diff --git a/v1/client.go b/v1/client.go
index a40e831..5d8b945 100644
--- a/v1/client.go
+++ b/v1/client.go
@@ -499,6 +499,37 @@ func (c *MgClient) MarkMessageRead(request MarkMessageReadRequest) (MarkMessageR
 	return resp, status, err
 }
 
+// AckMessage implements ack of message
+//
+// Example:
+//
+//	var client = v1.New("https://token.url", "cb8ccf05e38a47543ad8477d4999be73bff503ea6")
+//
+//	request := AckMessageRequest{
+//		ExternalMessageID: "274628",
+//		Channel: 10,
+//	}
+//
+//	status, err := client.AckMessage(request)
+//
+//	if err != nil {
+//		fmt.Printf("%v", err)
+//	}
+func (c *MgClient) AckMessage(request AckMessageRequest) (int, error) {
+	outgoing, _ := json.Marshal(&request)
+
+	data, status, err := c.PostRequest("/messages/ack", bytes.NewBuffer(outgoing))
+	if err != nil {
+		return status, err
+	}
+
+	if status != http.StatusOK {
+		return status, c.Error(data)
+	}
+
+	return status, err
+}
+
 // DeleteMessage implement delete message
 //
 // Example:
diff --git a/v1/types.go b/v1/types.go
index b0e9b6a..1c227fc 100644
--- a/v1/types.go
+++ b/v1/types.go
@@ -65,6 +65,15 @@ const (
 	OriginatorChannel
 )
 
+type ErrorType string
+const (
+	GeneralError ErrorType = "general"
+	CustomerNotExistsError = "customer_not_exists"
+	ReplyTimedOutError = "reply_timed_out"
+	SpamSuspicionError = "spam_suspicion"
+	AccessRestrictedError = "access_restricted"
+)
+
 // MgClient type
 type MgClient struct {
 	URL        string       `json:"url"`
@@ -303,6 +312,13 @@ type MarkMessageReadRequestMessage struct {
 	ExternalID string `json:"external_id"`
 }
 
+// AckMessageRequest type
+type AckMessageRequest struct {
+	ExternalMessageID string            `json:"external_message_id"`
+	Channel           uint64            `json:"channel"`
+	Error             *MessageSentError `json:"error,omitempty"`
+}
+
 // DeleteData struct
 type DeleteData struct {
 	Message Message `json:"message"`
@@ -322,6 +338,20 @@ type WebhookRequest struct {
 	Data WebhookData          `json:"data"`
 }
 
+// WebhookMessageSentResponse type
+// Consider using this structure while processing webhook request
+type WebhookMessageSentResponse struct {
+	ExternalMessageID string            `json:"external_message_id"`
+	Error             *MessageSentError `json:"error,omitempty"`
+	Async             bool              `json:"async"`
+}
+
+// MessageSentError type
+type MessageSentError struct {
+	Code    ErrorType `json:"code"`
+	Message string    `json:"message"`
+}
+
 // WebhookData request data
 type WebhookData struct {
 	ExternalUserID    string              `json:"external_user_id"`