Work on groups

Some dev/testing API calls are now turned off by default in production mode,
 see "restrictApi" settings entry, returning NON_PRODUCTION API error.

Corrections to how account's defaultGroupId works, removing "effective groupID"
 which overly complicated matters.
In relation to above, DEFAULT_GROUP (0) no longer exists and NO_GROUP(-1) now has
 the value 0 instead.
So transactions can no longer have txGroupId of DEFAULT_GROUP, which in turn
 required all the erroneous "effective groupID" code.

API call /addresses/{address} now supplies blockchain-wide defaultGroupId if
 account doesn't exist or if account's default not set and NO-GROUP not allowed.

API /transactions/pending now offloaded to repository instead of Java-based
 processing and filtering.

Transaction approval checks added to Block.isValid

Groups now have min/max approval block delays.
 Checks added to incoming unconfirmed, block generator, block.isValid, etc.

'needing approval' and 'meets approval threshold' now split into separate calls.

NB: settings.json no longer part of git repo

settings.json

@@ -1,6 +0,0 @@
-{
-  "rpcallowed": [
-    "::/0",
-    "0.0.0.0/0"
-  ]
-}

src/main/java/org/qora/api/ApiError.java

@@ -13,6 +13,7 @@ public enum ApiError {
 	NOT_YET_RELEASED(3, 422),
 	UNAUTHORIZED(4, 403),
 	REPOSITORY_ISSUE(5, 500),
+	NON_PRODUCTION(6, 403),
 
 	// VALIDATION
 	INVALID_SIGNATURE(101, 400),

src/main/java/org/qora/api/resource/AddressesResource.java

@@ -22,11 +22,14 @@ import org.qora.api.ApiErrors;
 import org.qora.api.ApiException;
 import org.qora.api.ApiExceptionFactory;
 import org.qora.asset.Asset;
+import org.qora.block.BlockChain;
 import org.qora.crypto.Crypto;
 import org.qora.data.account.AccountData;
+import org.qora.group.Group;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
+import org.qora.settings.Settings;
 import org.qora.transform.Transformer;
 import org.qora.utils.Base58;
 
@@ -55,7 +58,17 @@ public class AddressesResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			return repository.getAccountRepository().getAccount(address);
+			AccountData accountData = repository.getAccountRepository().getAccount(address);
+
+			// Not found?
+			if (accountData == null)
+				accountData = new AccountData(address, null, null, BlockChain.getInstance().getDefaultGroupId());
+
+			// If Blockchain config doesn't allow NO_GROUP then change this to blockchain's default groupID
+			if (accountData.getDefaultGroupId() == Group.NO_GROUP && !BlockChain.getInstance().getGrouplessAllowed())
+				accountData.setDefaultGroupId(BlockChain.getInstance().getDefaultGroupId());
+
+			return accountData;
 		} catch (ApiException e) {
 			throw e;
 		} catch (DataException e) {
@@ -227,8 +240,11 @@ public class AddressesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.NON_PRODUCTION, ApiError.REPOSITORY_ISSUE})
 	public String fromPublicKey(@PathParam("publickey") String publicKey58) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		// Decode public key
 		byte[] publicKey;
 		try {

src/main/java/org/qora/api/resource/AssetsResource.java

@@ -43,6 +43,7 @@ import org.qora.data.transaction.TransactionData;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
+import org.qora.settings.Settings;
 import org.qora.transaction.Transaction;
 import org.qora.transaction.Transaction.ValidationResult;
 import org.qora.transform.TransformationException;
@@ -554,9 +555,12 @@ public class AssetsResource {
 		}
 	)
 	@ApiErrors({
-		ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE, ApiError.TRANSACTION_INVALID
+		ApiError.NON_PRODUCTION, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE, ApiError.TRANSACTION_INVALID
 	})
 	public String cancelOrder(CancelAssetOrderTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -599,9 +603,12 @@ public class AssetsResource {
 		}
 	)
 	@ApiErrors({
-		ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE, ApiError.TRANSACTION_INVALID
+		ApiError.NON_PRODUCTION, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE, ApiError.TRANSACTION_INVALID
 	})
 	public String issueAsset(IssueAssetTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -644,9 +651,12 @@ public class AssetsResource {
 		}
 	)
 	@ApiErrors({
-		ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE, ApiError.TRANSACTION_INVALID
+		ApiError.NON_PRODUCTION, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE, ApiError.TRANSACTION_INVALID
 	})
 	public String createOrder(CreateAssetOrderTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 

src/main/java/org/qora/api/resource/GroupsResource.java

@@ -51,6 +51,7 @@ import org.qora.data.transaction.UpdateGroupTransactionData;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
+import org.qora.settings.Settings;
 import org.qora.transaction.Transaction;
 import org.qora.transaction.Transaction.ValidationResult;
 import org.qora.transform.TransformationException;
@@ -264,8 +265,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String createGroup(CreateGroupTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -307,8 +311,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String updateGroup(UpdateGroupTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -350,8 +357,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String addGroupAdmin(AddGroupAdminTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -393,8 +403,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String removeGroupAdmin(RemoveGroupAdminTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -436,8 +449,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String groupBan(GroupBanTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -479,8 +495,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String cancelGroupBan(CancelGroupBanTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -522,8 +541,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String groupKick(GroupKickTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -565,8 +587,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String groupInvite(GroupInviteTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -608,8 +633,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String cancelGroupInvite(CancelGroupInviteTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -651,8 +679,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String joinGroup(JoinGroupTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -694,8 +725,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String leaveGroup(LeaveGroupTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -829,8 +863,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String groupApproval(GroupApprovalTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -872,8 +909,11 @@ public class GroupsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String setGroup(SetGroupTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 

src/main/java/org/qora/api/resource/NamesResource.java

@@ -36,6 +36,7 @@ import org.qora.data.transaction.UpdateNameTransactionData;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
+import org.qora.settings.Settings;
 import org.qora.transaction.Transaction;
 import org.qora.transaction.Transaction.ValidationResult;
 import org.qora.transform.TransformationException;
@@ -158,8 +159,11 @@ public class NamesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String registerName(RegisterNameTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -201,8 +205,11 @@ public class NamesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String updateName(UpdateNameTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -244,8 +251,11 @@ public class NamesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String sellName(SellNameTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -287,8 +297,11 @@ public class NamesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String cancelSellName(CancelSellNameTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
@@ -330,8 +343,11 @@ public class NamesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
 	public String buyName(BuyNameTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 

src/main/java/org/qora/api/resource/PaymentsResource.java

@@ -21,6 +21,7 @@ import org.qora.data.transaction.PaymentTransactionData;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
+import org.qora.settings.Settings;
 import org.qora.transaction.Transaction;
 import org.qora.transaction.Transaction.ValidationResult;
 import org.qora.transform.TransformationException;
@@ -60,8 +61,11 @@ public class PaymentsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
-	public String buildTransaction(PaymentTransactionData transactionData) {
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	public String makePayment(PaymentTransactionData transactionData) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 

src/main/java/org/qora/api/resource/TransactionsResource.java

@@ -34,6 +34,7 @@ import org.qora.globalization.Translator;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
+import org.qora.settings.Settings;
 import org.qora.transaction.Transaction;
 import org.qora.transaction.Transaction.TransactionType;
 import org.qora.transaction.Transaction.ValidationResult;
@@ -246,7 +247,7 @@ public class TransactionsResource {
 	@ApiErrors({
 		ApiError.REPOSITORY_ISSUE
 	})
-	public List<TransactionData> getPendingTransactions(@QueryParam("groupId") Integer groupId, @Parameter(
+	public List<TransactionData> getPendingTransactions(@QueryParam("txGroupId") Integer txGroupId, @Parameter(
 		ref = "limit"
 	) @QueryParam("limit") Integer limit, @Parameter(
 		ref = "offset"
@@ -254,22 +255,7 @@ public class TransactionsResource {
 		ref = "reverse"
 	) @QueryParam("reverse") Boolean reverse) {
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			List<TransactionData> transactions = repository.getTransactionRepository().getUnconfirmedTransactions(null, null, reverse);
-
-			transactions.removeIf(transactionData -> {
-				if (groupId != null && groupId != transactionData.getTxGroupId())
-					return true;
-
-				try {
-					return !Transaction.fromData(repository, transactionData).needsGroupApproval();
-				} catch (DataException e) {
-					return true;
-				}
-			});
-
-			// Results slicing
-
-			return transactions;
+			return repository.getTransactionRepository().getPendingTransactions(txGroupId, limit, offset, reverse);
 		} catch (ApiException e) {
 			throw e;
 		} catch (DataException e) {
@@ -366,9 +352,12 @@ public class TransactionsResource {
 		}
 	)
 	@ApiErrors({
-		ApiError.INVALID_PRIVATE_KEY, ApiError.TRANSFORMATION_ERROR
+		ApiError.NON_PRODUCTION, ApiError.INVALID_PRIVATE_KEY, ApiError.TRANSFORMATION_ERROR
 	})
 	public String signTransaction(SimpleTransactionSignRequest signRequest) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		if (signRequest.transactionBytes.length == 0)
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.JSON);
 

src/main/java/org/qora/api/resource/UtilsResource.java

@@ -29,6 +29,7 @@ import org.qora.api.ApiError;
 import org.qora.api.ApiErrors;
 import org.qora.api.ApiExceptionFactory;
 import org.qora.crypto.Crypto;
+import org.qora.settings.Settings;
 import org.qora.transaction.Transaction.TransactionType;
 import org.qora.transform.transaction.TransactionTransformer;
 import org.qora.transform.transaction.TransactionTransformer.Transformation;
@@ -76,8 +77,11 @@ public class UtilsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_DATA})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.INVALID_DATA})
 	public String fromBase64(String base64) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try {
 			return HashCode.fromBytes(Base64.getDecoder().decode(base64.trim())).toString();
 		} catch (IllegalArgumentException e) {
@@ -109,8 +113,11 @@ public class UtilsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_DATA})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.INVALID_DATA})
 	public String base64from58(String base58) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		try {
 			return HashCode.fromBytes(Base58.decode(base58.trim())).toString();
 		} catch (NumberFormatException e) {
@@ -133,7 +140,11 @@ public class UtilsResource {
 			)
 		}
 	)
+	@ApiErrors({ApiError.NON_PRODUCTION})
 	public String toBase64(@PathParam("hex") String hex) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		return Base64.getEncoder().encodeToString(HashCode.fromString(hex).asBytes());
 	}
 
@@ -152,7 +163,11 @@ public class UtilsResource {
 			)
 		}
 	)
+	@ApiErrors({ApiError.NON_PRODUCTION})
 	public String toBase58(@PathParam("hex") String hex) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		return Base58.encode(HashCode.fromString(hex).asBytes());
 	}
 
