diff --git a/.gitignore b/.gitignore
index 2328e65..90f34a4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+.idea
 vendor
 tools
 test.php
diff --git a/composer.json b/composer.json
index 5c55c6c..81bf33b 100644
--- a/composer.json
+++ b/composer.json
@@ -4,9 +4,9 @@
     "type": "library",
     "license": "MIT",
     "autoload": {
-        "classmap": [
-            "src"
-        ]
+        "psr-4": {
+            "IPay\\": "src/"
+        }
     },
     "authors": [
         {
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index aab4991..4ca93a8 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -1,2 +1,6 @@
 parameters:
-	ignoreErrors: []
+	ignoreErrors:
+		-
+			message: "#^Property IPay\\\\Builders\\\\TransactionBuilder\\:\\:\\$resolver is never written, only read\\.$#"
+			count: 1
+			path: src/Builders/TransactionBuilder.php
diff --git a/src/Api/AbstractApi.php b/src/Api/AbstractApi.php
deleted file mode 100644
index c4b04a9..0000000
--- a/src/Api/AbstractApi.php
+++ /dev/null
@@ -1,63 +0,0 @@
-<?php
-
-namespace IPay\Api;
-
-use EventSauce\ObjectHydrator\DefinitionProvider;
-use EventSauce\ObjectHydrator\KeyFormatterWithoutConversion;
-use EventSauce\ObjectHydrator\ObjectMapper;
-use EventSauce\ObjectHydrator\ObjectMapperUsingReflection;
-use IPay\Builder\BodyBuilder;
-use IPay\IPayClient;
-use IPay\Session\SessionInterface;
-use Nette\Utils\Json;
-
-/**
- * @psalm-import-type ParametersType from BodyBuilder
- *
- * @template T of SessionInterface
- */
-abstract class AbstractApi
-{
-    protected ObjectMapper $objectMapper;
-
-    /**
-     * @param T $session
-     */
-    public function __construct(
-        protected IPayClient $iPayClient,
-        private SessionInterface $session,
-    ) {
-        $this->objectMapper = new ObjectMapperUsingReflection(
-            new DefinitionProvider(
-                keyFormatter: new KeyFormatterWithoutConversion(),
-            ),
-        );
-    }
-
-    /**
-     * @param ParametersType $parameters
-     *
-     * @return mixed[]
-     */
-    protected function post(string $uri, array $parameters = []): array
-    {
-        $response = $this->iPayClient->getClient()->post(
-            sprintf('ipay/wa/%s', $uri),
-            [],
-            BodyBuilder::from($parameters)
-                ->enhance($this->getSession()->getRequestParameters())
-                ->build()
-                ->encrypt()
-        );
-
-        return Json::decode((string) $response->getBody(), true);
-    }
-
-    /**
-     * @return T
-     */
-    public function getSession(): SessionInterface
-    {
-        return $this->session;
-    }
-}
diff --git a/src/Api/AuthenticatedApi.php b/src/Api/AuthenticatedApi.php
deleted file mode 100644
index ad9c919..0000000
--- a/src/Api/AuthenticatedApi.php
+++ /dev/null
@@ -1,87 +0,0 @@
-<?php
-
-namespace IPay\Api;
-
-use IPay\Builder\TransactionBuilder;
-use IPay\Entity\Account;
-use IPay\Entity\Customer;
-use IPay\Entity\Transaction;
-use IPay\IPayClient;
-use IPay\Session\AuthenticatedSession;
-use Symfony\Component\VarExporter\LazyGhostTrait;
-
-/**
- * @psalm-import-type ParametersType from TransactionBuilder
- *
- * @extends AbstractApi<AuthenticatedSession>
- */
-final class AuthenticatedApi extends AbstractApi
-{
-    use LazyGhostTrait {
-        createLazyGhost as private;
-        initializeLazyObject as private;
-        isLazyObjectInitialized as private;
-        resetLazyObject as private;
-    }
-
-    public Customer $customer;
-
-    /** @var list<Account> */
-    public array $accounts;
-
-    public function __construct(
-        IPayClient $iPayClient,
-        AuthenticatedSession $session,
-    ) {
-        parent::__construct($iPayClient, $session);
-        self::createLazyGhost(
-            initializer: $this->populateLazyProperties(...),
-            instance: $this,
-        );
-    }
-
-    private function populateLazyProperties(): void
-    {
-        $this->customer = $this->objectMapper->hydrateObject(
-            Customer::class,
-            $this->post('getCustomerDetails')['customerInfo'],
-        );
-        $this->accounts = $this->objectMapper->hydrateObjects(
-            Account::class,
-            $this->post('getEntitiesAndAccounts')['accounts'],
-        )->toArray();
-    }
-
-    public function transactions(?string $accountNumber = null): TransactionBuilder
-    {
-        return TransactionBuilder::from(
-            $this->getTransactions(...),
-            ['accountNumber' => $accountNumber ?? $this->customer->accountNumber],
-        );
-    }
-
-    /**
-     * @param ParametersType $parameters
-     *
-     * @return \Traversable<int, Transaction>
-     *
-     * @throws \IPay\Exception\SessionException
-     */
-    private function getTransactions(array $parameters): \Traversable
-    {
-        $parameters['pageNumber'] = 0;
-        do {
-            $transactions = $this->post(
-                'getHistTransactions',
-                $parameters
-            )['transactions'];
-            foreach ($this->objectMapper->hydrateObjects(
-                Transaction::class,
