diff --git a/README.md b/README.md
index 1c3a520..221e694 100644
--- a/README.md
+++ b/README.md
@@ -195,23 +195,23 @@ $clientJWT = new Client(
 
 ### Core Methods
 
-| Category           | Method                                               | Description                       |
-| ------------------ | ---------------------------------------------------- | --------------------------------- |
-| **Messages**       | `SendMessage(Message $message)`                      | Send SMS message                  |
-|                    | `GetMessageState(string $id)`                        | Get message status by ID          |
-|                    | `RequestInboxExport(MessagesExportRequest $request)` | Request inbox export via webhooks |
-| **Devices**        | `ListDevices()`                                      | List registered devices           |
-|                    | `RemoveDevice(string $id)`                           | Remove device by ID               |
-| **System**         | `HealthCheck()`                                      | Check API health status           |
-|                    | `GetLogs(?string $from, ?string $to)`                | Retrieve system logs              |
-| **Settings**       | `GetSettings()`                                      | Get account settings              |
-|                    | `PatchSettings(Settings $settings)`                  | Partially update account settings |
-|                    | `ReplaceSettings(Settings $settings)`                | Replace account settings          |
-| **Webhooks**       | `ListWebhooks()`                                     | List registered webhooks          |
-|                    | `RegisterWebhook(Webhook $webhook)`                  | Register new webhook              |
-|                    | `DeleteWebhook(string $id)`                          | Delete webhook by ID              |
-| **Authentication** | `GenerateToken(TokenRequest $request)`               | Generate a new JWT token          |
-|                    | `RevokeToken(string $jti)`                           | Revoke a JWT token by ID          |
+| Category           | Method                                       | Description                       |
+| ------------------ | -------------------------------------------- | --------------------------------- |
+| **Messages**       | `SendMessage(Message $message)`              | Send SMS message                  |
+|                    | `GetMessageState(string $id)`                | Get message status by ID          |
+|                    | `RefreshInbox(InboxRefreshRequest $request)` | Refresh inbox, deliver webhooks   |
+| **Devices**        | `ListDevices()`                              | List registered devices           |
+|                    | `RemoveDevice(string $id)`                   | Remove device by ID               |
+| **System**         | `HealthCheck()`                              | Check API health status           |
+|                    | `GetLogs(?string $from, ?string $to)`        | Retrieve system logs              |
+| **Settings**       | `GetSettings()`                              | Get account settings              |
+|                    | `PatchSettings(Settings $settings)`          | Partially update account settings |
+|                    | `ReplaceSettings(Settings $settings)`        | Replace account settings          |
+| **Webhooks**       | `ListWebhooks()`                             | List registered webhooks          |
+|                    | `RegisterWebhook(Webhook $webhook)`          | Register new webhook              |
+|                    | `DeleteWebhook(string $id)`                  | Delete webhook by ID              |
+| **Authentication** | `GenerateToken(TokenRequest $request)`       | Generate a new JWT token          |
+|                    | `RevokeToken(string $jti)`                   | Revoke a JWT token by ID          |
 
 ### Builder Methods
 ```php
diff --git a/src/Client.php b/src/Client.php
index c15791d..749c435 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -2,6 +2,7 @@
 
 namespace AndroidSmsGateway;
 
+use AndroidSmsGateway\Domain\InboxRefreshRequest;
 use AndroidSmsGateway\Domain\Message;
 use AndroidSmsGateway\Domain\MessageState;
 use AndroidSmsGateway\Domain\Device;
@@ -290,6 +291,7 @@ public function HealthCheck(): object {
     /**
      * Request inbox messages export
      *
+     * @deprecated Use RefreshInbox instead
      * @param MessagesExportRequest $request
      * @return object
      */
@@ -308,6 +310,22 @@ public function RequestInboxExport(MessagesExportRequest $request): object {
         return $response;
     }
 
+    /**
+     * Request inbox messages refresh
+     *
+     * @param InboxRefreshRequest $request
+     * @return void
+     */
+    public function RefreshInbox(InboxRefreshRequest $request): void {
+        $path = '/inbox/refresh';
+
+        $this->sendRequest(
+            'POST',
+            $path,
+            $request
+        );
+    }
+
     /**
      * Get logs within a specified time range
      *
diff --git a/src/Domain/InboxRefreshRequest.php b/src/Domain/InboxRefreshRequest.php
new file mode 100644
index 0000000..18fb66b
--- /dev/null
+++ b/src/Domain/InboxRefreshRequest.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+use AndroidSmsGateway\Enums\IncomingMessageType;
+use AndroidSmsGateway\Enums\WebhookDelivery;
+use AndroidSmsGateway\Interfaces\SerializableInterface;
+
+/**
+ * Inbox refresh request
+ */
+class InboxRefreshRequest implements SerializableInterface {
+    /**
+     * ID of the device to refresh messages for
+     */
+    private ?string $deviceId;
+
+    /**
+     * Start of the time range to refresh
+     */
+    private string $since;
+
+    /**
+     * End of the time range to refresh
+     */
+    private string $until;
+
+    /**
+     * List of message types to refresh
+     *
+     * @var array<int, IncomingMessageType>
+     */
+    private array $messageTypes;
+
+    /**
+     * Delivery mode for webhooks
+     */
+    private ?WebhookDelivery $webhookDelivery;
+
+
+    /**
+     * @param string|null $deviceId
+     * @param string $since
+     * @param string $until
+     * @param array<int, IncomingMessageType> $messageTypes
+     * @param WebhookDelivery|null $webhookDelivery
+     */
+    public function __construct(
+        ?string $deviceId,
+        string $since,
+        string $until,
+        array $messageTypes,
+        ?WebhookDelivery $webhookDelivery = null
+    ) {
+        $this->deviceId = $deviceId;
+        $this->since = $since;
+        $this->until = $until;
+        $this->messageTypes = $messageTypes;
+        $this->webhookDelivery = $webhookDelivery;
+    }
+
+    /**
+     * @return object
+     */
+    public function ToObject(): object {
+        $obj = [
+            'since' => $this->since,
+            'until' => $this->until,
+        ];
+
+        if ($this->deviceId !== null) {
+            $obj['deviceId'] = $this->deviceId;
+        }
+
+        if (!empty($this->messageTypes)) {
+            $obj['messageTypes'] = array_values(array_map(
+                static fn(IncomingMessageType $type): string => $type->Value(),
+                $this->messageTypes
+            ));
+        }
+
+        if ($this->webhookDelivery !== null) {
+            $obj['webhookDelivery'] = $this->webhookDelivery->Value();
+        }
+
+        return (object) $obj;
+    }
+}
diff --git a/src/Domain/MmsBatchDownloadedPayload.php b/src/Domain/MmsBatchDownloadedPayload.php
new file mode 100644
index 0000000..05634e9
--- /dev/null
+++ b/src/Domain/MmsBatchDownloadedPayload.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+/**
+ * Payload of an mms:batch:downloaded event (list of downloaded MMS messages).