@@ -173,7 +188,11 @@ public class UtilsResource {
 			)
 		}
 	)
+	@ApiErrors({ApiError.NON_PRODUCTION})
 	public String random(@QueryParam("length") Integer length) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		if (length == null)
 			length = 32;
 
@@ -200,8 +219,11 @@ public class UtilsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_DATA})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.INVALID_DATA})
 	public String getMnemonic(@QueryParam("entropy") String suppliedEntropy) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		/*
 		 * BIP39 word lists have 2048 entries so can be represented by 11 bits.
 		 * UUID (128bits) and another 4 bits gives 132 bits.
@@ -266,7 +288,11 @@ public class UtilsResource {
 			)
 		}
 	)
+	@ApiErrors({ApiError.NON_PRODUCTION})
 	public String fromMnemonic(String mnemonic) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		if (mnemonic.isEmpty())
 			return "false";
 
@@ -308,8 +334,11 @@ public class UtilsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_DATA})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.INVALID_DATA})
 	public String privateKey(@PathParam("entropy") String entropy58) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		byte[] entropy;
 		try {
 			entropy = Base58.decode(entropy58);
@@ -341,8 +370,11 @@ public class UtilsResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_DATA})
+	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.INVALID_DATA})
 	public String publicKey(@PathParam("privateKey") String privateKey58) {
+		if (Settings.getInstance().isRestrictedApi())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
 		byte[] privateKey;
 		try {
 			privateKey = Base58.decode(privateKey58);

src/main/java/org/qora/at/QoraATAPI.java

@@ -268,7 +268,7 @@ public class QoraATAPI extends API {
 		byte[] reference = this.getLastReference();
 		BigDecimal amount = BigDecimal.valueOf(unscaledAmount, 8);
 
-		ATTransactionData atTransactionData = new ATTransactionData(timestamp, Group.DEFAULT_GROUP, reference, this.atData.getATAddress(),
+		ATTransactionData atTransactionData = new ATTransactionData(timestamp, Group.NO_GROUP, reference, this.atData.getATAddress(),
 				recipient.getAddress(), amount, this.atData.getAssetId(), new byte[0], BigDecimal.ZERO.setScale(8));
 		AtTransaction atTransaction = new AtTransaction(this.repository, atTransactionData);
 
@@ -286,7 +286,7 @@ public class QoraATAPI extends API {
 		long timestamp = this.getNextTransactionTimestamp();
 		byte[] reference = this.getLastReference();
 
-		ATTransactionData atTransactionData = new ATTransactionData(timestamp, Group.DEFAULT_GROUP, reference,
+		ATTransactionData atTransactionData = new ATTransactionData(timestamp, Group.NO_GROUP, reference,
 				this.atData.getATAddress(), recipient.getAddress(), BigDecimal.ZERO, this.atData.getAssetId(), message, BigDecimal.ZERO.setScale(8));
 		AtTransaction atTransaction = new AtTransaction(this.repository, atTransactionData);
 
@@ -312,7 +312,7 @@ public class QoraATAPI extends API {
 		byte[] reference = this.getLastReference();
 		BigDecimal amount = BigDecimal.valueOf(finalBalance, 8);
 
-		ATTransactionData atTransactionData = new ATTransactionData(timestamp, Group.DEFAULT_GROUP, reference, this.atData.getATAddress(),
+		ATTransactionData atTransactionData = new ATTransactionData(timestamp, Group.NO_GROUP, reference, this.atData.getATAddress(),
 				creator.getAddress(), amount, this.atData.getAssetId(), new byte[0], BigDecimal.ZERO.setScale(8));
 		AtTransaction atTransaction = new AtTransaction(this.repository, atTransactionData);
 

src/main/java/org/qora/block/Block.java

@@ -83,6 +83,7 @@ public class Block {
 		TRANSACTION_INVALID(52),
 		TRANSACTION_PROCESSING_FAILED(53),
 		TRANSACTION_ALREADY_PROCESSED(54),
+		TRANSACTION_NEEDS_APPROVAL(55),
 		AT_STATES_MISMATCH(61);
 
 		public final int value;
@@ -834,6 +835,10 @@ public class Block {
 				if (this.repository.getTransactionRepository().isConfirmed(transaction.getTransactionData().getSignature()))
 					return ValidationResult.TRANSACTION_ALREADY_PROCESSED;
 
+				// Check transaction doesn't still need approval
+				if (transaction.needsGroupApproval() && !transaction.meetsGroupApprovalThreshold())
+					return ValidationResult.TRANSACTION_NEEDS_APPROVAL;
+
 				// Check transaction is even valid
 				// NOTE: in Gen1 there was an extra block height passed to DeployATTransaction.isValid
 				Transaction.ValidationResult validationResult = transaction.isValid();

src/main/java/org/qora/block/BlockChain.java

@@ -36,11 +36,12 @@ public class BlockChain {
 	private static BlockChain instance = null;
 
 	// Properties
+	private boolean isTestNet;
 	private BigDecimal unitFee;
 	private BigDecimal maxBytesPerUnitFee;
 	private BigDecimal minFeePerByte;
 	/** Maximum coin supply. */
-	private BigDecimal maxBalance;;
+	private BigDecimal maxBalance;
 	/** Number of blocks between recalculating block's generating balance. */
 	private int blockDifficultyInterval;
 	/** Minimum target time between blocks, in seconds. */
@@ -51,7 +52,7 @@ public class BlockChain {
 	private long blockTimestampMargin;
 	/** Whether transactions with txGroupId of NO_GROUP are allowed */
 	private boolean grouplessAllowed;
-	/** Default groupID when txGroupID and account's default groupID are both zero */
+	/** Default groupID when account's default groupID isn't set */
 	private int defaultGroupId = Group.NO_GROUP;
 	/** Map of which blockchain features are enabled when (height/timestamp) */
 	private Map<String, Map<FeatureValueType, Long>> featureTriggers;
@@ -74,6 +75,10 @@ public class BlockChain {
 
 	// Getters / setters
 
+	public boolean getIsTestNet() {
+		return this.isTestNet;
+	}
+
 	public BigDecimal getUnitFee() {
 		return this.unitFee;
 	}
@@ -190,11 +195,15 @@ public class BlockChain {
 
 		// If groupless is not allowed the defaultGroupId needs to be set
 		// XXX we could also check groupID exists, or at least created in genesis block, or in blockchain config
-		if (!grouplessAllowed && (defaultGroupId == null || defaultGroupId == Group.DEFAULT_GROUP || defaultGroupId == Group.NO_GROUP)) {
+		if (!grouplessAllowed && (defaultGroupId == null || defaultGroupId == Group.NO_GROUP)) {
 			LOGGER.error("defaultGroupId must be set to valid groupID in blockchain config if groupless transactions are not allowed");
 			throw new RuntimeException("defaultGroupId must be set to valid groupID in blockchain config if groupless transactions are not allowed");
 		}
 
+		boolean isTestNet = true;
+		if (json.containsKey("isTestNet"))
+			isTestNet = (Boolean) Settings.getTypedJson(json, "isTestNet", Boolean.class);
+
 		BigDecimal unitFee = Settings.getJsonBigDecimal(json, "unitFee");
 		long maxBytesPerUnitFee = (Long) Settings.getTypedJson(json, "maxBytesPerUnitFee", Long.class);
 		BigDecimal maxBalance = Settings.getJsonBigDecimal(json, "coinSupply");
@@ -229,6 +238,7 @@ public class BlockChain {
 		}
 
 		instance = new BlockChain();
+		instance.isTestNet = isTestNet;
 		instance.unitFee = unitFee;
 		instance.maxBytesPerUnitFee = BigDecimal.valueOf(maxBytesPerUnitFee).setScale(8);
 		instance.minFeePerByte = unitFee.divide(instance.maxBytesPerUnitFee, MathContext.DECIMAL32);

src/main/java/org/qora/block/BlockGenerator.java

@@ -169,16 +169,13 @@ public class BlockGenerator extends Thread {
 			}
 
 			// Ignore transactions that have not met group-admin approval threshold
-			if (transaction.needsGroupApproval()) {
+			if (transaction.needsGroupApproval() && !transaction.meetsGroupApprovalThreshold()) {
 				unconfirmedTransactions.remove(i);
 				--i;
 				continue;
 			}
 		}
 
-		// Discard any repository changes used to aid transaction validity checks
-		// repository.discardChanges(); // XXX possibly not needed any more thanks to savepoints?
-
 		// Attempt to add transactions until block is full, or we run out
 		// If a transaction makes the block invalid then skip it and it'll either expire or be in next block.
 		for (TransactionData transactionData : unconfirmedTransactions) {

src/main/java/org/qora/data/account/AccountData.java

@@ -29,7 +29,7 @@ public class AccountData {
 	}
 
 	public AccountData(String address) {
-		this(address, null, null, Group.DEFAULT_GROUP);
+		this(address, null, null, Group.NO_GROUP);
 	}
 
 	// Getters/Setters

src/main/java/org/qora/data/group/GroupData.java

@@ -21,6 +21,8 @@ public class GroupData {
 	private Long updated;
 	private boolean isOpen;
 	private ApprovalThreshold approvalThreshold;
+	private int minimumBlockDelay;
+	private int maximumBlockDelay;
 	/** Reference to CREATE_GROUP or UPDATE_GROUP transaction, used to rebuild group during orphaning. */
 	// No need to ever expose this via API
 	@XmlTransient
@@ -34,7 +36,7 @@ public class GroupData {
 	}
 
 	/** Constructs new GroupData with nullable groupId and nullable updated [timestamp] */
-	public GroupData(Integer groupId, String owner, String name, String description, long created, Long updated, boolean isOpen, ApprovalThreshold approvalThreshold, byte[] reference) {
+	public GroupData(Integer groupId, String owner, String name, String description, long created, Long updated, boolean isOpen, ApprovalThreshold approvalThreshold, int minBlockDelay, int maxBlockDelay, byte[] reference) {
 		this.groupId = groupId;
 		this.owner = owner;
 		this.groupName = name;
@@ -44,11 +46,13 @@ public class GroupData {
 		this.isOpen = isOpen;
 		this.approvalThreshold = approvalThreshold;
 		this.reference = reference;
+		this.minimumBlockDelay = minBlockDelay;
+		this.maximumBlockDelay = maxBlockDelay;
 	}
 
