diff --git a/core/api/current.txt b/core/api/current.txt
index fb0cff5fe53a5..1bf0d0e23782d 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -48771,6 +48771,10 @@ package android.view {
     field public static final int KEYCODE_STEM_2 = 266; // 0x10a
     field public static final int KEYCODE_STEM_3 = 267; // 0x10b
     field public static final int KEYCODE_STEM_PRIMARY = 264; // 0x108
+    field public static final int KEYCODE_STYLUS_BUTTON_PRIMARY = 308; // 0x134
+    field public static final int KEYCODE_STYLUS_BUTTON_SECONDARY = 309; // 0x135
+    field public static final int KEYCODE_STYLUS_BUTTON_TAIL = 311; // 0x137
+    field public static final int KEYCODE_STYLUS_BUTTON_TERTIARY = 310; // 0x136
     field public static final int KEYCODE_SWITCH_CHARSET = 95; // 0x5f
     field public static final int KEYCODE_SYM = 63; // 0x3f
     field public static final int KEYCODE_SYSRQ = 120; // 0x78
diff --git a/core/api/test-current.txt b/core/api/test-current.txt
index f780e6f3b39b5..085bd5510da7b 100644
--- a/core/api/test-current.txt
+++ b/core/api/test-current.txt
@@ -2854,7 +2854,7 @@ package android.view {
     method public static String actionToString(int);
     method public final void setDisplayId(int);
     field public static final int FLAG_IS_ACCESSIBILITY_EVENT = 2048; // 0x800
-    field public static final int LAST_KEYCODE = 307; // 0x133
+    field public static final int LAST_KEYCODE = 311; // 0x137
   }
 
   public final class KeyboardShortcutGroup implements android.os.Parcelable {
diff --git a/core/java/android/view/KeyEvent.java b/core/java/android/view/KeyEvent.java
index 6c238e5698c55..9789b5670fbb9 100644
--- a/core/java/android/view/KeyEvent.java
+++ b/core/java/android/view/KeyEvent.java
@@ -872,13 +872,33 @@ public class KeyEvent extends InputEvent implements Parcelable {
     public static final int KEYCODE_KEYBOARD_BACKLIGHT_UP = 306;
     /** Key code constant: Keyboard backlight toggle */
     public static final int KEYCODE_KEYBOARD_BACKLIGHT_TOGGLE = 307;
+    /**
+     * Key code constant: The primary button on the barrel of a stylus.
+     * This is usually the button closest to the tip of the stylus.
+     */
+    public static final int KEYCODE_STYLUS_BUTTON_PRIMARY = 308;
+    /**
+     * Key code constant: The secondary button on the barrel of a stylus.
+     * This is usually the second button from the tip of the stylus.
+     */
+    public static final int KEYCODE_STYLUS_BUTTON_SECONDARY = 309;
+    /**
+     * Key code constant: The tertiary button on the barrel of a stylus.
+     * This is usually the third button from the tip of the stylus.
+     */
+    public static final int KEYCODE_STYLUS_BUTTON_TERTIARY = 310;
+    /**
+     * Key code constant: A button on the tail end of a stylus.
+     * The use of this button does not usually correspond to the function of an eraser.
+     */
+    public static final int KEYCODE_STYLUS_BUTTON_TAIL = 311;
 
    /**
      * Integer value of the last KEYCODE. Increases as new keycodes are added to KeyEvent.
      * @hide
      */
     @TestApi
-    public static final int LAST_KEYCODE = KEYCODE_KEYBOARD_BACKLIGHT_TOGGLE;
+    public static final int LAST_KEYCODE = KEYCODE_STYLUS_BUTTON_TAIL;
 
     // NOTE: If you add a new keycode here you must also add it to:
     //  isSystem()
diff --git a/data/keyboards/Generic.kl b/data/keyboards/Generic.kl
index a186aca4648f4..af96c743f4000 100644
--- a/data/keyboards/Generic.kl
+++ b/data/keyboards/Generic.kl
@@ -302,6 +302,11 @@ key 317   BUTTON_THUMBL
 key 318   BUTTON_THUMBR
 
 
+key 329   STYLUS_BUTTON_TERTIARY
+key 331   STYLUS_BUTTON_PRIMARY
+key 332   STYLUS_BUTTON_SECONDARY
+
+
 # key 352 "KEY_OK"
 key 353   DPAD_CENTER
 # key 354 "KEY_GOTO"
@@ -424,6 +429,8 @@ key usage 0x0c007C KEYBOARD_BACKLIGHT_TOGGLE
 key usage 0x0c0173 MEDIA_AUDIO_TRACK
 key usage 0x0c019C PROFILE_SWITCH
 key usage 0x0c01A2 ALL_APPS
+key usage 0x0d0044 STYLUS_BUTTON_PRIMARY
+key usage 0x0d005a STYLUS_BUTTON_SECONDARY
 
 # Joystick and game controller axes.
 # Axes that are not mapped will be assigned generic axis numbers by the input subsystem.
diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index e332ac765633a..675819a772438 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -3052,6 +3052,13 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                     }
                 }
                 break;
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_PRIMARY:
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_SECONDARY:
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_TERTIARY:
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_TAIL:
+                Slog.wtf(TAG, "KEYCODE_STYLUS_BUTTON_* should be handled in"
+                        + " interceptKeyBeforeQueueing");
+                return key_consumed;
         }
 
         if (isValidGlobalKey(keyCode)
@@ -4104,6 +4111,14 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                 result &= ~ACTION_PASS_TO_USER;
                 break;
             }
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_PRIMARY:
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_SECONDARY:
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_TERTIARY:
+            case KeyEvent.KEYCODE_STYLUS_BUTTON_TAIL: {
+                // TODO(go/android-stylus-buttons): Handle stylus button presses.
+                result &= ~ACTION_PASS_TO_USER;
+                break;
+            }
         }
 
         if (useHapticFeedback) {