diff --git a/community_server/src/Controller/AppController.php b/community_server/src/Controller/AppController.php
index b9522c2e7..42d97d5d8 100644
--- a/community_server/src/Controller/AppController.php
+++ b/community_server/src/Controller/AppController.php
@@ -35,6 +35,7 @@ class AppController extends Controller
 {
 
     var $loginServerUrl = '';
+    var $blockchainType = 'mysql';
     /**
      * Initialization hook method.
      *
@@ -136,6 +137,23 @@ class AppController extends Controller
         } else {
             $this->loginServerUrl = Router::url('/', true);
         }
+        /*
+         * 
+         *    'GradidoBlockchain' => [
+         *      // type:
+         *      //   - mysql: centralized blockchain in mysql db, no cross group transactions
+         *      //   - hedera: send transaction over hedera
+         *    'type' => 'hedera',
+         *      // gradido nodes with blockchain (if type != mysql)
+         *    'nodes' => [
+         *        ['host' => 'http://192.168.178.225', 'port' => 13702]
+         *    ]
+         *  ],
+         */
+        $blockchain = Configure::read('GradidoBlockchain');
+        if($blockchain && isset($blockchain['type'])) {
+            $this->blockchainType = $blockchain['type'];
+        }
     }
 
     protected function requestLogin($session_id = 0, $redirect = true)
diff --git a/community_server/src/Controller/AppRequestsController.php b/community_server/src/Controller/AppRequestsController.php
index f2c0dbac6..fa59887c8 100644
--- a/community_server/src/Controller/AppRequestsController.php
+++ b/community_server/src/Controller/AppRequestsController.php
@@ -110,7 +110,8 @@ class AppRequestsController extends AppController
                 'amount' => $amount,
                 'target_group' => $group,
                 'target_email'  => $email,
-                'auto_sign' => $auto_sign
+                'auto_sign' => $auto_sign,
+                'blockchain_type' => $this->blockchainType
         ]), '/createTransaction');
 
         if('success' == $requestAnswear['state'] && 'success' == $requestAnswear['data']['state']) {
diff --git a/community_server/src/Controller/Component/JsonRequestClientComponent.php b/community_server/src/Controller/Component/JsonRequestClientComponent.php
index c73a00528..09856d7e2 100644
--- a/community_server/src/Controller/Component/JsonRequestClientComponent.php
+++ b/community_server/src/Controller/Component/JsonRequestClientComponent.php
@@ -15,7 +15,7 @@ use Cake\Core\Configure;
 
 class JsonRequestClientComponent extends Component
 {
-  public function sendTransaction($session_id, $base64Message, $user_balance = 0, $auto_sign = false) {
+  public function sendTransaction($session_id, $base64Message, $user_balance = 0, $auto_sign = false, $blockchain_type = 'mysql') {
     if(!is_numeric($session_id)) {
       return ['state' => 'error', 'type' => 'parameter error', 'msg' => 'session_id isn\'t numeric'];
     }
@@ -36,7 +36,8 @@ class JsonRequestClientComponent extends Component
         'session_id' => $session_id,
         'transaction_base64' => $base64Message,
         'balance' => $user_balance,
-        'auto_sign' => $auto_sign
+        'auto_sign' => $auto_sign,
+        'blockchain_type' => $this->blockchainType
     ]), '/checkTransaction');
       
   }
diff --git a/community_server/src/Controller/TransactionCreationsController.php b/community_server/src/Controller/TransactionCreationsController.php
index 77429d8d7..f439bd893 100644
--- a/community_server/src/Controller/TransactionCreationsController.php
+++ b/community_server/src/Controller/TransactionCreationsController.php
@@ -399,7 +399,8 @@ class TransactionCreationsController extends AppController
                         'memo' => $memo,
                         'amount' => $localAmountCent,
                         'target_pubkey'  => $pubKeyHex,
-                        'target_date' => $localTargetDateFrozen
+                        'target_date' => $localTargetDateFrozen,
+                        'blockchain_type' => $this->blockchainType
                     ]), '/createTransaction');
                     
                     if('success' != $requestAnswear['state']) {
@@ -580,7 +581,8 @@ class TransactionCreationsController extends AppController
                 $session_id,
                 $transaction_base64,
                 $user['balance'],
-                $auto_sign
+                $auto_sign,
+                $this->blockchainType
             );
             if ($requestResult['state'] != 'success') {                
                 $msg = 'error returned from login server';
diff --git a/community_server/src/Controller/TransactionSendCoinsController.php b/community_server/src/Controller/TransactionSendCoinsController.php
index 12aa3e69a..033e2343f 100644
--- a/community_server/src/Controller/TransactionSendCoinsController.php
+++ b/community_server/src/Controller/TransactionSendCoinsController.php
@@ -185,7 +185,8 @@ class TransactionSendCoinsController extends AppController
                 'memo' => $requestData['memo'],
                 'amount' => $amountCent,
                 'target_group' => $known_groups['data']['data']['groups'][$requestData['group']],
-                'target_email'  => $receiverEmail
+                'target_email'  => $receiverEmail,
+                'blockchain_type' => $this->blockchainType
             ]), '/createTransaction');
             
             if('success' == $requestAnswear['state'] && 'success' == $requestAnswear['data']['state']) {