diff --git a/CLAUDE.md b/CLAUDE.md
index 3995369..94252ff 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -135,6 +135,23 @@ e rode `php examples/asaas/charges.php` (ou `make asaas resource=charges`).
   `PHPay\Efi\`, `PHPay\MercadoPago\` → `src/Gateways/<Gateway>/`. Gateway novo
   precisa de um root novo no `composer.json` — não introduza `PHPay\Gateways\...`.
 
+## Valores monetários
+
+Use **`PHPay\Support\Money`**. Os gateways discordam da unidade — Asaas e Mercado
+Pago querem reais decimais, os outros sete querem centavos inteiros — e errar não
+quebra a integração, cobra o valor errado.
+
+- Fábricas: `Money::reais()` (aceita float, int e string em notação brasileira) e
+  `Money::centavos()`. Acessores na instância: `toReais()` e `toCentavos()`.
+- **Dentro dos gateways**, normalize com `Money::asReais()` ou `Money::asCentavos()`,
+  que aceitam `Money` ou número cru. Nunca leia o valor direto do parâmetro.
+- Todo método que recebe valor aceita `Money|int` (ou `Money|int|float` nos de reais).
+  Número cru é lido na unidade que aquele gateway sempre esperou — compatibilidade.
+- Onde o valor vive dentro do array de payload (Asaas, Mercado Pago, Efí), existe
+  `setAmount()`. Gateway novo com valor em array deve ter o mesmo.
+- `Money::reais()` **recusa mais de duas casas decimais** de propósito. Não "conserte"
+  isso com arredondamento: é o que impede erro de um centavo na conciliação.
+
 ## Particularidades por gateway
 
 - **Asaas** — `$sandbox` troca a base URL. Único com chaves Pix, porque é PSP.
diff --git a/README.md b/README.md
index ca63b8c..12517f4 100644
--- a/README.md
+++ b/README.md
@@ -263,30 +263,56 @@ Nos dois últimos, `isSandbox()` diz em qual ambiente você está:
 
 ### Unidade monetária
 
-**Este é o erro mais caro de cometer**, porque a cobrança sai com valor errado
-em vez de falhar:
+Os gateways discordam sobre a unidade, e **errar não quebra a integração — ela
+cobra o valor errado**. Mandar `100.50` num gateway de centavos cobra R$ 1,00,
+e você só descobre na conciliação.
 
-| Gateway | Unidade | R$ 100,50 é |
-| --- | --- | --- |
-| **Asaas** | Reais (decimal) | `100.50` |
-| **Mercado Pago** | Reais (decimal) | `100.50` |
-| **PagBank** | Centavos (inteiro) | `10050` |
-| **Pagar.me** | Centavos (inteiro) | `10050` |
-| **Cielo** | Centavos (inteiro) | `10050` |
-| **Rede** | Centavos (inteiro) | `10050` |
-| **AbacatePay** | Centavos (inteiro, mín. 100) | `10050` |
-| **Woovi** | Centavos (inteiro) | `10050` |
-| **Efí** | Centavos (inteiro) | `10050` |
+Use `Money` e o problema deixa de existir: você diz a unidade que tem, o
+gateway pede a unidade que precisa, e nenhum dos dois pode errar.
+
+```php
+use PHPay\Support\Money;
 
-Nos gateways que usam centavos, o PHPay **recusa valor decimal na validação**,
-antes de qualquer chamada:
+$valor = Money::reais(100.50);     // ou Money::centavos(10050)
+
+$asaas->charge()->setAmount($valor);          // vira 100.50
+$pagbank->charge()->addItem('Item', $valor);  // vira 10050
+```
+
+Também aceita string, que é o que um campo de formulário costuma entregar:
 
 ```php
-$phpay->charge()->addItem('Item', 100.50);
-// ValidationException: ... deve ser um inteiro em CENTAVOS maior que zero.
-//                      R$ 10,50 é 1050.
+Money::reais('100,50');      // notação brasileira
+Money::reais('1.234,56');    // com separador de milhar
+Money::reais('100.50');      // notação com ponto
 ```
 
+E tem o que um total precisa:
+
+```php
+$unitario = Money::reais(59.90);
+
+$unitario->multiply(2);              // R$ 119,80
+$unitario->plus(Money::reais(10));   // R$ 69,90
+$unitario->format();                 // 'R$ 59,90'
+```
+
+> `Money::reais(10 / 3)` **lança exceção** em vez de arredondar. Arredondamento
+> silencioso é como nascem erros de um centavo na conciliação — arredonde você
+> mesmo, ou use `Money::centavos()` para ser exato.
+
+#### Passando número cru
+
+Continua funcionando, e cada gateway lê na unidade que sempre esperou:
+
+| Gateway | Unidade do número cru | R$ 100,50 |
+| --- | --- | --- |
+| **Asaas**, **Mercado Pago** | Reais (decimal) | `100.50` |
+| **PagBank**, **Pagar.me**, **Cielo**, **Rede**, **AbacatePay**, **Woovi**, **Efí** | Centavos (inteiro) | `10050` |
+
+Nos que usam centavos, o PHPay recusa decimal na validação. Mas é justamente
+essa tabela que o `Money` torna desnecessária — **prefira o value object**.
+
 ---
 
 ## Gateways
diff --git a/examples/abacatepay/charges.php b/examples/abacatepay/charges.php
index f98f66d..9ef969c 100644
--- a/examples/abacatepay/charges.php
+++ b/examples/abacatepay/charges.php
@@ -4,6 +4,7 @@
 use PHPay\AbacatePay\Resources\Charge\Charge;
 use PHPay\Exceptions\PHPayException;
 use PHPay\PHPay;
+use PHPay\Support\Money;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -33,8 +34,8 @@
     */
     $cobranca = $phpay
         ->setCustomer($cliente)
-        ->addProduct('prod-1234', 'Assinatura PHPay', 2000)            /* R$ 20,00 */
-        ->addProduct('prod-5678', 'Camiseta', 5990, 2, 'Tamanho M')    /* R$ 59,90 cada */
+        ->addProduct('prod-1234', 'Assinatura PHPay', Money::reais(20.00))            /* R$ 20,00 */
+        ->addProduct('prod-5678', 'Camiseta', Money::reais(59.90), 2, 'Tamanho M')    /* R$ 59,90 cada */
         ->setUrls(
             completionUrl: 'https://exemplo.test/obrigado',
             returnUrl: 'https://exemplo.test/loja'
@@ -58,7 +59,7 @@
 
     PHPay::gateway($gateway)->charge()
         ->setCustomerId((string) ($criado['data']['id'] ?? ''))
-        ->addProduct('prod-1234', 'Assinatura PHPay', 2000)
+        ->addProduct('prod-1234', 'Assinatura PHPay', Money::reais(20.00))
         ->setUrls('https://exemplo.test/obrigado', 'https://exemplo.test/loja')
         ->create();
 
diff --git a/examples/asaas/charges.php b/examples/asaas/charges.php
index 3aea91b..2bc4ab2 100644
--- a/examples/asaas/charges.php
+++ b/examples/asaas/charges.php
@@ -4,6 +4,7 @@
 use PHPay\Asaas\Resources\Charge\Charge;
 use PHPay\Exceptions\PHPayException;
 use PHPay\PHPay;
+use PHPay\Support\Money;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -16,7 +17,6 @@
 
