diff --git a/README.md b/README.md
index c64ca90..650f8af 100644
--- a/README.md
+++ b/README.md
@@ -718,10 +718,9 @@ import "github.com/bartossh/Computantis/configuration"
 
 - [type Configuration](<#type-configuration>)
   - [func Read(path string) (Configuration, error)](<#func-read>)
-- [type DBConfig](<#type-dbconfig>)
 
 
-## type [Configuration](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L25-L32>)
+## type [Configuration](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L18-L25>)
 
 Configuration is the main configuration of the application that corresponds to the \*.yaml file that holds the configuration.
 
@@ -729,14 +728,14 @@ Configuration is the main configuration of the application that corresponds to t
 type Configuration struct {
     Bookkeeper   bookkeeping.Config    `yaml:"bookkeeper"`
     Server       server.Config         `yaml:"server"`
-    Database     DBConfig              `yaml:"database"`
+    Database     repohelper.DBConfig   `yaml:"database"`
     DataProvider dataprovider.Config   `yaml:"data_provider"`
     Validator    validator.Config      `yaml:"validator"`
     FileOperator fileoperations.Config `yaml:"file_operator"`
 }
 ```
 
-### func [Read](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L35>)
+### func [Read](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L28>)
 
 ```go
 func Read(path string) (Configuration, error)
@@ -744,19 +743,6 @@ func Read(path string) (Configuration, error)
 
 Read reads the configuration from the file and returns the Configuration with set fields according to the yaml setup.
 
-## type [DBConfig](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L16-L21>)
-
-Config contains configuration for the database.
-
-```go
-type DBConfig struct {
-    ConnStr      string `yaml:"conn_str"`         // ConnStr is the connection string to the database.
-    DatabaseName string `yaml:"database_name"`    // DatabaseName is the name of the database.
-    Token        string `yaml:"token"`            // Token is the token that is used to confirm api clients access.
-    TokenExpire  int64  `yaml:"token_expiration"` // TokenExpire is the number of seconds after which token expires.
-}
-```
-
 # dataprovider
 
 ```go
@@ -1048,6 +1034,158 @@ func (o *Observable[T]) Subscribe() *subscriber[T]
 
 Subscribe subscribes to the container.
 
+# repohelper
+
+```go
+import "github.com/bartossh/Computantis/repohelper"
+```
+
+## Index
+
+- [Variables](<#variables>)
+- [type AddressWriteFindChecker](<#type-addresswritefindchecker>)
+- [type BlockReadWriter](<#type-blockreadwriter>)
+- [type ConnectionCloser](<#type-connectioncloser>)
+- [type DBConfig](<#type-dbconfig>)
+  - [func (cfg DBConfig) Connect(ctx context.Context) (RepositoryProvider, error)](<#func-dbconfig-connect>)
+- [type Migrator](<#type-migrator>)
+- [type RepositoryProvider](<#type-repositoryprovider>)
+- [type TokenWriteCheckInvalidator](<#type-tokenwritecheckinvalidator>)
+- [type TransactionOperator](<#type-transactionoperator>)
+- [type ValidatorStatusReader](<#type-validatorstatusreader>)
+
+
+## Variables
+
+```go
+var (
+    ErrDatabaseNotSupported = fmt.Errorf("database not supported")
+)
+```
+
+## type [AddressWriteFindChecker](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L21-L25>)
+
+AddressWriteFindChecker abstracts address operations.
+
+```go
+type AddressWriteFindChecker interface {
+    WriteAddress(ctx context.Context, addr string) error
+    CheckAddressExists(ctx context.Context, addr string) (bool, error)
+    FindAddress(ctx context.Context, search string, limit int) ([]string, error)
+}
+```
+
+## type [BlockReadWriter](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L28-L32>)
+
+BlockReadWriter abstracts block operations.
+
+```go
+type BlockReadWriter interface {
+    LastBlock(ctx context.Context) (block.Block, error)
+    ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Block, error)
+    WriteBlock(ctx context.Context, block block.Block) error
+}
+```
+
+## type [ConnectionCloser](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L66-L68>)
+
+ConnectionCloser abstracts connection closing operations.
+
+```go
+type ConnectionCloser interface {
+    Disconnect(ctx context.Context) error
+}
+```
+
+## type [DBConfig](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L83-L88>)
+
+Config contains configuration for the database.
+
+```go
+type DBConfig struct {
+    ConnStr      string `yaml:"conn_str"`         // ConnStr is the connection string to the database.
+    DatabaseName string `yaml:"database_name"`    // DatabaseName is the name of the database.
+    Token        string `yaml:"token"`            // Token is the token that is used to confirm api clients access.
+    TokenExpire  int64  `yaml:"token_expiration"` // TokenExpire is the number of seconds after which token expires.
+}
+```
+
+### func \(DBConfig\) [Connect](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L91>)
+
+```go
+func (cfg DBConfig) Connect(ctx context.Context) (RepositoryProvider, error)
+```
+
+Connect connects to the proper database and returns that connection.
+
+## type [Migrator](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L35-L37>)
+
+MigrationRunner abstracts migration operations.
+
+```go
+type Migrator interface {
+    RunMigration(ctx context.Context) error
+}
+```
+
+## type [RepositoryProvider](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L71-L80>)
+
+RepositoryProvider is an interface that ensures that all required methods to run computantis are implemented.
+
+```go
+type RepositoryProvider interface {
+    AddressWriteFindChecker
+    BlockReadWriter
+    io.Writer
+    Migrator
+    TokenWriteCheckInvalidator
+    TransactionOperator
+    ValidatorStatusReader
+    ConnectionCloser
+}
+```
+
+## type [TokenWriteCheckInvalidator](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L40-L44>)
+
+TokenWriteCheckInvalidator abstracts token operations.
+
+```go
+type TokenWriteCheckInvalidator interface {
+    CheckToken(ctx context.Context, tkn string) (bool, error)
+    WriteToken(ctx context.Context, tkn string, expirationDate int64) error
+    InvalidateToken(ctx context.Context, token string) error
+}
+```
+
+## type [TransactionOperator](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L47-L57>)
+
+TransactionOperator abstracts transaction operations.
+
+```go
+type TransactionOperator interface {
+    WriteTransactionsInBlock(ctx context.Context, blockHash [32]byte, trxHash [][32]byte) error
+    FindTransactionInBlockHash(ctx context.Context, trxHash [32]byte) ([32]byte, error)
+    WriteTemporaryTransaction(ctx context.Context, trx *transaction.Transaction) error
+    RemoveAwaitingTransaction(ctx context.Context, trxHash [32]byte) error
+    WriteIssuerSignedTransactionForReceiver(ctx context.Context, receiverAddr string, trx *transaction.Transaction) error
+    ReadAwaitingTransactionsByReceiver(ctx context.Context, address string) ([]transaction.Transaction, error)
+    ReadAwaitingTransactionsByIssuer(ctx context.Context, address string) ([]transaction.Transaction, error)
+    MoveTransactionsFromTemporaryToPermanent(ctx context.Context, hash [][32]byte) error
+    ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)
+}
+```
+
+## type [ValidatorStatusReader](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L60-L63>)
+
+ValidatorStatusReader abstracts validator status operations.
+
+```go
+type ValidatorStatusReader interface {
+    ReadLastNValidatorStatuses(ctx context.Context, last int64) ([]validator.Status, error)
+    WriteValidatorStatus(ctx context.Context, vs *validator.Status) error
+}
+```
+
 # repomongo
 
 ```go
@@ -1057,7 +1195,7 @@ import "github.com/bartossh/Computantis/repomongo"
 ## Index
 
 - [type DataBase](<#type-database>)
-  - [func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)](<#func-connect>)
+  - [func Connect(ctx context.Context, conn, database string) (*DataBase, error)](<#func-connect>)
   - [func (db DataBase) CheckAddressExists(ctx context.Context, addr string) (bool, error)](<#func-database-checkaddressexists>)
   - [func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)](<#func-database-checktoken>)
   - [func (c DataBase) Disconnect(ctx context.Context) error](<#func-database-disconnect>)
@@ -1084,7 +1222,7 @@ import "github.com/bartossh/Computantis/repomongo"
 - [type Migration](<#type-migration>)
 
 
-## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L27-L29>)
+## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L26-L28>)
 
 Database provides database access for read, write and delete of repository entities.
 
