diff --git a/action_delete.go b/action_delete.go
new file mode 100644
index 0000000..cad06c6
--- /dev/null
+++ b/action_delete.go
@@ -0,0 +1,31 @@
+package devicemngmt
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/Selly-Modules/logger"
+	"go.mongodb.org/mongo-driver/bson"
+)
+
+// DeleteDeviceByDeviceID ...
+func (s Service) DeleteDeviceByDeviceID(deviceID string) error {
+	var (
+		ctx  = context.Background()
+		col  = s.getDeviceCollection()
+		cond = bson.M{
+			"deviceID": deviceID,
+		}
+	)
+
+	// Delete
+	if _, err := col.DeleteOne(ctx, cond); err != nil {
+		logger.Error("devicemngt - deleteDeviceByDeviceID", logger.LogData{
+			"deviceID": deviceID,
+			"err":      err.Error(),
+		})
+		return fmt.Errorf("error when delete device: %s", err.Error())
+	}
+
+	return nil
+}
diff --git a/action_get_userID.go b/action_get_userID.go
new file mode 100644
index 0000000..9c4d47f
--- /dev/null
+++ b/action_get_userID.go
@@ -0,0 +1,32 @@
+package devicemngmt
+
+import (
+	"context"
+
+	"github.com/Selly-Modules/logger"
+	"go.mongodb.org/mongo-driver/bson"
+)
+
+// GetUserIDByAuthToken ...
+func (s Service) GetUserIDByAuthToken(authToken string) (userID string) {
+	var (
+		ctx    = context.Background()
+		col    = s.getDeviceCollection()
+		device = Device{}
+		cond   = bson.M{
+			"authToken": authToken,
+		}
+	)
+
+	// Find
+	if err := col.FindOne(ctx, cond).Decode(&device); err != nil {
+		logger.Error("devicemngt - getUserIDByAuthToken", logger.LogData{
+			"authToken": authToken,
+			"err":       err.Error(),
+		})
+		return
+	}
+
+	userID = device.UserID
+	return
+}