 $charge = [
     'billingType' => 'BOLETO',
-    'value'       => 100.00,
     'dueDate'     => date('Y-m-d', strtotime('+3 days')),
     'description' => 'Cobrança de teste do PHPay',
 ];
@@ -34,6 +34,8 @@
     /* cria a cobrança criando também o cliente */
     $chargeCreated = $phpay
         ->setCharge($charge)
+        /* o Money cuida da unidade: aqui vira reais, em outros gateways vira centavos */
+        ->setAmount(Money::reais(100.00))
         ->setCustomer($customer)
         ->create();
 
diff --git a/examples/cielo/charges.php b/examples/cielo/charges.php
index 6c872c2..5c745e1 100644
--- a/examples/cielo/charges.php
+++ b/examples/cielo/charges.php
@@ -5,6 +5,7 @@
 use PHPay\Cielo\Resources\Charge\Charge;
 use PHPay\Exceptions\PHPayException;
 use PHPay\PHPay;
+use PHPay\Support\Money;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -25,7 +26,7 @@
     $venda = $phpay
         ->setOrderId('pedido-' . time())
         ->setCustomer(['Name' => NAME])
-        ->setPix(15700)
+        ->setPix(Money::reais(157.00))
         /* use uma chave estável do seu domínio para tornar o retry seguro */
         ->setRequestId('pedido-123456')
         ->create();
@@ -52,7 +53,7 @@
     $comCartao = PHPay::gateway(new CieloGateway(CIELO_MERCHANT_ID, CIELO_MERCHANT_KEY))
         ->charge()
         ->setCustomer(['Name' => NAME])
-        ->setCreditCard(15700, [
+        ->setCreditCard(Money::reais(157.00), [
             'CardNumber'     => '0000000000000001',
             'Holder'         => 'Mario Lucas',
             'ExpirationDate' => '12/2030',
diff --git a/examples/pagarme/charges.php b/examples/pagarme/charges.php
index 4f79ce5..29ec385 100644
--- a/examples/pagarme/charges.php
+++ b/examples/pagarme/charges.php
@@ -4,6 +4,7 @@
 use PHPay\PagarMe\PagarMeGateway;
 use PHPay\PagarMe\Resources\Charge\Charge;
 use PHPay\PHPay;
+use PHPay\Support\Money;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -33,7 +34,7 @@
     */
     $pedido = $phpay
         ->setCustomer($customer)
-        ->addItem('Assinatura PHPay', 10050)
+        ->addItem('Assinatura PHPay', Money::reais(100.50))
         ->setPix(1800)
         ->create();
 
@@ -56,7 +57,7 @@
     /* boleto, reaproveitando um cliente que já existe */
     PHPay::gateway($gateway)->charge()
         ->setCustomerId((string) $pedido['customer']['id'])
-        ->addItem('Camiseta', 5990, 2)
+        ->addItem('Camiseta', Money::reais(59.90), 2)
         ->setBoleto(date('Y-m-d', strtotime('+5 days')), ['Não receber após o vencimento'])
         ->create();
 
diff --git a/examples/pagbank/charges.php b/examples/pagbank/charges.php
index c32891d..3f6f336 100644
--- a/examples/pagbank/charges.php
+++ b/examples/pagbank/charges.php
@@ -5,6 +5,7 @@
 use PHPay\PagBank\PagBankGateway;
 use PHPay\PagBank\Resources\Charge\Charge;
 use PHPay\PHPay;
+use PHPay\Support\Money;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -31,8 +32,8 @@
     */
     $pedido = $phpay
         ->setCustomer($customer)
-        ->addItem('Assinatura PHPay', 10050)
-        ->setQrCode(10050)
+        ->addItem('Assinatura PHPay', Money::reais(100.50))
+        ->setQrCode(Money::reais(100.50))
         /* sem CRUD de webhook na API: a notificação é por pedido */
         ->setNotificationUrls(['https://exemplo.test/webhook/pagbank'])
         ->create();
@@ -52,7 +53,7 @@
     $comCartao = PHPay::gateway(new PagBankGateway(TOKEN_PAGBANK_SANDBOX))
         ->charge()
         ->setCustomer($customer)
-        ->addItem('Camiseta', 5990, 2)
+        ->addItem('Camiseta', Money::reais(59.90), 2)
         ->setCharges([[
             'reference_id'   => 'cobranca-1',
             'description'    => 'Camiseta',
diff --git a/examples/rede/charges.php b/examples/rede/charges.php
index dc7cd0c..c1c218b 100644
--- a/examples/rede/charges.php
+++ b/examples/rede/charges.php
@@ -5,6 +5,7 @@
 use PHPay\Rede\Enums\{TransactionKindEnum, TransactionStatusEnum};
 use PHPay\Rede\RedeGateway;
 use PHPay\Rede\Resources\Charge\Charge;
+use PHPay\Support\Money;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -31,7 +32,7 @@
     $transacao = $phpay
         ->setReference('pedido-' . time())
         ->setCard('5448280000000007', 'MARIO LUCAS', '12', '2030', '123')
-        ->setPayment(2099, TransactionKindEnum::CREDIT, installments: 1, capture: true)
+        ->setPayment(Money::reais(20.99), TransactionKindEnum::CREDIT, installments: 1, capture: true)
         ->setSoftDescriptor('PHPAY')
         ->create();
 
@@ -59,7 +60,7 @@
     $emDuasEtapas = PHPay::gateway($gateway)->charge()
         ->setReference('pedido-2-etapas-' . time())
         ->setCard('5448280000000007', 'MARIO LUCAS', '12', '2030', '123')
-        ->setPayment(5000, TransactionKindEnum::CREDIT, capture: false)
+        ->setPayment(Money::reais(50.00), TransactionKindEnum::CREDIT, capture: false)
         ->create();
 
     $phpay->capture((string) $emDuasEtapas['tid']);
diff --git a/examples/woovi/charges.php b/examples/woovi/charges.php
index aca9f1d..f5ec159 100644
--- a/examples/woovi/charges.php
+++ b/examples/woovi/charges.php
@@ -2,6 +2,7 @@
 
 use PHPay\Exceptions\PHPayException;
 use PHPay\PHPay;
+use PHPay\Support\Money;
 use PHPay\Woovi\Enums\PixKeyTypeEnum;
 use PHPay\Woovi\WooviGateway;
 
@@ -27,7 +28,7 @@
     $cobranca = $phpay->charge()
         ->setCorrelationId('pedido-' . time())
         ->setCustomer(['name' => NAME, 'email' => EMAIL])
-        ->create(10050);   /* R$ 100,50 */
+        ->create(Money::reais(100.50));   /* R$ 100,50 */
 
     echo $phpay->charge()->getPixCode($cobranca) . PHP_EOL;
 
@@ -47,7 +48,7 @@
 
     /* QR Code estático: sem valor, o pagador escolhe quanto pagar */
     $phpay->pix()->staticQrCode('Caixa 1');
-    $phpay->pix()->staticQrCode('Mensalidade', 4990, 'mensalidade-2026');
+    $phpay->pix()->staticQrCode('Mensalidade', Money::reais(49.90), 'mensalidade-2026');
 
     /* Webhooks com CRUD por API — também só aqui e no Asaas */
     $phpay->webhook([
@@ -61,7 +62,7 @@
     $phpay->subscription()
         ->setCustomer(['name' => NAME, 'email' => EMAIL])
         ->setDayGenerateCharge(10)
-        ->create(4990);
+        ->create(Money::reais(49.90));
 
     /* Cliente avulso */
     $phpay->customer(['name' => NAME, 'email' => EMAIL])->create();
diff --git a/src/Gateways/AbacatePay/Resources/Charge/Charge.php b/src/Gateways/AbacatePay/Resources/Charge/Charge.php
index 320b0fd..bc8cc7e 100644
--- a/src/Gateways/AbacatePay/Resources/Charge/Charge.php
+++ b/src/Gateways/AbacatePay/Resources/Charge/Charge.php
@@ -8,6 +8,7 @@
 use PHPay\AbacatePay\Resources\Charge\Interface\ChargeInterface;
 use PHPay\AbacatePay\Traits\HasAbacatePayClient;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 
 /**
  * billings of the AbacatePay API.
@@ -127,7 +128,7 @@ public function setProducts(array $products): ChargeInterface
     public function addProduct(
         string $externalId,
         string $name,
-        int $price,
+        Money|int $price,
         int $quantity = 1,
         ?string $description = null
     ): ChargeInterface {
@@ -141,7 +142,7 @@ public function addProduct(
             'externalId' => $externalId,
             'name'       => $name,
             'quantity'   => $quantity,
-            'price'      => $price,
+            'price'      => Money::asCentavos($price),
         ];
 
         if ($description !== null) {
diff --git a/src/Gateways/AbacatePay/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/AbacatePay/Resources/Charge/Interface/ChargeInterface.php
index 32b64e2..c41303f 100644
--- a/src/Gateways/AbacatePay/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/AbacatePay/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\AbacatePay\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -49,7 +51,7 @@ public function setProducts(array $products): ChargeInterface;
     public function addProduct(
         string $externalId,
         string $name,
-        int $price,
+        Money|int $price,
         int $quantity = 1,
         ?string $description = null
     ): ChargeInterface;
diff --git a/src/Gateways/Asaas/Resources/Charge/Charge.php b/src/Gateways/Asaas/Resources/Charge/Charge.php
index 38efb6e..0e42c8f 100644
--- a/src/Gateways/Asaas/Resources/Charge/Charge.php
+++ b/src/Gateways/Asaas/Resources/Charge/Charge.php
@@ -8,6 +8,7 @@
 use PHPay\Asaas\Resources\Customer\Customer;
 use PHPay\Asaas\Traits\HasAsaasClient;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 
 class Charge implements ChargeInterface
 {
@@ -59,6 +60,22 @@ public function setCharge(array $charge): ChargeInterface
         return $this;
     }
 