 	/** Constructs new GroupData with unassigned groupId */
-	public GroupData(String owner, String name, String description, long created, boolean isOpen, ApprovalThreshold approvalThreshold, byte[] reference) {
-		this(null, owner, name, description, created, null, isOpen, approvalThreshold, reference);
+	public GroupData(String owner, String name, String description, long created, boolean isOpen, ApprovalThreshold approvalThreshold, int minBlockDelay, int maxBlockDelay, byte[] reference) {
+		this(null, owner, name, description, created, null, isOpen, approvalThreshold, minBlockDelay, maxBlockDelay, reference);
 	}
 
 	// Getters / setters
@@ -117,4 +121,12 @@ public class GroupData {
 		this.approvalThreshold = approvalThreshold;
 	}
 
+	public int getMinimumBlockDelay() {
+		return this.minimumBlockDelay;
+	}
+
+	public int getMaximumBlockDelay() {
+		return this.maximumBlockDelay;
+	}
+
 }

src/main/java/org/qora/data/transaction/CreateGroupTransactionData.java

@@ -52,6 +52,10 @@ public class CreateGroupTransactionData extends TransactionData {
 		description = "how many group admins are required to approve group member transactions"
 	)
 	private ApprovalThreshold approvalThreshold;
+	@Schema(description = "minimum block delay before approval takes effect")
+	private int minimumBlockDelay;
+	@Schema(description = "maximum block delay before which transaction approval must be reached")
+	private int maximumBlockDelay;
 
 	// Constructors
 
@@ -61,7 +65,7 @@ public class CreateGroupTransactionData extends TransactionData {
 	}
 
 	public CreateGroupTransactionData(long timestamp, int txGroupId, byte[] reference, byte[] creatorPublicKey, String owner, String groupName, String description,
-			boolean isOpen, ApprovalThreshold approvalThreshold, Integer groupId, BigDecimal fee, byte[] signature) {
+			boolean isOpen, ApprovalThreshold approvalThreshold, int minimumBlockDelay, int maximumBlockDelay, Integer groupId, BigDecimal fee, byte[] signature) {
 		super(TransactionType.CREATE_GROUP, timestamp, txGroupId, reference, creatorPublicKey, fee, signature);
 
 		this.creatorPublicKey = creatorPublicKey;
@@ -70,6 +74,8 @@ public class CreateGroupTransactionData extends TransactionData {
 		this.description = description;
 		this.isOpen = isOpen;
 		this.approvalThreshold = approvalThreshold;
+		this.minimumBlockDelay = minimumBlockDelay;
+		this.maximumBlockDelay = maximumBlockDelay;
 		this.groupId = groupId;
 	}
 
@@ -95,6 +101,14 @@ public class CreateGroupTransactionData extends TransactionData {
 		return this.approvalThreshold;
 	}
 
+	public int getMinimumBlockDelay() {
+		return this.minimumBlockDelay;
+	}
+
+	public int getMaximumBlockDelay() {
+		return this.maximumBlockDelay;
+	}
+
 	public Integer getGroupId() {
 		return this.groupId;
 	}

src/main/java/org/qora/data/transaction/UpdateGroupTransactionData.java

@@ -51,6 +51,10 @@ public class UpdateGroupTransactionData extends TransactionData {
 		description = "new group member transaction approval threshold"
 	)
 	private ApprovalThreshold newApprovalThreshold;
+	@Schema(description = "new minimum block delay before approval takes effect")
+	private int newMinimumBlockDelay;
+	@Schema(description = "new maximum block delay before which transaction approval must be reached")
+	private int newMaximumBlockDelay;
 	/** Reference to CREATE_GROUP or UPDATE_GROUP transaction, used to rebuild group during orphaning. */
 	// For internal use when orphaning
 	@XmlTransient
@@ -71,7 +75,7 @@ public class UpdateGroupTransactionData extends TransactionData {
 	}
 
 	public UpdateGroupTransactionData(long timestamp, int txGroupId, byte[] reference, byte[] ownerPublicKey, int groupId,
-			String newOwner, String newDescription, boolean newIsOpen, ApprovalThreshold newApprovalThreshold, byte[] groupReference, BigDecimal fee, byte[] signature) {
+			String newOwner, String newDescription, boolean newIsOpen, ApprovalThreshold newApprovalThreshold, int newMinimumBlockDelay, int newMaximumBlockDelay, byte[] groupReference, BigDecimal fee, byte[] signature) {
 		super(TransactionType.UPDATE_GROUP, timestamp, txGroupId, reference, ownerPublicKey, fee, signature);
 
 		this.ownerPublicKey = ownerPublicKey;
@@ -80,13 +84,15 @@ public class UpdateGroupTransactionData extends TransactionData {
 		this.newDescription = newDescription;
 		this.newIsOpen = newIsOpen;
 		this.newApprovalThreshold = newApprovalThreshold;
+		this.newMinimumBlockDelay = newMinimumBlockDelay;
+		this.newMaximumBlockDelay = newMaximumBlockDelay;
 		this.groupReference = groupReference;
 	}
 
 	/** Constructor typically used after deserialization */
 	public UpdateGroupTransactionData(long timestamp, int txGroupId, byte[] reference, byte[] ownerPublicKey, int groupId,
-			String newOwner, String newDescription, boolean newIsOpen, ApprovalThreshold newApprovalThreshold, BigDecimal fee, byte[] signature) {
-		this(timestamp, txGroupId, reference, ownerPublicKey, groupId, newOwner, newDescription, newIsOpen, newApprovalThreshold, null, fee, signature);
+			String newOwner, String newDescription, boolean newIsOpen, ApprovalThreshold newApprovalThreshold, int newMinimumBlockDelay, int newMaximumBlockDelay, BigDecimal fee, byte[] signature) {
+		this(timestamp, txGroupId, reference, ownerPublicKey, groupId, newOwner, newDescription, newIsOpen, newApprovalThreshold, newMinimumBlockDelay, newMaximumBlockDelay, null, fee, signature);
 	}
 
 	// Getters / setters
@@ -115,6 +121,14 @@ public class UpdateGroupTransactionData extends TransactionData {
 		return this.newApprovalThreshold;
 	}
 
+	public int getNewMinimumBlockDelay() {
+		return this.newMinimumBlockDelay;
+	}
+
+	public int getNewMaximumBlockDelay() {
+		return this.newMaximumBlockDelay;
+	}
+
 	public byte[] getGroupReference() {
 		return this.groupReference;
 	}

src/main/java/org/qora/group/Group.java

@@ -46,7 +46,8 @@ public class Group {
 		public final int value;
 		public final boolean isPercentage;
 
-		private final static Map<Integer, ApprovalThreshold> map = stream(ApprovalThreshold.values()).collect(toMap(threshold -> threshold.value, threshold -> threshold));
+		private final static Map<Integer, ApprovalThreshold> map = stream(ApprovalThreshold.values())
+				.collect(toMap(threshold -> threshold.value, threshold -> threshold));
 
 		ApprovalThreshold(int value, boolean isPercentage) {
 			this.value = value;
@@ -65,23 +66,25 @@ public class Group {
 		}
 
 		/**
-		 * Returns whether transaction need approval.
+		 * Returns whether transaction meets approval threshold.
 		 * 
 		 * @param repository
-		 * @param txGroupId transaction's groupID
-		 * @param signature transaction's signature
+		 * @param txGroupId
+		 *            transaction's groupID
+		 * @param signature
+		 *            transaction's signature
 		 * @return true if approval still needed, false if transaction can be included in block
 		 * @throws DataException
 		 */
-		public boolean needsApproval(Repository repository, int txGroupId, byte[] signature) throws DataException {
+		public boolean meetsApprovalThreshold(Repository repository, int txGroupId, byte[] signature) throws DataException {
 			// Fetch total number of admins in group
 			final int totalAdmins = repository.getGroupRepository().countGroupAdmins(txGroupId);
-			
+
 			// Fetch total number of approvals for signature
 			// NOT simply number of GROUP_APPROVE transactions as some may be rejecting transaction, or changed opinions
 			final int currentApprovals = repository.getTransactionRepository().countTransactionApprovals(txGroupId, signature);
 
-			return !meetsTheshold(currentApprovals, totalAdmins);
+			return meetsTheshold(currentApprovals, totalAdmins);
 		}
 	}
 
@@ -91,8 +94,7 @@ public class Group {
 	private GroupData groupData;
 
 	// Useful constants
-	public static final int NO_GROUP = -1;
-	public static final int DEFAULT_GROUP = 0;
+	public static final int NO_GROUP = 0;
 
 	public static final int MAX_NAME_SIZE = 32;
 	public static final int MAX_DESCRIPTION_SIZE = 128;
@@ -113,7 +115,8 @@ public class Group {
 
 		this.groupData = new GroupData(createGroupTransactionData.getOwner(), createGroupTransactionData.getGroupName(),
 				createGroupTransactionData.getDescription(), createGroupTransactionData.getTimestamp(), createGroupTransactionData.getIsOpen(),
-				createGroupTransactionData.getApprovalThreshold(), createGroupTransactionData.getSignature());
+				createGroupTransactionData.getApprovalThreshold(), createGroupTransactionData.getMinimumBlockDelay(),
+				createGroupTransactionData.getMaximumBlockDelay(), createGroupTransactionData.getSignature());
 	}
 
 	/**

src/main/java/org/qora/repository/BlockRepository.java

@@ -44,6 +44,15 @@ public interface BlockRepository {
 	 */
 	public int getHeightFromSignature(byte[] signature) throws DataException;
 
+	/**
+	 * Return height of block with timestamp just before passed timestamp.
+	 * 
+	 * @param timestamp
+	 * @return height, or 0 if not found in blockchain.
+	 * @throws DataException
+	 */
+	public int getHeightFromTimestamp(long timestamp) throws DataException;
+
 	/**
 	 * Return highest block height from repository.
 	 * 

src/main/java/org/qora/repository/TransactionRepository.java

@@ -47,6 +47,20 @@ public interface TransactionRepository {
 	public List<TransactionData> getAssetTransactions(int assetId, ConfirmationStatus confirmationStatus, Integer limit, Integer offset, Boolean reverse)
 			throws DataException;
 
+	/**
+	 * Returns list of transactions pending approval, with optional txGgroupId filtering.
+	 * <p>
+	 * This is typically called by the API.
+	 * 
+	 * @param txGroupId
+	 * @param limit
+	 * @param offset
+	 * @param reverse
+	 * @return list of transactions, or empty if none.
+	 * @throws DataException
+	 */
+	public List<TransactionData> getPendingTransactions(Integer txGroupId, Integer limit, Integer offset, Boolean reverse) throws DataException;
+
 	/** Returns number of approvals for transaction with given signature. */
 	public int countTransactionApprovals(int txGroupId, byte[] signature) throws DataException;
 

src/main/java/org/qora/repository/hsqldb/HSQLDBBlockRepository.java

@@ -90,6 +90,18 @@ public class HSQLDBBlockRepository implements BlockRepository {
 		}
 	}
 
