feat: add API Gateway, RapidMail and Shopify integrations, update WireGuard configs, add Redis override and architecture docs

deployment/ansible/playbooks/regenerate-wireguard-client.yml

@@ -10,7 +10,6 @@
     wireguard_config_file: "{{ wireguard_config_path }}/{{ wireguard_interface }}.conf"
     wireguard_client_configs_path: "/etc/wireguard/clients"
     wireguard_local_client_configs_dir: "{{ playbook_dir }}/../wireguard-clients"
-    wireguard_dns_servers: []
 
   tasks:
     - name: Validate client name
@@ -81,7 +80,7 @@
 
     - name: Extract server IP from config
       set_fact:
-        server_vpn_ip: "{{ (wireguard_server_config_read.content | b64decode | regex_search('Address\\s*=\\s*([0-9.]+)')) | default(['10.8.0.1']) | first }}"
+        server_vpn_ip: "{{ (wireguard_server_config_read.content | b64decode | regex_findall('Address\\s*=\\s*([0-9.]+)') | first) | default('10.8.0.1') }}"
       failed_when: false
 
     - name: Extract WireGuard server IP octets

deployment/ansible/playbooks/test-wireguard-docker-container.yml

@@ -35,7 +35,7 @@
 
     - name: Extract client IP from config
       set_fact:
-        client_vpn_ip: "{{ (client_config_content.content | b64decode | regex_search('Address = ([0-9.]+)')) | default(['10.8.0.7']) | first }}"
+        client_vpn_ip: "{{ (client_config_content.content | b64decode | regex_findall('Address\\s*=\\s*([0-9.]+)') | first) | default('10.8.0.7') }}"
       failed_when: false
 
     - name: Display extracted client IP

deployment/ansible/wireguard-clients/mikepc.conf

@@ -3,13 +3,13 @@
 
 [Interface]
 # Client private key
-PrivateKey = wFxqFHe4R8IVzkAQSHaAwVfwQ2rfm5vCySZMpvPsVUQ=
+PrivateKey = iDCbQUsZ2u950CIFIMFw1cYUc7dBXFjUFF8kaK4E0H4=
 
 # Client IP address in VPN network
-Address = 10.8.0.3/24
+Address = 10.8.0.5/24
 
-# DNS server (optional)
-DNS = 1.1.1.1, 8.8.8.8
+# DNS servers provided via Ansible (optional)
+DNS = 10.8.0.1
 
 [Peer]
 # Server public key
@@ -24,4 +24,4 @@ Endpoint = 94.16.110.151:51820
 AllowedIPs = 10.8.0.0/24
 
 # Keep connection alive
-PersistentKeepalive = 25
+PersistentKeepalive = 25

docker-compose.redis-override.yml

@@ -0,0 +1,34 @@
+# Redis Stack Integration Override
+# Usage: docker compose -f docker-compose.base.yml -f docker-compose.production.yml -f docker-compose.postgres-override.yml -f docker-compose.redis-override.yml up -d
+#
+# This file overrides the application stack configuration to connect to the external Redis stack.
+# It follows the same pattern as docker-compose.postgres-override.yml for consistency.
+
+services:
+  php:
+    environment:
+      REDIS_HOST: redis-stack  # External Redis container name
+      REDIS_PORT: 6379
+      # REDIS_PASSWORD comes from Docker Secrets (not changed)
+    networks:
+      - app-internal
+
+  queue-worker:
+    environment:
+      REDIS_HOST: redis-stack
+      REDIS_PORT: 6379
+      # REDIS_PASSWORD comes from Docker Secrets (not changed)
+    networks:
+      - app-internal
+
+  scheduler:
+    environment:
+      REDIS_HOST: redis-stack
+      REDIS_PORT: 6379
+      # REDIS_PASSWORD comes from Docker Secrets (not changed)
+    networks:
+      - app-internal
+
+networks:
+  app-internal:
+    external: true