+    /**
+     * set the amount of the charge.
+     *
+     * Asaas takes reais as a decimal — pass a Money and the unit is handled
+     * for you, or a raw number, which is read as reais.
+     *
+     * @param Money|int|float $amount
+     * @return ChargeInterface
+     */
+    public function setAmount(Money|int|float $amount): ChargeInterface
+    {
+        $this->charge['value'] = Money::asReais($amount);
+
+        return $this;
+    }
+
     /**
      * set query params
      *
diff --git a/src/Gateways/Asaas/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/Asaas/Resources/Charge/Interface/ChargeInterface.php
index 6f2d687..d6ebfc5 100644
--- a/src/Gateways/Asaas/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/Asaas/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\Asaas\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -67,6 +69,14 @@ public function setCustomerId(string $customerId): ChargeInterface;
      */
     public function setCustomer(array $customer): ChargeInterface;
 
+    /**
+     * set the amount of the charge, in reais
+     *
+     * @param Money|int|float $amount
+     * @return ChargeInterface
+     */
+    public function setAmount(Money|int|float $amount): ChargeInterface;
+
     /**
      * set charge
      *
diff --git a/src/Gateways/Cielo/Resources/Charge/Charge.php b/src/Gateways/Cielo/Resources/Charge/Charge.php
index e3ca83b..dce5a39 100644
--- a/src/Gateways/Cielo/Resources/Charge/Charge.php
+++ b/src/Gateways/Cielo/Resources/Charge/Charge.php
@@ -8,6 +8,7 @@
 use PHPay\Cielo\Resources\Charge\Interface\ChargeInterface;
 use PHPay\Cielo\Traits\HasCieloClient;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 
 /**
  * sales of the Cielo E-commerce API 3.0.
@@ -107,11 +108,11 @@ public function setCustomer(array $customer): ChargeInterface
      * @param int $amount amount in cents
      * @return ChargeInterface
      */
-    public function setPix(int $amount): ChargeInterface
+    public function setPix(Money|int $amount): ChargeInterface
     {
         $this->sale['Payment'] = [
             'Type'   => PaymentTypeEnum::PIX->value,
-            'Amount' => $amount,
+            'Amount' => Money::asCentavos($amount),
         ];
 
         return $this;
@@ -124,11 +125,11 @@ public function setPix(int $amount): ChargeInterface
      * @param array<mixed> $options extra Payment fields, such as Demonstrative
      * @return ChargeInterface
      */
-    public function setBoleto(int $amount, array $options = []): ChargeInterface
+    public function setBoleto(Money|int $amount, array $options = []): ChargeInterface
     {
         $this->sale['Payment'] = array_merge([
             'Type'   => PaymentTypeEnum::BOLETO->value,
-            'Amount' => $amount,
+            'Amount' => Money::asCentavos($amount),
         ], $options);
 
         return $this;
@@ -144,14 +145,14 @@ public function setBoleto(int $amount, array $options = []): ChargeInterface
      * @return ChargeInterface
      */
     public function setCreditCard(
-        int $amount,
+        Money|int $amount,
         array $card,
         int $installments = 1,
         bool $capture = false
     ): ChargeInterface {
         $this->sale['Payment'] = [
             'Type'         => PaymentTypeEnum::CREDIT_CARD->value,
-            'Amount'       => $amount,
+            'Amount'       => Money::asCentavos($amount),
             'Installments' => $installments,
             'Capture'      => $capture,
             'CreditCard'   => $card,
@@ -268,9 +269,9 @@ public function getPixCode(string $paymentId): ?string
      * @return array<mixed>
      * @throws ApiException
      */
-    public function capture(string $paymentId, ?int $amount = null): array
+    public function capture(string $paymentId, Money|int|null $amount = null): array
     {
-        $query = $amount === null ? '' : '?amount=' . $amount;
+        $query = $amount === null ? '' : '?amount=' . Money::asCentavos($amount);
 
         return $this->put("1/sales/{$paymentId}/capture{$query}");
     }
@@ -286,9 +287,9 @@ public function capture(string $paymentId, ?int $amount = null): array
      * @return array<mixed>
      * @throws ApiException
      */
-    public function cancel(string $paymentId, ?int $amount = null): array
+    public function cancel(string $paymentId, Money|int|null $amount = null): array
     {
-        $query = $amount === null ? '' : '?amount=' . $amount;
+        $query = $amount === null ? '' : '?amount=' . Money::asCentavos($amount);
 
         return $this->put("1/sales/{$paymentId}/void{$query}");
     }
diff --git a/src/Gateways/Cielo/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/Cielo/Resources/Charge/Interface/ChargeInterface.php
index cc01533..e0904ad 100644
--- a/src/Gateways/Cielo/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/Cielo/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\Cielo\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -34,7 +36,7 @@ public function setCustomer(array $customer): ChargeInterface;
      * @param int $amount amount in cents
      * @return ChargeInterface
      */
-    public function setPix(int $amount): ChargeInterface;
+    public function setPix(Money|int $amount): ChargeInterface;
 
     /**
      * pay with boleto
@@ -43,7 +45,7 @@ public function setPix(int $amount): ChargeInterface;
      * @param array<mixed> $options
      * @return ChargeInterface
      */
-    public function setBoleto(int $amount, array $options = []): ChargeInterface;
+    public function setBoleto(Money|int $amount, array $options = []): ChargeInterface;
 
     /**
      * pay with a credit card
@@ -55,7 +57,7 @@ public function setBoleto(int $amount, array $options = []): ChargeInterface;
      * @return ChargeInterface
      */
     public function setCreditCard(
-        int $amount,
+        Money|int $amount,
         array $card,
         int $installments = 1,
         bool $capture = false
@@ -115,7 +117,7 @@ public function getPixCode(string $paymentId): ?string;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function capture(string $paymentId, ?int $amount = null): array;
+    public function capture(string $paymentId, Money|int|null $amount = null): array;
 
     /**
      * cancel or refund a sale
@@ -124,5 +126,5 @@ public function capture(string $paymentId, ?int $amount = null): array;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function cancel(string $paymentId, ?int $amount = null): array;
+    public function cancel(string $paymentId, Money|int|null $amount = null): array;
 }
diff --git a/src/Gateways/Cielo/Resources/Subscription/Interface/SubscriptionInterface.php b/src/Gateways/Cielo/Resources/Subscription/Interface/SubscriptionInterface.php
index 513ef53..e13f281 100644
--- a/src/Gateways/Cielo/Resources/Subscription/Interface/SubscriptionInterface.php
+++ b/src/Gateways/Cielo/Resources/Subscription/Interface/SubscriptionInterface.php
@@ -3,6 +3,7 @@
 namespace PHPay\Cielo\Resources\Subscription\Interface;
 
 use PHPay\Cielo\Enums\RecurrentIntervalEnum;
+use PHPay\Support\Money;
 
 interface SubscriptionInterface
 {
@@ -52,7 +53,7 @@ public function setEndDate(string $endDate): SubscriptionInterface;
      * @param int $amount amount in cents
      * @return array<mixed>
      */
-    public function create(int $amount): array;
+    public function create(Money|int $amount): array;
 
     /**
      * find a recurrence by id
@@ -85,7 +86,7 @@ public function reactivate(string $recurrentPaymentId): array;
      * @param int $amount amount in cents
      * @return array<mixed>
      */
-    public function updateAmount(string $recurrentPaymentId, int $amount): array;
+    public function updateAmount(string $recurrentPaymentId, Money|int $amount): array;
 