-                $transactions
-            )->getIterator() as $transaction) {
-                yield $transaction;
-            }
-            ++$parameters['pageNumber'];
-        } while (count($transactions) > 0);
-    }
-}
diff --git a/src/Api/UnauthenticatedApi.php b/src/Api/UnauthenticatedApi.php
deleted file mode 100644
index 317491b..0000000
--- a/src/Api/UnauthenticatedApi.php
+++ /dev/null
@@ -1,43 +0,0 @@
-<?php
-
-namespace IPay\Api;
-
-use IPay\Captcha\CaptchaSolver;
-use IPay\Session\AuthenticatedSession;
-use IPay\Session\UnauthenticatedSession;
-use Nette\Utils\Random;
-
-/**
- * @internal
- *
- * @extends AbstractApi<UnauthenticatedSession>
- */
-final class UnauthenticatedApi extends AbstractApi
-{
-    public function login(string $userName, string $accessCode): AuthenticatedApi
-    {
-        $parameters = get_defined_vars() + $this->bypassCaptcha();
-
-        /** @var array{sessionId: string, ...} */
-        $result = $this->post('signIn', $parameters);
-
-        return new AuthenticatedApi(
-            $this->iPayClient,
-            new AuthenticatedSession($result['sessionId'])
-        );
-    }
-
-    /**
-     * @return array{captchaId:string,captchaCode:string}
-     */
-    private function bypassCaptcha(): array
-    {
-        $captchaId = Random::generate(9, '0-9a-zA-Z');
-        $svg = (string) $this->iPayClient->getClient()
-            ->get(sprintf('api/get-captcha/%s', $captchaId))
-            ->getBody();
-        $captchaCode = CaptchaSolver::solve($svg);
-
-        return compact('captchaId', 'captchaCode');
-    }
-}
diff --git a/src/Builder/BodyBuilder.php b/src/Builder/BodyBuilder.php
deleted file mode 100644
index e72ed90..0000000
--- a/src/Builder/BodyBuilder.php
+++ /dev/null
@@ -1,67 +0,0 @@
-<?php
-
-namespace IPay\Builder;
-
-use IPay\Encryption\Encrypter;
-use Nette\Utils\Json;
-
-/**
- * @psalm-type ValueType = string|int
- * @psalm-type ParametersType = array<string, ValueType>
- *
- * @extends \ArrayObject<string, ValueType>
- */
-final class BodyBuilder extends \ArrayObject implements \Stringable, \JsonSerializable
-{
-    /**
-     * @param ParametersType $array
-     */
-    private function __construct(array $array)
-    {
-        parent::__construct($array);
-    }
-
-    /**
-     * @param ParametersType $parameters
-     */
-    public static function from(array $parameters): static
-    {
-        return new static($parameters);
-    }
-
-    /**
-     * @param ParametersType $parameters
-     */
-    public function enhance(array $parameters): static
-    {
-        return static::from($this->getArrayCopy() + $parameters);
-    }
-
-    public function build(): self
-    {
-        $this->ksort();
-
-        $this['signature'] = md5(http_build_query($this->getArrayCopy()));
-
-        return $this;
-    }
-
-    public function encrypt(): string
-    {
-        return static::from(['encrypted' => Encrypter::encrypt($this)]);
-    }
-
-    public function __toString(): string
-    {
-        return Json::encode($this);
-    }
-
-    /**
-     * @return ParametersType
-     */
-    #[\ReturnTypeWillChange]
-    public function jsonSerialize(): array
-    {
-        return $this->getArrayCopy();
-    }
-}
diff --git a/src/Builders/BodyBuilder.php b/src/Builders/BodyBuilder.php
new file mode 100644
index 0000000..66d0fea
--- /dev/null
+++ b/src/Builders/BodyBuilder.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace IPay\Builders;
+
+use IPay\Encryption\Encryptor;
+use Nette\Utils\Json;
+use Nette\Utils\Random;
+
+/**
+ * @psalm-type ValueType = string|int
+ * @psalm-type ParametersType = array<string, ValueType>
+ */
+final class BodyBuilder implements \Stringable, \JsonSerializable
+{
+    /**
+     * @param ParametersType $parameters
+     */
+    public function __construct(
+        private array $parameters = [],
+    ) {
+    }
+
+    public function setSessionId(string $value): void
+    {
+        $this->parameters['sessionId'] = $value;
+    }
+
+    /**
+     * @param ParametersType $parameters
+     */
+    public function build(array $parameters = []): self
+    {
+        $data = array_merge([
+            'lang' => 'en',
+            'requestId' => Random::generate(12, '0-9A-Z').'|'.time(),
+        ], $this->parameters, $parameters);
+        ksort($data);
+        $data['signature'] = md5(http_build_query($data));
+
+        return new self($data);
+    }
+
+    public function encrypt(): string
+    {
+        return new self(['encrypted' => Encryptor::encrypt($this)]);
+    }
+
+    public function __toString(): string
+    {
+        return Json::encode($this->parameters);
+    }
+
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+        return $this->parameters;
+    }
+}
diff --git a/src/Builder/TransactionBuilder.php b/src/Builders/TransactionBuilder.php
similarity index 53%
rename from src/Builder/TransactionBuilder.php
rename to src/Builders/TransactionBuilder.php
index 8dffe08..751f59f 100644
--- a/src/Builder/TransactionBuilder.php
+++ b/src/Builders/TransactionBuilder.php
@@ -1,42 +1,22 @@
 <?php
 