src/Framework/ApiGateway/ApiGateway.php

@@ -0,0 +1,288 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ApiGateway;
+
+use App\Framework\ApiGateway\Exceptions\ApiGatewayException;
+use App\Framework\ApiGateway\Metrics\ApiMetrics;
+use App\Framework\CircuitBreaker\CircuitBreaker;
+use App\Framework\CircuitBreaker\CircuitBreakerConfig;
+use App\Framework\CircuitBreaker\CircuitBreakerManager;
+use App\Framework\CircuitBreaker\Exceptions\CircuitBreakerException;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\HttpClient\ClientOptions;
+use App\Framework\HttpClient\ClientRequest;
+use App\Framework\HttpClient\ClientResponse;
+use App\Framework\HttpClient\HttpClient;
+use App\Framework\Logging\Logger;
+use App\Framework\Performance\OperationTracker;
+use App\Framework\Performance\PerformanceCategory;
+use App\Framework\Retry\RetryStrategy;
+use Throwable;
+
+/**
+ * Central API Gateway for all outbound API calls
+ *
+ * Provides cross-cutting concerns:
+ * - Circuit breaker pattern for resilience
+ * - Retry strategies for transient failures
+ * - Centralized logging and metrics
+ * - Request/response transformation
+ *
+ * Example usage:
+ *
+ * $request = new SendEmailApiRequest($email, $template);
+ * $response = $apiGateway->send($request);
+ */
+final readonly class ApiGateway
+{
+    public function __construct(
+        private HttpClient $httpClient,
+        private CircuitBreakerManager $circuitBreakerManager,
+        private ApiMetrics $metrics,
+        private OperationTracker $operationTracker,
+        private ?Logger $logger = null
+    ) {
+    }
+
+    /**
+     * Send an API request through the gateway
+     *
+     * @param ApiRequest $request The API request to send
+     * @return ClientResponse The response from the API
+     * @throws ApiGatewayException If the request fails after all retries
+     * @throws CircuitBreakerException If the circuit breaker is open
+     */
+    public function send(ApiRequest $request): ClientResponse
+    {
+        $service = $request->getEndpoint()->getServiceIdentifier();
+        $requestName = $request->getRequestName();
+
+        // Start performance tracking
+        $operationId = "api_gateway.{$service}.{$requestName}." . uniqid();
+        $snapshot = $this->operationTracker->startOperation(
+            operationId: $operationId,
+            category: PerformanceCategory::HTTP,
+            contextData: [
+                'service' => $service,
+                'request_name' => $requestName,
+                'method' => $request->getMethod()->value,
+                'endpoint' => $request->getEndpoint()->toString(),
+            ]
+        );
+
+        $retryAttempts = 0;
+        $circuitBreakerTriggered = false;
+
+        // Log request start
+        $this->logger?->info("[ApiGateway] Sending request", [
+            'operation_id' => $operationId,
+            'service' => $service,
+            'request_name' => $requestName,
+            'method' => $request->getMethod()->value,
+            'endpoint' => $request->getEndpoint()->toString(),
+        ]);
+
+        // Get circuit breaker for this service
+        $circuitBreaker = $this->circuitBreakerManager->getCircuitBreaker($service);
+        $circuitBreakerConfig = CircuitBreakerConfig::forHttpClient();
+
+        // Check circuit breaker status (throws if open)
+        try {
+            $circuitBreaker->check($service, $circuitBreakerConfig);
+        } catch (CircuitBreakerException $e) {
+            $circuitBreakerTriggered = true;
+
+            $this->logger?->warning("[ApiGateway] Circuit breaker open", [
+                'operation_id' => $operationId,
+                'service' => $service,
+                'request_name' => $requestName,
+            ]);
+
+            // Record failure and metrics
+            $completedSnapshot = $this->operationTracker->failOperation($operationId, $e);
+            if ($completedSnapshot !== null) {
+                $this->recordMetrics($service, $requestName, $completedSnapshot, false, 0, true);
+            }
+
+            throw $e;
+        }
+
+        // Convert ApiRequest to ClientRequest
+        $clientRequest = $this->buildClientRequest($request);
+
+        // Execute with retry strategy if configured
+        $retryStrategy = $request->getRetryStrategy();
+
+        try {
+            if ($retryStrategy !== null) {
+                $result = $this->sendWithRetry($clientRequest, $retryStrategy, $service, $requestName, $operationId);
+                $response = $result['response'];
+                $retryAttempts = $result['attempts'];
+            } else {
+                $response = $this->httpClient->send($clientRequest);
+            }
+
+            // Record success with circuit breaker
+            $circuitBreaker->recordSuccess($service, $circuitBreakerConfig);
+
+            $this->logger?->info("[ApiGateway] Request successful", [
+                'operation_id' => $operationId,
+                'service' => $service,
+                'request_name' => $requestName,
+                'status' => $response->status->value,
+                'retry_attempts' => $retryAttempts,
+            ]);
+
+            // Complete operation tracking and record metrics