     /**
      * change how often the recurrence charges
diff --git a/src/Gateways/Cielo/Resources/Subscription/Subscription.php b/src/Gateways/Cielo/Resources/Subscription/Subscription.php
index f5438ed..a163c6d 100644
--- a/src/Gateways/Cielo/Resources/Subscription/Subscription.php
+++ b/src/Gateways/Cielo/Resources/Subscription/Subscription.php
@@ -8,6 +8,7 @@
 use PHPay\Cielo\Resources\Subscription\Interface\SubscriptionInterface;
 use PHPay\Cielo\Traits\HasCieloClient;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 
 /**
  * recurrences of the Cielo E-commerce API 3.0.
@@ -135,7 +136,7 @@ public function setEndDate(string $endDate): SubscriptionInterface
      * @return array<mixed>
      * @throws ValidationException|ApiException
      */
-    public function create(int $amount): array
+    public function create(Money|int $amount): array
     {
         $this->sale['MerchantOrderId'] = $this->sale['MerchantOrderId'] ?? uniqid('phpay_');
 
@@ -146,7 +147,7 @@ public function create(int $amount): array
 
         $this->sale['Payment'] = [
             'Type'             => PaymentTypeEnum::CREDIT_CARD->value,
-            'Amount'           => $amount,
+            'Amount'           => Money::asCentavos($amount),
             'Installments'     => 1,
             'CreditCard'       => $this->card,
             'RecurrentPayment' => $recurrent,
@@ -201,11 +202,13 @@ public function reactivate(string $recurrentPaymentId): array
      * @return array<mixed>
      * @throws ValidationException|ApiException
      */
-    public function updateAmount(string $recurrentPaymentId, int $amount): array
+    public function updateAmount(string $recurrentPaymentId, Money|int $amount): array
     {
-        CieloRecurrentRequest::validateAmount($amount);
+        $centavos = Money::asCentavos($amount);
 
-        return $this->putValue("1/RecurrentPayment/{$recurrentPaymentId}/Amount", $amount);
+        CieloRecurrentRequest::validateAmount($centavos);
+
+        return $this->putValue("1/RecurrentPayment/{$recurrentPaymentId}/Amount", $centavos);
     }
 
     /**
diff --git a/src/Gateways/Efi/Resources/Charge/Charge.php b/src/Gateways/Efi/Resources/Charge/Charge.php
index 093f7aa..64b1cfd 100644
--- a/src/Gateways/Efi/Resources/Charge/Charge.php
+++ b/src/Gateways/Efi/Resources/Charge/Charge.php
@@ -7,6 +7,7 @@
 use PHPay\Efi\Resources\Charge\Interface\ChargeInterface;
 use PHPay\Efi\Traits\HasEfiClient;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 
 class Charge implements ChargeInterface
 {
@@ -80,6 +81,22 @@ public function setCustomer(array $customer): Charge
         return $this;
     }
 
+    /**
+     * set the amount of the charge.
+     *
+     * Efí takes cents as an integer — pass a Money and the unit is handled
+     * for you, or a raw integer, which is read as cents.
+     *
+     * @param Money|int $amount
+     * @return ChargeInterface
+     */
+    public function setAmount(Money|int $amount): ChargeInterface
+    {
+        $this->charge['value'] = Money::asCentavos($amount);
+
+        return $this;
+    }
+
     /**
      * set filters
      *
diff --git a/src/Gateways/Efi/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/Efi/Resources/Charge/Interface/ChargeInterface.php
index 9a2f49d..2d4ef23 100644
--- a/src/Gateways/Efi/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/Efi/Resources/Charge/Interface/ChargeInterface.php
@@ -3,9 +3,18 @@
 namespace PHPay\Efi\Resources\Charge\Interface;
 
 use PHPay\Efi\Resources\Charge\Charge;
+use PHPay\Support\Money;
 
 interface ChargeInterface
 {
+    /**
+     * set the amount of the charge, in cents
+     *
+     * @param Money|int $amount
+     * @return ChargeInterface
+     */
+    public function setAmount(Money|int $amount): ChargeInterface;
+
     /**
      * get all charges
      *
diff --git a/src/Gateways/MercadoPago/Resources/Charge/Charge.php b/src/Gateways/MercadoPago/Resources/Charge/Charge.php
index a423ffb..c316a05 100644
--- a/src/Gateways/MercadoPago/Resources/Charge/Charge.php
+++ b/src/Gateways/MercadoPago/Resources/Charge/Charge.php
@@ -7,6 +7,7 @@
 use PHPay\MercadoPago\Requests\MercadoPagoChargeRequest;
 use PHPay\MercadoPago\Resources\Charge\Interface\ChargeInterface;
 use PHPay\MercadoPago\Traits\HasMercadoPagoClient;
+use PHPay\Support\Money;
 
 class Charge implements ChargeInterface
 {
@@ -61,6 +62,22 @@ public function setCharge(array $charge): ChargeInterface
         return $this;
     }
 
+    /**
+     * set the amount of the charge.
+     *
+     * Mercado Pago takes reais as a decimal — pass a Money and the unit is
+     * handled for you, or a raw number, which is read as reais.
+     *
+     * @param Money|int|float $amount
+     * @return ChargeInterface
+     */
+    public function setAmount(Money|int|float $amount): ChargeInterface
+    {
+        $this->charge['transaction_amount'] = Money::asReais($amount);
+
+        return $this;
+    }
+
     /**
      * set the payer of the charge.
      *
diff --git a/src/Gateways/MercadoPago/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/MercadoPago/Resources/Charge/Interface/ChargeInterface.php
index ef9fdf1..b74915c 100644
--- a/src/Gateways/MercadoPago/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/MercadoPago/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\MercadoPago\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -12,6 +14,14 @@ interface ChargeInterface
      */
     public function setCharge(array $charge): ChargeInterface;
 
+    /**
+     * set the amount of the charge, in reais
+     *
+     * @param Money|int|float $amount
+     * @return ChargeInterface
+     */
+    public function setAmount(Money|int|float $amount): ChargeInterface;
+
     /**
      * set the payer of the charge
      *
diff --git a/src/Gateways/PagBank/Resources/Charge/Charge.php b/src/Gateways/PagBank/Resources/Charge/Charge.php
index 14fd37b..ac67039 100644
--- a/src/Gateways/PagBank/Resources/Charge/Charge.php
+++ b/src/Gateways/PagBank/Resources/Charge/Charge.php
@@ -7,6 +7,7 @@
 use PHPay\PagBank\Requests\PagBankOrderRequest;
 use PHPay\PagBank\Resources\Charge\Interface\ChargeInterface;
 use PHPay\PagBank\Traits\HasPagBankClient;
+use PHPay\Support\Money;
 
 /**
  * orders and charges of the PagBank Orders API.
@@ -96,7 +97,7 @@ public function setItems(array $items): ChargeInterface
      * @param int $quantity
      * @return ChargeInterface
      */
-    public function addItem(string $name, int $unitAmount, int $quantity = 1): ChargeInterface
+    public function addItem(string $name, Money|int $unitAmount, int $quantity = 1): ChargeInterface
     {
         $items = $this->order['items'] ?? [];
 
@@ -108,7 +109,7 @@ public function addItem(string $name, int $unitAmount, int $quantity = 1): Charg
             'reference_id' => uniqid('item_'),
             'name'         => $name,
             'quantity'     => $quantity,
-            'unit_amount'  => $unitAmount,
+            'unit_amount'  => Money::asCentavos($unitAmount),
         ];
 