@@ -1094,10 +1232,10 @@ type DataBase struct {
 }
 ```
 
-### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L32>)
+### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L31>)
 
 ```go
-func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)
+func Connect(ctx context.Context, conn, database string) (*DataBase, error)
 ```
 
 Connect creates new connection to the repository and returns pointer to the DataBase.
@@ -1118,7 +1256,7 @@ func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)
 
 CheckToken checks if token exists in the database is valid and didn't expire.
 
-### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L48>)
+### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L47>)
 
 ```go
 func (c DataBase) Disconnect(ctx context.Context) error
@@ -1306,7 +1444,7 @@ import "github.com/bartossh/Computantis/repopostgre"
 
 - [Variables](<#variables>)
 - [type DataBase](<#type-database>)
-  - [func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)](<#func-connect>)
+  - [func Connect(ctx context.Context, conn, database string) (*DataBase, error)](<#func-connect>)
   - [func (db DataBase) CheckAddressExists(ctx context.Context, addr string) (bool, error)](<#func-database-checkaddressexists>)
   - [func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)](<#func-database-checktoken>)
   - [func (db DataBase) Disconnect(ctx context.Context) error](<#func-database-disconnect>)
@@ -1322,6 +1460,7 @@ import "github.com/bartossh/Computantis/repopostgre"
   - [func (db DataBase) ReadLastNValidatorStatuses(ctx context.Context, last int64) ([]validator.Status, error)](<#func-database-readlastnvalidatorstatuses>)
   - [func (db DataBase) ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)](<#func-database-readtemporarytransactions>)
   - [func (db DataBase) RemoveAwaitingTransaction(ctx context.Context, trxHash [32]byte) error](<#func-database-removeawaitingtransaction>)
+  - [func (DataBase) RunMigration(_ context.Context) error](<#func-database-runmigration>)
   - [func (db DataBase) Write(p []byte) (n int, err error)](<#func-database-write>)
   - [func (db DataBase) WriteAddress(ctx context.Context, addr string) error](<#func-database-writeaddress>)
   - [func (db DataBase) WriteBlock(ctx context.Context, block block.Block) error](<#func-database-writeblock>)
@@ -1345,7 +1484,7 @@ var (
 )
 ```
 
-## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L24-L26>)
+## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L22-L24>)
 
 Database provides database access for read, write and delete of repository entities.
 
@@ -1355,10 +1494,10 @@ type DataBase struct {
 }
 ```
 
-### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L29>)
+### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L27>)
 
 ```go
-func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)
+func Connect(ctx context.Context, conn, database string) (*DataBase, error)
 ```
 
 Connect creates new connection to the repository and returns pointer to the DataBase.
@@ -1379,7 +1518,7 @@ func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)
 
 CheckToken checks if token exists in the database is valid and didn't expire.
 
-### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L39>)
+### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L37>)
 
 ```go
 func (db DataBase) Disconnect(ctx context.Context) error
@@ -1395,7 +1534,7 @@ func (db DataBase) FindAddress(ctx context.Context, search string, limit int) ([
 
 FindAddress finds address in the database.
 
-### func \(DataBase\) [FindTransactionInBlockHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/search.go#L46>)
+### func \(DataBase\) [FindTransactionInBlockHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/search.go#L47>)
 
 ```go
 func (db DataBase) FindTransactionInBlockHash(ctx context.Context, trxHash [32]byte) ([32]byte, error)
@@ -1403,7 +1542,7 @@ func (db DataBase) FindTransactionInBlockHash(ctx context.Context, trxHash [32]b
 
 FindTransactionInBlockHash finds Block hash in to which Transaction with given hash was added.
 
-### func \(DataBase\) [InvalidateToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L45>)
+### func \(DataBase\) [InvalidateToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L44>)
 
 ```go
 func (db DataBase) InvalidateToken(ctx context.Context, token string) error
@@ -1411,7 +1550,7 @@ func (db DataBase) InvalidateToken(ctx context.Context, token string) error
 
 InvalidateToken invalidates token.
 
-### func \(DataBase\) [LastBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L11>)
+### func \(DataBase\) [LastBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L12>)
 
 ```go
 func (db DataBase) LastBlock(ctx context.Context) (block.Block, error)
@@ -1419,7 +1558,7 @@ func (db DataBase) LastBlock(ctx context.Context) (block.Block, error)
 
 LastBlock returns last block from the database.
 
-### func \(DataBase\) [MoveTransactionsFromTemporaryToPermanent](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L106>)
+### func \(DataBase\) [MoveTransactionsFromTemporaryToPermanent](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L108>)
 
 ```go
 func (db DataBase) MoveTransactionsFromTemporaryToPermanent(ctx context.Context, hash [][32]byte) error
@@ -1427,7 +1566,7 @@ func (db DataBase) MoveTransactionsFromTemporaryToPermanent(ctx context.Context,
 
 MoveTransactionsFromTemporaryToPermanent moves transactions from temporary storage to permanent storage.
 
-### func \(DataBase\) [Ping](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L44>)
+### func \(DataBase\) [Ping](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L42>)
 
 ```go
 func (db DataBase) Ping(ctx context.Context) error
@@ -1435,7 +1574,7 @@ func (db DataBase) Ping(ctx context.Context) error
 
 Ping checks if the connection to the database is still alive.
 
-### func \(DataBase\) [ReadAwaitingTransactionsByIssuer](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L82>)
+### func \(DataBase\) [ReadAwaitingTransactionsByIssuer](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L83>)
 
 ```go
 func (db DataBase) ReadAwaitingTransactionsByIssuer(ctx context.Context, address string) ([]transaction.Transaction, error)
@@ -1451,7 +1590,7 @@ func (db DataBase) ReadAwaitingTransactionsByReceiver(ctx context.Context, addre
 
 ReadAwaitingTransactionsByReceiver reads all transactions paired with given receiver address.
 
-### func \(DataBase\) [ReadBlockByHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L26>)
+### func \(DataBase\) [ReadBlockByHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L41>)
 
 ```go
 func (db DataBase) ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Block, error)
@@ -1467,7 +1606,7 @@ func (db DataBase) ReadLastNValidatorStatuses(ctx context.Context, last int64) (
 
 ReadLastNValidatorStatuses reads last validator statuses from the database.
 
-### func \(DataBase\) [ReadTemporaryTransactions](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L119>)
+### func \(DataBase\) [ReadTemporaryTransactions](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L125>)
 
 ```go
 func (db DataBase) ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)
@@ -1483,6 +1622,14 @@ func (db DataBase) RemoveAwaitingTransaction(ctx context.Context, trxHash [32]by
 
 RemoveAwaitingTransaction removes transaction from the awaiting transaction storage.
 
+### func \(DataBase\) [RunMigration](<https://github.com/bartossh/Computantis/blob/main/repopostgre/migrations.go#L7>)
+
+```go
+func (DataBase) RunMigration(_ context.Context) error
+```
+
+RunMigration satisfies the RepositoryProvider interface as PostgreSQL migrations are run on when database is created in docker\-compose\-postgresql.yml.
+
 ### func \(DataBase\) [Write](<https://github.com/bartossh/Computantis/blob/main/repopostgre/logger.go#L12>)
 
 ```go
@@ -1499,7 +1646,7 @@ func (db DataBase) WriteAddress(ctx context.Context, addr string) error
 
 WriteAddress writes address to the database.
 
-### func \(DataBase\) [WriteBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L41>)
+### func \(DataBase\) [WriteBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L69>)
 
 ```go
 func (db DataBase) WriteBlock(ctx context.Context, block block.Block) error
@@ -1523,7 +1670,7 @@ func (db DataBase) WriteTemporaryTransaction(ctx context.Context, trx *transacti
 
 WriteTemporaryTransaction writes transaction to the temporary storage.
 
-### func \(DataBase\) [WriteToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L35>)
+### func \(DataBase\) [WriteToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L34>)
 
 ```go
 func (db DataBase) WriteToken(ctx context.Context, tkn string, expirationDate int64) error
diff --git a/client/client_test.go b/client/client_test.go
index c31c7b3..b518098 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -58,7 +58,7 @@ func TestFullClientApiCycle(t *testing.T) {
 		wallet.New)
 	err := issuer.ValidateApiVersion()
 	assert.Nil(t, err)
-	err = issuer.NewWallet("wpg6d0grqJjyRicC8oI0/w6IGivm5ypFNTO/wwPGW9A=")
+	err = issuer.NewWallet("G8OH7lHu5qfWVumWom0ySN29lakog8nhzSPEwROMjvhdI6VgZ6GoPcdJmoIo7sF3lxQNJMOTKxpYBr6zF992WN86uB7xTEJZ")
 	assert.Nil(t, err)
 
 	receiver := NewClient(
@@ -72,7 +72,7 @@ func TestFullClientApiCycle(t *testing.T) {
 		wallet.New)
 	err = receiver.ValidateApiVersion()
 	assert.Nil(t, err)
-	err = receiver.NewWallet("GWFuhvyFnmMg1/vhPCfoa9ct1pAMC1pWwlRg4kt0D/w=")
+	err = receiver.NewWallet("jykkeD6Tr6xikkYwC805kVoFThm8VGEHStTFk1lIU6RgEf7p3vjFpPQFI3VP9SYeARjYh2jecMSYsmgddjZZcy32iySHijJQ")
 	assert.Nil(t, err)
 
 	receiverAddr, err := receiver.Address()
@@ -89,6 +89,9 @@ func TestFullClientApiCycle(t *testing.T) {
 
 	err = receiver.ConfirmTransaction(&awaitedTrx[0])
 	assert.Nil(t, err)
+	if err != nil {
+		fmt.Printf("err: %v\n", err.Error())
+	}
 
 	issuer.FlushWalletFromMemory()
 	receiver.FlushWalletFromMemory()
diff --git a/cmd/central/main.go b/cmd/central/main.go
index 3e426ca..ffac11c 100644
--- a/cmd/central/main.go
+++ b/cmd/central/main.go
@@ -13,7 +13,6 @@ import (
 	"github.com/bartossh/Computantis/dataprovider"
 	"github.com/bartossh/Computantis/logging"
 	"github.com/bartossh/Computantis/reactive"
-	"github.com/bartossh/Computantis/repomongo"
 	"github.com/bartossh/Computantis/server"
 	"github.com/bartossh/Computantis/wallet"
 )
@@ -39,7 +38,7 @@ func main() {
 		cancel()
 	}()
 