+            $completedSnapshot = $this->operationTracker->completeOperation($operationId);
+            if ($completedSnapshot !== null) {
+                $this->recordMetrics($service, $requestName, $completedSnapshot, true, $retryAttempts, false);
+            }
+
+            return $response;
+        } catch (Throwable $exception) {
+            // Record failure with circuit breaker
+            $circuitBreaker->recordFailure($service, $exception, $circuitBreakerConfig);
+
+            $this->logger?->error("[ApiGateway] Request failed", [
+                'operation_id' => $operationId,
+                'service' => $service,
+                'request_name' => $requestName,
+                'error' => $exception->getMessage(),
+                'exception_class' => get_class($exception),
+                'retry_attempts' => $retryAttempts,
+            ]);
+
+            // Record failure and metrics
+            $completedSnapshot = $this->operationTracker->failOperation($operationId, $exception);
+            if ($completedSnapshot !== null) {
+                $this->recordMetrics($service, $requestName, $completedSnapshot, false, $retryAttempts, $circuitBreakerTriggered);
+            }
+
+            throw new ApiGatewayException(
+                "API request failed for {$requestName}",
+                0,
+                $exception
+            );
+        }
+    }
+
+    /**
+     * Build ClientRequest from ApiRequest
+     */
+    private function buildClientRequest(ApiRequest $request): ClientRequest
+    {
+        // Convert timeout Duration to seconds for ClientOptions
+        $timeoutSeconds = $request->getTimeout()->toSeconds();
+
+        $options = new ClientOptions(
+            timeout: $timeoutSeconds,
+            connectTimeout: min(3, $timeoutSeconds), // Connect timeout max 3s or total timeout
+        );
+
+        // Use factory method for JSON requests if payload is present
+        if ($request instanceof HasPayload) {
+            return ClientRequest::json(
+                method: $request->getMethod(),
+                url: $request->getEndpoint()->toString(),
+                data: $request->getPayload(),
+                options: $options
+            )->with([
+                'headers' => $request->getHeaders(),
+            ]);
+        }
+
+        // Simple request without body
+        return new ClientRequest(
+            method: $request->getMethod(),
+            url: $request->getEndpoint()->toString(),
+            headers: $request->getHeaders(),
+            body: '',
+            options: $options
+        );
+    }
+
+    /**
+     * Send request with retry strategy
+     *
+     * @return array{response: ClientResponse, attempts: int}
+     */
+    private function sendWithRetry(
+        ClientRequest $request,
+        RetryStrategy $retryStrategy,
+        string $service,
+        string $requestName,
+        string $operationId
+    ): array {
+        $attempt = 0;
+
+        while (true) {
+            try {
+                if ($attempt > 0) {
+                    $this->logger?->info("[ApiGateway] Retry attempt", [
+                        'operation_id' => $operationId,
+                        'service' => $service,
+                        'request_name' => $requestName,
+                        'attempt' => $attempt,
+                    ]);
+                }
+
+                $response = $this->httpClient->send($request);
+
+                return [
+                    'response' => $response,
+                    'attempts' => $attempt,
+                ];
+            } catch (Throwable $exception) {
+                $attempt++;
+
+                if (!$retryStrategy->shouldRetry($exception, $attempt)) {
+                    $this->logger?->warning("[ApiGateway] Retry limit reached", [
+                        'operation_id' => $operationId,
+                        'service' => $service,
+                        'request_name' => $requestName,
+                        'attempts' => $attempt,
+                    ]);
+
+                    throw $exception;
+                }
+
+                $delay = $retryStrategy->getDelay($attempt);
+
+                $this->logger?->info("[ApiGateway] Retrying after delay", [
+                    'operation_id' => $operationId,
+                    'service' => $service,
+                    'request_name' => $requestName,
+                    'attempt' => $attempt,
+                    'delay_ms' => $delay->toMilliseconds(),
+                ]);
+
+                // Sleep before retry
+                usleep($delay->toMicroseconds());
+            }
+        }
+    }
+
+    /**
+     * Record metrics from performance snapshot
+     */
+    private function recordMetrics(
+        string $service,
+        string $requestName,
+        \App\Framework\Performance\PerformanceSnapshot $snapshot,
+        bool $success,
+        int $retryAttempts,
+        bool $circuitBreakerTriggered
+    ): void {
+        $this->metrics->recordRequest(
+            service: $service,
+            requestName: $requestName,
+            durationMs: $snapshot->duration->toMilliseconds(),
+            success: $success,
+            retryAttempts: $retryAttempts,
+            circuitBreakerTriggered: $circuitBreakerTriggered
+        );
+    }
+}

