diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9718dd86..6c840074 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -59,7 +59,7 @@ list(GET BLUEZ_VERSIONS 0 BLUEZ_VERSION_MAJOR)
 list(GET BLUEZ_VERSIONS 1 BLUEZ_VERSION_MINOR)
 add_definitions(-DBLUEZ_VERSION_MAJOR=${BLUEZ_VERSION_MAJOR} -DBLUEZ_VERSION_MINOR=${BLUEZ_VERSION_MINOR})
 
-set(GATTLIB_FORCE_DBUS OFF CACHE BOOLEAN "Build gattlib with D-Bus support on Bluez version < v5.42")
+set(GATTLIB_FORCE_DBUS OFF CACHE BOOL "Build gattlib with D-Bus support on Bluez version < v5.42")
 
 if (BLUEZ_VERSION_MAJOR LESS 5)
   set(GATTLIB_DBUS FALSE)
diff --git a/bluez/gattlib_read_write.c b/bluez/gattlib_read_write.c
index f6705297..3df666ab 100644
--- a/bluez/gattlib_read_write.c
+++ b/bluez/gattlib_read_write.c
@@ -35,6 +35,14 @@ struct gattlib_result_read_uuid_t {
 	size_t*        buffer_len;
 	gatt_read_cb_t callback;
 	int            completed;
+	void*          user_data;
+};
+
+struct gattlib_result_write_uuid_t {
+    const void*     buffer;
+    size_t          buffer_len;
+    gatt_write_cb_t callback;
+    void*           user_data;
 };
 
 static void gattlib_result_read_uuid_cb(guint8 status, const guint8 *pdu, guint16 len, gpointer user_data) {
@@ -64,7 +72,7 @@ static void gattlib_result_read_uuid_cb(guint8 status, const guint8 *pdu, guint1
 		value += 2;
 
 		if (gattlib_result->callback) {
-			gattlib_result->callback(value, buffer_len);
+			gattlib_result->callback(value, buffer_len, gattlib_result->user_data);
 		} else {
 			void* buffer = malloc(buffer_len);
 			if (buffer == NULL) {
@@ -135,7 +143,7 @@ int gattlib_read_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid,
 }
 
 int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid,
-				    gatt_read_cb_t gatt_read_cb)
+				    gatt_read_cb_t gatt_read_cb, void* user_data)
 {
 	gattlib_context_t* conn_context = connection->context;
 	struct gattlib_result_read_uuid_t* gattlib_result;
@@ -151,6 +159,7 @@ int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid,
 	gattlib_result->buffer_len     = 0;
 	gattlib_result->callback       = gatt_read_cb;
 	gattlib_result->completed      = FALSE;
+	gattlib_result->user_data      = user_data;
 
 	uuid_to_bt_uuid(uuid, &bt_uuid);
 
@@ -187,6 +196,48 @@ int gattlib_write_char_by_handle(gatt_connection_t* connection, uint16_t handle,
 	return 0;
 }
 
+void gattlib_write_result_cb_async(guint8 status, const guint8 *pdu, guint16 len, gpointer user_data) {
+    struct gattlib_result_write_uuid_t* gattlib_result = (struct gattlib_result_write_uuid_t*)user_data;
+
+    if(gattlib_result->callback) {
+        gattlib_result->callback(status, gattlib_result->buffer, gattlib_result->buffer_len, gattlib_result->user_data);
+    }
+}
+
+int gattlib_write_char_by_handle_async(gatt_connection_t* connection, uint16_t handle, const void* buffer, size_t buffer_len, gatt_write_cb_t gatt_write_cb, void* user_data) {
+    gattlib_context_t* conn_context = connection->context;
+
+    struct gattlib_result_write_uuid_t* gattlib_result = malloc(sizeof(struct gattlib_result_write_uuid_t));
+    if (gattlib_result == NULL) {
+        return GATTLIB_OUT_OF_MEMORY;
+    }
+    gattlib_result->callback       = gatt_write_cb;
+    gattlib_result->buffer         = buffer;
+    gattlib_result->buffer_len     = buffer_len;
+    gattlib_result->user_data      = user_data;
+
+    guint ret = gatt_write_char(conn_context->attrib, handle, (void*)buffer, buffer_len,
+                                gattlib_write_result_cb_async, gattlib_result);
+    if (ret == 0) {
+        return 1;
+    }
+
+    return 0;
+}
+
+int gattlib_write_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, const void* buffer, size_t buffer_len, gatt_write_cb_t gatt_write_cb, void* user_data) {
+    uint16_t handle = 0;
+    int ret;
+
+    ret = get_handle_from_uuid(connection, uuid, &handle);
+    if (ret) {
+        fprintf(stderr, "Fail to find handle for UUID.\n");
+        return ret;
+    }
+
+    return gattlib_write_char_by_handle_async(connection, handle, buffer, buffer_len, gatt_write_cb, user_data);
+}
+
 int gattlib_write_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, const void* buffer, size_t buffer_len) {
 	uint16_t handle = 0;
 	int ret;
diff --git a/dbus/gattlib_char.c b/dbus/gattlib_char.c
index 0b7064dc..201dae37 100644
--- a/dbus/gattlib_char.c
+++ b/dbus/gattlib_char.c
@@ -290,7 +290,7 @@ int gattlib_read_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, void
 	}
 }
 
-int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, gatt_read_cb_t gatt_read_cb) {
+int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, gatt_read_cb_t gatt_read_cb, void *user_data) {
 	int ret = GATTLIB_SUCCESS;
 
 	struct dbus_characteristic dbus_characteristic = get_characteristic_from_uuid(connection, uuid);
@@ -304,7 +304,7 @@ int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid,
 
 		percentage = org_bluez_battery1_get_percentage(dbus_characteristic.battery);
 