-namespace IPay\Builder;
+namespace IPay\Builders;
 
-use IPay\Entity\Transaction;
-use IPay\Enum\TransactionType;
+use IPay\Enums\TransactionType;
+use IPay\ValueObjects\Transaction;
 
 /**
  * @psalm-import-type ParametersType from BodyBuilder
  *
- * @psalm-type GetterType = \Closure(ParametersType):\Traversable<Transaction>
- *
  * @implements \IteratorAggregate<int,Transaction>
  */
 final class TransactionBuilder implements \IteratorAggregate
 {
-    /**
-     * @param GetterType     $getter
-     * @param ParametersType $parameters
-     */
-    private function __construct(
-        private \Closure $getter,
-        private array $parameters,
-    ) {
-    }
+    /** @var \Closure(ParametersType):\Traversable<Transaction> */
+    private \Closure $resolver;
 
-    /**
-     * @param GetterType     $getter
-     * @param ParametersType $parameters
-     */
-    public static function from(
-        \Closure $getter,
-        array $parameters,
-    ): self {
-        return new self(
-            $getter,
-            $parameters,
-        );
-    }
+    /** @var ParametersType */
+    private array $parameters = [];
 
     public function between(
         \DateTimeInterface $from,
@@ -65,6 +45,6 @@ public function type(TransactionType $type): self
 
     public function getIterator(): \Traversable
     {
-        return ($this->getter)($this->parameters);
+        return ($this->resolver)($this->parameters);
     }
 }
diff --git a/src/Contracts/AbstractApi.php b/src/Contracts/AbstractApi.php
new file mode 100644
index 0000000..c2ada03
--- /dev/null
+++ b/src/Contracts/AbstractApi.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace IPay\Contracts;
+
+use IPay\Builders\TransactionBuilder;
+use IPay\ValueObjects\Account;
+use IPay\ValueObjects\Customer;
+
+abstract class AbstractApi
+{
+    public Customer $customer;
+
+    /** @var list<Account> */
+    public array $accounts;
+
+    abstract public function transactions(?string $accountNumber = null): TransactionBuilder;
+}
diff --git a/src/Encryption/Encrypter.php b/src/Encryption/Encryptor.php
similarity index 96%
rename from src/Encryption/Encrypter.php
rename to src/Encryption/Encryptor.php
index c20a8f1..dd94323 100644
--- a/src/Encryption/Encrypter.php
+++ b/src/Encryption/Encryptor.php
@@ -4,7 +4,7 @@
 
 use phpseclib\Crypt\RSA;
 