-	db, err := repomongo.Connect(ctx, cfg.Database)
+	db, err := cfg.Database.Connect(ctx)
 	if err != nil {
 		fmt.Println(err)
 		c <- os.Interrupt
diff --git a/cmd/validator/main.go b/cmd/validator/main.go
index 260b669..0091a50 100644
--- a/cmd/validator/main.go
+++ b/cmd/validator/main.go
@@ -12,7 +12,6 @@ import (
 	"github.com/bartossh/Computantis/configuration"
 	"github.com/bartossh/Computantis/fileoperations"
 	"github.com/bartossh/Computantis/logging"
-	"github.com/bartossh/Computantis/repomongo"
 	"github.com/bartossh/Computantis/validator"
 	"github.com/bartossh/Computantis/wallet"
 	"github.com/bartossh/Computantis/webhooks"
@@ -30,7 +29,7 @@ func main() {
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt)
 
-	db, err := repomongo.Connect(ctx, cfg.Database)
+	db, err := cfg.Database.Connect(ctx)
 	if err != nil {
 		fmt.Println(err)
 		c <- os.Interrupt
diff --git a/configuration/configuration.go b/configuration/configuration.go
index 270cb5d..cfc1b62 100644
--- a/configuration/configuration.go
+++ b/configuration/configuration.go
@@ -7,25 +7,18 @@ import (
 	"github.com/bartossh/Computantis/bookkeeping"
 	"github.com/bartossh/Computantis/dataprovider"
 	"github.com/bartossh/Computantis/fileoperations"
+	"github.com/bartossh/Computantis/repohelper"
 	"github.com/bartossh/Computantis/server"
 	"github.com/bartossh/Computantis/validator"
 	"gopkg.in/yaml.v2"
 )
 
-// Config contains configuration for the database.
-type DBConfig struct {
-	ConnStr      string `yaml:"conn_str"`         // ConnStr is the connection string to the database.
-	DatabaseName string `yaml:"database_name"`    // DatabaseName is the name of the database.
-	Token        string `yaml:"token"`            // Token is the token that is used to confirm api clients access.
-	TokenExpire  int64  `yaml:"token_expiration"` // TokenExpire is the number of seconds after which token expires.
-}
-
 // Configuration is the main configuration of the application that corresponds to the *.yaml file
 // that holds the configuration.
 type Configuration struct {
 	Bookkeeper   bookkeeping.Config    `yaml:"bookkeeper"`
 	Server       server.Config         `yaml:"server"`
-	Database     DBConfig              `yaml:"database"`
+	Database     repohelper.DBConfig   `yaml:"database"`
 	DataProvider dataprovider.Config   `yaml:"data_provider"`
 	Validator    validator.Config      `yaml:"validator"`
 	FileOperator fileoperations.Config `yaml:"file_operator"`
diff --git a/docker_postgres_init.sql b/docker_postgres_init.sql
index ac4c6d5..07bc3ab 100644
--- a/docker_postgres_init.sql
+++ b/docker_postgres_init.sql
@@ -7,9 +7,7 @@ CREATE DATABASE computantis
     TABLESPACE = pg_default
     CONNECTION LIMIT = -1;
 
-CREATE USER computantis WITH PASSWORD 'computantis';
-
-GRANT ALL PRIVILEGES ON DATABASE computantis TO computantis;
+\c computantis
 
 CREATE TABLE IF NOT EXISTS addresses (
    id serial PRIMARY KEY,
@@ -67,8 +65,8 @@ CREATE INDEX transaction_awaiting_receiver_address ON transactionsAwaitingReceiv
 
 CREATE TABLE IF NOT EXISTS blocks (
    id serial PRIMARY KEY,
-   index INTEGER UNIQUE NOT NULL,
-   created_at INTEGER NOT NULL,
+   index BIGINT UNIQUE NOT NULL,
+   timestamp BIGINT NOT NULL,
    nonce INTEGER NOT NULL,
    difficulty INTEGER NOT NULL,
    hash BYTEA UNIQUE NOT NULL,
@@ -79,7 +77,7 @@ CREATE TABLE IF NOT EXISTS blocks (
 CREATE INDEX block_index ON blocks USING HASH (index);
 CREATE INDEX block_hash ON blocks USING HASH (hash);
 CREATE INDEX block_prev_hash ON blocks USING HASH (prev_hash);
-CREATE INDEX block_created_at ON blocks USING BTREE (created_at);
+CREATE INDEX block_created_at ON blocks USING BTREE (timestamp);
 
 CREATE TABLE IF NOT EXISTS transactionsInBlock (
    id serial PRIMARY KEY,
@@ -94,7 +92,7 @@ CREATE TABLE IF NOT EXISTS tokens (
    id serial PRIMARY KEY,
    token VARCHAR (100) UNIQUE NOT NULL,
    valid BOOLEAN NOT NULL,
-   expiration_date INTEGER NOT NULL
+   expiration_date BIGINT NOT NULL
 );
 
 CREATE INDEX token_token ON tokens USING HASH (token);
@@ -118,4 +116,12 @@ CREATE TABLE IF NOT EXISTS validatorStatus (
 );
 
 CREATE INDEX validator_index ON validatorStatus USING HASH (index);
-CREATE INDEX validator_created_at ON validatorStatus USING BTREE (created_at);
\ No newline at end of file
+CREATE INDEX validator_created_at ON validatorStatus USING BTREE (created_at);
+
+
+CREATE USER computantis WITH ENCRYPTED PASSWORD 'computantis';
+
+GRANT ALL PRIVILEGES ON DATABASE computantis TO computantis;
+GRANT ALL PRIVILEGES ON SCHEMA public TO computantis;
+GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA public TO computantis;
+GRANT ALL ON ALL TABLES IN SCHEMA public TO computantis;
diff --git a/docs/docs.md b/docs/docs.md
index 2a44041..505b272 100644
--- a/docs/docs.md
+++ b/docs/docs.md
@@ -649,10 +649,9 @@ import "github.com/bartossh/Computantis/configuration"
 
 - [type Configuration](<#type-configuration>)
   - [func Read(path string) (Configuration, error)](<#func-read>)
-- [type DBConfig](<#type-dbconfig>)
 
 
-## type [Configuration](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L25-L32>)
+## type [Configuration](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L18-L25>)
 
 Configuration is the main configuration of the application that corresponds to the \*.yaml file that holds the configuration.
 
@@ -660,14 +659,14 @@ Configuration is the main configuration of the application that corresponds to t
 type Configuration struct {
     Bookkeeper   bookkeeping.Config    `yaml:"bookkeeper"`
     Server       server.Config         `yaml:"server"`
-    Database     DBConfig              `yaml:"database"`
+    Database     repohelper.DBConfig   `yaml:"database"`
     DataProvider dataprovider.Config   `yaml:"data_provider"`
     Validator    validator.Config      `yaml:"validator"`
     FileOperator fileoperations.Config `yaml:"file_operator"`
 }
 ```
 
-### func [Read](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L35>)
+### func [Read](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L28>)
 
 ```go
 func Read(path string) (Configuration, error)
@@ -675,19 +674,6 @@ func Read(path string) (Configuration, error)
 
 Read reads the configuration from the file and returns the Configuration with set fields according to the yaml setup.
 