+ */
+final class MmsBatchDownloadedPayload {
+    /** @var MmsDownloadedPayload[] */
+    private array $messages;
+
+    /**
+     * @param MmsDownloadedPayload[] $messages
+     */
+    public function __construct(array $messages) {
+        $this->messages = $messages;
+    }
+
+    /**
+     * @param object $obj
+     * @return self
+     */
+    public static function FromObject(object $obj): self {
+        $messages = [];
+        if (isset($obj->messages) && is_array($obj->messages)) {
+            $messages = array_map(
+                static fn($m) => MmsDownloadedPayload::FromObject($m),
+                $obj->messages
+            );
+        }
+
+        return new self($messages);
+    }
+
+    /**
+     * @return MmsDownloadedPayload[]
+     */
+    public function Messages(): array {
+        return $this->messages;
+    }
+}
diff --git a/src/Domain/MmsBatchReceivedPayload.php b/src/Domain/MmsBatchReceivedPayload.php
new file mode 100644
index 0000000..8a34298
--- /dev/null
+++ b/src/Domain/MmsBatchReceivedPayload.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+/**
+ * Payload of an mms:batch:received event (list of received MMS messages).
+ */
+final class MmsBatchReceivedPayload {
+    /** @var MmsReceivedPayload[] */
+    private array $messages;
+
+    /**
+     * @param MmsReceivedPayload[] $messages
+     */
+    public function __construct(array $messages) {
+        $this->messages = $messages;
+    }
+
+    /**
+     * @param object $obj
+     * @return self
+     */
+    public static function FromObject(object $obj): self {
+        $messages = [];
+        if (isset($obj->messages) && is_array($obj->messages)) {
+            $messages = array_map(
+                static fn($m) => MmsReceivedPayload::FromObject($m),
+                $obj->messages
+            );
+        }
+
+        return new self($messages);
+    }
+
+    /**
+     * @return MmsReceivedPayload[]
+     */
+    public function Messages(): array {
+        return $this->messages;
+    }
+}
diff --git a/src/Domain/SmsBatchDataReceivedPayload.php b/src/Domain/SmsBatchDataReceivedPayload.php
new file mode 100644
index 0000000..da1f300
--- /dev/null
+++ b/src/Domain/SmsBatchDataReceivedPayload.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+/**
+ * Payload of an sms:batch:data-received event (list of received data SMS messages).
+ */
+final class SmsBatchDataReceivedPayload {
+    /** @var SmsDataReceivedPayload[] */
+    private array $messages;
+
+    /**
+     * @param SmsDataReceivedPayload[] $messages
+     */
+    public function __construct(array $messages) {
+        $this->messages = $messages;
+    }
+
+    /**
+     * @param object $obj
+     * @return self
+     */
+    public static function FromObject(object $obj): self {
+        $messages = [];
+        if (isset($obj->messages) && is_array($obj->messages)) {
+            $messages = array_map(
+                static fn($m) => SmsDataReceivedPayload::FromObject($m),
+                $obj->messages
+            );
+        }
+
+        return new self($messages);
+    }
+
+    /**
+     * @return SmsDataReceivedPayload[]
+     */
+    public function Messages(): array {
+        return $this->messages;
+    }
+}
diff --git a/src/Domain/SmsBatchReceivedPayload.php b/src/Domain/SmsBatchReceivedPayload.php
new file mode 100644
index 0000000..5ae0ca2
--- /dev/null
+++ b/src/Domain/SmsBatchReceivedPayload.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+/**
+ * Payload of an sms:batch:received event (list of received SMS messages).
+ */
+final class SmsBatchReceivedPayload {
+    /** @var SmsReceivedPayload[] */
+    private array $messages;
+
+    /**
+     * @param SmsReceivedPayload[] $messages
+     */
+    public function __construct(array $messages) {
+        $this->messages = $messages;
+    }
+
+    /**
+     * @param object $obj
+     * @return self
+     */
+    public static function FromObject(object $obj): self {
+        $messages = [];
+        if (isset($obj->messages) && is_array($obj->messages)) {
+            $messages = array_map(
+                static fn($m) => SmsReceivedPayload::FromObject($m),
+                $obj->messages
+            );
+        }
+
+        return new self($messages);
+    }
+
+    /**
+     * @return SmsReceivedPayload[]
+     */
+    public function Messages(): array {
+        return $this->messages;
+    }
+}
diff --git a/src/Domain/SmsDataReceivedPayload.php b/src/Domain/SmsDataReceivedPayload.php
new file mode 100644
index 0000000..305ed93
--- /dev/null
+++ b/src/Domain/SmsDataReceivedPayload.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+/**
+ * Payload of an sms:data-received event (base64-encoded content).
+ */
+final class SmsDataReceivedPayload {
+    private string $messageId;
+    private string $phoneNumber;
+    private string $sender;
+    private ?string $recipient;
+    private ?int $simNumber;
+    private string $data;
+    private string $receivedAt;
+
+    public function __construct(
+        string $messageId,
+        string $phoneNumber,
+        string $sender,
+        ?string $recipient,
+        ?int $simNumber,
+        string $data,
+        string $receivedAt
+    ) {
+        $this->messageId = $messageId;
+        $this->phoneNumber = $phoneNumber;
+        $this->sender = $sender;
+        $this->recipient = $recipient;
+        $this->simNumber = $simNumber;
+        $this->data = $data;
+        $this->receivedAt = $receivedAt;
+    }
+
+    /**
+     * @param object $obj
+     * @return self
+     */
+    public static function FromObject(object $obj): self {
+        return new self(
+            $obj->messageId,
+            $obj->phoneNumber,
+            $obj->sender,
+            $obj->recipient ?? null,
+            $obj->simNumber ?? null,
+            $obj->data,
+            $obj->receivedAt
+        );
+    }
+
+    public function MessageId(): string {
+        return $this->messageId;
+    }
+
+    public function PhoneNumber(): string {
+        return $this->phoneNumber;
+    }
+
+    public function Sender(): string {
+        return $this->sender;
+    }
+
+    public function Recipient(): ?string {
+        return $this->recipient;
+    }
+
+    public function SimNumber(): ?int {
+        return $this->simNumber;
+    }
+
+    public function Data(): string {
+        return $this->data;
+    }
+
+    public function ReceivedAt(): string {
+        return $this->receivedAt;
+    }
+}
diff --git a/src/Domain/SmsReceivedPayload.php b/src/Domain/SmsReceivedPayload.php
new file mode 100644
index 0000000..8a8a307
--- /dev/null
+++ b/src/Domain/SmsReceivedPayload.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace AndroidSmsGateway\Domain;
+
+/**
+ * Payload of an sms:received event.