src/Framework/ApiGateway/ApiRequest.php

@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ApiGateway;
+
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\{Headers, Method as HttpMethod};
+use App\Framework\Retry\RetryStrategy;
+
+/**
+ * Interface for API requests that can be sent through the ApiGateway
+ *
+ * Domain-specific modules implement this interface to define their API calls
+ * with proper configuration (timeout, retry strategy, headers, etc.)
+ *
+ * For requests with body payload (POST/PUT/PATCH), also implement HasPayload.
+ *
+ * Example implementations:
+ * - SendEmailApiRequest (RapidMail) implements ApiRequest, HasPayload
+ * - CreateOrderApiRequest (Shopify) implements ApiRequest, HasPayload
+ * - GetOrderApiRequest (Shopify) implements ApiRequest (no payload)
+ *
+ * @see HasPayload For requests with request body
+ */
+interface ApiRequest
+{
+    /**
+     * Get the API endpoint URL
+     */
+    public function getEndpoint(): ApiEndpoint;
+
+    /**
+     * Get the HTTP method (GET, POST, PUT, DELETE, etc.)
+     */
+    public function getMethod(): HttpMethod;
+
+    /**
+     * Get the request timeout
+     */
+    public function getTimeout(): Duration;
+
+    /**
+     * Get the retry strategy for this request
+     *
+     * @return RetryStrategy|null Null means no retries
+     */
+    public function getRetryStrategy(): ?RetryStrategy;
+
+    /**
+     * Get request headers
+     */
+    public function getHeaders(): Headers;
+
+    /**
+     * Get a human-readable name for this request (for logging/metrics)
+     *
+     * Examples: "rapidmail.send_email", "shopify.create_order", "stripe.charge"
+     */
+    public function getRequestName(): string;
+}

src/Framework/ApiGateway/Exceptions/ApiGatewayException.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ApiGateway\Exceptions;
+
+use RuntimeException;
+
+/**
+ * Exception thrown when API Gateway operations fail
+ */
+final class ApiGatewayException extends RuntimeException
+{
+}

src/Framework/ApiGateway/HasPayload.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ApiGateway;
+
+/**
+ * Marker interface for API requests that have a request body payload
+ *
+ * Requests implementing this interface:
+ * - POST, PUT, PATCH requests with JSON/form data
+ * - Requests that need body serialization
+ *
+ * Requests NOT implementing this:
+ * - GET, DELETE, HEAD requests (query params only)
+ * - Requests without body data
+ *
+ * Usage in ApiGateway:
+ * ```
+ * if ($request instanceof HasPayload) {
+ *     $clientRequest = ClientRequest::json(..., $request->getPayload());
+ * } else {
+ *     $clientRequest = new ClientRequest(...); // No body
+ * }
+ * ```
+ */
+interface HasPayload
+{
+    /**
+     * Get the request payload/body data
+     *
+     * @return array Request body data (will be JSON-encoded)
+     */
+    public function getPayload(): array;
+}