-## type [DBConfig](<https://github.com/bartossh/Computantis/blob/main/configuration/configuration.go#L16-L21>)
-
-Config contains configuration for the database.
-
-```go
-type DBConfig struct {
-    ConnStr      string `yaml:"conn_str"`         // ConnStr is the connection string to the database.
-    DatabaseName string `yaml:"database_name"`    // DatabaseName is the name of the database.
-    Token        string `yaml:"token"`            // Token is the token that is used to confirm api clients access.
-    TokenExpire  int64  `yaml:"token_expiration"` // TokenExpire is the number of seconds after which token expires.
-}
-```
-
 # dataprovider
 
 ```go
@@ -979,6 +965,158 @@ func (o *Observable[T]) Subscribe() *subscriber[T]
 
 Subscribe subscribes to the container.
 
+# repohelper
+
+```go
+import "github.com/bartossh/Computantis/repohelper"
+```
+
+## Index
+
+- [Variables](<#variables>)
+- [type AddressWriteFindChecker](<#type-addresswritefindchecker>)
+- [type BlockReadWriter](<#type-blockreadwriter>)
+- [type ConnectionCloser](<#type-connectioncloser>)
+- [type DBConfig](<#type-dbconfig>)
+  - [func (cfg DBConfig) Connect(ctx context.Context) (RepositoryProvider, error)](<#func-dbconfig-connect>)
+- [type Migrator](<#type-migrator>)
+- [type RepositoryProvider](<#type-repositoryprovider>)
+- [type TokenWriteCheckInvalidator](<#type-tokenwritecheckinvalidator>)
+- [type TransactionOperator](<#type-transactionoperator>)
+- [type ValidatorStatusReader](<#type-validatorstatusreader>)
+
+
+## Variables
+
+```go
+var (
+    ErrDatabaseNotSupported = fmt.Errorf("database not supported")
+)
+```
+
+## type [AddressWriteFindChecker](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L21-L25>)
+
+AddressWriteFindChecker abstracts address operations.
+
+```go
+type AddressWriteFindChecker interface {
+    WriteAddress(ctx context.Context, addr string) error
+    CheckAddressExists(ctx context.Context, addr string) (bool, error)
+    FindAddress(ctx context.Context, search string, limit int) ([]string, error)
+}
+```
+
+## type [BlockReadWriter](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L28-L32>)
+
+BlockReadWriter abstracts block operations.
+
+```go
+type BlockReadWriter interface {
+    LastBlock(ctx context.Context) (block.Block, error)
+    ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Block, error)
+    WriteBlock(ctx context.Context, block block.Block) error
+}
+```
+
+## type [ConnectionCloser](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L66-L68>)
+
+ConnectionCloser abstracts connection closing operations.
+
+```go
+type ConnectionCloser interface {
+    Disconnect(ctx context.Context) error
+}
+```
+
+## type [DBConfig](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L83-L88>)
+
+Config contains configuration for the database.
+
+```go
+type DBConfig struct {
+    ConnStr      string `yaml:"conn_str"`         // ConnStr is the connection string to the database.
+    DatabaseName string `yaml:"database_name"`    // DatabaseName is the name of the database.
+    Token        string `yaml:"token"`            // Token is the token that is used to confirm api clients access.
+    TokenExpire  int64  `yaml:"token_expiration"` // TokenExpire is the number of seconds after which token expires.
+}
+```
+
+### func \(DBConfig\) [Connect](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L91>)
+
+```go
+func (cfg DBConfig) Connect(ctx context.Context) (RepositoryProvider, error)
+```
+
+Connect connects to the proper database and returns that connection.
+
+## type [Migrator](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L35-L37>)
+
+MigrationRunner abstracts migration operations.
+
+```go
+type Migrator interface {
+    RunMigration(ctx context.Context) error
+}
+```
+
+## type [RepositoryProvider](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L71-L80>)
+
+RepositoryProvider is an interface that ensures that all required methods to run computantis are implemented.
+
+```go
+type RepositoryProvider interface {
+    AddressWriteFindChecker
+    BlockReadWriter
+    io.Writer
+    Migrator
+    TokenWriteCheckInvalidator
+    TransactionOperator
+    ValidatorStatusReader
+    ConnectionCloser
+}
+```
+
+## type [TokenWriteCheckInvalidator](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L40-L44>)
+
+TokenWriteCheckInvalidator abstracts token operations.
+
+```go
+type TokenWriteCheckInvalidator interface {
+    CheckToken(ctx context.Context, tkn string) (bool, error)
+    WriteToken(ctx context.Context, tkn string, expirationDate int64) error
+    InvalidateToken(ctx context.Context, token string) error
+}
+```
+
+## type [TransactionOperator](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L47-L57>)
+
+TransactionOperator abstracts transaction operations.
+
+```go
+type TransactionOperator interface {
+    WriteTransactionsInBlock(ctx context.Context, blockHash [32]byte, trxHash [][32]byte) error
+    FindTransactionInBlockHash(ctx context.Context, trxHash [32]byte) ([32]byte, error)
+    WriteTemporaryTransaction(ctx context.Context, trx *transaction.Transaction) error
+    RemoveAwaitingTransaction(ctx context.Context, trxHash [32]byte) error
+    WriteIssuerSignedTransactionForReceiver(ctx context.Context, receiverAddr string, trx *transaction.Transaction) error
+    ReadAwaitingTransactionsByReceiver(ctx context.Context, address string) ([]transaction.Transaction, error)
+    ReadAwaitingTransactionsByIssuer(ctx context.Context, address string) ([]transaction.Transaction, error)
+    MoveTransactionsFromTemporaryToPermanent(ctx context.Context, hash [][32]byte) error
+    ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)
+}
+```
+
+## type [ValidatorStatusReader](<https://github.com/bartossh/Computantis/blob/main/repohelper/repohelper.go#L60-L63>)
+
+ValidatorStatusReader abstracts validator status operations.
+
+```go
+type ValidatorStatusReader interface {
+    ReadLastNValidatorStatuses(ctx context.Context, last int64) ([]validator.Status, error)
+    WriteValidatorStatus(ctx context.Context, vs *validator.Status) error
+}
+```
+
 # repomongo
 
 ```go
@@ -988,7 +1126,7 @@ import "github.com/bartossh/Computantis/repomongo"
 ## Index
 
 - [type DataBase](<#type-database>)
-  - [func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)](<#func-connect>)
+  - [func Connect(ctx context.Context, conn, database string) (*DataBase, error)](<#func-connect>)
   - [func (db DataBase) CheckAddressExists(ctx context.Context, addr string) (bool, error)](<#func-database-checkaddressexists>)
   - [func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)](<#func-database-checktoken>)
   - [func (c DataBase) Disconnect(ctx context.Context) error](<#func-database-disconnect>)
@@ -1015,7 +1153,7 @@ import "github.com/bartossh/Computantis/repomongo"
 - [type Migration](<#type-migration>)
 
 
-## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L27-L29>)
+## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L26-L28>)
 
 Database provides database access for read, write and delete of repository entities.
 
@@ -1025,10 +1163,10 @@ type DataBase struct {
 }
 ```
 
-### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L32>)
+### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L31>)
 
 ```go
-func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)
+func Connect(ctx context.Context, conn, database string) (*DataBase, error)
 ```
 
 Connect creates new connection to the repository and returns pointer to the DataBase.
@@ -1049,7 +1187,7 @@ func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)
 
 CheckToken checks if token exists in the database is valid and didn't expire.
 
-### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L48>)
+### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repomongo/mongorepo.go#L47>)
 
 ```go
 func (c DataBase) Disconnect(ctx context.Context) error
@@ -1237,7 +1375,7 @@ import "github.com/bartossh/Computantis/repopostgre"
 
 - [Variables](<#variables>)
 - [type DataBase](<#type-database>)
-  - [func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)](<#func-connect>)
+  - [func Connect(ctx context.Context, conn, database string) (*DataBase, error)](<#func-connect>)
   - [func (db DataBase) CheckAddressExists(ctx context.Context, addr string) (bool, error)](<#func-database-checkaddressexists>)
   - [func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)](<#func-database-checktoken>)
   - [func (db DataBase) Disconnect(ctx context.Context) error](<#func-database-disconnect>)
@@ -1253,6 +1391,7 @@ import "github.com/bartossh/Computantis/repopostgre"
   - [func (db DataBase) ReadLastNValidatorStatuses(ctx context.Context, last int64) ([]validator.Status, error)](<#func-database-readlastnvalidatorstatuses>)
   - [func (db DataBase) ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)](<#func-database-readtemporarytransactions>)
   - [func (db DataBase) RemoveAwaitingTransaction(ctx context.Context, trxHash [32]byte) error](<#func-database-removeawaitingtransaction>)
+  - [func (DataBase) RunMigration(_ context.Context) error](<#func-database-runmigration>)
   - [func (db DataBase) Write(p []byte) (n int, err error)](<#func-database-write>)
   - [func (db DataBase) WriteAddress(ctx context.Context, addr string) error](<#func-database-writeaddress>)
   - [func (db DataBase) WriteBlock(ctx context.Context, block block.Block) error](<#func-database-writeblock>)
@@ -1276,7 +1415,7 @@ var (
 )
 ```
 
-## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L24-L26>)
+## type [DataBase](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L22-L24>)
 
 Database provides database access for read, write and delete of repository entities.
 
@@ -1286,10 +1425,10 @@ type DataBase struct {
 }
 ```
 
-### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L29>)
+### func [Connect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L27>)
 
 ```go
-func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error)
+func Connect(ctx context.Context, conn, database string) (*DataBase, error)
 ```
 
 Connect creates new connection to the repository and returns pointer to the DataBase.
@@ -1310,7 +1449,7 @@ func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error)
 
 CheckToken checks if token exists in the database is valid and didn't expire.
 
-### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L39>)
+### func \(DataBase\) [Disconnect](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L37>)
 
 ```go
 func (db DataBase) Disconnect(ctx context.Context) error
@@ -1326,7 +1465,7 @@ func (db DataBase) FindAddress(ctx context.Context, search string, limit int) ([
 
 FindAddress finds address in the database.
 
-### func \(DataBase\) [FindTransactionInBlockHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/search.go#L46>)
+### func \(DataBase\) [FindTransactionInBlockHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/search.go#L47>)
 
 ```go
 func (db DataBase) FindTransactionInBlockHash(ctx context.Context, trxHash [32]byte) ([32]byte, error)
@@ -1334,7 +1473,7 @@ func (db DataBase) FindTransactionInBlockHash(ctx context.Context, trxHash [32]b
 
 FindTransactionInBlockHash finds Block hash in to which Transaction with given hash was added.
 
-### func \(DataBase\) [InvalidateToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L45>)
+### func \(DataBase\) [InvalidateToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L44>)
 
 ```go
 func (db DataBase) InvalidateToken(ctx context.Context, token string) error
@@ -1342,7 +1481,7 @@ func (db DataBase) InvalidateToken(ctx context.Context, token string) error
 
 InvalidateToken invalidates token.
 
-### func \(DataBase\) [LastBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L11>)
+### func \(DataBase\) [LastBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L12>)
 
 ```go
 func (db DataBase) LastBlock(ctx context.Context) (block.Block, error)
@@ -1350,7 +1489,7 @@ func (db DataBase) LastBlock(ctx context.Context) (block.Block, error)
 
 LastBlock returns last block from the database.
 