+ */
+final class SmsReceivedPayload {
+    private string $messageId;
+    private string $phoneNumber;
+    private string $sender;
+    private ?string $recipient;
+    private ?int $simNumber;
+    private string $message;
+    private string $receivedAt;
+
+    public function __construct(
+        string $messageId,
+        string $phoneNumber,
+        string $sender,
+        ?string $recipient,
+        ?int $simNumber,
+        string $message,
+        string $receivedAt
+    ) {
+        $this->messageId = $messageId;
+        $this->phoneNumber = $phoneNumber;
+        $this->sender = $sender;
+        $this->recipient = $recipient;
+        $this->simNumber = $simNumber;
+        $this->message = $message;
+        $this->receivedAt = $receivedAt;
+    }
+
+    /**
+     * @param object $obj
+     * @return self
+     */
+    public static function FromObject(object $obj): self {
+        return new self(
+            $obj->messageId,
+            $obj->phoneNumber,
+            $obj->sender,
+            $obj->recipient ?? null,
+            $obj->simNumber ?? null,
+            $obj->message,
+            $obj->receivedAt
+        );
+    }
+
+    public function MessageId(): string {
+        return $this->messageId;
+    }
+
+    public function PhoneNumber(): string {
+        return $this->phoneNumber;
+    }
+
+    public function Sender(): string {
+        return $this->sender;
+    }
+
+    public function Recipient(): ?string {
+        return $this->recipient;
+    }
+
+    public function SimNumber(): ?int {
+        return $this->simNumber;
+    }
+
+    public function Message(): string {
+        return $this->message;
+    }
+
+    public function ReceivedAt(): string {
+        return $this->receivedAt;
+    }
+}
diff --git a/src/Enums/IncomingMessageType.php b/src/Enums/IncomingMessageType.php
new file mode 100644
index 0000000..d9daf55
--- /dev/null
+++ b/src/Enums/IncomingMessageType.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace AndroidSmsGateway\Enums;
+
+final class IncomingMessageType {
+    public const SMS = 'SMS';
+    public const DATA_SMS = 'DATA_SMS';
+    public const MMS = 'MMS';
+    public const MMS_DOWNLOADED = 'MMS_DOWNLOADED';
+
+    private const _ALL_ = [
+        self::SMS,
+        self::DATA_SMS,
+        self::MMS,
+        self::MMS_DOWNLOADED,
+    ];
+
+    private string $value;
+
+    private function __construct(string $value) {
+        if (!in_array($value, self::_ALL_)) {
+            throw new \InvalidArgumentException('Invalid value');
+        }
+
+        $this->value = $value;
+    }
+
+    public static function SMS(): self {
+        return new self(self::SMS);
+    }
+
+    public static function DATA_SMS(): self {
+        return new self(self::DATA_SMS);
+    }
+
+    public static function MMS(): self {
+        return new self(self::MMS);
+    }
+
+    public static function MMS_DOWNLOADED(): self {
+        return new self(self::MMS_DOWNLOADED);
+    }
+
+    public static function FromValue(string $value): self {
+        return new self($value);
+    }
+
+    public function Value(): string {
+        return $this->value;
+    }
+
+    public function __toString(): string {
+        return $this->value;
+    }
+}
diff --git a/src/Enums/WebhookDelivery.php b/src/Enums/WebhookDelivery.php
new file mode 100644
index 0000000..b9ef658
--- /dev/null
+++ b/src/Enums/WebhookDelivery.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace AndroidSmsGateway\Enums;
+
+final class WebhookDelivery {
+    public const DISABLED = 'Disabled';
+    public const INDIVIDUAL = 'Individual';
+    public const BATCH = 'Batch';
+
+    private const _ALL_ = [
+        self::DISABLED,
+        self::INDIVIDUAL,
+        self::BATCH,
+    ];
+
+    private string $value;
+
+    private function __construct(string $value) {
+        if (!in_array($value, self::_ALL_)) {
+            throw new \InvalidArgumentException('Invalid value');
+        }
+
+        $this->value = $value;
+    }
+
+    public static function DISABLED(): self {
+        return new self(self::DISABLED);
+    }
+
+    public static function INDIVIDUAL(): self {
+        return new self(self::INDIVIDUAL);
+    }
+
+    public static function BATCH(): self {
+        return new self(self::BATCH);
+    }
+
+    public static function FromValue(string $value): self {
+        return new self($value);
+    }
+
+    public function Value(): string {
+        return $this->value;
+    }
+
+    public function __toString(): string {
+        return $this->value;
+    }
+}
diff --git a/src/Enums/WebhookEvent.php b/src/Enums/WebhookEvent.php
index 353dbd1..8c021cd 100644
--- a/src/Enums/WebhookEvent.php
+++ b/src/Enums/WebhookEvent.php
@@ -12,6 +12,10 @@ final class WebhookEvent {
     public const APP_STARTED = 'app:started';
     public const MMS_RECEIVED = 'mms:received';
     public const MMS_DOWNLOADED = 'mms:downloaded';
+    public const SMS_BATCH_RECEIVED = 'sms:batch:received';
+    public const SMS_DATA_BATCH_RECEIVED = 'sms:batch:data-received';
+    public const MMS_BATCH_RECEIVED = 'mms:batch:received';
+    public const MMS_BATCH_DOWNLOADED = 'mms:batch:downloaded';
 
     private const _ALL_ = [
         self::SMS_RECEIVED,
@@ -23,6 +27,10 @@ final class WebhookEvent {
         self::APP_STARTED,
         self::MMS_RECEIVED,
         self::MMS_DOWNLOADED,
+        self::SMS_BATCH_RECEIVED,
+        self::SMS_DATA_BATCH_RECEIVED,
+        self::MMS_BATCH_RECEIVED,
+        self::MMS_BATCH_DOWNLOADED,
     ];
 
     private string $value;
@@ -71,6 +79,22 @@ public static function MMS_DOWNLOADED(): self {
         return new self(self::MMS_DOWNLOADED);
     }
 
+    public static function SMS_BATCH_RECEIVED(): self {
+        return new self(self::SMS_BATCH_RECEIVED);
+    }
+
+    public static function SMS_DATA_BATCH_RECEIVED(): self {
+        return new self(self::SMS_DATA_BATCH_RECEIVED);
+    }
+
+    public static function MMS_BATCH_RECEIVED(): self {
+        return new self(self::MMS_BATCH_RECEIVED);
+    }
+
+    public static function MMS_BATCH_DOWNLOADED(): self {
+        return new self(self::MMS_BATCH_DOWNLOADED);
+    }
+
     public static function FromValue(string $value): self {
         return new self($value);