src/Framework/ApiGateway/Metrics/ApiMetrics.php

@@ -0,0 +1,302 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ApiGateway\Metrics;
+
+use App\Framework\Metrics\MetricsCollection;
+
+/**
+ * Collects and tracks metrics for API Gateway operations
+ */
+final class ApiMetrics
+{
+    /** @var array<string, array{requests: int, successes: int, failures: int, total_duration_ms: float, avg_duration_ms: float}> */
+    private array $statsByService = [];
+
+    /** @var array<string, array{requests: int, successes: int, failures: int, total_duration_ms: float, avg_duration_ms: float}> */
+    private array $statsByRequestName = [];
+
+    private int $totalRequests = 0;
+    private int $totalSuccesses = 0;
+    private int $totalFailures = 0;
+    private float $totalDurationMs = 0.0;
+
+    /** @var array<string, int> */
+    private array $retryCountByService = [];
+
+    /** @var array<string, int> */
+    private array $circuitBreakerOpenCountByService = [];
+
+    public function recordRequest(
+        string $service,
+        string $requestName,
+        float $durationMs,
+        bool $success,
+        int $retryAttempts = 0,
+        bool $circuitBreakerTriggered = false
+    ): void {
+        // Total stats
+        $this->totalRequests++;
+        if ($success) {
+            $this->totalSuccesses++;
+        } else {
+            $this->totalFailures++;
+        }
+        $this->totalDurationMs += $durationMs;
+
+        // Per-service stats
+        if (!isset($this->statsByService[$service])) {
+            $this->statsByService[$service] = [
+                'requests' => 0,
+                'successes' => 0,
+                'failures' => 0,
+                'total_duration_ms' => 0.0,
+                'avg_duration_ms' => 0.0,
+            ];
+        }
+
+        $this->statsByService[$service]['requests']++;
+        if ($success) {
+            $this->statsByService[$service]['successes']++;
+        } else {
+            $this->statsByService[$service]['failures']++;
+        }
+        $this->statsByService[$service]['total_duration_ms'] += $durationMs;
+        $this->statsByService[$service]['avg_duration_ms'] =
+            $this->statsByService[$service]['total_duration_ms'] / $this->statsByService[$service]['requests'];
+
+        // Per-request-name stats
+        if (!isset($this->statsByRequestName[$requestName])) {
+            $this->statsByRequestName[$requestName] = [
+                'requests' => 0,
+                'successes' => 0,
+                'failures' => 0,
+                'total_duration_ms' => 0.0,
+                'avg_duration_ms' => 0.0,
+            ];
+        }
+
+        $this->statsByRequestName[$requestName]['requests']++;
+        if ($success) {
+            $this->statsByRequestName[$requestName]['successes']++;
+        } else {
+            $this->statsByRequestName[$requestName]['failures']++;
+        }
+        $this->statsByRequestName[$requestName]['total_duration_ms'] += $durationMs;
+        $this->statsByRequestName[$requestName]['avg_duration_ms'] =
+            $this->statsByRequestName[$requestName]['total_duration_ms'] / $this->statsByRequestName[$requestName]['requests'];
+
+        // Retry tracking
+        if ($retryAttempts > 0) {
+            if (!isset($this->retryCountByService[$service])) {
+                $this->retryCountByService[$service] = 0;
+            }
+            $this->retryCountByService[$service] += $retryAttempts;
+        }
+
+        // Circuit breaker tracking
+        if ($circuitBreakerTriggered) {
+            if (!isset($this->circuitBreakerOpenCountByService[$service])) {
+                $this->circuitBreakerOpenCountByService[$service] = 0;
+            }
+            $this->circuitBreakerOpenCountByService[$service]++;
+        }
+    }
+
+    public function getStats(): array
+    {
+        return [
+            'total' => [
+                'requests' => $this->totalRequests,
+                'successes' => $this->totalSuccesses,
+                'failures' => $this->totalFailures,
+                'success_rate' => $this->getSuccessRate(),
+                'avg_duration_ms' => $this->getAverageDuration(),
+            ],
+            'by_service' => $this->statsByService,
+            'by_request_name' => $this->statsByRequestName,
+            'retry_counts' => $this->retryCountByService,
+            'circuit_breaker_opens' => $this->circuitBreakerOpenCountByService,
+        ];
+    }
+
+    public function getSuccessRate(): float
+    {
+        if ($this->totalRequests === 0) {
+            return 0.0;
+        }
+
+        return $this->totalSuccesses / $this->totalRequests;
+    }
+
+    public function getAverageDuration(): float
+    {
+        if ($this->totalRequests === 0) {
+            return 0.0;
+        }
+
+        return $this->totalDurationMs / $this->totalRequests;
+    }
+
+    public function getServiceStats(string $service): ?array
+    {
+        return $this->statsByService[$service] ?? null;
+    }
+
+    public function getRequestNameStats(string $requestName): ?array
