diff --git a/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.cpp b/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.cpp
index 6d6d7f16781a..0e880894c8b0 100644
--- a/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.cpp
+++ b/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.cpp
@@ -52,3 +52,29 @@ BluetoothGattDescriptor::WrapObject(JSContext* aContext,
 {
   return BluetoothGattDescriptorBinding::Wrap(aContext, this, aGivenProto);
 }
+
+void
+BluetoothGattDescriptor::GetValue(JSContext* cx,
+                                  JS::MutableHandle<JSObject*> aValue) const
+{
+  MOZ_ASSERT(aValue);
+
+  aValue.set(mValue.IsEmpty()
+             ? nullptr
+             : ArrayBuffer::Create(cx, mValue.Length(), mValue.Elements()));
+}
+
+already_AddRefed<Promise>
+BluetoothGattDescriptor::ReadValue(ErrorResult& aRv)
+{
+  // TODO: This will be implemented by later patch set in the same bug.
+  return nullptr;
+}
+
+already_AddRefed<Promise>
+BluetoothGattDescriptor::WriteValue(
+  const RootedTypedArray<ArrayBuffer>& aValue, ErrorResult& aRv)
+{
+  // TODO: This will be implemented by later patch set in the same bug.
+  return nullptr;
+}
diff --git a/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.h b/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.h
index 0689a614107c..4078179718d6 100644
--- a/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.h
+++ b/dom/bluetooth/bluetooth2/BluetoothGattDescriptor.h
@@ -10,6 +10,8 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/BluetoothGattDescriptorBinding.h"
 #include "mozilla/dom/bluetooth/BluetoothCommon.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/TypedArray.h"
 #include "nsCOMPtr.h"
 #include "nsWrapperCache.h"
 #include "nsPIDOMWindow.h"
@@ -40,6 +42,15 @@ public:
     aUuidStr = mUuidStr;
   }
 
+  void GetValue(JSContext* cx, JS::MutableHandle<JSObject*> aValue) const;
+
+  /****************************************************************************
+   * Methods (Web API Implementation)
+   ***************************************************************************/
+  already_AddRefed<Promise> ReadValue(ErrorResult& aRv);
+  already_AddRefed<Promise> WriteValue(
+    const RootedTypedArray<ArrayBuffer>& aValue, ErrorResult& aRv);
+
   /****************************************************************************
    * Others
    ***************************************************************************/
@@ -81,6 +92,11 @@ private:
    * UUID string of this GATT descriptor.
    */
   nsString mUuidStr;
+
+  /**
+   * Value of this GATT descriptor.
+   */
+  nsTArray<uint8_t> mValue;
 };
 
 END_BLUETOOTH_NAMESPACE
diff --git a/dom/webidl/BluetoothGattDescriptor.webidl b/dom/webidl/BluetoothGattDescriptor.webidl
index 5f2d8be56578..5db729100ab4 100644
--- a/dom/webidl/BluetoothGattDescriptor.webidl
+++ b/dom/webidl/BluetoothGattDescriptor.webidl
@@ -9,4 +9,10 @@ interface BluetoothGattDescriptor
 {
   readonly attribute BluetoothGattCharacteristic            characteristic;
   readonly attribute DOMString                              uuid;
+  readonly attribute ArrayBuffer?                           value;
+
+  [NewObject]
+  Promise<ArrayBuffer>  readValue();
+  [NewObject]
+  Promise<void>         writeValue(ArrayBuffer value);
 };