     }
diff --git a/tests/ClientTest.php b/tests/ClientTest.php
index 6ad4955..4bbf742 100644
--- a/tests/ClientTest.php
+++ b/tests/ClientTest.php
@@ -3,6 +3,7 @@
 namespace AndroidSmsGateway\Tests;
 
 use AndroidSmsGateway\Client;
+use AndroidSmsGateway\Domain\InboxRefreshRequest;
 use AndroidSmsGateway\Domain\Message;
 use AndroidSmsGateway\Domain\MessagesExportRequest;
 use AndroidSmsGateway\Domain\MessageState;
@@ -10,8 +11,11 @@
 use AndroidSmsGateway\Domain\Webhook;
 use AndroidSmsGateway\Domain\TokenRequest;
 use AndroidSmsGateway\Domain\TokenResponse;
+use AndroidSmsGateway\Enums\IncomingMessageType;
 use AndroidSmsGateway\Enums\ProcessState;
+use AndroidSmsGateway\Enums\WebhookDelivery;
 use AndroidSmsGateway\Enums\WebhookEvent;
+use AndroidSmsGateway\Exceptions\HttpException;
 use Http\Client\Curl\Client as CurlClient;
 use Http\Discovery\Psr17FactoryDiscovery;
 use Http\Mock\Client as MockClient;
@@ -253,6 +257,90 @@ public function testRequestInboxExport(): void {
         $this->assertEquals('accepted', $result->status);
     }
 
+    public function testRefreshInbox(): void {
+        $request = new InboxRefreshRequest(
+            null,
+            '2020-01-01T00:00:00Z',
+            '2020-01-02T00:00:00Z',
+            [IncomingMessageType::SMS(), IncomingMessageType::DATA_SMS()],
+            WebhookDelivery::BATCH()
+        );
+
+        $responseMock = self::mockResponse('', 202);
+
+        $this->mockClient->addResponse($responseMock);
+
+        $this->client->RefreshInbox($request);
+        $req = $this->mockClient->getLastRequest();
+        $this->assertEquals('POST', $req->getMethod());
+        $this->assertEquals('/3rdparty/v1/inbox/refresh', $req->getUri()->getPath());
+        $this->assertEquals(
+            'Basic ' . base64_encode(self::MOCK_LOGIN . ':' . self::MOCK_PASSWORD),
+            $req->getHeaderLine('Authorization')
+        );
+        $this->assertEquals(
+            'application/json',
+            $req->getHeaderLine('Content-Type')
+        );
+
+        $body = json_decode((string) $req->getBody(), true);
+        $this->assertIsArray($body);
+        $this->assertEquals('Batch', $body['webhookDelivery']);
+        $this->assertEquals('2020-01-01T00:00:00Z', $body['since']);
+        $this->assertEquals('2020-01-02T00:00:00Z', $body['until']);
+        $this->assertEquals(['SMS', 'DATA_SMS'], $body['messageTypes']);
+    }
+
+    public function testRefreshInboxServerError(): void {
+        $request = new InboxRefreshRequest(
+            null,
+            '2020-01-01T00:00:00Z',
+            '2020-01-02T00:00:00Z',
+            [IncomingMessageType::SMS()],
+            WebhookDelivery::BATCH()
+        );
+
+        $responseMock = self::mockResponse(
+            '{"message":"internal error"}',
+            500,
+            ['Content-Type' => 'application/json']
+        );
+
+        $this->mockClient->addResponse($responseMock);
+
+        try {
+            $this->client->RefreshInbox($request);
+            $this->fail('Expected HttpException to be thrown');
+        } catch (HttpException $e) {
+            $this->assertSame(500, $e->getCode());
+            $this->assertSame(500, $e->getResponse()->getStatusCode());
+        }
+    }
+
+    public function testRefreshInboxClientError(): void {
+        $request = new InboxRefreshRequest(
+            null,
+            '2020-01-01T00:00:00Z',
+            '2020-01-02T00:00:00Z',
+            [],
+        );
+
+        $responseMock = self::mockResponse(
+            '{"message":"invalid request"}',
+            400,
+            ['Content-Type' => 'application/json']
+        );
+
+        $this->mockClient->addResponse($responseMock);
+
+        try {
+            $this->client->RefreshInbox($request);
+            $this->fail('Expected HttpException to be thrown');
+        } catch (HttpException $e) {
+            $this->assertSame(400, $e->getCode());
+        }
+    }
+
     public function testGetLogs(): void {
         $responseMock = self::mockResponse(
             '[{"id":1,"message":"Test log","module":"test","priority":"INFO","createdAt":"2020-01-01T00:00:00Z"}]',
diff --git a/tests/Domain/InboxRefreshRequestTest.php b/tests/Domain/InboxRefreshRequestTest.php
new file mode 100644
index 0000000..bd03ad1
--- /dev/null
+++ b/tests/Domain/InboxRefreshRequestTest.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\InboxRefreshRequest;
+use AndroidSmsGateway\Enums\IncomingMessageType;
+use AndroidSmsGateway\Enums\WebhookDelivery;
+use PHPUnit\Framework\TestCase;
+
+class InboxRefreshRequestTest extends TestCase {
+    public function testToObjectOmitsUnsetFields(): void {
+        $request = new InboxRefreshRequest(
+            null,
+            '2026-01-01T00:00:00Z',
+            '2026-01-02T00:00:00Z',
+            [],
+            null
+        );
+
+        $this->assertSame([
+            'since' => '2026-01-01T00:00:00Z',
+            'until' => '2026-01-02T00:00:00Z',
+        ], $this->decode($request));
+    }
+
+    public function testToObjectEmitsSetFields(): void {
+        $request = new InboxRefreshRequest(
+            'dev-123',
+            '2026-01-01T00:00:00Z',
+            '2026-01-02T00:00:00Z',
+            [IncomingMessageType::SMS(), IncomingMessageType::DATA_SMS()],
+            WebhookDelivery::BATCH()
+        );
+
+        $this->assertSame([
+            'since' => '2026-01-01T00:00:00Z',
+            'until' => '2026-01-02T00:00:00Z',
+            'deviceId' => 'dev-123',
+            'messageTypes' => ['SMS', 'DATA_SMS'],
+            'webhookDelivery' => 'Batch',
+        ], $this->decode($request));
+    }
+
+    public function testToObjectEmitsWebhookDeliveryOnly(): void {
+        $request = new InboxRefreshRequest(
+            null,
+            '2026-01-01T00:00:00Z',
+            '2026-01-02T00:00:00Z',
+            [],
+            WebhookDelivery::INDIVIDUAL()
+        );
+
+        $this->assertSame([
+            'since' => '2026-01-01T00:00:00Z',
+            'until' => '2026-01-02T00:00:00Z',
+            'webhookDelivery' => 'Individual',
+        ], $this->decode($request));
+    }
+
+    public function testToObjectEmitsSparseMessageTypesAsJsonArray(): void {
+        $request = new InboxRefreshRequest(