-### func \(DataBase\) [MoveTransactionsFromTemporaryToPermanent](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L106>)
+### func \(DataBase\) [MoveTransactionsFromTemporaryToPermanent](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L108>)
 
 ```go
 func (db DataBase) MoveTransactionsFromTemporaryToPermanent(ctx context.Context, hash [][32]byte) error
@@ -1358,7 +1497,7 @@ func (db DataBase) MoveTransactionsFromTemporaryToPermanent(ctx context.Context,
 
 MoveTransactionsFromTemporaryToPermanent moves transactions from temporary storage to permanent storage.
 
-### func \(DataBase\) [Ping](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L44>)
+### func \(DataBase\) [Ping](<https://github.com/bartossh/Computantis/blob/main/repopostgre/repopostgre.go#L42>)
 
 ```go
 func (db DataBase) Ping(ctx context.Context) error
@@ -1366,7 +1505,7 @@ func (db DataBase) Ping(ctx context.Context) error
 
 Ping checks if the connection to the database is still alive.
 
-### func \(DataBase\) [ReadAwaitingTransactionsByIssuer](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L82>)
+### func \(DataBase\) [ReadAwaitingTransactionsByIssuer](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L83>)
 
 ```go
 func (db DataBase) ReadAwaitingTransactionsByIssuer(ctx context.Context, address string) ([]transaction.Transaction, error)
@@ -1382,7 +1521,7 @@ func (db DataBase) ReadAwaitingTransactionsByReceiver(ctx context.Context, addre
 
 ReadAwaitingTransactionsByReceiver reads all transactions paired with given receiver address.
 
-### func \(DataBase\) [ReadBlockByHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L26>)
+### func \(DataBase\) [ReadBlockByHash](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L41>)
 
 ```go
 func (db DataBase) ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Block, error)
@@ -1398,7 +1537,7 @@ func (db DataBase) ReadLastNValidatorStatuses(ctx context.Context, last int64) (
 
 ReadLastNValidatorStatuses reads last validator statuses from the database.
 
-### func \(DataBase\) [ReadTemporaryTransactions](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L119>)
+### func \(DataBase\) [ReadTemporaryTransactions](<https://github.com/bartossh/Computantis/blob/main/repopostgre/transaction.go#L125>)
 
 ```go
 func (db DataBase) ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)
@@ -1414,6 +1553,14 @@ func (db DataBase) RemoveAwaitingTransaction(ctx context.Context, trxHash [32]by
 
 RemoveAwaitingTransaction removes transaction from the awaiting transaction storage.
 
+### func \(DataBase\) [RunMigration](<https://github.com/bartossh/Computantis/blob/main/repopostgre/migrations.go#L7>)
+
+```go
+func (DataBase) RunMigration(_ context.Context) error
+```
+
+RunMigration satisfies the RepositoryProvider interface as PostgreSQL migrations are run on when database is created in docker\-compose\-postgresql.yml.
+
 ### func \(DataBase\) [Write](<https://github.com/bartossh/Computantis/blob/main/repopostgre/logger.go#L12>)
 
 ```go
@@ -1430,7 +1577,7 @@ func (db DataBase) WriteAddress(ctx context.Context, addr string) error
 
 WriteAddress writes address to the database.
 
-### func \(DataBase\) [WriteBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L41>)
+### func \(DataBase\) [WriteBlock](<https://github.com/bartossh/Computantis/blob/main/repopostgre/block.go#L69>)
 
 ```go
 func (db DataBase) WriteBlock(ctx context.Context, block block.Block) error
@@ -1454,7 +1601,7 @@ func (db DataBase) WriteTemporaryTransaction(ctx context.Context, trx *transacti
 
 WriteTemporaryTransaction writes transaction to the temporary storage.
 
-### func \(DataBase\) [WriteToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L35>)
+### func \(DataBase\) [WriteToken](<https://github.com/bartossh/Computantis/blob/main/repopostgre/token.go#L34>)
 
 ```go
 func (db DataBase) WriteToken(ctx context.Context, tkn string, expirationDate int64) error
diff --git a/mongodb_queries/create_tokens.js b/queries_mongo/create_tokens.js
similarity index 100%
rename from mongodb_queries/create_tokens.js
rename to queries_mongo/create_tokens.js
diff --git a/queries_postgresql/insert_token.sql b/queries_postgresql/insert_token.sql
new file mode 100644
index 0000000..1cda359
--- /dev/null
+++ b/queries_postgresql/insert_token.sql
@@ -0,0 +1,3 @@
+INSERT INTO tokens (token, valid, expiration_date) VALUES ('80fda91a43989fa81347aa011e0f1e0fdde4eaabb408bf426166a62c80456c30', true, 9223372036854775807);
+INSERT INTO tokens (token, valid, expiration_date) VALUES ('G8OH7lHu5qfWVumWom0ySN29lakog8nhzSPEwROMjvhdI6VgZ6GoPcdJmoIo7sF3lxQNJMOTKxpYBr6zF992WN86uB7xTEJZ', true, 9223372036854775807);
+INSERT INTO tokens (token, valid, expiration_date) VALUES ('jykkeD6Tr6xikkYwC805kVoFThm8VGEHStTFk1lIU6RgEf7p3vjFpPQFI3VP9SYeARjYh2jecMSYsmgddjZZcy32iySHijJQ', true, 9223372036854775807);
diff --git a/queries_postgresql/set_tokens _true.sql b/queries_postgresql/set_tokens _true.sql
new file mode 100644
index 0000000..411b922
--- /dev/null
+++ b/queries_postgresql/set_tokens _true.sql	
@@ -0,0 +1,3 @@
+UPDATE tokens SET valid = ? WHERE token = ?, true, "80fda91a43989fa81347aa011e0f1e0fdde4eaabb408bf426166a62c80456c30";
+UPDATE tokens SET valid = ? WHERE token = ?, true, "G8OH7lHu5qfWVumWom0ySN29lakog8nhzSPEwROMjvhdI6VgZ6GoPcdJmoIo7sF3lxQNJMOTKxpYBr6zF992WN86uB7xTEJZ";
+UPDATE tokens SET valid = ? WHERE token = ?, true, "jykkeD6Tr6xikkYwC805kVoFThm8VGEHStTFk1lIU6RgEf7p3vjFpPQFI3VP9SYeARjYh2jecMSYsmgddjZZcy32iySHijJQ";
\ No newline at end of file
diff --git a/repohelper/repohelper.go b/repohelper/repohelper.go
new file mode 100644
index 0000000..5072f9e
--- /dev/null
+++ b/repohelper/repohelper.go
@@ -0,0 +1,100 @@
+package repohelper
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/bartossh/Computantis/block"
+	"github.com/bartossh/Computantis/repomongo"
+	"github.com/bartossh/Computantis/repopostgre"
+	"github.com/bartossh/Computantis/transaction"
+	"github.com/bartossh/Computantis/validator"
+)
+
+var (
+	ErrDatabaseNotSupported = fmt.Errorf("database not supported")
+)
+
+// AddressWriteFindChecker abstracts address operations.
+type AddressWriteFindChecker interface {
+	WriteAddress(ctx context.Context, addr string) error
+	CheckAddressExists(ctx context.Context, addr string) (bool, error)
+	FindAddress(ctx context.Context, search string, limit int) ([]string, error)
+}
+
+// BlockReadWriter abstracts block operations.
+type BlockReadWriter interface {
+	LastBlock(ctx context.Context) (block.Block, error)
+	ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Block, error)
+	WriteBlock(ctx context.Context, block block.Block) error
+}
+
+// MigrationRunner abstracts migration operations.
+type Migrator interface {
+	RunMigration(ctx context.Context) error
+}
+
+// TokenWriteCheckInvalidator abstracts token operations.
+type TokenWriteCheckInvalidator interface {
+	CheckToken(ctx context.Context, tkn string) (bool, error)
+	WriteToken(ctx context.Context, tkn string, expirationDate int64) error
+	InvalidateToken(ctx context.Context, token string) error
+}
+
+// TransactionOperator abstracts transaction operations.
+type TransactionOperator interface {
+	WriteTransactionsInBlock(ctx context.Context, blockHash [32]byte, trxHash [][32]byte) error
+	FindTransactionInBlockHash(ctx context.Context, trxHash [32]byte) ([32]byte, error)
+	WriteTemporaryTransaction(ctx context.Context, trx *transaction.Transaction) error
+	RemoveAwaitingTransaction(ctx context.Context, trxHash [32]byte) error
+	WriteIssuerSignedTransactionForReceiver(ctx context.Context, receiverAddr string, trx *transaction.Transaction) error
+	ReadAwaitingTransactionsByReceiver(ctx context.Context, address string) ([]transaction.Transaction, error)
+	ReadAwaitingTransactionsByIssuer(ctx context.Context, address string) ([]transaction.Transaction, error)
+	MoveTransactionsFromTemporaryToPermanent(ctx context.Context, hash [][32]byte) error
+	ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error)
+}
+
+// ValidatorStatusReader abstracts validator status operations.
+type ValidatorStatusReader interface {
+	ReadLastNValidatorStatuses(ctx context.Context, last int64) ([]validator.Status, error)
+	WriteValidatorStatus(ctx context.Context, vs *validator.Status) error
+}
+
+// ConnectionCloser abstracts connection closing operations.
+type ConnectionCloser interface {
+	Disconnect(ctx context.Context) error
+}
+
+// RepositoryProvider is an interface that ensures that all required methods to run computantis are implemented.
+type RepositoryProvider interface {
+	AddressWriteFindChecker
+	BlockReadWriter
+	io.Writer
+	Migrator
+	TokenWriteCheckInvalidator
+	TransactionOperator
+	ValidatorStatusReader
+	ConnectionCloser
+}
+
+// Config contains configuration for the database.
+type DBConfig struct {
+	ConnStr      string `yaml:"conn_str"`         // ConnStr is the connection string to the database.
+	DatabaseName string `yaml:"database_name"`    // DatabaseName is the name of the database.
+	Token        string `yaml:"token"`            // Token is the token that is used to confirm api clients access.
+	TokenExpire  int64  `yaml:"token_expiration"` // TokenExpire is the number of seconds after which token expires.
+}
+
+// Connect connects to the proper database and returns that connection.
+func (cfg DBConfig) Connect(ctx context.Context) (RepositoryProvider, error) {
+	switch {
+	case strings.Contains(cfg.ConnStr, "postgres"):
+		return repopostgre.Connect(ctx, cfg.ConnStr, cfg.DatabaseName)
+	case strings.Contains(cfg.ConnStr, "mongodb"):
+		return repomongo.Connect(ctx, cfg.ConnStr, cfg.DatabaseName)
+	}
+
+	return nil, ErrDatabaseNotSupported
+}
diff --git a/repomongo/mongorepo.go b/repomongo/mongorepo.go
index 045600c..98ceaa0 100644
--- a/repomongo/mongorepo.go
+++ b/repomongo/mongorepo.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"time"
 
