diff --git a/instance.go b/instance.go
index c82af94..2e50444 100644
--- a/instance.go
+++ b/instance.go
@@ -14,6 +14,8 @@ type Instance struct {
 	Scheduler *asynq.Scheduler
 }
 
+var instance Instance
+
 // NewInstance ...
 func NewInstance(cfg Config) Instance {
 	// Init redis connection
@@ -24,7 +26,6 @@ func NewInstance(cfg Config) Instance {
 	}
 
 	// Init instance
-	instance := Instance{}
 	instance.Server = initServer(redisConn, cfg)
 	instance.Scheduler = initScheduler(redisConn)
 	instance.Client = initClient(redisConn)
diff --git a/task.go b/task.go
index 5190f41..ba5b3e0 100644
--- a/task.go
+++ b/task.go
@@ -1,22 +1,11 @@
 package queue
 
 import (
-	"encoding/json"
-	"errors"
-	"fmt"
-
 	"github.com/hibiken/asynq"
 )
 
 // RunTask ...
-func RunTask(client *asynq.Client, typename string, data map[string]interface{}, retryTimes int) (*asynq.TaskInfo, error) {
-	// Convert to []byte
-	payload, err := json.Marshal(data)
-	if err != nil {
-		msg := fmt.Sprintf("task type: %s - error when create new task: %s", typename, err.Error())
-		return nil, errors.New(msg)
-	}
-
+func (i Instance) RunTask(typename string, payload []byte, retryTimes int) (*asynq.TaskInfo, error) {
 	// Create task and options
 	task := asynq.NewTask(typename, payload)
 	options := make([]asynq.Option, 0)
@@ -28,25 +17,18 @@ func RunTask(client *asynq.Client, typename string, data map[string]interface{},
 	options = append(options, asynq.MaxRetry(retryTimes))
 
 	// Enqueue task
-	return client.Enqueue(task, options...)
+	return i.Client.Enqueue(task, options...)
 }
 
 // ScheduledTask create new task and run at specific time
 // cronSpec follow cron expression
 // https://www.freeformatter.com/cron-expression-generator-quartz.html
-func ScheduledTask(scheduler *asynq.Scheduler, typename string, data map[string]interface{}, cronSpec string) (string, error) {
-	// Convert to []byte
-	payload, err := json.Marshal(data)
-	if err != nil {
-		msg := fmt.Sprintf("task type: %s - error when create new task: %s", typename, err.Error())
-		return "", errors.New(msg)
-	}
-
+func (i Instance) ScheduledTask(typename string, payload []byte, cronSpec string) (string, error) {
 	// Create task and options
 	task := asynq.NewTask(typename, payload)
 
 	// TODO: Support options later
 	// options := make([]asynq.Option, 0)
 
-	return scheduler.Register(cronSpec, task)
+	return i.Scheduler.Register(cronSpec, task)
 }