-final class Encrypter
+final class Encryptor
 {
     private const IPAY_PUBLIC_KEY = <<<PUBLIC
 -----BEGIN PUBLIC KEY-----
diff --git a/src/Enum/TransactionType.php b/src/Enums/TransactionType.php
similarity index 83%
rename from src/Enum/TransactionType.php
rename to src/Enums/TransactionType.php
index 6461d13..4365ca7 100644
--- a/src/Enum/TransactionType.php
+++ b/src/Enums/TransactionType.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace IPay\Enum;
+namespace IPay\Enums;
 
 enum TransactionType: string
 {
diff --git a/src/Exception/LoginException.php b/src/Exceptions/LoginException.php
similarity index 65%
rename from src/Exception/LoginException.php
rename to src/Exceptions/LoginException.php
index 08bc614..1d0678b 100644
--- a/src/Exception/LoginException.php
+++ b/src/Exceptions/LoginException.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace IPay\Exception;
+namespace IPay\Exceptions;
 
 class LoginException extends \Exception
 {
diff --git a/src/Exception/SessionException.php b/src/Exceptions/SessionException.php
similarity index 66%
rename from src/Exception/SessionException.php
rename to src/Exceptions/SessionException.php
index d5c97f2..f457eda 100644
--- a/src/Exception/SessionException.php
+++ b/src/Exceptions/SessionException.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace IPay\Exception;
+namespace IPay\Exceptions;
 
 class SessionException extends \Exception
 {
diff --git a/src/Http/Plugin/ExceptionThrower.php b/src/Http/Plugins/ExceptionThrower.php
similarity index 92%
rename from src/Http/Plugin/ExceptionThrower.php
rename to src/Http/Plugins/ExceptionThrower.php
index a60305b..63a2b78 100644
--- a/src/Http/Plugin/ExceptionThrower.php
+++ b/src/Http/Plugins/ExceptionThrower.php
@@ -1,11 +1,11 @@
 <?php
 
-namespace IPay\Http\Plugin;
+namespace IPay\Http\Plugins;
 
 use Http\Client\Common\Plugin;
 use Http\Promise\Promise;
-use IPay\Exception\LoginException;
-use IPay\Exception\SessionException;
+use IPay\Exceptions\LoginException;
+use IPay\Exceptions\SessionException;
 use Nette\Utils\Json;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;
diff --git a/src/IPayClient.php b/src/IPayClient.php
index 35b2fdd..6a6a78f 100644
--- a/src/IPayClient.php
+++ b/src/IPayClient.php
@@ -2,6 +2,10 @@
 
 namespace IPay;
 
+use EventSauce\ObjectHydrator\DefinitionProvider;
+use EventSauce\ObjectHydrator\KeyFormatterWithoutConversion;
+use EventSauce\ObjectHydrator\ObjectMapper;
+use EventSauce\ObjectHydrator\ObjectMapperUsingReflection;
 use Http\Client\Common\HttpMethodsClient;
 use Http\Client\Common\HttpMethodsClientInterface;
 use Http\Client\Common\Plugin\BaseUriPlugin;
@@ -9,19 +13,33 @@
 use Http\Client\Common\PluginClient;
 use Http\Discovery\Psr17FactoryDiscovery;
 use Http\Discovery\Psr18ClientDiscovery;
-use IPay\Api\AuthenticatedApi;
-use IPay\Api\UnauthenticatedApi;
-use IPay\Http\Plugin\ExceptionThrower;
-use IPay\Session\UnauthenticatedSession;
+use IPay\Builders\BodyBuilder;
+use IPay\Builders\TransactionBuilder;
+use IPay\Captcha\CaptchaSolver;
+use IPay\Contracts\AbstractApi;
+use IPay\Http\Plugins\ExceptionThrower;
+use IPay\ValueObjects\Account;
+use IPay\ValueObjects\Customer;
+use IPay\ValueObjects\Transaction;
+use Nette\Utils\Json;
+use Nette\Utils\Random;
+use Symfony\Component\VarExporter\LazyGhostTrait;
 