-	"github.com/bartossh/Computantis/configuration"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 	"go.mongodb.org/mongo-driver/mongo/readpref"
@@ -29,19 +28,19 @@ type DataBase struct {
 }
 
 // Connect creates new connection to the repository and returns pointer to the DataBase.
-func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error) {
-	conn, err := mongo.Connect(ctx, options.Client().ApplyURI(cfg.ConnStr))
+func Connect(ctx context.Context, conn, database string) (*DataBase, error) {
+	cli, err := mongo.Connect(ctx, options.Client().ApplyURI(conn))
 	if err != nil {
 		return nil, err
 	}
 
 	ctxx, cancel := context.WithTimeout(ctx, time.Second*5)
 	defer cancel()
-	if err := conn.Ping(ctxx, readpref.Primary()); err != nil {
+	if err := cli.Ping(ctxx, readpref.Primary()); err != nil {
 		return nil, err
 	}
 
-	return &DataBase{*conn.Database(cfg.DatabaseName)}, nil
+	return &DataBase{*cli.Database(database)}, nil
 }
 
 // Disconnect disconnects user from database
diff --git a/repopostgre/address.go b/repopostgre/address.go
index d7b10b5..af39b28 100644
--- a/repopostgre/address.go
+++ b/repopostgre/address.go
@@ -7,7 +7,7 @@ import (
 
 // WriteAddress writes address to the database.
 func (db DataBase) WriteAddress(ctx context.Context, addr string) error {
-	_, err := db.inner.ExecContext(ctx, `INSERT INTO addresses(public_key) VALUES(?)`, addr)
+	_, err := db.inner.ExecContext(ctx, `INSERT INTO addresses(public_key) VALUES($1)`, addr)
 	if err != nil {
 		return errors.Join(ErrInsertFailed, err)
 	}
@@ -17,7 +17,7 @@ func (db DataBase) WriteAddress(ctx context.Context, addr string) error {
 // CheckAddressExists checks if address exists in the database.
 func (db DataBase) CheckAddressExists(ctx context.Context, addr string) (bool, error) {
 	var exists bool
-	err := db.inner.QueryRowContext(ctx, `SELECT EXISTS(SELECT 1 FROM addresses WHERE public_key = ?)`, addr).Scan(&exists)
+	err := db.inner.QueryRowContext(ctx, `SELECT EXISTS(SELECT 1 FROM addresses WHERE public_key = $1)`, addr).Scan(&exists)
 	if err != nil {
 		return false, errors.Join(ErrSelectFailed, err)
 	}
diff --git a/repopostgre/block.go b/repopostgre/block.go
index a215b25..9b68743 100644
--- a/repopostgre/block.go
+++ b/repopostgre/block.go
@@ -5,18 +5,33 @@ import (
 	"errors"
 
 	"github.com/bartossh/Computantis/block"
+	"github.com/lib/pq"
 )
 
 // LastBlock returns last block from the database.
 func (db DataBase) LastBlock(ctx context.Context) (block.Block, error) {
-	res, err := db.inner.QueryContext(ctx, "SELECT * FROM blocks ORDER BY index DESC LIMIT 1")
+	rows, err := db.inner.QueryContext(ctx, "SELECT * FROM blocks ORDER BY index DESC LIMIT 1")
 	if err != nil {
 		return block.Block{}, errors.Join(ErrSelectFailed, err)
 	}
+	defer rows.Close()
 
 	var b block.Block
-	if err := res.Scan(&b.ID, &b.Index, &b.Timestamp, &b.Nonce, &b.Difficulty, &b.Hash, &b.PrevHash, &b.TrxHashes); err != nil {
-		return block.Block{}, errors.Join(ErrScanFailed, err)
+	h := make([]byte, 0, 32)
+	prevH := make([]byte, 0, 32)
+	trxHashes := [][]byte{}
+	for rows.Next() {
+		if err := rows.Scan(&b.ID, &b.Index, &b.Timestamp, &b.Nonce, &b.Difficulty, &h, &prevH, pq.Array(&trxHashes)); err != nil {
+			return block.Block{}, errors.Join(ErrScanFailed, err)
+		}
+	}
+
+	copy(b.Hash[:], h)
+	copy(b.PrevHash[:], prevH)
+	for _, hash := range trxHashes {
+		h := [32]byte{}
+		copy(h[:], hash)
+		b.TrxHashes = append(b.TrxHashes, h)
 	}
 
 	return b, nil
@@ -24,14 +39,27 @@ func (db DataBase) LastBlock(ctx context.Context) (block.Block, error) {
 
 // ReadBlockByHash returns block with given hash.
 func (db DataBase) ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Block, error) {
-	res, err := db.inner.QueryContext(ctx, "SELECT * FROM blocks WHERE hash = $1", hash)
+	rows, err := db.inner.QueryContext(ctx, "SELECT * FROM blocks WHERE hash = $1", hash)
 	if err != nil {
 		return block.Block{}, errors.Join(ErrSelectFailed, err)
 	}
+	defer rows.Close()
 
 	var b block.Block
-	if err := res.Scan(&b.ID, &b.Index, &b.Timestamp, &b.Nonce, &b.Difficulty, &b.Hash, &b.PrevHash, &b.TrxHashes); err != nil {
-		return block.Block{}, errors.Join(ErrScanFailed, err)
+	h := make([]byte, 0, 32)
+	prevH := make([]byte, 32)
+	trxHashes := [][]byte{}
+	for rows.Next() {
+		if err := rows.Scan(&b.ID, &b.Index, &b.Timestamp, &b.Nonce, &b.Difficulty, &h, &prevH, pq.Array(&trxHashes)); err != nil {
+			return block.Block{}, errors.Join(ErrScanFailed, err)
+		}
+	}
+	copy(b.Hash[:], h)
+	copy(b.PrevHash[:], prevH)
+	for _, hash := range trxHashes {
+		h := [32]byte{}
+		copy(h[:], hash)
+		b.TrxHashes = append(b.TrxHashes, h)
 	}
 
 	return b, nil
@@ -39,10 +67,14 @@ func (db DataBase) ReadBlockByHash(ctx context.Context, hash [32]byte) (block.Bl
 
 // WriteBlock writes block to the database.
 func (db DataBase) WriteBlock(ctx context.Context, block block.Block) error {
+	trxHashes := make([][]byte, len(block.TrxHashes))
+	for _, hash := range block.TrxHashes {
+		trxHashes = append(trxHashes, hash[:])
+	}
 	_, err := db.inner.ExecContext(ctx,
 		`INSERT INTO 
 				blocks (index, timestamp, nonce, difficulty, hash, prev_hash, trx_hashes) VALUES ($1, $2, $3, $4, $5, $6, $7)`,
-		block.Index, block.Timestamp, block.Nonce, block.Difficulty, block.Hash, block.PrevHash, block.TrxHashes)
+		block.Index, block.Timestamp, block.Nonce, block.Difficulty, block.Hash[:], block.PrevHash[:], pq.Array(trxHashes))
 	if err != nil {
 		return errors.Join(ErrInsertFailed, err)
 	}
diff --git a/repopostgre/migrations.go b/repopostgre/migrations.go
new file mode 100644
index 0000000..1745555
--- /dev/null
+++ b/repopostgre/migrations.go
@@ -0,0 +1,9 @@
+package repopostgre
+
+import "context"
+
+// RunMigration satisfies the RepositoryProvider interface
+// as PostgreSQL migrations are run on when database is created in docker-compose-postgresql.yml.
+func (DataBase) RunMigration(_ context.Context) error {
+	return nil
+}
diff --git a/repopostgre/repopostgre.go b/repopostgre/repopostgre.go
index dcd2d91..68ba499 100644
--- a/repopostgre/repopostgre.go
+++ b/repopostgre/repopostgre.go
@@ -6,8 +6,6 @@ import (
 