         $this->order['items'] = $items;
@@ -141,9 +142,9 @@ public function setCharges(array $charges): ChargeInterface
      * @param string|null $expiresAt defaults to 23:59:59 of the next day
      * @return ChargeInterface
      */
-    public function setQrCode(int $amount, ?string $expiresAt = null): ChargeInterface
+    public function setQrCode(Money|int $amount, ?string $expiresAt = null): ChargeInterface
     {
-        $qrCode = ['amount' => ['value' => $amount]];
+        $qrCode = ['amount' => ['value' => Money::asCentavos($amount)]];
 
         if ($expiresAt !== null) {
             $qrCode['expiration_date'] = $expiresAt;
@@ -265,11 +266,11 @@ public function getPixCode(string $id): ?string
      * @throws ApiException
      * @see https://developer.pagbank.com.br/reference/cancelar-pagamento
      */
-    public function refund(string $id, ?int $amount = null): array
+    public function refund(string $id, Money|int|null $amount = null): array
     {
         return $this->post(
             "charges/{$id}/cancel",
-            $amount === null ? [] : ['amount' => ['value' => $amount]]
+            $amount === null ? [] : ['amount' => ['value' => Money::asCentavos($amount)]]
         );
     }
 }
diff --git a/src/Gateways/PagBank/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/PagBank/Resources/Charge/Interface/ChargeInterface.php
index 580c5cb..4ade719 100644
--- a/src/Gateways/PagBank/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/PagBank/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\PagBank\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -36,7 +38,7 @@ public function setItems(array $items): ChargeInterface;
      * @param int $quantity
      * @return ChargeInterface
      */
-    public function addItem(string $name, int $unitAmount, int $quantity = 1): ChargeInterface;
+    public function addItem(string $name, Money|int $unitAmount, int $quantity = 1): ChargeInterface;
 
     /**
      * set the charges of the order (card or boleto)
@@ -53,7 +55,7 @@ public function setCharges(array $charges): ChargeInterface;
      * @param string|null $expiresAt
      * @return ChargeInterface
      */
-    public function setQrCode(int $amount, ?string $expiresAt = null): ChargeInterface;
+    public function setQrCode(Money|int $amount, ?string $expiresAt = null): ChargeInterface;
 
     /**
      * set the urls notified about order events
@@ -109,5 +111,5 @@ public function getPixCode(string $id): ?string;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function refund(string $id, ?int $amount = null): array;
+    public function refund(string $id, Money|int|null $amount = null): array;
 }
diff --git a/src/Gateways/PagarMe/Resources/Charge/Charge.php b/src/Gateways/PagarMe/Resources/Charge/Charge.php
index a5d7ea2..2682cb9 100644
--- a/src/Gateways/PagarMe/Resources/Charge/Charge.php
+++ b/src/Gateways/PagarMe/Resources/Charge/Charge.php
@@ -8,6 +8,7 @@
 use PHPay\PagarMe\Requests\PagarMeOrderRequest;
 use PHPay\PagarMe\Resources\Charge\Interface\ChargeInterface;
 use PHPay\PagarMe\Traits\HasPagarMeClient;
+use PHPay\Support\Money;
 
 /**
  * orders and charges of the Pagar.me Core API v5.
@@ -120,7 +121,7 @@ public function setItems(array $items): ChargeInterface
      * @param int $quantity
      * @return ChargeInterface
      */
-    public function addItem(string $description, int $amount, int $quantity = 1): ChargeInterface
+    public function addItem(string $description, Money|int $amount, int $quantity = 1): ChargeInterface
     {
         $items = $this->order['items'] ?? [];
 
@@ -131,7 +132,7 @@ public function addItem(string $description, int $amount, int $quantity = 1): Ch
         $items[] = [
             'code'        => uniqid('item_'),
             'description' => $description,
-            'amount'      => $amount,
+            'amount'      => Money::asCentavos($amount),
             'quantity'    => $quantity,
         ];
 
@@ -318,11 +319,11 @@ public function getPixCode(string $id): ?string
      * @return array<mixed>
      * @throws ApiException
      */
-    public function capture(string $id, ?int $amount = null): array
+    public function capture(string $id, Money|int|null $amount = null): array
     {
         return $this->post(
             "charges/{$id}/capture",
-            $amount === null ? [] : ['amount' => $amount]
+            $amount === null ? [] : ['amount' => Money::asCentavos($amount)]
         );
     }
 
@@ -337,12 +338,12 @@ public function capture(string $id, ?int $amount = null): array
      * @return array<mixed>
      * @throws ApiException
      */
-    public function cancel(string $id, ?int $amount = null): array
+    public function cancel(string $id, Money|int|null $amount = null): array
     {
         return $this->request(
             'DELETE',
             "charges/{$id}",
-            ['json' => $amount === null ? [] : ['amount' => $amount]]
+            ['json' => $amount === null ? [] : ['amount' => Money::asCentavos($amount)]]
         );
     }
 }
diff --git a/src/Gateways/PagarMe/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/PagarMe/Resources/Charge/Interface/ChargeInterface.php
index 35ac7d9..45b3898 100644
--- a/src/Gateways/PagarMe/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/PagarMe/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\PagarMe\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -44,7 +46,7 @@ public function setItems(array $items): ChargeInterface;
      * @param int $quantity
      * @return ChargeInterface
      */
-    public function addItem(string $description, int $amount, int $quantity = 1): ChargeInterface;
+    public function addItem(string $description, Money|int $amount, int $quantity = 1): ChargeInterface;
 
     /**
      * set the payments of the order
@@ -132,7 +134,7 @@ public function getPixCode(string $id): ?string;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function capture(string $id, ?int $amount = null): array;
+    public function capture(string $id, Money|int|null $amount = null): array;
 
     /**
      * cancel a charge, refunding fully or partially
@@ -141,5 +143,5 @@ public function capture(string $id, ?int $amount = null): array;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function cancel(string $id, ?int $amount = null): array;
+    public function cancel(string $id, Money|int|null $amount = null): array;
 }
diff --git a/src/Gateways/Rede/Resources/Charge/Charge.php b/src/Gateways/Rede/Resources/Charge/Charge.php
index b31b7d6..a130293 100644
--- a/src/Gateways/Rede/Resources/Charge/Charge.php
+++ b/src/Gateways/Rede/Resources/Charge/Charge.php
@@ -9,6 +9,7 @@
 use PHPay\Rede\Resources\Authorization\Authorization;
 use PHPay\Rede\Resources\Charge\Interface\ChargeInterface;
 use PHPay\Rede\Traits\HasRedeClient;
+use PHPay\Support\Money;
 
 /**
  * transactions of the e.Rede v2 API.
@@ -113,12 +114,12 @@ public function setCard(
      * @return ChargeInterface
      */
     public function setPayment(
-        int $amount,
+        Money|int $amount,
         TransactionKindEnum $kind = TransactionKindEnum::CREDIT,
         int $installments = 1,
         bool $capture = true
     ): ChargeInterface {
-        $this->transaction['amount']       = $amount;
+        $this->transaction['amount']       = Money::asCentavos($amount);
         $this->transaction['kind']         = $kind->value;
         $this->transaction['installments'] = $installments;
         $this->transaction['capture']      = $capture;
@@ -208,10 +209,10 @@ public function getStatus(string $tid): ?string
      * @return array<mixed>
      * @throws ApiException
      */
-    public function capture(string $tid, ?int $amount = null): array
+    public function capture(string $tid, Money|int|null $amount = null): array
     {
         return $this->request('PUT', "transactions/{$tid}", $this->authorized([
-            'json' => $amount === null ? [] : ['amount' => $amount],
+            'json' => $amount === null ? [] : ['amount' => Money::asCentavos($amount)],
         ]));
     }
 
@@ -223,10 +224,10 @@ public function capture(string $tid, ?int $amount = null): array
      * @return array<mixed>
      * @throws ApiException
      */
-    public function refund(string $tid, ?int $amount = null): array
+    public function refund(string $tid, Money|int|null $amount = null): array
     {
         return $this->request('POST', "transactions/{$tid}/refunds", $this->authorized([
-            'json' => $amount === null ? [] : ['amount' => $amount],
+            'json' => $amount === null ? [] : ['amount' => Money::asCentavos($amount)],
         ]));
     }
 
diff --git a/src/Gateways/Rede/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/Rede/Resources/Charge/Interface/ChargeInterface.php
index a9b529c..fc1927d 100644
--- a/src/Gateways/Rede/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/Rede/Resources/Charge/Interface/ChargeInterface.php
@@ -3,6 +3,7 @@
 namespace PHPay\Rede\Resources\Charge\Interface;
 
 use PHPay\Rede\Enums\TransactionKindEnum;
+use PHPay\Support\Money;
 
 interface ChargeInterface
 {
@@ -50,7 +51,7 @@ public function setCard(
      * @return ChargeInterface
      */
     public function setPayment(
-        int $amount,
+        Money|int $amount,
         TransactionKindEnum $kind = TransactionKindEnum::CREDIT,
         int $installments = 1,
         bool $capture = true
@@ -102,7 +103,7 @@ public function getStatus(string $tid): ?string;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function capture(string $tid, ?int $amount = null): array;
+    public function capture(string $tid, Money|int|null $amount = null): array;
 