+	@Override
+	public int getHeightFromTimestamp(long timestamp) throws DataException {
+		try (ResultSet resultSet = this.repository.checkedExecute("SELECT MAX(height) FROM Blocks WHERE generation <= ?", new Timestamp(timestamp))) {
+			if (resultSet == null)
+				return 0;
+
+			return resultSet.getInt(1);
+		} catch (SQLException e) {
+			throw new DataException("Error obtaining block height from repository", e);
+		}
+	}
+
 	@Override
 	public int getBlockchainHeight() throws DataException {
 		try (ResultSet resultSet = this.repository.checkedExecute("SELECT MAX(height) FROM Blocks LIMIT 1")) {

src/main/java/org/qora/repository/hsqldb/HSQLDBDatabaseUpdates.java

@@ -558,6 +558,16 @@ public class HSQLDBDatabaseUpdates {
 							+ "PRIMARY KEY (signature), FOREIGN KEY (signature) REFERENCES Transactions (signature) ON DELETE CASCADE)");
 					break;
 
+				case 35:
+					// Group-based transaction approval min/max block delay
+					stmt.execute("ALTER TABLE Groups ADD COLUMN min_block_delay INT NOT NULL DEFAULT 0 BEFORE reference");
+					stmt.execute("ALTER TABLE Groups ADD COLUMN max_block_delay INT NOT NULL DEFAULT 1440 BEFORE reference");
+					stmt.execute("ALTER TABLE CreateGroupTransactions ADD COLUMN min_block_delay INT NOT NULL DEFAULT 0 BEFORE group_id");
+					stmt.execute("ALTER TABLE CreateGroupTransactions ADD COLUMN max_block_delay INT NOT NULL DEFAULT 1440 BEFORE group_id");
+					stmt.execute("ALTER TABLE UpdateGroupTransactions ADD COLUMN new_min_block_delay INT NOT NULL DEFAULT 0 BEFORE group_reference");
+					stmt.execute("ALTER TABLE UpdateGroupTransactions ADD COLUMN new_max_block_delay INT NOT NULL DEFAULT 1440 BEFORE group_reference");
+					break;
+
 				default:
 					// nothing to do
 					return false;

src/main/java/org/qora/repository/hsqldb/HSQLDBGroupRepository.java

@@ -30,7 +30,7 @@ public class HSQLDBGroupRepository implements GroupRepository {
 	@Override
 	public GroupData fromGroupId(int groupId) throws DataException {
 		try (ResultSet resultSet = this.repository
-				.checkedExecute("SELECT group_name, owner, description, created, updated, reference, is_open, approval_threshold FROM Groups WHERE group_id = ?", groupId)) {
+				.checkedExecute("SELECT group_name, owner, description, created, updated, reference, is_open, approval_threshold, min_block_delay, max_block_delay FROM Groups WHERE group_id = ?", groupId)) {
 			if (resultSet == null)
 				return null;
 
@@ -48,7 +48,10 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 			ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(8));
 
-			return new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, reference);
+			int minBlockDelay = resultSet.getInt(9);
+			int maxBlockDelay = resultSet.getInt(10);
+
+			return new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, minBlockDelay, maxBlockDelay, reference);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch group info from repository", e);
 		}
@@ -57,7 +60,7 @@ public class HSQLDBGroupRepository implements GroupRepository {
 	@Override
 	public GroupData fromGroupName(String groupName) throws DataException {
 		try (ResultSet resultSet = this.repository
-				.checkedExecute("SELECT group_id, owner, description, created, updated, reference, is_open, approval_threshold FROM Groups WHERE group_name = ?", groupName)) {
+				.checkedExecute("SELECT group_id, owner, description, created, updated, reference, is_open, approval_threshold, min_block_delay, max_block_delay FROM Groups WHERE group_name = ?", groupName)) {
 			if (resultSet == null)
 				return null;
 
@@ -75,7 +78,10 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 			ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(8));
 
-			return new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, reference);
+			int minBlockDelay = resultSet.getInt(9);
+			int maxBlockDelay = resultSet.getInt(10);
+
+			return new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, minBlockDelay, maxBlockDelay, reference);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch group info from repository", e);
 		}
@@ -101,7 +107,7 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 	@Override
 	public List<GroupData> getAllGroups(Integer limit, Integer offset, Boolean reverse) throws DataException {
-		String sql = "SELECT group_id, owner, group_name, description, created, updated, reference, is_open, approval_threshold FROM Groups ORDER BY group_name";
+		String sql = "SELECT group_id, owner, group_name, description, created, updated, reference, is_open, approval_threshold, min_block_delay, max_block_delay FROM Groups ORDER BY group_name";
 		if (reverse != null && reverse)
 			sql += " DESC";
 		sql += HSQLDBRepository.limitOffsetSql(limit, offset);
@@ -128,7 +134,10 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 				ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(9));
 
-				groups.add(new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, reference));
+				int minBlockDelay = resultSet.getInt(10);
+				int maxBlockDelay = resultSet.getInt(11);
+
+				groups.add(new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, minBlockDelay, maxBlockDelay, reference));
 			} while (resultSet.next());
 
 			return groups;
@@ -139,7 +148,7 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 	@Override
 	public List<GroupData> getGroupsByOwner(String owner, Integer limit, Integer offset, Boolean reverse) throws DataException {
-		String sql = "SELECT group_id, group_name, description, created, updated, reference, is_open, approval_threshold FROM Groups WHERE owner = ? ORDER BY group_name";
+		String sql = "SELECT group_id, group_name, description, created, updated, reference, is_open, approval_threshold, min_block_delay, max_block_delay FROM Groups WHERE owner = ? ORDER BY group_name";
 		if (reverse != null && reverse)
 			sql += " DESC";
 		sql += HSQLDBRepository.limitOffsetSql(limit, offset);
@@ -165,7 +174,10 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 				ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(8));
 
-				groups.add(new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, reference));
+				int minBlockDelay = resultSet.getInt(9);
+				int maxBlockDelay = resultSet.getInt(10);
+
+				groups.add(new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, minBlockDelay, maxBlockDelay, reference));
 			} while (resultSet.next());
 
 			return groups;
@@ -176,7 +188,8 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 	@Override
 	public List<GroupData> getGroupsWithMember(String member, Integer limit, Integer offset, Boolean reverse) throws DataException {
-		String sql = "SELECT group_id, owner, group_name, description, created, updated, reference, is_open, approval_threshold FROM Groups JOIN GroupMembers USING (group_id) WHERE address = ? ORDER BY group_name";
+		String sql = "SELECT group_id, owner, group_name, description, created, updated, reference, is_open, approval_threshold min_block_delay, max_block_delay FROM Groups "
+				+ "JOIN GroupMembers USING (group_id) WHERE address = ? ORDER BY group_name";
 		if (reverse != null && reverse)
 			sql += " DESC";
 		sql += HSQLDBRepository.limitOffsetSql(limit, offset);
@@ -203,7 +216,10 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 				ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(9));
 
-				groups.add(new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, reference));
+				int minBlockDelay = resultSet.getInt(10);
+				int maxBlockDelay = resultSet.getInt(11);
+
+				groups.add(new GroupData(groupId, owner, groupName, description, created, updated, isOpen, approvalThreshold, minBlockDelay, maxBlockDelay, reference));
 			} while (resultSet.next());
 
 			return groups;
@@ -222,7 +238,8 @@ public class HSQLDBGroupRepository implements GroupRepository {
 
 		saveHelper.bind("group_id", groupData.getGroupId()).bind("owner", groupData.getOwner()).bind("group_name", groupData.getGroupName())
 				.bind("description", groupData.getDescription()).bind("created", new Timestamp(groupData.getCreated())).bind("updated", updatedTimestamp)
-				.bind("reference", groupData.getReference()).bind("is_open", groupData.getIsOpen()).bind("approval_threshold", groupData.getApprovalThreshold().value);
+				.bind("reference", groupData.getReference()).bind("is_open", groupData.getIsOpen()).bind("approval_threshold", groupData.getApprovalThreshold().value)
+				.bind("min_block_delay", groupData.getMinimumBlockDelay()).bind("max_block_delay", groupData.getMaximumBlockDelay());
 
 		try {
 			saveHelper.execute(this.repository);

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBCreateGroupTransactionRepository.java

@@ -18,8 +18,9 @@ public class HSQLDBCreateGroupTransactionRepository extends HSQLDBTransactionRep
 	}
 
 	TransactionData fromBase(long timestamp, int txGroupId, byte[] reference, byte[] creatorPublicKey, BigDecimal fee, byte[] signature) throws DataException {
-		try (ResultSet resultSet = this.repository
-				.checkedExecute("SELECT owner, group_name, description, is_open, approval_threshold, group_id FROM CreateGroupTransactions WHERE signature = ?", signature)) {
+		try (ResultSet resultSet = this.repository.checkedExecute(
+				"SELECT owner, group_name, description, is_open, approval_threshold, min_block_delay, max_block_delay, group_id FROM CreateGroupTransactions WHERE signature = ?",
+				signature)) {
 			if (resultSet == null)
 				return null;
 
@@ -30,12 +31,15 @@ public class HSQLDBCreateGroupTransactionRepository extends HSQLDBTransactionRep
 
 			ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(5));
 
-			Integer groupId = resultSet.getInt(6);
+			int minBlockDelay = resultSet.getInt(6);
+			int maxBlockDelay = resultSet.getInt(7);
+
+			Integer groupId = resultSet.getInt(8);
 			if (resultSet.wasNull())
 				groupId = null;
 
 			return new CreateGroupTransactionData(timestamp, txGroupId, reference, creatorPublicKey, owner, groupName, description, isOpen, approvalThreshold,
-					groupId, fee, signature);
+					minBlockDelay, maxBlockDelay, groupId, fee, signature);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch create group transaction from repository", e);
 		}
@@ -51,7 +55,8 @@ public class HSQLDBCreateGroupTransactionRepository extends HSQLDBTransactionRep
 				.bind("owner", createGroupTransactionData.getOwner()).bind("group_name", createGroupTransactionData.getGroupName())
 				.bind("description", createGroupTransactionData.getDescription()).bind("is_open", createGroupTransactionData.getIsOpen())
 				.bind("approval_threshold", createGroupTransactionData.getApprovalThreshold().value)
-				.bind("group_id", createGroupTransactionData.getGroupId());
+				.bind("min_block_delay", createGroupTransactionData.getMinimumBlockDelay())
+				.bind("max_block_delay", createGroupTransactionData.getMaximumBlockDelay()).bind("group_id", createGroupTransactionData.getGroupId());
 
 		try {
 			saveHelper.execute(this.repository);