-final class IPayClient
+/**
+ * @phpstan-import-type ParametersType from BodyBuilder
+ */
+final class IPayClient extends AbstractApi
 {
+    use LazyGhostTrait;
+
     /**
-     * @throws Exception\LoginException
+     * @throws Exceptions\LoginException
      */
-    public static function fromCredentials(string $username, string $password): AuthenticatedApi
+    public static function fromCredentials(string $username, string $password): AbstractApi
     {
-        $ipayClient = new self(
+        return new self(
+            $username,
+            $password,
             new HttpMethodsClient(
                 new PluginClient(Psr18ClientDiscovery::find(), [
                     new BaseUriPlugin(
@@ -35,18 +53,113 @@ public static function fromCredentials(string $username, string $password): Auth
                 Psr17FactoryDiscovery::findStreamFactory(),
             ),
         );
-
-        return (new UnauthenticatedApi($ipayClient, new UnauthenticatedSession()))
-            ->login($username, $password);
     }
 
     private function __construct(
+        string $username,
+        string $password,
         private HttpMethodsClientInterface $client,
+        private BodyBuilder $bodyBuilder = new BodyBuilder(),
+        private ObjectMapper $objectMapper = new ObjectMapperUsingReflection(
+            new DefinitionProvider(
+                keyFormatter: new KeyFormatterWithoutConversion(),
+            ),
+        ),
     ) {
+        /** @var array{sessionId: string, ...} */
+        $response = $this->post('signIn', [
+            'userName' => $username,
+            'accessCode' => $password,
+        ] + $this->bypassCaptcha());
+        $bodyBuilder->setSessionId($response['sessionId']);
+        self::createLazyGhost(
+            initializer: $this->populateLazyProperties(...),
+            instance: $this,
+        );
+    }
+
+    private function populateLazyProperties(): void
+    {
+        $this->customer = $this->objectMapper->hydrateObject(
+            Customer::class,
+            $this->post('getCustomerDetails')['customerInfo'],
+        );
+        $this->accounts = $this->objectMapper->hydrateObjects(
+            Account::class,
+            $this->post('getEntitiesAndAccounts')['accounts'],
+        )->toArray();
+    }
+
+    /**
+     * @suppress 1416
+     */
+    public function transactions(?string $accountNumber = null): TransactionBuilder
+    {
+        $that = $this;
+
+        return (\Closure::bind(function () use ($that, $accountNumber): TransactionBuilder {
+            $builder = new TransactionBuilder();
+            $builder->resolver = \Closure::bind(function (array $parameters): \Traversable {
+                return $this->getTransactions($parameters);
+            }, $that, $that::class);
+            $builder->parameters['accountNumber'] = $accountNumber ?? $that->customer->accountNumber;
+
+            return $builder;
+        }, null, TransactionBuilder::class))();
     }
 