 	"database/sql"
 
-	"github.com/bartossh/Computantis/configuration"
-
 	_ "github.com/lib/pq"
 )
 
@@ -26,8 +24,8 @@ type DataBase struct {
 }
 
 // Connect creates new connection to the repository and returns pointer to the DataBase.
-func Connect(ctx context.Context, cfg configuration.DBConfig) (*DataBase, error) {
-	db, err := sql.Open("postgres", fmt.Sprintf("%s/%s?sslmode=disable", cfg.ConnStr, cfg.DatabaseName))
+func Connect(ctx context.Context, conn, database string) (*DataBase, error) {
+	db, err := sql.Open("postgres", fmt.Sprintf("%s/%s?sslmode=disable", conn, database))
 	if err != nil {
 		return nil, err
 	}
diff --git a/repopostgre/repopostgre_test.go b/repopostgre/repopostgre_test.go
index 370c715..9f76192 100644
--- a/repopostgre/repopostgre_test.go
+++ b/repopostgre/repopostgre_test.go
@@ -1,3 +1,5 @@
+//go:build integration
+
 package repopostgre
 
 import (
@@ -6,7 +8,7 @@ import (
 	"os"
 	"testing"
 
-	"github.com/bartossh/Computantis/configuration"
+	"github.com/bartossh/Computantis/repohelper"
 	"github.com/joho/godotenv"
 	"github.com/stretchr/testify/assert"
 )
@@ -20,7 +22,7 @@ func TestConnection(t *testing.T) {
 	passwd := os.Getenv("MONGO_DB_PASSWORD")
 	dbName := os.Getenv("MONGO_DB_NAME")
 
-	cfg := configuration.DBConfig{
+	cfg := repohelper.DBConfig{
 		ConnStr:      fmt.Sprintf("postgres://%s:%s@localhost:5432", user, passwd),
 		DatabaseName: dbName,
 		Token:        "19130b090d70afb384b6ebcb8572701a974e3a1090947bfc785b980841bfb054",
diff --git a/repopostgre/search.go b/repopostgre/search.go
index 271f759..76a7b51 100644
--- a/repopostgre/search.go
+++ b/repopostgre/search.go
@@ -8,7 +8,7 @@ func (db DataBase) FindAddress(ctx context.Context, search string, limit int) ([
 		limit = 1000
 	}
 	var addresses []string
-	rows, err := db.inner.QueryContext(ctx, `SELECT public_key FROM addresses WHERE public_key LIKE ? LIMIT ?`, search, limit)
+	rows, err := db.inner.QueryContext(ctx, "SELECT public_key FROM addresses WHERE public_key LIKE $1 LIMIT $2", search, limit)
 	if err != nil {
 		return nil, err
 	}
@@ -34,7 +34,8 @@ func (db DataBase) WriteTransactionsInBlock(ctx context.Context, blockHash [32]b
 	defer tx.Rollback()
 
 	for _, trx := range trxHash {
-		if _, err := tx.ExecContext(ctx, `INSERT INTO transactionsInBlock (block_hash, transaction_hash) VALUES (?, ?)`, blockHash, trx); err != nil {
+		if _, err := tx.ExecContext(ctx,
+			"INSERT INTO transactionsInBlock (block_hash, transaction_hash) VALUES ($1, $2)", blockHash[:], trx); err != nil {
 			return err
 		}
 	}
@@ -44,9 +45,12 @@ func (db DataBase) WriteTransactionsInBlock(ctx context.Context, blockHash [32]b
 
 // FindTransactionInBlockHash finds Block hash in to which Transaction with given hash was added.
 func (db DataBase) FindTransactionInBlockHash(ctx context.Context, trxHash [32]byte) ([32]byte, error) {
-	var blockHash [32]byte
-	if err := db.inner.QueryRowContext(ctx, `SELECT block_hash FROM transactionsInBlock WHERE transaction_hash = ?`, trxHash).Scan(&blockHash); err != nil {
+	blockHash := make([]byte, 0, 32)
+	if err := db.inner.QueryRowContext(ctx, "SELECT block_hash FROM transactionsInBlock WHERE transaction_hash = $1", trxHash[:]).
+		Scan(&blockHash); err != nil {
 		return [32]byte{}, err
 	}
-	return blockHash, nil
+	var bh [32]byte
+	copy(bh[:], blockHash)
+	return bh, nil
 }
diff --git a/repopostgre/token.go b/repopostgre/token.go
index f3acb38..32dd205 100644
--- a/repopostgre/token.go
+++ b/repopostgre/token.go
@@ -14,8 +14,7 @@ import (
 func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error) {
 	var t token.Token
 	if err := db.inner.QueryRowContext(ctx,
-		`SELECT token, valid, expiration_date 
-			FROM tokens WHERE token = ?`, tkn).
+		"SELECT token, valid, expiration_date FROM tokens WHERE token = $1", tkn).
 		Scan(&t.Token, &t.Valid, &t.ExpirationDate); err != nil {
 		if err == sql.ErrNoRows {
 			return false, nil
@@ -35,7 +34,7 @@ func (db DataBase) CheckToken(ctx context.Context, tkn string) (bool, error) {
 func (db DataBase) WriteToken(ctx context.Context, tkn string, expirationDate int64) error {
 	if _, err := db.inner.ExecContext(ctx,
 		`INSERT INTO tokens (token, valid, expiration_date) 
-			VALUES (?, ?, ?)`, tkn, true, expirationDate); err != nil {
+			VALUES ($1, $2, $3)`, tkn, true, expirationDate); err != nil {
 		return errors.Join(ErrInsertFailed, err)
 	}
 	return nil
@@ -44,7 +43,7 @@ func (db DataBase) WriteToken(ctx context.Context, tkn string, expirationDate in
 // InvalidateToken invalidates token.
 func (db DataBase) InvalidateToken(ctx context.Context, token string) error {
 	if _, err := db.inner.ExecContext(ctx,
-		`UPDATE tokens SET valid = ? WHERE token = ?`, false, token); err != nil {
+		"UPDATE tokens SET valid = false WHERE token = $1", token); err != nil {
 		return errors.Join(ErrRemoveFailed, err)
 	}
 	return nil
diff --git a/repopostgre/transaction.go b/repopostgre/transaction.go
index c25213f..4854b63 100644
--- a/repopostgre/transaction.go
+++ b/repopostgre/transaction.go
@@ -14,7 +14,7 @@ func (db DataBase) WriteTemporaryTransaction(ctx context.Context, trx *transacti
 		`INSERT INTO 
 			transactionsTemporary(
 				created_at, hash, issuer_address, receiver_address, subject, data, issuer_signature, receiver_signature
-			) VALUES(?, ?, ?, ?, ?, ?, ?, ?)`,
+			) VALUES($1, $2, $3, $4, $5, $6, $7, $8)`,
 		trx.CreatedAt, trx.Hash[:], trx.IssuerAddress,
 		trx.ReceiverAddress, trx.Subject, trx.Data,
 		trx.IssuerSignature, trx.ReceiverSignature)
@@ -26,7 +26,7 @@ func (db DataBase) WriteTemporaryTransaction(ctx context.Context, trx *transacti
 
 // RemoveAwaitingTransaction removes transaction from the awaiting transaction storage.
 func (db DataBase) RemoveAwaitingTransaction(ctx context.Context, trxHash [32]byte) error {
-	_, err := db.inner.ExecContext(ctx, `DELETE FROM transactionsAwaitingReceiver WHERE hash = ?`, trxHash[:])
+	_, err := db.inner.ExecContext(ctx, "DELETE FROM transactionsAwaitingReceiver WHERE hash = $1", trxHash[:])
 	if err != nil {
 		errors.Join(ErrRemoveFailed, err)
 	}
@@ -42,31 +42,32 @@ func (db DataBase) WriteIssuerSignedTransactionForReceiver(
 	_, err := db.inner.ExecContext(
 		ctx,
 		`INSERT INTO 
-			transactionsTemporary(
+			transactionsAwaitingReceiver(
 				created_at, hash, issuer_address, receiver_address, subject, data, issuer_signature, receiver_signature
-			) VALUES(?, ?, ?, ?, ?, ?, ?, ?)`,
+			) VALUES($1, $2, $3, $4, $5, $6, $7, $8)`,
 		trx.CreatedAt, trx.Hash[:], trx.IssuerAddress,
 		receiverAddr, trx.Subject, trx.Data,
 		trx.IssuerSignature, trx.ReceiverSignature)
 	if err != nil {
-		errors.Join(ErrInsertFailed, err)
+		return errors.Join(ErrInsertFailed, err)
 	}
 	return nil
 }
 
 // ReadAwaitingTransactionsByReceiver reads all transactions paired with given receiver address.
 func (db DataBase) ReadAwaitingTransactionsByReceiver(ctx context.Context, address string) ([]transaction.Transaction, error) {
-	rows, err := db.inner.QueryContext(ctx, `SELECT * FROM transactionsAwaitingReceiver WHERE receiver_address = ?`, address)
+	rows, err := db.inner.QueryContext(ctx, "SELECT * FROM transactionsAwaitingReceiver WHERE receiver_address = $1", address)
 	if err != nil {
 		return nil, errors.Join(ErrSelectFailed, err)
 	}
 	defer rows.Close()
+
 	var trxsAwaiting []transaction.Transaction
 	for rows.Next() {
 		var trx transaction.Transaction
-		var hash [32]byte
+		hash := make([]byte, 0, 32)
 		err := rows.Scan(
-			&trx.CreatedAt, &hash, &trx.IssuerAddress,
+			&trx.ID, &trx.CreatedAt, &hash, &trx.IssuerAddress,
 			&trx.ReceiverAddress, &trx.Subject, &trx.Data,
 			&trx.IssuerSignature, &trx.ReceiverSignature)
 		if err != nil {
@@ -80,17 +81,18 @@ func (db DataBase) ReadAwaitingTransactionsByReceiver(ctx context.Context, addre
 