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBTransactionRepository.java

@@ -9,6 +9,7 @@ import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Arrays;
+import static java.util.Arrays.stream;
 import java.util.Calendar;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -19,10 +20,12 @@ import org.qora.api.resource.TransactionsResource.ConfirmationStatus;
 import org.qora.data.PaymentData;
 import org.qora.data.transaction.GroupApprovalTransactionData;
 import org.qora.data.transaction.TransactionData;
+import org.qora.group.Group;
 import org.qora.repository.DataException;
 import org.qora.repository.TransactionRepository;
 import org.qora.repository.hsqldb.HSQLDBRepository;
 import org.qora.repository.hsqldb.HSQLDBSaver;
+import org.qora.transaction.Transaction;
 import org.qora.transaction.Transaction.TransactionType;
 
 import static org.qora.transaction.Transaction.TransactionType.*;
@@ -384,7 +387,7 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 
 		sql += HSQLDBRepository.limitOffsetSql(limit, offset);
 
-		LOGGER.trace(sql);
+		LOGGER.trace(String.format("Transaction search SQL: %s", sql));
 
 		try (ResultSet resultSet = this.repository.checkedExecute(sql, bindParams.toArray())) {
 			if (resultSet == null)
@@ -488,6 +491,59 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 		}
 	}
 
+	@Override
+	public List<TransactionData> getPendingTransactions(Integer txGroupId, Integer limit, Integer offset, Boolean reverse) throws DataException {
+		String[] txTypesNeedingApproval = stream(Transaction.TransactionType.values())
+		.filter(txType -> txType.needsApproval)
+		.map(txType -> String.valueOf(txType.value))
+		.toArray(String[]::new);
+
+		String txTypes = String.join(", ", txTypesNeedingApproval);
+
+		/*
+		 *  We only want transactions matching certain types needing approval,
+		 *  with txGroupId not set to NO_GROUP and where auto-approval won't
+		 *  happen due to the transaction creator being an admin of that group.
+		 */
+		String sql = "SELECT signature FROM UnconfirmedTransactions "
+				+ "NATURAL JOIN Transactions "
+				+ "LEFT OUTER JOIN Accounts ON Accounts.public_key = Transactions.creator "
+				+ "LEFT OUTER JOIN GroupAdmins ON GroupAdmins.admin = Accounts.account "
+				+ "WHERE Transactions.tx_group_id != ? AND GroupAdmins.admin IS NULL "
+				+ "AND Transactions.type IN (" + txTypes + ") "
+				+ "ORDER BY creation";
+		if (reverse != null && reverse)
+			sql += " DESC";
+		sql += ", signature";
+		if (reverse != null && reverse)
+			sql += " DESC";
+		sql += HSQLDBRepository.limitOffsetSql(limit, offset);
+
+		List<TransactionData> transactions = new ArrayList<TransactionData>();
+
+		// Find transactions with no corresponding row in BlockTransactions
+		try (ResultSet resultSet = this.repository.checkedExecute(sql, Group.NO_GROUP)) {
+			if (resultSet == null)
+				return transactions;
+
+			do {
+				byte[] signature = resultSet.getBytes(1);
+
+				TransactionData transactionData = this.fromSignature(signature);
+
+				if (transactionData == null)
+					// Something inconsistent with the repository
+					throw new DataException("Unable to fetch unconfirmed transaction from repository?");
+
+				transactions.add(transactionData);
+			} while (resultSet.next());
+
+			return transactions;
+		} catch (SQLException | DataException e) {
+			throw new DataException("Unable to fetch unconfirmed transactions from repository", e);
+		}
+	}
+
 	@Override
 	public int countTransactionApprovals(int txGroupId, byte[] signature) throws DataException {
 		// Fetch total number of approvals for signature

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBUpdateGroupTransactionRepository.java

@@ -19,7 +19,7 @@ public class HSQLDBUpdateGroupTransactionRepository extends HSQLDBTransactionRep
 
 	TransactionData fromBase(long timestamp, int txGroupId, byte[] reference, byte[] creatorPublicKey, BigDecimal fee, byte[] signature) throws DataException {
 		try (ResultSet resultSet = this.repository.checkedExecute(
-				"SELECT group_id, new_owner, new_description, new_is_open, new_approval_threshold, group_reference FROM UpdateGroupTransactions WHERE signature = ?",
+				"SELECT group_id, new_owner, new_description, new_is_open, new_approval_threshold, new_min_block_delay, new_max_block_delay, group_reference FROM UpdateGroupTransactions WHERE signature = ?",
 				signature)) {
 			if (resultSet == null)
 				return null;
@@ -30,9 +30,11 @@ public class HSQLDBUpdateGroupTransactionRepository extends HSQLDBTransactionRep
 			boolean newIsOpen = resultSet.getBoolean(4);
 			ApprovalThreshold newApprovalThreshold = ApprovalThreshold.valueOf(resultSet.getInt(5));
 			byte[] groupReference = resultSet.getBytes(6);
+			int newMinBlockDelay = resultSet.getInt(7);
+			int newMaxBlockDelay = resultSet.getInt(8);
 
 			return new UpdateGroupTransactionData(timestamp, txGroupId, reference, creatorPublicKey, groupId, newOwner, newDescription, newIsOpen,
-					newApprovalThreshold, groupReference, fee, signature);
+					newApprovalThreshold, newMinBlockDelay, newMaxBlockDelay, groupReference, fee, signature);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch update group transaction from repository", e);
 		}
@@ -48,6 +50,8 @@ public class HSQLDBUpdateGroupTransactionRepository extends HSQLDBTransactionRep
 				.bind("group_id", updateGroupTransactionData.getGroupId()).bind("new_owner", updateGroupTransactionData.getNewOwner())
 				.bind("new_description", updateGroupTransactionData.getNewDescription()).bind("new_is_open", updateGroupTransactionData.getNewIsOpen())
 				.bind("new_approval_threshold", updateGroupTransactionData.getNewApprovalThreshold().value)
+				.bind("new_min_block_delay", updateGroupTransactionData.getNewMinimumBlockDelay())
+				.bind("new_max_block_delay", updateGroupTransactionData.getNewMaximumBlockDelay())
 				.bind("group_reference", updateGroupTransactionData.getGroupReference());
 
 		try {

src/main/java/org/qora/settings/Settings.java

@@ -27,6 +27,7 @@ public class Settings {
 	private String userpath = "";
 	private boolean useBitcoinTestNet = false;
 	private boolean wipeUnconfirmedOnStart = false;
+	private Boolean restrictedApi;
 	private String blockchainConfigPath = "blockchain.json";
 	/** Maximum number of unconfirmed transactions allowed per account */
 	private int maxUnconfirmedPerAccount = 100;
@@ -143,6 +144,9 @@ public class Settings {
 		if (json.containsKey("apiEnabled"))
 			this.apiEnabled = ((Boolean) json.get("apiEnabled")).booleanValue();
 
+		if (json.containsKey("restrictedApi"))
+			this.restrictedApi = ((Boolean) json.get("restrictedApi")).booleanValue();
+
 		// Peer-to-peer networking
 
 		if (json.containsKey("listenPort"))
@@ -208,6 +212,14 @@ public class Settings {
 		return this.apiEnabled;
 	}
 
+	public boolean isRestrictedApi() {
+		if (this.restrictedApi != null)
+			return this.restrictedApi;
+
+		// Not set in config file, so restrict if not testnet
+		return !BlockChain.getInstance().getIsTestNet();
+	}
+
 	public int getListenPort() {
 		return this.listenPort;
 	}

src/main/java/org/qora/transaction/GroupApprovalTransaction.java

@@ -69,15 +69,14 @@ public class GroupApprovalTransaction extends Transaction {
 		if (pendingTransactionData == null)
 			return ValidationResult.TRANSACTION_UNKNOWN;
 
+		// Check pending transaction's groupID matches our transaction's groupID
+		if (groupApprovalTransactionData.getTxGroupId() != pendingTransactionData.getTxGroupId())
+			return ValidationResult.GROUP_ID_MISMATCH;
+
 		// Check pending transaction is not already in a block
 		if (this.repository.getTransactionRepository().getHeightFromSignature(groupApprovalTransactionData.getPendingSignature()) != 0)
 			return ValidationResult.TRANSACTION_ALREADY_CONFIRMED;
 
-		// Check pending transaction's groupID matches our transaction's groupID
-		int effectiveTxGroupId = this.getEffectiveGroupId();
-		if (effectiveTxGroupId != pendingTransactionData.getTxGroupId())
-			return ValidationResult.GROUP_ID_MISMATCH;
-
 		Account admin = getAdmin();
 
 		// Can't cast approval decision if not an admin

src/main/java/org/qora/transaction/GroupInviteTransaction.java

@@ -10,7 +10,6 @@ import org.qora.account.PublicKeyAccount;
 import org.qora.asset.Asset;
 import org.qora.crypto.Crypto;
 import org.qora.data.transaction.GroupInviteTransactionData;
-import org.qora.data.group.GroupData;
 import org.qora.data.transaction.TransactionData;
 import org.qora.group.Group;
 import org.qora.repository.DataException;
@@ -74,6 +73,12 @@ public class GroupInviteTransaction extends Transaction {
 
 	@Override
 	public ValidationResult isValid() throws DataException {
+		int groupId = groupInviteTransactionData.getGroupId();
+
+		// Check transaction's groupID matches group's ID
+		if (groupInviteTransactionData.getTxGroupId() != groupId)
+			return ValidationResult.GROUP_ID_MISMATCH;
+
 		// Check time to live zero (infinite) or positive
 		if (groupInviteTransactionData.getTimeToLive() < 0)
 			return ValidationResult.INVALID_LIFETIME;
@@ -82,31 +87,24 @@ public class GroupInviteTransaction extends Transaction {
 		if (!Crypto.isValidAddress(groupInviteTransactionData.getInvitee()))
 			return ValidationResult.INVALID_ADDRESS;
 
-		GroupData groupData = this.repository.getGroupRepository().fromGroupId(groupInviteTransactionData.getGroupId());
-
 		// Check group exists
-		if (groupData == null)
+		if (!this.repository.getGroupRepository().groupExists(groupId))
 			return ValidationResult.GROUP_DOES_NOT_EXIST;
 
-		// Check transaction's groupID matches group's ID
-		int effectiveTxGroupId = this.getEffectiveGroupId();
-		if (effectiveTxGroupId != groupInviteTransactionData.getTxGroupId())
-			return ValidationResult.GROUP_ID_MISMATCH;
-
 		Account admin = getAdmin();
 