+    {
+        return $this->statsByRequestName[$requestName] ?? null;
+    }
+
+    /**
+     * Collect metrics for Prometheus export
+     */
+    public function collectMetrics(MetricsCollection $collection): void
+    {
+        // Total request counter
+        $collection->counter(
+            'api_gateway_requests_total',
+            (float) $this->totalRequests,
+            'Total number of API gateway requests'
+        );
+
+        // Success counter
+        $collection->counter(
+            'api_gateway_requests_success_total',
+            (float) $this->totalSuccesses,
+            'Total number of successful API gateway requests'
+        );
+
+        // Failure counter
+        $collection->counter(
+            'api_gateway_requests_failure_total',
+            (float) $this->totalFailures,
+            'Total number of failed API gateway requests'
+        );
+
+        // Success rate gauge
+        $collection->gauge(
+            'api_gateway_success_rate',
+            $this->getSuccessRate(),
+            'Success rate of API gateway requests (0.0 to 1.0)'
+        );
+
+        // Average duration gauge
+        $collection->gauge(
+            'api_gateway_request_duration_ms',
+            $this->getAverageDuration(),
+            'Average duration of API gateway requests in milliseconds'
+        );
+
+        // Per-service metrics
+        foreach ($this->statsByService as $service => $stats) {
+            $labels = ['service' => $service];
+
+            $collection->counter(
+                'api_gateway_requests_total',
+                (float) $stats['requests'],
+                'Total requests per service',
+                $labels
+            );
+
+            $collection->counter(
+                'api_gateway_requests_success_total',
+                (float) $stats['successes'],
+                'Successful requests per service',
+                $labels
+            );
+
+            $collection->counter(
+                'api_gateway_requests_failure_total',
+                (float) $stats['failures'],
+                'Failed requests per service',
+                $labels
+            );
+
+            $collection->gauge(
+                'api_gateway_request_duration_ms',
+                $stats['avg_duration_ms'],
+                'Average request duration per service in milliseconds',
+                $labels
+            );
+
+            // Success rate per service
+            $successRate = $stats['requests'] > 0
+                ? $stats['successes'] / $stats['requests']
+                : 0.0;
+
+            $collection->gauge(
+                'api_gateway_success_rate',
+                $successRate,
+                'Success rate per service',
+                $labels
+            );
+        }
+
+        // Per-request-name metrics
+        foreach ($this->statsByRequestName as $requestName => $stats) {
+            $labels = ['request_name' => $requestName];
+
+            $collection->counter(
+                'api_gateway_requests_total',
+                (float) $stats['requests'],
+                'Total requests per request name',
+                $labels
+            );
+
+            $collection->counter(
+                'api_gateway_requests_success_total',
+                (float) $stats['successes'],
+                'Successful requests per request name',
+                $labels
+            );
+
+            $collection->counter(
+                'api_gateway_requests_failure_total',
+                (float) $stats['failures'],
+                'Failed requests per request name',
+                $labels
+            );
+
+            $collection->gauge(
+                'api_gateway_request_duration_ms',
+                $stats['avg_duration_ms'],
+                'Average request duration per request name in milliseconds',
+                $labels
+            );
+        }
+
+        // Retry metrics per service
+        foreach ($this->retryCountByService as $service => $retryCount) {
+            $collection->counter(
+                'api_gateway_retries_total',
+                (float) $retryCount,
+                'Total number of retry attempts per service',
+                ['service' => $service]
+            );
+        }
+
+        // Circuit breaker metrics per service
+        foreach ($this->circuitBreakerOpenCountByService as $service => $openCount) {
+            $collection->counter(
+                'api_gateway_circuit_breaker_open_total',
+                (float) $openCount,
+                'Total number of circuit breaker opens per service',
+                ['service' => $service]
+            );
+        }
+    }
+
+    public function reset(): void
+    {
+        $this->statsByService = [];
+        $this->statsByRequestName = [];
+        $this->totalRequests = 0;
+        $this->totalSuccesses = 0;
+        $this->totalFailures = 0;
+        $this->totalDurationMs = 0.0;
+        $this->retryCountByService = [];
+        $this->circuitBreakerOpenCountByService = [];
+    }
+}