+            null,
+            '2026-01-01T00:00:00Z',
+            '2026-01-02T00:00:00Z',
+            [5 => IncomingMessageType::SMS(), 2 => IncomingMessageType::DATA_SMS()],
+            null
+        );
+
+        $this->assertSame(['SMS', 'DATA_SMS'], $this->decode($request)['messageTypes']);
+        $this->assertSame(
+            '{"since":"2026-01-01T00:00:00Z","until":"2026-01-02T00:00:00Z","messageTypes":["SMS","DATA_SMS"]}',
+            json_encode($request->ToObject(), JSON_THROW_ON_ERROR)
+        );
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    private function decode(InboxRefreshRequest $request): array {
+        $json = json_encode($request->ToObject(), JSON_THROW_ON_ERROR);
+
+        /** @var array<string, mixed> $decoded */
+        $decoded = json_decode($json, true);
+
+        return $decoded;
+    }
+}
diff --git a/tests/Domain/IncomingMessageTypeTest.php b/tests/Domain/IncomingMessageTypeTest.php
new file mode 100644
index 0000000..4102718
--- /dev/null
+++ b/tests/Domain/IncomingMessageTypeTest.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Enums\IncomingMessageType;
+use PHPUnit\Framework\TestCase;
+
+class IncomingMessageTypeTest extends TestCase {
+    public function testConstantsRoundtrip(): void {
+        $values = [
+            IncomingMessageType::SMS,
+            IncomingMessageType::DATA_SMS,
+            IncomingMessageType::MMS,
+            IncomingMessageType::MMS_DOWNLOADED,
+        ];
+
+        foreach ($values as $value) {
+            $type = IncomingMessageType::FromValue($value);
+
+            $this->assertSame($value, $type->Value());
+        }
+    }
+
+    public function testFactories(): void {
+        $this->assertSame(IncomingMessageType::SMS, IncomingMessageType::SMS()->Value());
+        $this->assertSame(IncomingMessageType::DATA_SMS, IncomingMessageType::DATA_SMS()->Value());
+        $this->assertSame(IncomingMessageType::MMS, IncomingMessageType::MMS()->Value());
+        $this->assertSame(IncomingMessageType::MMS_DOWNLOADED, IncomingMessageType::MMS_DOWNLOADED()->Value());
+    }
+
+    public function testValue(): void {
+        $type = IncomingMessageType::FromValue(IncomingMessageType::MMS);
+
+        $this->assertSame(IncomingMessageType::MMS, $type->Value());
+    }
+
+    public function testToString(): void {
+        $type = IncomingMessageType::FromValue(IncomingMessageType::DATA_SMS);
+
+        $this->assertSame(IncomingMessageType::DATA_SMS, (string) $type);
+    }
+
+    public function testFromValueInvalid(): void {
+        foreach (['', 'sms', 'TEXT', 'SMS '] as $value) {
+            try {
+                IncomingMessageType::FromValue($value);
+
+                $this->fail('Expected InvalidArgumentException for value "' . $value . '"');
+            } catch (\InvalidArgumentException $e) {
+                $this->assertSame('Invalid value', $e->getMessage());
+            }
+        }
+    }
+}
diff --git a/tests/Domain/MmsBatchDownloadedPayloadTest.php b/tests/Domain/MmsBatchDownloadedPayloadTest.php
new file mode 100644
index 0000000..c6ca8ef
--- /dev/null
+++ b/tests/Domain/MmsBatchDownloadedPayloadTest.php
@@ -0,0 +1,92 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\MmsBatchDownloadedPayload;
+use AndroidSmsGateway\Domain\MmsDownloadedAttachment;
+use AndroidSmsGateway\Domain\MmsDownloadedPayload;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use stdClass;
+
+final class MmsBatchDownloadedPayloadTest extends TestCase {
+    public function testCanBeInstantiated(): void {
+        $payload = new MmsBatchDownloadedPayload([]);
+        $this->assertInstanceOf(MmsBatchDownloadedPayload::class, $payload);
+    }
+
+    public function testFromObjectMapsMessagesToInnerPayloadInstancesWithAttachments(): void {
+        $json = '{"messages":['
+            . '{"messageId":"mms-1","phoneNumber":"+79990001111","sender":"+79990002222","receivedAt":"2026-08-18T10:00:00Z","subject":"Hello","body":"Hello World!","attachments":['
+            . '{"partId":1,"contentType":"image/jpeg","name":"photo.jpg","data":"SGVsbG8gV29ybGQh","size":1024},'
+            . '{"partId":2,"contentType":"audio/amr","name":null,"data":null,"size":null}'
+            . ']},'
+            . '{"messageId":"mms-2","phoneNumber":"+79990003333","sender":"+79990004444","receivedAt":"2026-08-18T10:01:00Z","recipient":"+79990003333","simNumber":1,"attachments":[]},'
+            . '{"messageId":"mms-3","phoneNumber":"+79990005555","sender":"+79990006666","receivedAt":"2026-08-18T10:02:00Z"}'
+            . ']}';
+
+        $batch = MmsBatchDownloadedPayload::FromObject(self::decodeObject($json));
+        $messages = $batch->Messages();
+
+        $this->assertCount(3, $messages);
+        $this->assertContainsOnlyInstancesOf(MmsDownloadedPayload::class, $messages);
+
+        $this->assertSame('mms-1', $messages[0]->MessageId());
+        $this->assertSame('+79990001111', $messages[0]->PhoneNumber());
+        $this->assertSame('+79990002222', $messages[0]->Sender());
+        $this->assertSame('Hello', $messages[0]->Subject());
+        $this->assertSame('Hello World!', $messages[0]->Body());
+        $this->assertNull($messages[0]->Recipient());
+        $this->assertNull($messages[0]->SimNumber());
+        $attachments = $messages[0]->Attachments();
+        $this->assertCount(2, $attachments);
+        $this->assertContainsOnlyInstancesOf(MmsDownloadedAttachment::class, $attachments);
+        $this->assertSame(1, $attachments[0]->PartId());
+        $this->assertSame('image/jpeg', $attachments[0]->ContentType());
+        $this->assertSame('photo.jpg', $attachments[0]->Name());
+        $this->assertSame('SGVsbG8gV29ybGQh', $attachments[0]->Data());
+        $this->assertSame(1024, $attachments[0]->Size());
+        $this->assertSame(2, $attachments[1]->PartId());
+        $this->assertSame('audio/amr', $attachments[1]->ContentType());
+        $this->assertNull($attachments[1]->Name());
+        $this->assertNull($attachments[1]->Data());
+        $this->assertNull($attachments[1]->Size());
+
+        $this->assertSame('mms-2', $messages[1]->MessageId());
+        $this->assertSame('+79990003333', $messages[1]->Recipient());
+        $this->assertSame(1, $messages[1]->SimNumber());