 		// Can't invite if not an admin
-		if (!this.repository.getGroupRepository().adminExists(groupInviteTransactionData.getGroupId(), admin.getAddress()))
+		if (!this.repository.getGroupRepository().adminExists(groupId, admin.getAddress()))
 			return ValidationResult.NOT_GROUP_ADMIN;
 
 		Account invitee = getInvitee();
 
 		// Check invitee not already in group
-		if (this.repository.getGroupRepository().memberExists(groupInviteTransactionData.getGroupId(), invitee.getAddress()))
+		if (this.repository.getGroupRepository().memberExists(groupId, invitee.getAddress()))
 			return ValidationResult.ALREADY_GROUP_MEMBER;
 
 		// Check invitee is not banned
-		if (this.repository.getGroupRepository().banExists(groupInviteTransactionData.getGroupId(), invitee.getAddress()))
+		if (this.repository.getGroupRepository().banExists(groupId, invitee.getAddress()))
 			return ValidationResult.BANNED_FROM_GROUP;
 
 		// Check fee is positive

src/main/java/org/qora/transaction/JoinGroupTransaction.java

@@ -9,7 +9,6 @@ import org.qora.account.Account;
 import org.qora.account.PublicKeyAccount;
 import org.qora.asset.Asset;
 import org.qora.data.transaction.JoinGroupTransactionData;
-import org.qora.data.group.GroupData;
 import org.qora.data.transaction.TransactionData;
 import org.qora.group.Group;
 import org.qora.repository.DataException;
@@ -66,23 +65,28 @@ public class JoinGroupTransaction extends Transaction {
 
 	@Override
 	public ValidationResult isValid() throws DataException {
-		GroupData groupData = this.repository.getGroupRepository().fromGroupId(joinGroupTransactionData.getGroupId());
+		int groupId = joinGroupTransactionData.getGroupId();
+
+		// Check txGroupId
+		int txGroupId = joinGroupTransactionData.getTxGroupId();
+		if (txGroupId != Group.NO_GROUP && txGroupId != groupId)
+			return ValidationResult.GROUP_ID_MISMATCH;
 
 		// Check group exists
-		if (groupData == null)
+		if (!this.repository.getGroupRepository().groupExists(groupId))
 			return ValidationResult.GROUP_DOES_NOT_EXIST;
 
 		Account joiner = getJoiner();
 
-		if (this.repository.getGroupRepository().memberExists(joinGroupTransactionData.getGroupId(), joiner.getAddress()))
+		if (this.repository.getGroupRepository().memberExists(groupId, joiner.getAddress()))
 			return ValidationResult.ALREADY_GROUP_MEMBER;
 
 		// Check member is not banned
-		if (this.repository.getGroupRepository().banExists(joinGroupTransactionData.getGroupId(), joiner.getAddress()))
+		if (this.repository.getGroupRepository().banExists(groupId, joiner.getAddress()))
 			return ValidationResult.BANNED_FROM_GROUP;
 
 		// Check join request doesn't already exist
-		if (this.repository.getGroupRepository().joinRequestExists(joinGroupTransactionData.getGroupId(), joiner.getAddress()))
+		if (this.repository.getGroupRepository().joinRequestExists(groupId, joiner.getAddress()))
 			return ValidationResult.JOIN_REQUEST_EXISTS;
 
 		// Check fee is positive

src/main/java/org/qora/transaction/SetGroupTransaction.java

@@ -8,7 +8,6 @@ import java.util.List;
 import org.qora.account.Account;
 import org.qora.asset.Asset;
 import org.qora.data.transaction.SetGroupTransactionData;
-import org.qora.data.group.GroupData;
 import org.qora.data.transaction.TransactionData;
 import org.qora.group.Group;
 import org.qora.repository.DataException;
@@ -61,10 +60,8 @@ public class SetGroupTransaction extends Transaction {
 
 	@Override
 	public ValidationResult isValid() throws DataException {
-		GroupData groupData = this.repository.getGroupRepository().fromGroupId(setGroupTransactionData.getDefaultGroupId());
-
 		// Check group exists
-		if (groupData == null)
+		if (!this.repository.getGroupRepository().groupExists(setGroupTransactionData.getDefaultGroupId()))
 			return ValidationResult.GROUP_DOES_NOT_EXIST;
 
 		Account creator = getCreator();
@@ -94,7 +91,7 @@ public class SetGroupTransaction extends Transaction {
 
 		Integer previousDefaultGroupId = this.repository.getAccountRepository().getDefaultGroupId(creator.getAddress());
 		if (previousDefaultGroupId == null)
-			previousDefaultGroupId = Group.DEFAULT_GROUP;
+			previousDefaultGroupId = Group.NO_GROUP;
 
 		setGroupTransactionData.setPreviousDefaultGroupId(previousDefaultGroupId);
 
@@ -118,7 +115,7 @@ public class SetGroupTransaction extends Transaction {
 
 		Integer previousDefaultGroupId = setGroupTransactionData.getPreviousDefaultGroupId();
 		if (previousDefaultGroupId == null)
-			previousDefaultGroupId = Group.DEFAULT_GROUP;
+			previousDefaultGroupId = Group.NO_GROUP;
 
 		creator.setDefaultGroupId(previousDefaultGroupId);
 

src/main/java/org/qora/transaction/Transaction.java

@@ -16,6 +16,7 @@ import org.qora.account.PrivateKeyAccount;
 import org.qora.account.PublicKeyAccount;
 import org.qora.block.BlockChain;
 import org.qora.data.block.BlockData;
+import org.qora.data.group.GroupData;
 import org.qora.data.transaction.TransactionData;
 import org.qora.group.Group;
 import org.qora.repository.DataException;
@@ -37,43 +38,43 @@ public abstract class Transaction {
 	// Transaction types
 	public enum TransactionType {
 		// NOTE: must be contiguous or reflection fails
-		GENESIS(1, true),
+		GENESIS(1, false),
 		PAYMENT(2, false),
-		REGISTER_NAME(3, false),
-		UPDATE_NAME(4, false),
+		REGISTER_NAME(3, true),
+		UPDATE_NAME(4, true),
 		SELL_NAME(5, false),
 		CANCEL_SELL_NAME(6, false),
 		BUY_NAME(7, false),
-		CREATE_POLL(8, false),
+		CREATE_POLL(8, true),
 		VOTE_ON_POLL(9, false),
-		ARBITRARY(10, false),
-		ISSUE_ASSET(11, false),
+		ARBITRARY(10, true),
+		ISSUE_ASSET(11, true),
 		TRANSFER_ASSET(12, false),
 		CREATE_ASSET_ORDER(13, false),
 		CANCEL_ASSET_ORDER(14, false),
 		MULTI_PAYMENT(15, false),
-		DEPLOY_AT(16, false),
-		MESSAGE(17, false),
+		DEPLOY_AT(16, true),
+		MESSAGE(17, true),
 		DELEGATION(18, false),
 		SUPERNODE(19, false),
-		AIRDROP(20, true),
-		AT(21, true),
-		CREATE_GROUP(22, false),
+		AIRDROP(20, false),
+		AT(21, false),
+		CREATE_GROUP(22, true),
 		UPDATE_GROUP(23, true),
-		ADD_GROUP_ADMIN(24, true),
-		REMOVE_GROUP_ADMIN(25, true),
-		GROUP_BAN(26, true),
-		CANCEL_GROUP_BAN(27, true),
-		GROUP_KICK(28, true),
-		GROUP_INVITE(29, true),
-		CANCEL_GROUP_INVITE(30, true),
-		JOIN_GROUP(31, true),
-		LEAVE_GROUP(32, true),
-		GROUP_APPROVAL(33, true),
-		SET_GROUP(34, true);
+		ADD_GROUP_ADMIN(24, false),
+		REMOVE_GROUP_ADMIN(25, false),
+		GROUP_BAN(26, false),
+		CANCEL_GROUP_BAN(27, false),
+		GROUP_KICK(28, false),
+		GROUP_INVITE(29, false),
+		CANCEL_GROUP_INVITE(30, false),
+		JOIN_GROUP(31, false),
+		LEAVE_GROUP(32, false),
+		GROUP_APPROVAL(33, false),
+		SET_GROUP(34, false);
 
 		public final int value;
-		public final boolean skipsApproval;
+		public final boolean needsApproval;
 		public final String valueString;
 		public final String className;
 		public final Class<?> clazz;
@@ -81,9 +82,9 @@ public abstract class Transaction {
 
 		private final static Map<Integer, TransactionType> map = stream(TransactionType.values()).collect(toMap(type -> type.value, type -> type));
 
-		TransactionType(int value, boolean skipsApproval) {
+		TransactionType(int value, boolean needsApproval) {
 			this.value = value;
-			this.skipsApproval = skipsApproval;
+			this.needsApproval = needsApproval;
 			this.valueString = String.valueOf(value);
 
 			String[] classNameParts = this.name().toLowerCase().split("_");
@@ -495,19 +496,20 @@ public abstract class Transaction {
 	}
 
 	private boolean isValidTxGroupId() throws DataException {
-		// Does this transaction type bypass approval?
-		if (this.transactionData.getType().skipsApproval)
-			return true;
+		int txGroupId = this.transactionData.getTxGroupId();
 
-		int txGroupId = this.getEffectiveGroupId();
+		// Handling NO_GROUP
 		if (txGroupId == Group.NO_GROUP)
-			return true;
+			// true if NO_GROUP allowed, false otherwise
+			return BlockChain.getInstance().getGrouplessAllowed();
 
-		Group group = new Group(repository, txGroupId);
-		if (group.getGroupData() == null) {
-			// Group no longer exists? Possibly due to blockchain orphaning undoing group creation?
+		// Group even exist?
+		if (!this.repository.getGroupRepository().groupExists(txGroupId))
 			return false;
-		}
+
+		// Does this transaction type bypass approval?
+		if (!this.transactionData.getType().needsApproval)
+			return true;
 
 		GroupRepository groupRepository = this.repository.getGroupRepository();
 
@@ -615,6 +617,17 @@ public abstract class Transaction {
 		if (transaction.getDeadline() <= blockTimestamp || transaction.getDeadline() < NTP.getTime())
 			return false;
 
+		// Is transaction is past max approval period?
+		if (transaction.needsGroupApproval()) {
+			int txGroupId = transactionData.getTxGroupId();
+			GroupData groupData = repository.getGroupRepository().fromGroupId(txGroupId);
+
+			int creationBlockHeight = repository.getBlockRepository().getHeightFromTimestamp(transactionData.getTimestamp());
+			int currentBlockHeight = repository.getBlockRepository().getBlockchainHeight();
+			if (currentBlockHeight > creationBlockHeight + groupData.getMaximumBlockDelay())
+				return false;
+		}
+
 		// Check transaction is currently valid
 		if (transaction.isValid() != Transaction.ValidationResult.OK)
 			return false;
@@ -628,72 +641,47 @@ public abstract class Transaction {
 	}
 
