diff --git a/.clang-tidy b/.clang-tidy
index 8336d3f..0fe4ea1 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -1,6 +1,3 @@
-# Turn all the warnings from the checks above into errors.
-WarningsAsErrors: "*"
-
 #HeaderFilterRegex: "^.*external/drm_hwcomposer/.*.h$"
 
 FormatStyle: google
diff --git a/Android.bp b/Android.bp
index 3e2fa94..6be50d6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -12,6 +12,23 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+package {
+    default_applicable_licenses: ["external_drm_hwcomposer_license"],
+}
+
+// Added automatically by a large-scale-change
+// See: http://go/android-license-faq
+license {
+    name: "external_drm_hwcomposer_license",
+    visibility: [":__subpackages__"],
+    license_kinds: [
+        "SPDX-license-identifier-Apache-2.0",
+    ],
+    license_text: [
+        "NOTICE",
+    ],
+}
+
 cc_library_headers {
     name: "drm_hwcomposer_headers",
     vendor: true,
@@ -175,7 +192,7 @@
     ],
 
     shared_libs: [
-        "android.hardware.graphics.composer3-V3-ndk",
+        "android.hardware.graphics.composer3-V4-ndk",
         "libbase",
         "libbinder_ndk",
         "liblog",
diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..d97975c
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,3 @@
+third_party {
+  license_type: NOTICE
+}
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..39f2084
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,4 @@
+adelva@google.com
+jstultz@google.com
+marcheu@google.com
+seanpaul@google.com
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
new file mode 100644
index 0000000..1f413f7
--- /dev/null
+++ b/PREUPLOAD.cfg
@@ -0,0 +1,3 @@
+[Hook Scripts]
+
+check hooks installed = hooks/check-hooks-installed
\ No newline at end of file
diff --git a/hooks/check-hooks-installed b/hooks/check-hooks-installed
new file mode 100755
index 0000000..45e5c73
--- /dev/null
+++ b/hooks/check-hooks-installed
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# Gerrit hook that runs on repo upload. Checks to ensure that the pre-upload hook
+# has been installed.
+
+cmd=$(git config hookcmd.check-non-public-commits.command)
+if [ -z "$cmd" ]; then
+  echo "Please install hooks by running: hooks/install-hooks.sh"
+  exit 1
+fi
\ No newline at end of file
diff --git a/hooks/check-non-public-commits b/hooks/check-non-public-commits
new file mode 100755
index 0000000..fc20795
--- /dev/null
+++ b/hooks/check-non-public-commits
@@ -0,0 +1,44 @@
+#!/bin/bash
+
+# git pre-push hook to detect whether a developer is attempting to push
+# non-public commits to a public repository.
+
+remote="$1"
+url="$2"
+
+# Don't bother checking if this is being pushed to gerrit.
+if [[ "$url" = "sso://googleplex-android/platform/external/drm_hwcomposer" ]] ||
+   [[ "$url" = "sso://android.googlesource.com/platform/external/drm_hwcomposer" ]]
+then
+  exit 0
+fi
+
+while read local_ref local_sha remote_ref remote_sha
+do
+  # Gather a list of all commits that are to be pushed to the remote.
+  # remote_sha will be 000000 if there is no corresponding remote branch.
+  if [[ "$remote_sha" =~ "0000000000" ]]; then
+    commits=$(git rev-list $local_sha --not --remotes=$remote)
+  else
+    commits=$(git rev-list $remote_sha..$local_sha)
+  fi
+
+  # Check each commit message for the prohibited prefix.
+  for commit in $commits; do
+    # Get the commit message.
+    message=$(git log -1 --pretty=%B $commit)
+
+    # Check if the commit message starts with "ANDROID:"
+    if [[ "$message" == "ANDROID"* ]] ||
+       [[ "$message" == "INTERNAL"* ]] ||
+       [[ "$message" == "DO NOT MERGE"* ]]; then
+      echo "Error: Commit message starts with downstream tag:"
+      echo "$message"
+      echo "It looks like you're trying to push internal changes to an externally "
+      echo "visible repository: $url"
+      exit 1
+    fi
+  done
+done
+
+exit 0
diff --git a/hooks/install-hooks.sh b/hooks/install-hooks.sh
new file mode 100755
index 0000000..cc5d967
--- /dev/null
+++ b/hooks/install-hooks.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+# Install hooks.
+git config --add hookcmd.check-non-public-commits.command "[ ! -d hooks ] || hooks/check-non-public-commits"
+git config --add hook.pre-push.command check-non-public-commits
\ No newline at end of file
diff --git a/hwc3/ComposerClient.cpp b/hwc3/ComposerClient.cpp
index 2aed2bc..76eb52a 100644
--- a/hwc3/ComposerClient.cpp
+++ b/hwc3/ComposerClient.cpp
@@ -30,6 +30,7 @@
 #include <aidl/android/hardware/graphics/composer3/Composition.h>
 #include <aidl/android/hardware/graphics/composer3/DisplayRequest.h>
 #include <aidl/android/hardware/graphics/composer3/IComposerClient.h>
+#include <aidl/android/hardware/graphics/composer3/Lut.h>
 #include <aidl/android/hardware/graphics/composer3/PowerMode.h>
 #include <aidl/android/hardware/graphics/composer3/PresentOrValidate.h>
 #include <aidl/android/hardware/graphics/composer3/RenderIntent.h>
@@ -552,6 +553,9 @@
   if (command.sidebandStream) {
     cmd_result_writer_->AddError(hwc3::Error::kUnsupported);
   }
+  if (command.luts) {
+    cmd_result_writer_->AddError(hwc3::Error::kUnsupported);
+  }
   // TODO: Blocking region handling missing.
   // TODO: Layer surface damage.
   // TODO: Layer visible region.
diff --git a/hwc3/hwc3-drm.xml b/hwc3/hwc3-drm.xml
index 911f7f8..7debcf9 100644
--- a/hwc3/hwc3-drm.xml
+++ b/hwc3/hwc3-drm.xml
@@ -1,7 +1,7 @@
 <manifest version="1.0" type="device">
     <hal format="aidl">
         <name>android.hardware.graphics.composer3</name>
-        <version>3</version>
+        <version>4</version>
         <interface>
             <name>IComposer</name>
             <instance>default</instance>
diff --git a/tests/Android.bp b/tests/Android.bp
index 6f44b9c..43fd3fa 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -19,6 +19,15 @@
     ],
 }
 
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "external_drm_hwcomposer_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["external_drm_hwcomposer_license"],
+}
+
 // Tool for listening and dumping uevents
 cc_test {
     name: "hwc-drm-uevent-print",