-    public function getClient(): HttpMethodsClientInterface
+    /**
+     * @param ParametersType $parameters
+     *
+     * @return \Traversable<int, Transaction>
+     *
+     * @throws Exceptions\SessionException
+     */
+    private function getTransactions(array $parameters): \Traversable
+    {
+        $parameters['pageNumber'] = 0;
+        do {
+            $transactions = $this->post(
+                'getHistTransactions',
+                $parameters
+            )['transactions'];
+            foreach ($this->objectMapper->hydrateObjects(
+                Transaction::class,
+                $transactions
+            )->getIterator() as $transaction) {
+                yield $transaction;
+            }
+            ++$parameters['pageNumber'];
+        } while (count($transactions) > 0);
+    }
+
+    /**
+     * @param ParametersType $parameters
+     *
+     * @return mixed[]
+     */
+    private function post(string $uri, array $parameters = []): array
     {
-        return $this->client;
+        $response = $this->client->post(
+            sprintf('ipay/wa/%s', $uri),
+            [],
+            $this->bodyBuilder->build($parameters)->encrypt(),
+        );
+
+        return Json::decode((string) $response->getBody(), true);
+    }
+
+    /**
+     * @return array{captchaId:string,captchaCode:string}
+     */
+    private function bypassCaptcha(): array
+    {
+        $captchaId = Random::generate(9, '0-9a-zA-Z');
+        $svg = (string) $this->client
+            ->get(sprintf('api/get-captcha/%s', $captchaId))
+            ->getBody();
+        $captchaCode = CaptchaSolver::solve($svg);
+
+        return compact('captchaId', 'captchaCode');
     }
 }
diff --git a/src/Session/AuthenticatedSession.php b/src/Session/AuthenticatedSession.php
deleted file mode 100644
index 81b2153..0000000
--- a/src/Session/AuthenticatedSession.php
+++ /dev/null
@@ -1,15 +0,0 @@
-<?php
-
-namespace IPay\Session;
-
-final class AuthenticatedSession extends UnauthenticatedSession
-{
-    public function __construct(public string $id)
-    {
-    }
-
-    public function getRequestParameters(): array
-    {
-        return ['sessionId' => $this->id, ...parent::getRequestParameters()];
-    }
-}
diff --git a/src/Session/SessionInterface.php b/src/Session/SessionInterface.php
deleted file mode 100644
index 1cd088c..0000000
--- a/src/Session/SessionInterface.php
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-
-namespace IPay\Session;
-
-interface SessionInterface
-{
-    /**
-     * @return string[]
-     */
-    public function getRequestParameters(): array;
-}
diff --git a/src/Session/UnauthenticatedSession.php b/src/Session/UnauthenticatedSession.php
deleted file mode 100644
index b48bf3d..0000000
--- a/src/Session/UnauthenticatedSession.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-namespace IPay\Session;
-
-use Nette\Utils\Random;
-
-class UnauthenticatedSession implements SessionInterface
-{
-    public function getRequestParameters(): array
-    {
-        return [
-            'lang' => 'en',
-            'requestId' => Random::generate(12, '0-9A-Z').'|'.time(),
-        ];
-    }
-}
diff --git a/src/Entity/Account.php b/src/ValueObjects/Account.php
similarity index 60%
rename from src/Entity/Account.php
rename to src/ValueObjects/Account.php
index 0c4676a..4e7713e 100644
--- a/src/Entity/Account.php
+++ b/src/ValueObjects/Account.php
@@ -1,29 +1,9 @@
 <?php
 
-namespace IPay\Entity;
+namespace IPay\ValueObjects;
 
 use EventSauce\ObjectHydrator\Constructor;
 
-readonly class AccountState
-{
-    private function __construct(
-        public int $availableBalance,
-        public int $balance,
-    ) {
-    }
-
-    #[Constructor]
-    public static function create(
-        int $availableBalance,
-        int $balance,
-    ): self {
-        return new self(
-            $availableBalance,
-            $balance,
-        );
-    }
-}
-
 readonly class Account
 {
     private function __construct(
diff --git a/src/ValueObjects/AccountState.php b/src/ValueObjects/AccountState.php
new file mode 100644
index 0000000..cf5f7b0
--- /dev/null
+++ b/src/ValueObjects/AccountState.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace IPay\ValueObjects;
+
+use EventSauce\ObjectHydrator\Constructor;
+
+readonly class AccountState
+{
+    private function __construct(
+        public int $availableBalance,
+        public int $balance,
+    ) {
+    }
+
+    #[Constructor]
+    public static function create(
+        int $availableBalance,
+        int $balance,
+    ): self {
+        return new self(
+            $availableBalance,
+            $balance,
+        );
+    }
+}
diff --git a/src/Entity/Customer.php b/src/ValueObjects/Customer.php
similarity index 95%
rename from src/Entity/Customer.php
rename to src/ValueObjects/Customer.php
index 9d256fd..3dac8d9 100644
--- a/src/Entity/Customer.php
+++ b/src/ValueObjects/Customer.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace IPay\Entity;
+namespace IPay\ValueObjects;
 
 use EventSauce\ObjectHydrator\Constructor;
 
diff --git a/src/Entity/Transaction.php b/src/ValueObjects/Transaction.php
similarity index 97%
rename from src/Entity/Transaction.php
rename to src/ValueObjects/Transaction.php
index 1620aee..3295a5d 100644
--- a/src/Entity/Transaction.php
+++ b/src/ValueObjects/Transaction.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace IPay\Entity;
+namespace IPay\ValueObjects;
 
 use EventSauce\ObjectHydrator\Constructor;
 use EventSauce\ObjectHydrator\PropertyCasters\CastToDateTimeImmutable;