diff --git a/appstore/api/validator.go b/appstore/api/validator.go
new file mode 100644
index 0000000..86f8538
--- /dev/null
+++ b/appstore/api/validator.go
@@ -0,0 +1,32 @@
+package api
+
+import (
+	"context"
+	"errors"
+)
+
+// IAPAPIClient is an interface to call validation API in App Store Server API
+type IAPAPIClient interface {
+	Verify(ctx context.Context, transactionId string) (*TransactionInfoResponse, error)
+}
+
+type APIClient struct {
+	productionCli *StoreClient
+	sandboxCli    *StoreClient
+}
+
+func NewAPIClient(config StoreConfig) *APIClient {
+	prodConf := config
+	prodConf.Sandbox = false
+	sandboxConf := config
+	sandboxConf.Sandbox = true
+	return &APIClient{productionCli: NewStoreClient(&prodConf), sandboxCli: NewStoreClient(&sandboxConf)}
+}
+
+func (c *APIClient) Verify(ctx context.Context, transactionId string) (*TransactionInfoResponse, error) {
+	result, err := c.productionCli.GetTransactionInfo(ctx, transactionId)
+	if err != nil && errors.Is(err, TransactionIdNotFoundError) {
+		result, err = c.sandboxCli.GetTransactionInfo(ctx, transactionId)
+	}
+	return result, err
+}
diff --git a/appstore/validator.go b/appstore/validator.go
index b5dbe74..fc34afd 100644
--- a/appstore/validator.go
+++ b/appstore/validator.go
@@ -39,7 +39,7 @@ type Client struct {
 	httpCli       *http.Client
 }
 
-// list of errore
+// list of errors
 var (
 	ErrAppStoreServer = errors.New("AppStore server error")