     /**
      * refund a transaction, fully or partially
@@ -111,5 +112,5 @@ public function capture(string $tid, ?int $amount = null): array;
      * @param int|null $amount amount in cents
      * @return array<mixed>
      */
-    public function refund(string $tid, ?int $amount = null): array;
+    public function refund(string $tid, Money|int|null $amount = null): array;
 }
diff --git a/src/Gateways/Woovi/Resources/Charge/Charge.php b/src/Gateways/Woovi/Resources/Charge/Charge.php
index e040604..5644851 100644
--- a/src/Gateways/Woovi/Resources/Charge/Charge.php
+++ b/src/Gateways/Woovi/Resources/Charge/Charge.php
@@ -4,6 +4,7 @@
 
 use GuzzleHttp\Client;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 use PHPay\Woovi\Requests\WooviChargeRequest;
 use PHPay\Woovi\Resources\Charge\Interface\ChargeInterface;
 use PHPay\Woovi\Traits\HasWooviClient;
@@ -114,9 +115,9 @@ public function setQueryParams(array $queryParams): ChargeInterface
      * @return array<mixed>
      * @throws ValidationException|ApiException
      */
-    public function create(int $value): array
+    public function create(Money|int $value): array
     {
-        $this->charge['value']         = $value;
+        $this->charge['value']         = Money::asCentavos($value);
         $this->charge['correlationID'] = $this->charge['correlationID'] ?? uniqid('phpay_');
 
         WooviChargeRequest::validate($this->charge);
diff --git a/src/Gateways/Woovi/Resources/Charge/Interface/ChargeInterface.php b/src/Gateways/Woovi/Resources/Charge/Interface/ChargeInterface.php
index 4374d88..7dd67e0 100644
--- a/src/Gateways/Woovi/Resources/Charge/Interface/ChargeInterface.php
+++ b/src/Gateways/Woovi/Resources/Charge/Interface/ChargeInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\Woovi\Resources\Charge\Interface;
 
+use PHPay\Support\Money;
+
 interface ChargeInterface
 {
     /**
@@ -42,7 +44,7 @@ public function setQueryParams(array $queryParams): ChargeInterface;
      * @param int $value amount in cents
      * @return array<mixed>
      */
-    public function create(int $value): array;
+    public function create(Money|int $value): array;
 
     /**
      * find a charge by correlationID or by the gateway id
diff --git a/src/Gateways/Woovi/Resources/Pix/Interface/PixInterface.php b/src/Gateways/Woovi/Resources/Pix/Interface/PixInterface.php
index 173c4d6..723389c 100644
--- a/src/Gateways/Woovi/Resources/Pix/Interface/PixInterface.php
+++ b/src/Gateways/Woovi/Resources/Pix/Interface/PixInterface.php
@@ -2,6 +2,7 @@
 
 namespace PHPay\Woovi\Resources\Pix\Interface;
 
+use PHPay\Support\Money;
 use PHPay\Woovi\Enums\PixKeyTypeEnum;
 
 interface PixInterface
@@ -38,7 +39,7 @@ public function verifyKey(string $key): array;
      * @param string|null $correlationId
      * @return array<mixed>
      */
-    public function staticQrCode(string $name, ?int $value = null, ?string $correlationId = null): array;
+    public function staticQrCode(string $name, Money|int|null $value = null, ?string $correlationId = null): array;
 
     /**
      * list static QR Codes
diff --git a/src/Gateways/Woovi/Resources/Pix/Pix.php b/src/Gateways/Woovi/Resources/Pix/Pix.php
index 37bc3cc..fa90cca 100644
--- a/src/Gateways/Woovi/Resources/Pix/Pix.php
+++ b/src/Gateways/Woovi/Resources/Pix/Pix.php
@@ -4,6 +4,7 @@
 
 use GuzzleHttp\Client;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 use PHPay\Woovi\Enums\PixKeyTypeEnum;
 use PHPay\Woovi\Requests\WooviPixKeyRequest;
 use PHPay\Woovi\Resources\Pix\Interface\PixInterface;
@@ -104,12 +105,12 @@ public function verifyKey(string $key): array
      * @return array<mixed>
      * @throws ValidationException|ApiException
      */
-    public function staticQrCode(string $name, ?int $value = null, ?string $correlationId = null): array
+    public function staticQrCode(string $name, Money|int|null $value = null, ?string $correlationId = null): array
     {
         $payload = ['name' => $name];
 
         if ($value !== null) {
-            $payload['value'] = $value;
+            $payload['value'] = Money::asCentavos($value);
         }
 
         if ($correlationId !== null) {
diff --git a/src/Gateways/Woovi/Resources/Subscription/Interface/SubscriptionInterface.php b/src/Gateways/Woovi/Resources/Subscription/Interface/SubscriptionInterface.php
index 19e1b62..754ba70 100644
--- a/src/Gateways/Woovi/Resources/Subscription/Interface/SubscriptionInterface.php
+++ b/src/Gateways/Woovi/Resources/Subscription/Interface/SubscriptionInterface.php
@@ -2,6 +2,8 @@
 
 namespace PHPay\Woovi\Resources\Subscription\Interface;
 
+use PHPay\Support\Money;
+
 interface SubscriptionInterface
 {
     /**
@@ -26,7 +28,7 @@ public function setDayGenerateCharge(int $day): SubscriptionInterface;
      * @param int $value amount in cents
      * @return array<mixed>
      */
-    public function create(int $value): array;
+    public function create(Money|int $value): array;
 
     /**
      * find a subscription by id
diff --git a/src/Gateways/Woovi/Resources/Subscription/Subscription.php b/src/Gateways/Woovi/Resources/Subscription/Subscription.php
index 28ee532..89cb47d 100644
--- a/src/Gateways/Woovi/Resources/Subscription/Subscription.php
+++ b/src/Gateways/Woovi/Resources/Subscription/Subscription.php
@@ -4,6 +4,7 @@
 
 use GuzzleHttp\Client;
 use PHPay\Exceptions\{ApiException, ValidationException};
+use PHPay\Support\Money;
 use PHPay\Woovi\Requests\WooviSubscriptionRequest;
 use PHPay\Woovi\Resources\Subscription\Interface\SubscriptionInterface;
 use PHPay\Woovi\Traits\HasWooviClient;
@@ -77,9 +78,9 @@ public function setDayGenerateCharge(int $day): SubscriptionInterface
      * @return array<mixed>
      * @throws ValidationException|ApiException
      */
-    public function create(int $value): array
+    public function create(Money|int $value): array
     {
-        $this->subscription['value'] = $value;
+        $this->subscription['value'] = Money::asCentavos($value);
 
         WooviSubscriptionRequest::validate($this->subscription);
 