 	/**
-	 * Returns transaction's effective groupID, using default values where necessary.
-	 */
-	public int getEffectiveGroupId() throws DataException {
-		int txGroupId = this.transactionData.getTxGroupId();
-
-		// If transaction's groupID is NO_GROUP then group-ness doesn't apply
-		if (txGroupId == Group.NO_GROUP) {
-			if (BlockChain.getInstance().getGrouplessAllowed())
-				return txGroupId;
-			else
-				txGroupId = Group.DEFAULT_GROUP;
-		}
-
-		// If transaction's groupID is not DEFAULT_GROUP then no further processing required
-		if (txGroupId != Group.DEFAULT_GROUP)
-			return txGroupId;
-
-		// Try using account's default groupID
-		PublicKeyAccount creator = this.getCreator();
-		txGroupId = creator.getDefaultGroupId();
-
-		// If transaction's groupID is NO_GROUP then group-ness doesn't apply
-		if (txGroupId == Group.NO_GROUP) {
-			if (BlockChain.getInstance().getGrouplessAllowed())
-				return txGroupId;
-			else
-				txGroupId = Group.DEFAULT_GROUP;
-		}
-
-		// If txGroupId now not DEFAULT_GROUP then no further processing required
-		if (txGroupId != Group.DEFAULT_GROUP)
-			return txGroupId;
-
-		// Still zero? Use blockchain default
-		return BlockChain.getInstance().getDefaultGroupId();
-	}
-
-	/**
-	 * Returns whether transaction still requires group-admin approval.
+	 * Returns whether transaction needs to go through group-admin approval.
 	 * 
 	 * @throws DataException
 	 */
 	public boolean needsGroupApproval() throws DataException {
 		// Does this transaction type bypass approval?
-		if (this.transactionData.getType().skipsApproval)
+		if (!this.transactionData.getType().needsApproval)
 			return false;
 
-		int txGroupId = this.getEffectiveGroupId();
+		int txGroupId = this.transactionData.getTxGroupId();
 
 		if (txGroupId == Group.NO_GROUP)
 			return false;
 
-		Group group = new Group(repository, txGroupId);
-		if (group.getGroupData() == null) {
+		GroupRepository groupRepository = this.repository.getGroupRepository();
+
+		if (!groupRepository.groupExists(txGroupId))
 			// Group no longer exists? Possibly due to blockchain orphaning undoing group creation?
 			return true;
-		}
-
-		GroupRepository groupRepository = this.repository.getGroupRepository();
 
 		// If transaction's creator is group admin then auto-approve
 		PublicKeyAccount creator = this.getCreator();
 		if (groupRepository.adminExists(txGroupId, creator.getAddress()))
 			return false;
 
-		return group.getGroupData().getApprovalThreshold().needsApproval(repository, txGroupId, this.transactionData.getSignature());
+		return true;
+	}
+
+	public boolean meetsGroupApprovalThreshold() throws DataException {
+		int txGroupId = this.transactionData.getTxGroupId();
+
+		Group group = new Group(repository, txGroupId);
+		GroupData groupData = group.getGroupData();
+
+		// Is transaction is outside of min/max approval period?
+		int creationBlockHeight = this.repository.getBlockRepository().getHeightFromTimestamp(this.transactionData.getTimestamp());
+		int currentBlockHeight = this.repository.getBlockRepository().getBlockchainHeight();
+		if (currentBlockHeight < creationBlockHeight + groupData.getMinimumBlockDelay() || currentBlockHeight > creationBlockHeight + groupData.getMaximumBlockDelay())
+			return false;
+
+		return group.getGroupData().getApprovalThreshold().meetsApprovalThreshold(repository, txGroupId, this.transactionData.getSignature());
 	}
 
 	/**

src/main/java/org/qora/transform/transaction/CreateGroupTransactionTransformer.java

@@ -15,6 +15,7 @@ import org.qora.transform.TransformationException;
 import org.qora.utils.Serialization;
 
 import com.google.common.base.Utf8;
+import com.google.common.primitives.Ints;
 
 public class CreateGroupTransactionTransformer extends TransactionTransformer {
 
@@ -42,6 +43,8 @@ public class CreateGroupTransactionTransformer extends TransactionTransformer {
 		layout.add("group's description", TransformationType.STRING);
 		layout.add("is group \"open\"?", TransformationType.BOOLEAN);
 		layout.add("group transaction approval threshold", TransformationType.BYTE);
+		layout.add("minimum block delay for transaction approvals", TransformationType.INT);
+		layout.add("maximum block delay for transaction approvals", TransformationType.INT);
 		layout.add("fee", TransformationType.AMOUNT);
 		layout.add("signature", TransformationType.SIGNATURE);
 	}
@@ -68,13 +71,17 @@ public class CreateGroupTransactionTransformer extends TransactionTransformer {
 
 		ApprovalThreshold approvalThreshold = ApprovalThreshold.valueOf(byteBuffer.get());
 
+		int minBlockDelay = byteBuffer.getInt();
+
+		int maxBlockDelay = byteBuffer.getInt();
+
 		BigDecimal fee = Serialization.deserializeBigDecimal(byteBuffer);
 
 		byte[] signature = new byte[SIGNATURE_LENGTH];
 		byteBuffer.get(signature);
 
-		return new CreateGroupTransactionData(timestamp, txGroupId, reference, creatorPublicKey, owner, groupName, description, isOpen, approvalThreshold, null,
-				fee, signature);
+		return new CreateGroupTransactionData(timestamp, txGroupId, reference, creatorPublicKey, owner, groupName, description, isOpen, approvalThreshold,
+				minBlockDelay, maxBlockDelay, null, fee, signature);
 	}
 
 	public static int getDataLength(TransactionData transactionData) throws TransformationException {
@@ -102,6 +109,10 @@ public class CreateGroupTransactionTransformer extends TransactionTransformer {
 
 			bytes.write((byte) createGroupTransactionData.getApprovalThreshold().value);
 
+			bytes.write(Ints.toByteArray(createGroupTransactionData.getMinimumBlockDelay()));
+
+			bytes.write(Ints.toByteArray(createGroupTransactionData.getMaximumBlockDelay()));
+
 			Serialization.serializeBigDecimal(bytes, createGroupTransactionData.getFee());
 
 			if (createGroupTransactionData.getSignature() != null)

src/main/java/org/qora/transform/transaction/UpdateGroupTransactionTransformer.java

@@ -70,13 +70,17 @@ public class UpdateGroupTransactionTransformer extends TransactionTransformer {
 
 		ApprovalThreshold newApprovalThreshold = ApprovalThreshold.valueOf(byteBuffer.get());
 
+		int newMinBlockDelay = byteBuffer.getInt();
+
+		int newMaxBlockDelay = byteBuffer.getInt();
+
 		BigDecimal fee = Serialization.deserializeBigDecimal(byteBuffer);
 
 		byte[] signature = new byte[SIGNATURE_LENGTH];
 		byteBuffer.get(signature);
 
 		return new UpdateGroupTransactionData(timestamp, txGroupId, reference, ownerPublicKey, groupId, newOwner, newDescription, newIsOpen,
-				newApprovalThreshold, fee, signature);
+				newApprovalThreshold, newMinBlockDelay, newMaxBlockDelay, fee, signature);
 	}
 
 	public static int getDataLength(TransactionData transactionData) throws TransformationException {
@@ -103,6 +107,10 @@ public class UpdateGroupTransactionTransformer extends TransactionTransformer {
 
 			bytes.write((byte) updateGroupTransactionData.getNewApprovalThreshold().value);
 
+			bytes.write(Ints.toByteArray(updateGroupTransactionData.getNewMinimumBlockDelay()));
+
+			bytes.write(Ints.toByteArray(updateGroupTransactionData.getNewMaximumBlockDelay()));
+
 			Serialization.serializeBigDecimal(bytes, updateGroupTransactionData.getFee());
 
 			if (updateGroupTransactionData.getSignature() != null)

src/main/java/org/qora/v1feeder.java

@@ -496,13 +496,13 @@ public class v1feeder extends Thread {
 
 					BigDecimal fee = BigDecimal.ZERO.setScale(8);
 
-					TransactionData transactionData = new ATTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender, recipient, amount, Asset.QORA, message, fee);
+					TransactionData transactionData = new ATTransactionData(timestamp, Group.NO_GROUP, reference, sender, recipient, amount, Asset.QORA, message, fee);
 					byte[] digest;
 					try {
 						digest = Crypto.digest(AtTransactionTransformer.toBytes(transactionData));
 						byte[] signature = Bytes.concat(digest, digest);
 
-						transactionData = new ATTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender, recipient, amount, Asset.QORA, message, fee, signature);
+						transactionData = new ATTransactionData(timestamp, Group.NO_GROUP, reference, sender, recipient, amount, Asset.QORA, message, fee, signature);
 					} catch (TransformationException e) {
 						throw new RuntimeException("Couldn't transform AT Transaction into bytes", e);
 					}

src/main/resources/i18n/ApiError_en.properties

@@ -7,6 +7,7 @@ NO_BALANCE=not enough balance
 NOT_YET_RELEASED=that feature is not yet released
 UNAUTHORIZED=api call unauthorized
 REPOSITORY_ISSUE=repository error
+NON_PRODUCTION=This API call is not permitted for production systems
 
 # Validation
 INVALID_SIGNATURE=invalid signature

src/test/java/org/qora/test/ATTests.java

@@ -47,7 +47,7 @@ public class ATTests extends Common {
 		byte[] reference = Base58.decode("2D3jX1pEgu6irsQ7QzJb85QP1D9M45dNyP5M9a3WFHndU5ZywF4F5pnUurcbzMnGMcTwpAY6H7DuLw8cUBU66ao1");
 		byte[] signature = Base58.decode("2dZ4megUyNoYYY7qWmuSd4xw1yUKgPPF97yBbeddh8aKuC8PLpz7Xvf3r6Zjv1zwGrR8fEAHuaztCPD4KQp76KdL");
 
-		DeployAtTransactionData transactionData = new DeployAtTransactionData(timestamp, Group.DEFAULT_GROUP, reference, creatorPublicKey, name, description, ATType,
+		DeployAtTransactionData transactionData = new DeployAtTransactionData(timestamp, Group.NO_GROUP, reference, creatorPublicKey, name, description, ATType,
 				tags, creationBytes, amount, Asset.QORA, fee, signature);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {

src/test/java/org/qora/test/SaveTests.java

@@ -23,7 +23,7 @@ public class SaveTests extends Common {
 			byte[] signature = Base58.decode(signature58);
 			PublicKeyAccount sender = new PublicKeyAccount(repository, "Qsender".getBytes());
 