 // RemoveAwaitingTransaction removes transaction from the awaiting transaction storage.
 func (db DataBase) ReadAwaitingTransactionsByIssuer(ctx context.Context, address string) ([]transaction.Transaction, error) {
-	rows, err := db.inner.QueryContext(ctx, `SELECT * FROM transactionsAwaitingIssuer WHERE issuer_address = ?`, address)
+	rows, err := db.inner.QueryContext(ctx, "SELECT * FROM transactionsAwaitingReceiver WHERE issuer_address = $1", address)
 	if err != nil {
 		return nil, errors.Join(ErrSelectFailed, err)
 	}
 	defer rows.Close()
+
 	var trxsAwaiting []transaction.Transaction
 	for rows.Next() {
 		var trx transaction.Transaction
-		var hash [32]byte
+		hash := make([]byte, 0, 32)
 		err := rows.Scan(
-			&trx.CreatedAt, &hash, &trx.IssuerAddress,
+			&trx.ID, &trx.CreatedAt, &hash, &trx.IssuerAddress,
 			&trx.ReceiverAddress, &trx.Subject, &trx.Data,
 			&trx.IssuerSignature, &trx.ReceiverSignature)
 		if err != nil {
@@ -104,11 +106,15 @@ func (db DataBase) ReadAwaitingTransactionsByIssuer(ctx context.Context, address
 
 // MoveTransactionsFromTemporaryToPermanent moves transactions from temporary storage to permanent storage.
 func (db DataBase) MoveTransactionsFromTemporaryToPermanent(ctx context.Context, hash [][32]byte) error {
-	_, err := db.inner.ExecContext(ctx, `INSERT INTO transactionsPermanent SELECT * FROM transactionsTemporary WHERE hash = ?`, hash)
+	hs := make([][]byte, 0, len(hash))
+	for _, h := range hash {
+		hs = append(hs, h[:])
+	}
+	_, err := db.inner.ExecContext(ctx, "INSERT INTO transactionsPermanent SELECT * FROM transactionsTemporary WHERE hash = $1", hs)
 	if err != nil {
 		return errors.Join(ErrMoveFailed, err)
 	}
-	_, err = db.inner.ExecContext(ctx, `DELETE FROM transactionsTemporary WHERE hash = ?`, hash)
+	_, err = db.inner.ExecContext(ctx, "DELETE FROM transactionsTemporary WHERE hash = $1", hs)
 	if err != nil {
 		return errors.Join(ErrRemoveFailed, err)
 	}
@@ -117,17 +123,18 @@ func (db DataBase) MoveTransactionsFromTemporaryToPermanent(ctx context.Context,
 
 // ReadTemporaryTransactions reads all transactions from the temporary storage.
 func (db DataBase) ReadTemporaryTransactions(ctx context.Context) ([]transaction.Transaction, error) {
-	rows, err := db.inner.QueryContext(ctx, `SELECT * FROM transactionsTemporary`)
+	rows, err := db.inner.QueryContext(ctx, "SELECT * FROM transactionsTemporary")
 	if err != nil {
 		return nil, errors.Join(ErrSelectFailed, err)
 	}
 	defer rows.Close()
+
 	var trxsAwaiting []transaction.Transaction
 	for rows.Next() {
 		var trx transaction.Transaction
-		var hash [32]byte
+		hash := make([]byte, 0, 32)
 		err := rows.Scan(
-			&trx.CreatedAt, &hash, &trx.IssuerAddress,
+			&trx.ID, &trx.CreatedAt, &hash, &trx.IssuerAddress,
 			&trx.ReceiverAddress, &trx.Subject, &trx.Data,
 			&trx.IssuerSignature, &trx.ReceiverSignature)
 		if err != nil {
diff --git a/repopostgre/validator.go b/repopostgre/validator.go
index d62a815..32eecac 100644
--- a/repopostgre/validator.go
+++ b/repopostgre/validator.go
@@ -21,15 +21,16 @@ func (db DataBase) WriteValidatorStatus(ctx context.Context, vs *validator.Statu
 
 // ReadLastNValidatorStatuses reads last validator statuses from the database.
 func (db DataBase) ReadLastNValidatorStatuses(ctx context.Context, last int64) ([]validator.Status, error) {
-	res, err := db.inner.QueryContext(ctx, "SELECT * FROM validator_status ORDER BY index DESC LIMIT $1", last)
+	rows, err := db.inner.QueryContext(ctx, "SELECT * FROM validator_status ORDER BY index DESC LIMIT $1", last)
 	if err != nil {
 		return nil, errors.Join(ErrSelectFailed, err)
 	}
+	defer rows.Close()
 
 	var results []validator.Status
-	for res.Next() {
+	for rows.Next() {
 		var vs validator.Status
-		if err := res.Scan(&vs.Index, &vs.Valid, &vs.CreatedAt); err != nil {
+		if err := rows.Scan(&vs.ID, &vs.Index, &vs.Valid, &vs.CreatedAt); err != nil {
 			return nil, errors.Join(ErrScanFailed, err)
 		}
 		results = append(results, vs)
diff --git a/server_settings_example_mongo.yaml b/server_settings_example_mongo.yaml
new file mode 100644
index 0000000..2f744a3
--- /dev/null
+++ b/server_settings_example_mongo.yaml
@@ -0,0 +1,21 @@
+bookkeeper:
+  difficulty: 1
+  block_write_timestamp: 300
+  block_transactions_size: 25
+server:
+  port: 8080
+  data_size_bytes: 15000000
+database:
+  conn_str: "mongodb://computantis:computantis@localhost:27017/?authSource=admin&authMechanism=SCRAM-SHA-256&readPreference=primary&&ssl=false&directConnection=true"
+  database_name: "computantis"
+  token: "a6858eLd1GHvoGXrq6nNhEiHrEmkRN3tXu5dYqCjiMUL9sRfUz1iBns0kEnPizzrLfj2TZGU2Wel52fJ6YDNiVrdtvf2kZm4"
+  token_expiration: 604800
+dataprovider:
+  longevity: 300
+validator:
+  websocket: "ws://localhost:8080/ws"
+  port: 9090
+  toke: "some token from the provider"
+file_operator:
+  wallet_path: "path/to/your/wallet"
+  wallet_passwd: "passwd to your wallet"
\ No newline at end of file
diff --git a/server_settings_example.yaml b/server_settings_example_postgresql.yaml
similarity index 89%
rename from server_settings_example.yaml
rename to server_settings_example_postgresql.yaml
index 37f0103..e7fa7e3 100644
--- a/server_settings_example.yaml
+++ b/server_settings_example_postgresql.yaml
@@ -6,7 +6,7 @@ server:
   port: 8080
   data_size_bytes: 15000000
 database:
-  conn_str: "mongodb://user:psswd@localhost:27017"
+  conn_str: "postgres://computantis:computantis@localhost:5432"
   database_name: "computantis"
   token: "a6858eLd1GHvoGXrq6nNhEiHrEmkRN3tXu5dYqCjiMUL9sRfUz1iBns0kEnPizzrLfj2TZGU2Wel52fJ6YDNiVrdtvf2kZm4"
   token_expiration: 604800
diff --git a/stress/stress_test.go b/stress/stress_test.go
index 46c9ea0..f2825a3 100644
--- a/stress/stress_test.go
+++ b/stress/stress_test.go
@@ -24,13 +24,13 @@ func TestFullClientApiCycle(t *testing.T) {
 	issuer := client.NewClient("http://localhost:8080", 5*time.Second, wallet.Helper{}, fileoperations.Helper{}, wallet.New)
 	err := issuer.ValidateApiVersion()
 	assert.Nil(t, err)
-	err = issuer.NewWallet("wpg6d0grqJjyRicC8oI0/w6IGivm5ypFNTO/wwPGW9A=")
+	err = issuer.NewWallet("G8OH7lHu5qfWVumWom0ySN29lakog8nhzSPEwROMjvhdI6VgZ6GoPcdJmoIo7sF3lxQNJMOTKxpYBr6zF992WN86uB7xTEJZ")
 	assert.Nil(t, err)
 
 	receiver := client.NewClient("http://localhost:8080", 5*time.Second, wallet.Helper{}, fileoperations.Helper{}, wallet.New)
 	err = receiver.ValidateApiVersion()
 	assert.Nil(t, err)
-	err = receiver.NewWallet("GWFuhvyFnmMg1/vhPCfoa9ct1pAMC1pWwlRg4kt0D/w=")
+	err = receiver.NewWallet("jykkeD6Tr6xikkYwC805kVoFThm8VGEHStTFk1lIU6RgEf7p3vjFpPQFI3VP9SYeARjYh2jecMSYsmgddjZZcy32iySHijJQ")
 	assert.Nil(t, err)
 
 	now := time.Now()