diff --git a/src/Support/Money.php b/src/Support/Money.php
new file mode 100644
index 0000000..901d88a
--- /dev/null
+++ b/src/Support/Money.php
@@ -0,0 +1,230 @@
+<?php
+
+namespace PHPay\Support;
+
+use PHPay\Exceptions\ValidationException;
+
+/**
+ * a monetary value, held in cents.
+ *
+ * Brazilian gateways disagree on the unit they expect: Asaas and Mercado Pago
+ * take reais as a decimal, while PagBank, Pagar.me, Cielo, Rede, AbacatePay,
+ * Woovi and Efí take cents as an integer. Getting that wrong does not break
+ * the integration — it charges the wrong amount, silently.
+ *
+ * This type ends that. You say which unit you have, the gateway asks for the
+ * unit it needs, and neither side can be wrong:
+ *
+ *     Money::reais(100.50)      // or Money::reais('100,50')
+ *     Money::centavos(10050)
+ */
+final class Money
+{
+    /**
+     * construct
+     *
+     * @param int $cents
+     */
+    private function __construct(
+        private readonly int $cents
+    ) {
+    }
+
+    /**
+     * build from an amount in cents.
+     *
+     * @param int $cents
+     * @return self
+     * @throws ValidationException
+     */
+    public static function centavos(int $cents): self
+    {
+        if ($cents < 0) {
+            throw ValidationException::make('PHPay', self::messages()->negative);
+        }
+
+        return new self($cents);
+    }
+
+    /**
+     * build from an amount in reais.
+     *
+     * accepts a float, an int, or a string in either notation — `'100.50'`
+     * and `'100,50'` both work, which is what a form field usually hands you.
+     *
+     * a value with more than two decimal places is refused rather than
+     * rounded: silent rounding is how one-cent reconciliation bugs are born.
+     * Round it yourself, or use centavos().
+     *
+     * @param int|float|string $amount
+     * @return self
+     * @throws ValidationException
+     */
+    public static function reais(int|float|string $amount): self
+    {
+        $normalized = self::normalize($amount);
+
+        if ($normalized < 0) {
+            throw ValidationException::make('PHPay', self::messages()->negative);
+        }
+
+        $cents = $normalized * 100;
+
+        if (abs($cents - round($cents)) > 0.000001) {
+            throw ValidationException::make('PHPay', self::messages()->precision);
+        }
+
+        return new self((int) round($cents));
+    }
+
+    /**
+     * the amount in cents, for the gateways that take an integer.
+     *
+     * @return int
+     */
+    public function toCentavos(): int
+    {
+        return $this->cents;
+    }
+
+    /**
+     * the amount in reais, for the gateways that take a decimal.
+     *
+     * @return float
+     */
+    public function toReais(): float
+    {
+        return round($this->cents / 100, 2);
+    }
+
+    /**
+     * multiply by a whole number of units — a line of N identical products.
+     *
+     * @param int $times
+     * @return self
+     * @throws ValidationException
+     */
+    public function multiply(int $times): self
+    {
+        if ($times < 0) {
+            throw ValidationException::make('PHPay', self::messages()->negativeMultiplier);
+        }
+
+        return new self($this->cents * $times);
+    }
+
+    /**
+     * add another amount.
+     *
+     * @param self $other
+     * @return self
+     */
+    public function plus(self $other): self
+    {
+        return new self($this->cents + $other->cents);
+    }
+
+    /**
+     * whether two amounts are the same.
+     *
+     * @param self $other
+     * @return bool
+     */
+    public function equals(self $other): bool
+    {
+        return $this->cents === $other->cents;
+    }
+
+    /**
+     * whether the amount is zero.
+     *
+     * @return bool
+     */
+    public function isZero(): bool
+    {
+        return $this->cents === 0;
+    }
+
+    /**
+     * the amount written the way a Brazilian reads it.
+     *
+     * @return string
+     */
+    public function format(): string
+    {
+        return 'R$ ' . number_format($this->toReais(), 2, ',', '.');
+    }
+
+    /**
+     * take whatever a caller passed — a Money, an int, a float — and give
+     * back the cents a gateway needs.
+     *
+     * a bare int is read as cents, which is what the gateways that use this
+     * helper already expected before Money existed.
+     *
+     * @param self|int $amount
+     * @return int
+     * @throws ValidationException
+     */
+    public static function asCentavos(self|int $amount): int
+    {
+        return $amount instanceof self ? $amount->toCentavos() : self::centavos($amount)->toCentavos();
+    }
+
+    /**
+     * take whatever a caller passed and give back the reais a gateway needs.
+     *
+     * a bare int or float is read as reais, which is what the gateways that
+     * use this helper already expected before Money existed.
+     *
+     * @param self|int|float $amount
+     * @return float
+     * @throws ValidationException
+     */
+    public static function asReais(self|int|float $amount): float
+    {
+        return $amount instanceof self ? $amount->toReais() : self::reais($amount)->toReais();
+    }
+
+    /**
+     * messages for validation
+     *
+     * @return object{negative: string, precision: string, notNumeric: string, negativeMultiplier: string}
+     */
+    public static function messages(): object
+    {
+        return (object) [
+            'negative'           => 'Um valor monetário não pode ser negativo.',
+            'precision'          => 'Um valor em reais não pode ter mais de duas casas decimais. Arredonde antes, ou use Money::centavos() para ser exato.',
+            'notNumeric'         => 'O valor precisa ser numérico. Aceita float, int ou string em qualquer notação: "100.50" ou "100,50".',
+            'negativeMultiplier' => 'A quantidade usada em multiply() não pode ser negativa.',
+        ];
+    }
+
+    /**
+     * turn whatever came in into a float in reais.
+     *
+     * @param int|float|string $amount
+     * @return float
+     * @throws ValidationException
+     */
+    private static function normalize(int|float|string $amount): float
+    {
+        if (is_string($amount)) {
+            $limpo = trim($amount);
+
+            /* "1.234,56" vira "1234.56"; "100,50" vira "100.50" */
+            if (str_contains($limpo, ',')) {
+                $limpo = str_replace(['.', ','], ['', '.'], $limpo);
+            }
+
+            if (!is_numeric($limpo)) {
+                throw ValidationException::make('PHPay', self::messages()->notNumeric);
+            }
+
+            return (float) $limpo;
+        }
+
+        return (float) $amount;
+    }
+}
diff --git a/tests/Unit/Support/MoneyAcrossGatewaysTest.php b/tests/Unit/Support/MoneyAcrossGatewaysTest.php
new file mode 100644
index 0000000..7d9f199
--- /dev/null
+++ b/tests/Unit/Support/MoneyAcrossGatewaysTest.php
@@ -0,0 +1,135 @@
+<?php
+
+use PHPay\AbacatePay\Resources\Charge\Charge as AbacateCharge;
+use PHPay\Asaas\Resources\Charge\Charge as AsaasCharge;
+use PHPay\Cielo\Resources\Charge\Charge as CieloCharge;
+use PHPay\Efi\Resources\Charge\Charge as EfiCharge;
+use PHPay\MercadoPago\Resources\Charge\Charge as MpCharge;
+use PHPay\PagarMe\Resources\Charge\Charge as PagarMeCharge;
+use PHPay\PagBank\Resources\Charge\Charge as PagBankCharge;
+use PHPay\Rede\Enums\TransactionKindEnum;
+use PHPay\Rede\RedeGateway;
+use PHPay\Support\Money;
+use PHPay\Woovi\Resources\Charge\Charge as WooviCharge;
+
+/*
+| O ponto do value object: R$ 100,50 é 100.50 em dois gateways e 10050 em sete.
+| O MESMO objeto produz o número certo em cada um, sem quem integra precisar
+| saber qual é qual.
+*/
+
+it('manda reais nos gateways que esperam decimal', function () {
+    $valor = Money::reais(100.50);
+
+    $asaas = [];
+    (new AsaasCharge('token', true, mockClient([jsonResponse([])], $asaas)))
+        ->setCharge(['billingType' => 'PIX', 'dueDate' => '2026-01-10'])
+        ->setCustomerId('cus_1')
+        ->setAmount($valor)
+        ->create();
+
+    $mp = [];
+    (new MpCharge('TEST-token', mockClient([jsonResponse([])], $mp)))
+        ->setCharge(['payment_method_id' => 'pix'])