-			PaymentTransactionData paymentTransactionData = new PaymentTransactionData(Instant.now().getEpochSecond(), Group.DEFAULT_GROUP, reference,
+			PaymentTransactionData paymentTransactionData = new PaymentTransactionData(Instant.now().getEpochSecond(), Group.NO_GROUP, reference,
 					sender.getPublicKey(), "Qrecipient", BigDecimal.valueOf(12345L), BigDecimal.ONE, signature);
 
 			repository.getTransactionRepository().save(paymentTransactionData);

src/test/java/org/qora/test/TransactionTests.java

@@ -121,7 +121,7 @@ public class TransactionTests {
 
 		// Create test generator account
 		generator = new PrivateKeyAccount(repository, generatorSeed);
-		accountRepository.setLastReference(new AccountData(generator.getAddress(), generatorSeed, generator.getPublicKey(), Group.DEFAULT_GROUP));
+		accountRepository.setLastReference(new AccountData(generator.getAddress(), generatorSeed, generator.getPublicKey(), Group.NO_GROUP));
 		accountRepository.save(new AccountBalanceData(generator.getAddress(), Asset.QORA, initialGeneratorBalance));
 
 		// Create test sender account
@@ -129,7 +129,7 @@ public class TransactionTests {
 
 		// Mock account
 		reference = senderSeed;
-		accountRepository.setLastReference(new AccountData(sender.getAddress(), reference, sender.getPublicKey(), Group.DEFAULT_GROUP));
+		accountRepository.setLastReference(new AccountData(sender.getAddress(), reference, sender.getPublicKey(), Group.NO_GROUP));
 
 		// Mock balance
 		accountRepository.save(new AccountBalanceData(sender.getAddress(), Asset.QORA, initialSenderBalance));
@@ -147,7 +147,7 @@ public class TransactionTests {
 		BigDecimal amount = genericPaymentAmount;
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		PaymentTransactionData paymentTransactionData = new PaymentTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), recipient, amount, fee);
+		PaymentTransactionData paymentTransactionData = new PaymentTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), recipient, amount, fee);
 
 		Transaction paymentTransaction = new PaymentTransaction(repository, paymentTransactionData);
 		paymentTransaction.sign(sender);
@@ -164,7 +164,7 @@ public class TransactionTests {
 		BigDecimal amount = BigDecimal.valueOf(1_000L);
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		PaymentTransactionData paymentTransactionData = new PaymentTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), recipient.getAddress(),
+		PaymentTransactionData paymentTransactionData = new PaymentTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), recipient.getAddress(),
 				amount, fee);
 
 		Transaction paymentTransaction = new PaymentTransaction(repository, paymentTransactionData);
@@ -225,7 +225,7 @@ public class TransactionTests {
 
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		RegisterNameTransactionData registerNameTransactionData = new RegisterNameTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), sender.getAddress(),
+		RegisterNameTransactionData registerNameTransactionData = new RegisterNameTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), sender.getAddress(),
 				name, data, fee);
 
 		Transaction registerNameTransaction = new RegisterNameTransaction(repository, registerNameTransactionData);
@@ -281,7 +281,7 @@ public class TransactionTests {
 
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		UpdateNameTransactionData updateNameTransactionData = new UpdateNameTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(),
+		UpdateNameTransactionData updateNameTransactionData = new UpdateNameTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(),
 				newOwner.getAddress(), name, newData, nameReference, fee);
 
 		Transaction updateNameTransaction = new UpdateNameTransaction(repository, updateNameTransactionData);
@@ -327,7 +327,7 @@ public class TransactionTests {
 
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		SellNameTransactionData sellNameTransactionData = new SellNameTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), name, amount, fee);
+		SellNameTransactionData sellNameTransactionData = new SellNameTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), name, amount, fee);
 
 		Transaction sellNameTransaction = new SellNameTransaction(repository, sellNameTransactionData);
 		sellNameTransaction.sign(sender);
@@ -378,7 +378,7 @@ public class TransactionTests {
 
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		CancelSellNameTransactionData cancelSellNameTransactionData = new CancelSellNameTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), name, fee);
+		CancelSellNameTransactionData cancelSellNameTransactionData = new CancelSellNameTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), name, fee);
 
 		Transaction cancelSellNameTransaction = new CancelSellNameTransaction(repository, cancelSellNameTransactionData);
 		cancelSellNameTransaction.sign(sender);
@@ -443,7 +443,7 @@ public class TransactionTests {
 
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		BuyNameTransactionData buyNameTransactionData = new BuyNameTransactionData(timestamp, Group.DEFAULT_GROUP, buyersReference, buyer.getPublicKey(),
+		BuyNameTransactionData buyNameTransactionData = new BuyNameTransactionData(timestamp, Group.NO_GROUP, buyersReference, buyer.getPublicKey(),
 				name, originalNameData.getSalePrice(), seller, nameReference, fee);
 
 		Transaction buyNameTransaction = new BuyNameTransaction(repository, buyNameTransactionData);
@@ -496,7 +496,7 @@ public class TransactionTests {
 		Account recipient = new PublicKeyAccount(repository, recipientSeed);
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
-		CreatePollTransactionData createPollTransactionData = new CreatePollTransactionData(timestamp, Group.DEFAULT_GROUP, reference,
+		CreatePollTransactionData createPollTransactionData = new CreatePollTransactionData(timestamp, Group.NO_GROUP, reference,
 				sender.getPublicKey(), recipient.getAddress(), pollName, description, pollOptions, fee);
 
 		Transaction createPollTransaction = new CreatePollTransaction(repository, createPollTransactionData);
@@ -550,7 +550,7 @@ public class TransactionTests {
 
 		for (int optionIndex = 0; optionIndex <= pollOptionsSize; ++optionIndex) {
 			// Make a vote-on-poll transaction
-			VoteOnPollTransactionData voteOnPollTransactionData = new VoteOnPollTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), pollName,
+			VoteOnPollTransactionData voteOnPollTransactionData = new VoteOnPollTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), pollName,
 					optionIndex, fee);
 
 			Transaction voteOnPollTransaction = new VoteOnPollTransaction(repository, voteOnPollTransactionData);
@@ -622,7 +622,7 @@ public class TransactionTests {
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
 
-		IssueAssetTransactionData issueAssetTransactionData = new IssueAssetTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(),
+		IssueAssetTransactionData issueAssetTransactionData = new IssueAssetTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(),
 				sender.getAddress(), assetName, description, quantity, isDivisible, fee);
 
 		Transaction issueAssetTransaction = new IssueAssetTransaction(repository, issueAssetTransactionData);
@@ -712,7 +712,7 @@ public class TransactionTests {
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
 
-		TransferAssetTransactionData transferAssetTransactionData = new TransferAssetTransactionData(timestamp, Group.DEFAULT_GROUP, reference,
+		TransferAssetTransactionData transferAssetTransactionData = new TransferAssetTransactionData(timestamp, Group.NO_GROUP, reference,
 				sender.getPublicKey(), recipient.getAddress(), amount, assetId, fee);
 
 		Transaction transferAssetTransaction = new TransferAssetTransaction(repository, transferAssetTransactionData);
@@ -817,7 +817,7 @@ public class TransactionTests {
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
 
-		CreateAssetOrderTransactionData createOrderTransactionData = new CreateAssetOrderTransactionData(timestamp, Group.DEFAULT_GROUP, buyersReference, buyer.getPublicKey(), haveAssetId,
+		CreateAssetOrderTransactionData createOrderTransactionData = new CreateAssetOrderTransactionData(timestamp, Group.NO_GROUP, buyersReference, buyer.getPublicKey(), haveAssetId,
 				wantAssetId, amount, price, fee);
 		Transaction createOrderTransaction = new CreateAssetOrderTransaction(this.repository, createOrderTransactionData);
 		createOrderTransaction.sign(buyer);
@@ -898,7 +898,7 @@ public class TransactionTests {
 		BigDecimal fee = BigDecimal.ONE;
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
 		byte[] buyersReference = buyer.getLastReference();
-		CancelAssetOrderTransactionData cancelOrderTransactionData = new CancelAssetOrderTransactionData(timestamp, Group.DEFAULT_GROUP, buyersReference, buyer.getPublicKey(), orderId, fee);
+		CancelAssetOrderTransactionData cancelOrderTransactionData = new CancelAssetOrderTransactionData(timestamp, Group.NO_GROUP, buyersReference, buyer.getPublicKey(), orderId, fee);
 
 		Transaction cancelOrderTransaction = new CancelAssetOrderTransaction(this.repository, cancelOrderTransactionData);
 		cancelOrderTransaction.sign(buyer);
@@ -973,7 +973,7 @@ public class TransactionTests {
 		long timestamp = parentBlockData.getTimestamp() + 1_000;
 		BigDecimal senderPreTradeWantBalance = sender.getConfirmedBalance(wantAssetId);
 
-		CreateAssetOrderTransactionData createOrderTransactionData = new CreateAssetOrderTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), haveAssetId,
+		CreateAssetOrderTransactionData createOrderTransactionData = new CreateAssetOrderTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), haveAssetId,
 				wantAssetId, amount, price, fee);
 		Transaction createOrderTransaction = new CreateAssetOrderTransaction(this.repository, createOrderTransactionData);
 		createOrderTransaction.sign(sender);
@@ -1082,7 +1082,7 @@ public class TransactionTests {
 			payments.add(paymentData);
 		}
 
-		MultiPaymentTransactionData multiPaymentTransactionData = new MultiPaymentTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), payments, fee);
+		MultiPaymentTransactionData multiPaymentTransactionData = new MultiPaymentTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), payments, fee);
 
 		Transaction multiPaymentTransaction = new MultiPaymentTransaction(repository, multiPaymentTransactionData);
 		multiPaymentTransaction.sign(sender);
@@ -1151,7 +1151,7 @@ public class TransactionTests {
 		boolean isText = true;
 		boolean isEncrypted = false;
 
-		MessageTransactionData messageTransactionData = new MessageTransactionData(timestamp, Group.DEFAULT_GROUP, reference, sender.getPublicKey(), version,
+		MessageTransactionData messageTransactionData = new MessageTransactionData(timestamp, Group.NO_GROUP, reference, sender.getPublicKey(), version,
 				recipient.getAddress(), Asset.QORA, amount, data, isText, isEncrypted, fee);
 
 		Transaction messageTransaction = new MessageTransaction(repository, messageTransactionData);