+        $this->assertSame([], $messages[1]->Attachments());
+
+        $this->assertSame('mms-3', $messages[2]->MessageId());
+        $this->assertSame([], $messages[2]->Attachments());
+        $this->assertNull($messages[2]->Subject());
+        $this->assertNull($messages[2]->Body());
+    }
+
+    public function testFromObjectWithMissingMessagesReturnsEmptyArray(): void {
+        $batch = MmsBatchDownloadedPayload::FromObject(self::decodeObject('{}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithNonArrayMessagesReturnsEmptyArray(): void {
+        $batch = MmsBatchDownloadedPayload::FromObject(self::decodeObject('{"messages":"not-an-array"}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithObjectMessagesReturnsEmptyArray(): void {
+        $batch = MmsBatchDownloadedPayload::FromObject(self::decodeObject('{"messages":{}}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    private static function decodeObject(string $json): stdClass {
+        $obj = json_decode($json, false);
+        if (!$obj instanceof stdClass) {
+            throw new RuntimeException('Test fixture must decode to an object: ' . $json);
+        }
+
+        return $obj;
+    }
+}
diff --git a/tests/Domain/MmsBatchReceivedPayloadTest.php b/tests/Domain/MmsBatchReceivedPayloadTest.php
new file mode 100644
index 0000000..c27e657
--- /dev/null
+++ b/tests/Domain/MmsBatchReceivedPayloadTest.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\MmsBatchReceivedPayload;
+use AndroidSmsGateway\Domain\MmsReceivedPayload;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use stdClass;
+
+final class MmsBatchReceivedPayloadTest extends TestCase {
+    public function testCanBeInstantiated(): void {
+        $payload = new MmsBatchReceivedPayload([]);
+        $this->assertInstanceOf(MmsBatchReceivedPayload::class, $payload);
+    }
+
+    public function testFromObjectMapsMessagesToInnerPayloadInstances(): void {
+        $json = '{"messages":['
+            . '{"messageId":"mms-1","phoneNumber":"+79990001111","sender":"+79990002222","transactionId":"tx-1","contentClass":"MMS","size":1024,"receivedAt":"2026-08-18T10:00:00Z"},'
+            . '{"messageId":"mms-2","phoneNumber":"+79990003333","sender":"+79990004444","transactionId":"tx-2","contentClass":"text","size":0,"receivedAt":"2026-08-18T10:01:00Z","recipient":"+79990003333","simNumber":1,"subject":"Hello"},'
+            . '{"messageId":"mms-3","phoneNumber":"+79990005555","sender":"+79990006666","transactionId":"tx-3","contentClass":"image","size":1048576,"receivedAt":"2026-08-18T10:02:00Z"}'
+            . ']}';
+
+        $batch = MmsBatchReceivedPayload::FromObject(self::decodeObject($json));
+        $messages = $batch->Messages();
+
+        $this->assertCount(3, $messages);
+        $this->assertContainsOnlyInstancesOf(MmsReceivedPayload::class, $messages);
+        $this->assertSame('mms-1', $messages[0]->MessageId());
+        $this->assertSame('tx-1', $messages[0]->TransactionId());
+        $this->assertSame('MMS', $messages[0]->ContentClass());
+        $this->assertSame(1024, $messages[0]->Size());
+        $this->assertNull($messages[0]->Recipient());
+        $this->assertNull($messages[0]->SimNumber());
+        $this->assertNull($messages[0]->Subject());
+        $this->assertSame('mms-2', $messages[1]->MessageId());
+        $this->assertSame('tx-2', $messages[1]->TransactionId());
+        $this->assertSame('text', $messages[1]->ContentClass());
+        $this->assertSame(0, $messages[1]->Size());
+        $this->assertSame('+79990003333', $messages[1]->Recipient());
+        $this->assertSame(1, $messages[1]->SimNumber());
+        $this->assertSame('Hello', $messages[1]->Subject());
+        $this->assertSame('mms-3', $messages[2]->MessageId());
+        $this->assertSame('tx-3', $messages[2]->TransactionId());
+        $this->assertSame(1048576, $messages[2]->Size());
+    }
+
+    public function testFromObjectWithMissingMessagesReturnsEmptyArray(): void {
+        $batch = MmsBatchReceivedPayload::FromObject(self::decodeObject('{}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithNonArrayMessagesReturnsEmptyArray(): void {
+        $batch = MmsBatchReceivedPayload::FromObject(self::decodeObject('{"messages":"not-an-array"}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithObjectMessagesReturnsEmptyArray(): void {
+        $batch = MmsBatchReceivedPayload::FromObject(self::decodeObject('{"messages":{}}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    private static function decodeObject(string $json): stdClass {
+        $obj = json_decode($json, false);
+        if (!$obj instanceof stdClass) {
+            throw new RuntimeException('Test fixture must decode to an object: ' . $json);
+        }
+
+        return $obj;
+    }
+}
diff --git a/tests/Domain/SmsBatchDataReceivedPayloadTest.php b/tests/Domain/SmsBatchDataReceivedPayloadTest.php
new file mode 100644
index 0000000..1fbbfa7
--- /dev/null
+++ b/tests/Domain/SmsBatchDataReceivedPayloadTest.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\SmsBatchDataReceivedPayload;
+use AndroidSmsGateway\Domain\SmsDataReceivedPayload;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use stdClass;
+
+final class SmsBatchDataReceivedPayloadTest extends TestCase {
+    public function testCanBeInstantiated(): void {
+        $payload = new SmsBatchDataReceivedPayload([]);
+        $this->assertInstanceOf(SmsBatchDataReceivedPayload::class, $payload);
+    }
+
+    public function testFromObjectMapsMessagesToInnerPayloadInstances(): void {
+        $json = '{"messages":['
+            . '{"messageId":"d1","phoneNumber":"+79990001111","sender":"+79990002222","data":"SGVsbG8=","receivedAt":"2026-08-18T10:00:00Z"},'
+            . '{"messageId":"d2","phoneNumber":"+79990003333","sender":"+79990004444","recipient":"+79990003333","simNumber":2,"data":"V29ybGQ=","receivedAt":"2026-08-18T10:01:00Z"},'
+            . '{"messageId":"d3","phoneNumber":"+79990005555","sender":"+79990006666","data":"IQ==","receivedAt":"2026-08-18T10:02:00Z"}'
+            . ']}';
+
+        $batch = SmsBatchDataReceivedPayload::FromObject(self::decodeObject($json));
+        $messages = $batch->Messages();
+
+        $this->assertCount(3, $messages);