-		gatt_read_cb((const void*)&percentage, sizeof(percentage));
+		gatt_read_cb((const void*)&percentage, sizeof(percentage), user_data);
 
 		return GATTLIB_SUCCESS;
 	} else {
@@ -334,7 +334,7 @@ int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid,
 	gsize n_elements;
 	gconstpointer const_buffer = g_variant_get_fixed_array(out_value, &n_elements, sizeof(guchar));
 	if (const_buffer) {
-		gatt_read_cb(const_buffer, n_elements);
+		gatt_read_cb(const_buffer, n_elements, user_data);
 	}
 
 	g_object_unref(dbus_characteristic.gatt);
@@ -396,6 +396,14 @@ int gattlib_write_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, cons
 	return ret;
 }
 
+int gattlib_write_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, const void* buffer, size_t buffer_len, gatt_write_cb_t gatt_write_cb, void* user_data) {
+    int ret = gattlib_write_char_by_uuid(connection, uuid, buffer, buffer_len);
+    if(gatt_write_cb) {
+        gatt_write_cb(ret, buffer, buffer_len, user_data);
+    }
+    return ret;
+}
+
 int gattlib_write_char_by_handle(gatt_connection_t* connection, uint16_t handle, const void* buffer, size_t buffer_len)
 {
 	int ret;
@@ -411,6 +419,15 @@ int gattlib_write_char_by_handle(gatt_connection_t* connection, uint16_t handle,
 	return ret;
 }
 
+int gattlib_write_char_by_handle_async(gatt_connection_t* connection, uint16_t handle, const void* buffer, size_t buffer_len, gatt_write_cb_t gatt_write_cb, void* user_data) {
+    int ret = gattlib_write_char_by_handle(connection, handle, buffer, buffer_len);
+    if(gatt_write_cb) {
+        gatt_write_cb(ret, buffer, buffer_len, user_data);
+    }
+    return ret;
+}
+
+
 int gattlib_write_without_response_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, const void* buffer, size_t buffer_len)
 {
 	int ret;
diff --git a/include/gattlib.h b/include/gattlib.h
index 17cec7e1..12b2cb62 100644
--- a/include/gattlib.h
+++ b/include/gattlib.h
@@ -201,7 +201,16 @@ typedef void (*gatt_connect_cb_t)(gatt_connection_t* connection, void* user_data
  * @param buffer_len Length of the read data
  *
  */
-typedef void* (*gatt_read_cb_t)(const void *buffer, size_t buffer_len);
+typedef void* (*gatt_read_cb_t)(const void *buffer, size_t buffer_len, void* user_data);
+
+/**
+ * @brief Callback called when GATT characteristic write value has been sent
+ *
+ * @param buffer contains the value written.
+ * @param buffer_len Length of the write data
+ *
+ */
+typedef void* (*gatt_write_cb_t)(int status, const void *buffer, size_t buffer_len, void* user_data);
 
 
 /**
@@ -447,10 +456,11 @@ int gattlib_read_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, void*
  * @param connection Active GATT connection
  * @param uuid UUID of the GATT characteristic to read
  * @param gatt_read_cb is the callback to read when the GATT characteristic is available
+ * @param user_data is the user specific data to pass to the callback
  *
  * @return GATTLIB_SUCCESS on success or GATTLIB_* error code
  */
-int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, gatt_read_cb_t gatt_read_cb);
+int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, gatt_read_cb_t gatt_read_cb, void* user_data);
 
 /**
  * @brief Function to write to the GATT characteristic UUID
@@ -464,6 +474,21 @@ int gattlib_read_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid,
  */
 int gattlib_write_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, const void* buffer, size_t buffer_len);
 
+
+/**
+ * @brief Function to write to the GATT characteristic UUID
+ *
+ * @param connection Active GATT connection
+ * @param uuid UUID of the GATT characteristic to read
+ * @param buffer contains the values to write to the GATT characteristic
+ * @param buffer_len is the length of the buffer to write
+ * @param gatt_write_cb is the function to call at the end of the write
+ * @param user_data user data for the callback
+ *
+ * @return GATTLIB_SUCCESS on success or GATTLIB_* error code
+ */
+int gattlib_write_char_by_uuid_async(gatt_connection_t* connection, uuid_t* uuid, const void* buffer, size_t buffer_len, gatt_write_cb_t gatt_write_cb, void* user_data);
+
 /**
  * @brief Function to write to the GATT characteristic handle
  *
@@ -476,6 +501,20 @@ int gattlib_write_char_by_uuid(gatt_connection_t* connection, uuid_t* uuid, cons
  */
 int gattlib_write_char_by_handle(gatt_connection_t* connection, uint16_t handle, const void* buffer, size_t buffer_len);
 
+/**
+ * @brief Function to write to the GATT characteristic handle
+ *
+ * @param connection Active GATT connection
+ * @param handle is the handle of the GATT characteristic
+ * @param buffer contains the values to write to the GATT characteristic
+ * @param buffer_len is the length of the buffer to write
+ * @param gatt_write_cb is the function to call at the end of the write
+ * @param user_data user data for the callback
+ *
+ * @return GATTLIB_SUCCESS on success or GATTLIB_* error code
+ */
+int gattlib_write_char_by_handle_async(gatt_connection_t* connection, uint16_t handle, const void* buffer, size_t buffer_len, gatt_write_cb_t gatt_write_cb, void* user_data);
+
 /**
  * @brief Function to write without response to the GATT characteristic UUID
  *