+    /**
+     * Returns the PerFrameMetadataKeys that are supported by this device.
+     *
+     * @param display is the display on which to create the layer.
+     * @return keys is the vector of PerFrameMetadataKey keys that are
+     *        supported by this device.
+     * @return error is NONE upon success. Otherwise,
+     *         UNSUPPORTED if not supported on underlying HAL
+     */
+    getPerFrameMetadataKeys_2_3(Display display)
+          generates (Error error,
+                     vec<PerFrameMetadataKey> keys);
+
+    /**
+     * Returns the high dynamic range (HDR) capabilities of the given display,
+     * which are invariant with regard to the active configuration.
+     *
+     * Displays which are not HDR-capable must return no types.
+     *
+     * @param display is the display to query.
+     * @return error is NONE upon success. Otherwise,
+     *         BAD_DISPLAY when an invalid display handle was passed in.
+     * @return types is an array of HDR types, may have 0 elements if the
+     *         display is not HDR-capable.
+     * @return maxLuminance is the desired content maximum luminance for this
+     *         display in cd/m^2.
+     * @return maxAverageLuminance - the desired content maximum frame-average
+     *         luminance for this display in cd/m^2.
+     * @return minLuminance is the desired content minimum luminance for this
+     *         display in cd/m^2.
+     */
+    @callflow(next="*")
+    getHdrCapabilities_2_3(Display display)
+            generates (Error error,
+                       vec<Hdr> types,
+                       float maxLuminance,
+                       float maxAverageLuminance,
+                       float minLuminance);
 };