+        $this->assertContainsOnlyInstancesOf(SmsDataReceivedPayload::class, $messages);
+        $this->assertSame('d1', $messages[0]->MessageId());
+        $this->assertSame('SGVsbG8=', $messages[0]->Data());
+        $this->assertNull($messages[0]->Recipient());
+        $this->assertSame('d2', $messages[1]->MessageId());
+        $this->assertSame('V29ybGQ=', $messages[1]->Data());
+        $this->assertSame('+79990003333', $messages[1]->Recipient());
+        $this->assertSame(2, $messages[1]->SimNumber());
+        $this->assertSame('d3', $messages[2]->MessageId());
+        $this->assertSame('IQ==', $messages[2]->Data());
+    }
+
+    public function testFromObjectWithMissingMessagesReturnsEmptyArray(): void {
+        $batch = SmsBatchDataReceivedPayload::FromObject(self::decodeObject('{}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithNonArrayMessagesReturnsEmptyArray(): void {
+        $batch = SmsBatchDataReceivedPayload::FromObject(self::decodeObject('{"messages":"not-an-array"}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithObjectMessagesReturnsEmptyArray(): void {
+        $batch = SmsBatchDataReceivedPayload::FromObject(self::decodeObject('{"messages":{}}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    private static function decodeObject(string $json): stdClass {
+        $obj = json_decode($json, false);
+        if (!$obj instanceof stdClass) {
+            throw new RuntimeException('Test fixture must decode to an object: ' . $json);
+        }
+
+        return $obj;
+    }
+}
diff --git a/tests/Domain/SmsBatchReceivedPayloadTest.php b/tests/Domain/SmsBatchReceivedPayloadTest.php
new file mode 100644
index 0000000..d881586
--- /dev/null
+++ b/tests/Domain/SmsBatchReceivedPayloadTest.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\SmsBatchReceivedPayload;
+use AndroidSmsGateway\Domain\SmsReceivedPayload;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use stdClass;
+
+final class SmsBatchReceivedPayloadTest extends TestCase {
+    public function testCanBeInstantiated(): void {
+        $payload = new SmsBatchReceivedPayload([]);
+        $this->assertInstanceOf(SmsBatchReceivedPayload::class, $payload);
+    }
+
+    public function testFromObjectMapsMessagesToInnerPayloadInstances(): void {
+        $json = '{"messages":['
+            . '{"messageId":"m1","phoneNumber":"+79990001111","sender":"+79990002222","message":"first","receivedAt":"2026-08-18T10:00:00Z"},'
+            . '{"messageId":"m2","phoneNumber":"+79990003333","sender":"+79990004444","recipient":"+79990003333","simNumber":2,"message":"second","receivedAt":"2026-08-18T10:01:00Z"},'
+            . '{"messageId":"m3","phoneNumber":"+79990005555","sender":"+79990006666","message":"third","receivedAt":"2026-08-18T10:02:00Z"}'
+            . ']}';
+
+        $batch = SmsBatchReceivedPayload::FromObject(self::decodeObject($json));
+        $messages = $batch->Messages();
+
+        $this->assertCount(3, $messages);
+        $this->assertContainsOnlyInstancesOf(SmsReceivedPayload::class, $messages);
+        $this->assertSame('m1', $messages[0]->MessageId());
+        $this->assertSame('first', $messages[0]->Message());
+        $this->assertNull($messages[0]->Recipient());
+        $this->assertSame('m2', $messages[1]->MessageId());
+        $this->assertSame('second', $messages[1]->Message());
+        $this->assertSame('+79990003333', $messages[1]->Recipient());
+        $this->assertSame(2, $messages[1]->SimNumber());
+        $this->assertSame('m3', $messages[2]->MessageId());
+        $this->assertSame('third', $messages[2]->Message());
+    }
+
+    public function testFromObjectWithMissingMessagesReturnsEmptyArray(): void {
+        $batch = SmsBatchReceivedPayload::FromObject(self::decodeObject('{}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithNonArrayMessagesReturnsEmptyArray(): void {
+        $batch = SmsBatchReceivedPayload::FromObject(self::decodeObject('{"messages":"not-an-array"}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    public function testFromObjectWithObjectMessagesReturnsEmptyArray(): void {
+        $batch = SmsBatchReceivedPayload::FromObject(self::decodeObject('{"messages":{}}'));
+
+        $this->assertSame([], $batch->Messages());
+    }
+
+    private static function decodeObject(string $json): stdClass {
+        $obj = json_decode($json, false);
+        if (!$obj instanceof stdClass) {
+            throw new RuntimeException('Test fixture must decode to an object: ' . $json);
+        }
+
+        return $obj;
+    }
+}
diff --git a/tests/Domain/SmsDataReceivedPayloadTest.php b/tests/Domain/SmsDataReceivedPayloadTest.php
new file mode 100644
index 0000000..d9a4e1c
--- /dev/null
+++ b/tests/Domain/SmsDataReceivedPayloadTest.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\SmsDataReceivedPayload;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use stdClass;
+
+final class SmsDataReceivedPayloadTest extends TestCase {
+    /**
+     * @return array<string, array{string, string, string, string, ?string, ?int, string, string}>
+     */
+    public static function payloadProvider(): array {
+        return [
+            'with recipient and simNumber' => [
+                '{"messageId":"data-1","phoneNumber":"+79990001111","sender":"+79990001234","recipient":"+79990001111","simNumber":2,"data":"SGVsbG8gV29ybGQh","receivedAt":"2026-08-18T10:00:00Z"}',
+                'data-1',
+                '+79990001111',
+                '+79990001234',
+                '+79990001111',
+                2,
+                'SGVsbG8gV29ybGQh',
+                '2026-08-18T10:00:00Z'
+            ],
+            'without optional fields and empty data' => [
+                '{"messageId":"data-2","phoneNumber":"+79990002222","sender":"+79990003333","data":"","receivedAt":"2026-08-18T11:00:00Z"}',
+                'data-2',
+                '+79990002222',
+                '+79990003333',
+                null,
+                null,
+                '',
+                '2026-08-18T11:00:00Z'
+            ],
+            'extreme values' => [
+                '{"messageId":"data-3-very-long-identifier","phoneNumber":"+100000000000000","sender":"","recipient":"+100000000000000","simNumber":0,"data":"QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVphYmNkZWZnaGlqa2xtbm9wcXJzdHV2d3h5ejAxMjM0NTY3ODk=","receivedAt":"1970-01-01T00:00:00Z"}',