+        ->setPayer(['email' => 'fale@phpay.io'])
+        ->setAmount($valor)
+        ->create();
+
+    expect(recordedBody($asaas)['value'])->toBe(100.50)
+        ->and(recordedBody($mp)['transaction_amount'])->toBe(100.50);
+})->group('support');
+
+it('manda centavos nos gateways que esperam inteiro', function () {
+    $valor = Money::reais(100.50);
+
+    $pagbank = [];
+    (new PagBankCharge('token', true, mockClient([jsonResponse([])], $pagbank)))
+        ->setCustomer(['name' => 'Mário', 'email' => 'a@b.com', 'tax_id' => '12345678901'])
+        ->addItem('Item', $valor)
+        ->setQrCode($valor)
+        ->create();
+
+    $pagarme = [];
+    (new PagarMeCharge('sk_test_x', mockClient([jsonResponse([])], $pagarme)))
+        ->setCustomerId('cus_1')
+        ->addItem('Item', $valor)
+        ->setPix()
+        ->create();
+
+    $abacate = [];
+    (new AbacateCharge('token', mockClient([jsonResponse([])], $abacate)))
+        ->setCustomerId('cus_1')
+        ->addProduct('p1', 'Item', $valor)
+        ->setUrls('https://a.test/ok', 'https://a.test/volta')
+        ->create();
+
+    $woovi = [];
+    (new WooviCharge('app-id', true, mockClient([jsonResponse([])], $woovi)))
+        ->setCorrelationId('pedido-1')
+        ->create($valor);
+
+    $cielo = [];
+    (new CieloCharge('id', 'key', true, mockClient([jsonResponse([])], $cielo)))
+        ->setCustomer(['Name' => 'Mário'])
+        ->setPix($valor)
+        ->create();
+
+    expect(recordedBody($pagbank)['items'][0]['unit_amount'])->toBe(10050)
+        ->and(recordedBody($pagbank)['qr_codes'][0]['amount']['value'])->toBe(10050)
+        ->and(recordedBody($pagarme)['items'][0]['amount'])->toBe(10050)
+        ->and(recordedBody($abacate)['products'][0]['price'])->toBe(10050)
+        ->and(recordedBody($woovi)['value'])->toBe(10050)
+        ->and(recordedBody($cielo)['Payment']['Amount'])->toBe(10050);
+})->group('support');
+
+it('manda centavos também na rede e no efí', function () {
+    $valor = Money::reais(100.50);
+
+    $rede    = [];
+    $oauth   = [];
+    $gateway = new RedeGateway(
+        'pv',
+        'segredo',
+        true,
+        mockClient([jsonResponse([])], $rede),
+        mockClient([jsonResponse(['access_token' => 'tok', 'expires_in' => 3600])], $oauth)
+    );
+
+    $gateway->charge()
+        ->setReference('pedido-1')
+        ->setCard('5448280000000007', 'M L', '12', '2030', '123')
+        ->setPayment($valor, TransactionKindEnum::CREDIT)
+        ->create();
+
+    $efi = [];
+    (new EfiCharge(['access_token' => 'tok', 'token_type' => 'Bearer'], [
+        'description' => 'Item',
+        'expire_at'   => date('Y-m-d', strtotime('+1 day')),
+    ], true, mockClient([jsonResponse([])], $efi)))
+        ->setAmount($valor)
+        ->setCustomer(['name' => 'Mário', 'cpf_cnpj' => '12345678901'])
+        ->create();
+
+    expect(recordedBody($rede)['amount'])->toBe(10050)
+        ->and(recordedBody($efi)['items'][0]['value'])->toBe(10050);
+})->group('support');
+
+it('número cru continua sendo lido na unidade que o gateway já esperava', function () {
+    /* compatibilidade: quem passava int antes do Money continua funcionando */
+    $pagbank = [];
+    (new PagBankCharge('token', true, mockClient([jsonResponse([])], $pagbank)))
+        ->setCustomer(['name' => 'Mário', 'email' => 'a@b.com', 'tax_id' => '12345678901'])
+        ->addItem('Item', 10050)
+        ->setQrCode(10050)
+        ->create();
+
+    $asaas = [];
+    (new AsaasCharge('token', true, mockClient([jsonResponse([])], $asaas)))
+        ->setCharge(['billingType' => 'PIX', 'dueDate' => '2026-01-10'])
+        ->setCustomerId('cus_1')
+        ->setAmount(100.50)
+        ->create();
+
+    expect(recordedBody($pagbank)['items'][0]['unit_amount'])->toBe(10050)
+        ->and(recordedBody($asaas)['value'])->toBe(100.50);
+})->group('support');
diff --git a/tests/Unit/Support/MoneyTest.php b/tests/Unit/Support/MoneyTest.php
new file mode 100644
index 0000000..790d355
--- /dev/null
+++ b/tests/Unit/Support/MoneyTest.php
@@ -0,0 +1,100 @@
+<?php
+
+use PHPay\Exceptions\ValidationException;
+use PHPay\Support\Money;
+
+it('converte entre reais e centavos sem perder valor', function (int|float|string $reais, int $centavos) {
+    expect(Money::reais($reais)->toCentavos())->toBe($centavos)
+        ->and(Money::centavos($centavos)->toReais())->toBe(round((float) str_replace(',', '.', (string) $reais), 2));
+})->with([
+    [100.50, 10050],
+    [1, 100],
+    [0.07, 7],
+    [0.01, 1],
+    [0, 0],
+    ['100.50', 10050],
+    ['100,50', 10050],
+])->group('support');
+
+it('entende o formato brasileiro com separador de milhar', function () {
+    expect(Money::reais('1.234,56')->toCentavos())->toBe(123456)
+        ->and(Money::reais('1234.56')->toCentavos())->toBe(123456);
+})->group('support');
+
+it('sobrevive à imprecisão de float', function () {
+    /* 0.07 * 100 dá 7.000000000000001 em ponto flutuante */
+    expect(Money::reais(0.07)->toCentavos())->toBe(7)
+        ->and(Money::reais(0.29)->toCentavos())->toBe(29)
+        ->and(Money::reais(1.15)->toCentavos())->toBe(115)
+        ->and(Money::reais(19.99)->toCentavos())->toBe(1999);
+})->group('support');
+
+it('recusa mais de duas casas decimais em vez de arredondar calado', function () {
+    expect(fn () => Money::reais(10 / 3))
+        ->toThrow(ValidationException::class, 'duas casas decimais');
+
+    expect(fn () => Money::reais(1.005))
+        ->toThrow(ValidationException::class, 'duas casas decimais');
+})->group('support');
+
+it('recusa valor negativo', function () {
+    expect(fn () => Money::reais(-1))->toThrow(ValidationException::class, 'não pode ser negativo');
+    expect(fn () => Money::centavos(-1))->toThrow(ValidationException::class, 'não pode ser negativo');
+})->group('support');
+
+it('recusa string que não é número', function () {
+    expect(fn () => Money::reais('cem reais'))
+        ->toThrow(ValidationException::class, 'precisa ser numérico');
+})->group('support');
+
+it('multiplica e soma', function () {
+    $unitario = Money::reais(59.90);
+
+    expect($unitario->multiply(2)->toCentavos())->toBe(11980)
+        ->and($unitario->plus(Money::reais(10))->toCentavos())->toBe(6990)
+        ->and($unitario->multiply(0)->isZero())->toBeTrue();
+
+    expect(fn () => $unitario->multiply(-1))
+        ->toThrow(ValidationException::class, 'não pode ser negativa');
+})->group('support');
+
+it('é imutável: operações devolvem outro objeto', function () {
+    $original = Money::reais(100);
+    $dobro    = $original->multiply(2);
+
+    expect($original->toCentavos())->toBe(10000)
+        ->and($dobro->toCentavos())->toBe(20000)
+        ->and($original)->not->toBe($dobro);
+})->group('support');
+
+it('compara por valor', function () {
+    expect(Money::reais(100.50)->equals(Money::centavos(10050)))->toBeTrue()
+        ->and(Money::reais(100.50)->equals(Money::reais(100.51)))->toBeFalse();
+})->group('support');
+
+it('formata do jeito que se lê no brasil', function () {
+    expect(Money::reais(100.50)->format())->toBe('R$ 100,50')
+        ->and(Money::centavos(1)->format())->toBe('R$ 0,01')
+        ->and(Money::reais(1234.56)->format())->toBe('R$ 1.234,56');
+})->group('support');
+
+it('normaliza o que o gateway recebe, seja Money ou número cru', function () {
+    /* int cru continua sendo lido como centavos, como antes do Money existir */
+    expect(Money::asCentavos(10050))->toBe(10050)
+        ->and(Money::asCentavos(Money::reais(100.50)))->toBe(10050);
+
+    /* e como reais nos gateways que usam decimal */
+    expect(Money::asReais(100.50))->toBe(100.50)
+        ->and(Money::asReais(Money::centavos(10050)))->toBe(100.50);
+})->group('support');
+
+it('impede o erro que motivou o value object', function () {
+    /*
+    | R$ 100,50 num gateway de centavos: quem manda 100.50 cru cobra R$ 1,00.
+    | Com Money, o mesmo objeto dá o número certo para cada unidade.
+    */
+    $valor = Money::reais(100.50);
+
+    expect($valor->toCentavos())->toBe(10050)
+        ->and($valor->toReais())->toBe(100.50);
+})->group('support');