+                'data-3-very-long-identifier',
+                '+100000000000000',
+                '',
+                '+100000000000000',
+                0,
+                'QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVphYmNkZWZnaGlqa2xtbm9wcXJzdHV2d3h5ejAxMjM0NTY3ODk=',
+                '1970-01-01T00:00:00Z'
+            ]
+        ];
+    }
+
+    public function testCanBeInstantiated(): void {
+        $payload = new SmsDataReceivedPayload('data-1', '+79990001111', '+79990001234', '+79990001111', 2, 'SGVsbG8=', '2026-08-18T10:00:00Z');
+        $this->assertInstanceOf(SmsDataReceivedPayload::class, $payload);
+    }
+
+    /**
+     * @dataProvider payloadProvider
+     */
+    public function testFromObjectParsesAllFields(
+        string $json,
+        string $messageId,
+        string $phoneNumber,
+        string $sender,
+        ?string $recipient,
+        ?int $simNumber,
+        string $data,
+        string $receivedAt
+    ): void {
+        $payload = SmsDataReceivedPayload::FromObject(self::decodeObject($json));
+
+        $this->assertSame($messageId, $payload->MessageId());
+        $this->assertSame($phoneNumber, $payload->PhoneNumber());
+        $this->assertSame($sender, $payload->Sender());
+        $this->assertSame($recipient, $payload->Recipient());
+        $this->assertSame($simNumber, $payload->SimNumber());
+        $this->assertSame($data, $payload->Data());
+        $this->assertSame($receivedAt, $payload->ReceivedAt());
+    }
+
+    public function testFromObjectDefaultsAbsentOptionalFieldsToNull(): void {
+        $payload = SmsDataReceivedPayload::FromObject(self::decodeObject(
+            '{"messageId":"data-4","phoneNumber":"+79990004444","sender":"+79990005555","data":"SGVsbG8=","receivedAt":"2026-08-18T12:00:00Z"}'
+        ));
+
+        $this->assertNull($payload->Recipient());
+        $this->assertNull($payload->SimNumber());
+    }
+
+    private static function decodeObject(string $json): stdClass {
+        $obj = json_decode($json, false);
+        if (!$obj instanceof stdClass) {
+            throw new RuntimeException('Test fixture must decode to an object: ' . $json);
+        }
+
+        return $obj;
+    }
+}
diff --git a/tests/Domain/SmsReceivedPayloadTest.php b/tests/Domain/SmsReceivedPayloadTest.php
new file mode 100644
index 0000000..eaa1568
--- /dev/null
+++ b/tests/Domain/SmsReceivedPayloadTest.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace AndroidSmsGateway\Tests\Domain;
+
+use AndroidSmsGateway\Domain\SmsReceivedPayload;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use stdClass;
+
+final class SmsReceivedPayloadTest extends TestCase {
+    /**
+     * @return array<string, array{string, string, string, string, ?string, ?int, string, string}>
+     */
+    public static function payloadProvider(): array {
+        return [
+            'with recipient and simNumber' => [
+                '{"messageId":"msg-1","phoneNumber":"+79990001111","sender":"+79990001234","recipient":"+79990001111","simNumber":1,"message":"Hello World!","receivedAt":"2026-08-18T10:00:00Z"}',
+                'msg-1',
+                '+79990001111',
+                '+79990001234',
+                '+79990001111',
+                1,
+                'Hello World!',
+                '2026-08-18T10:00:00Z'
+            ],
+            'without optional fields' => [
+                '{"messageId":"msg-2","phoneNumber":"+79990002222","sender":"+79990003333","message":"","receivedAt":"2026-08-18T11:00:00Z"}',
+                'msg-2',
+                '+79990002222',
+                '+79990003333',
+                null,
+                null,
+                '',
+                '2026-08-18T11:00:00Z'
+            ],
+            'extreme values' => [
+                '{"messageId":"msg-3-very-long-identifier","phoneNumber":"+100000000000000","sender":"","recipient":"+100000000000000","simNumber":0,"message":"First line\nSecond line","receivedAt":"1970-01-01T00:00:00Z"}',
+                'msg-3-very-long-identifier',
+                '+100000000000000',
+                '',
+                '+100000000000000',
+                0,
+                "First line\nSecond line",
+                '1970-01-01T00:00:00Z'
+            ]
+        ];
+    }
+
+    public function testCanBeInstantiated(): void {
+        $payload = new SmsReceivedPayload('msg-1', '+79990001111', '+79990001234', '+79990001111', 1, 'Hello', '2026-08-18T10:00:00Z');
+        $this->assertInstanceOf(SmsReceivedPayload::class, $payload);
+    }
+
+    /**
+     * @dataProvider payloadProvider
+     */
+    public function testFromObjectParsesAllFields(
+        string $json,
+        string $messageId,
+        string $phoneNumber,
+        string $sender,
+        ?string $recipient,
+        ?int $simNumber,
+        string $message,
+        string $receivedAt
+    ): void {
+        $payload = SmsReceivedPayload::FromObject(self::decodeObject($json));
+
+        $this->assertSame($messageId, $payload->MessageId());
+        $this->assertSame($phoneNumber, $payload->PhoneNumber());
+        $this->assertSame($sender, $payload->Sender());
+        $this->assertSame($recipient, $payload->Recipient());
+        $this->assertSame($simNumber, $payload->SimNumber());
+        $this->assertSame($message, $payload->Message());
+        $this->assertSame($receivedAt, $payload->ReceivedAt());
+    }
+
+    public function testFromObjectDefaultsAbsentOptionalFieldsToNull(): void {
+        $payload = SmsReceivedPayload::FromObject(self::decodeObject(
+            '{"messageId":"msg-4","phoneNumber":"+79990004444","sender":"+79990005555","message":"No extras","receivedAt":"2026-08-18T12:00:00Z"}'
+        ));
+
+        $this->assertNull($payload->Recipient());
+        $this->assertNull($payload->SimNumber());
+    }
+
+    private static function decodeObject(string $json): stdClass {
+        $obj = json_decode($json, false);
+        if (!$obj instanceof stdClass) {
+            throw new RuntimeException('Test fixture must decode to an object: ' . $json);
+        }
+
+        return $obj;
+    }
+}