src/Framework/ApiGateway/ValueObjects/ApiEndpoint.php

@@ -0,0 +1,92 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ApiGateway\ValueObjects;
+
+use App\Framework\Http\Url\Url;
+use InvalidArgumentException;
+
+/**
+ * Value Object representing an API endpoint URL
+ *
+ * Wraps the framework's Url interface with additional API-specific functionality
+ * for service identification and circuit breaker grouping
+ */
+final readonly class ApiEndpoint
+{
+    public function __construct(
+        public Url $url
+    ) {
+        $this->validate();
+    }
+
+    public static function fromString(string $url): self
+    {
+        return new self(Url::parse($url));
+    }
+
+    public static function fromUrl(Url $url): self
+    {
+        return new self($url);
+    }
+
+    private function validate(): void
+    {
+        // Must be HTTP or HTTPS
+        $scheme = $this->url->getScheme();
+        if (!in_array($scheme, ['http', 'https'], true)) {
+            throw new InvalidArgumentException(
+                "API endpoint must use HTTP or HTTPS, got: {$scheme}"
+            );
+        }
+
+        // Must have a host
+        if (empty($this->url->getHost())) {
+            throw new InvalidArgumentException('API endpoint must have a valid host');
+        }
+    }
+
+    /**
+     * Get the base domain for this endpoint (for circuit breaker identification)
+     *
+     * Example: https://api.example.com/v1/users -> api.example.com
+     */
+    public function getDomain(): string
+    {
+        return $this->url->getHost();
+    }
+
+    /**
+     * Get a service identifier for this endpoint (for metrics/circuit breaker)
+     *
+     * Example: https://api.rapidmail.com/v1/send -> rapidmail
+     */
+    public function getServiceIdentifier(): string
+    {
+        $domain = $this->getDomain();
+
+        // Extract main domain name (e.g., "rapidmail" from "api.rapidmail.com")
+        $parts = explode('.', $domain);
+        if (count($parts) >= 2) {
+            return $parts[count($parts) - 2]; // Second-to-last part
+        }
+
+        return $domain;
+    }
+
+    public function toString(): string
+    {
+        return $this->url->toString();
+    }
+
+    public function __toString(): string
+    {
+        return $this->toString();
+    }
+
+    public function equals(self $other): bool
+    {
+        return $this->url->equals($other->url);
+    }
+}

src/Infrastructure/Api/RapidMail/ApiRequests/CreateRecipientApiRequest.php

@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ApiRequests;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\HasPayload;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\ExponentialBackoffStrategy;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\RapidMail\RapidMailConfig;
+
+/**
+ * Domain-specific API request for creating recipients in RapidMail
+ *
+ * Example usage:
+ *
+ * $request = new CreateRecipientApiRequest(
+ *     config: $rapidMailConfig,
+ *     recipientData: [
+ *         'email' => 'user@example.com',
+ *         'firstname' => 'John',
+ *         'lastname' => 'Doe'
+ *     ]
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class CreateRecipientApiRequest implements ApiRequest, HasPayload
+{
+    public function __construct(
+        private RapidMailConfig $config,
+        private array $recipientData
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        $url = rtrim($this->config->baseUrl, '/') . '/recipients';
+
+        return ApiEndpoint::fromUrl(Url::parse($url));
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::POST;
+    }
+
+    public function getPayload(): array
+    {
+        return $this->recipientData;
+    }
+
+    public function getTimeout(): Duration
+    {
+        return Duration::fromSeconds((int) $this->config->timeout);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        // Exponential backoff: 1s, 2s, 4s
+        return new ExponentialBackoffStrategy(
+            maxAttempts: 3,
+            baseDelaySeconds: 1,
+            maxDelaySeconds: 10
+        );
+    }
+
+    public function getHeaders(): Headers
+    {
+        // Basic Auth
+        $credentials = base64_encode("{$this->config->username}:{$this->config->password}");
+
+        return new Headers([
+            'Authorization' => "Basic {$credentials}",
+            'Content-Type' => 'application/json',
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'rapidmail.create_recipient';
+    }
+}

src/Infrastructure/Api/RapidMail/ApiRequests/DeleteRecipientApiRequest.php

@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ApiRequests;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\ExponentialBackoffStrategy;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\RapidMail\RapidMailConfig;
+
+/**
+ * Domain-specific API request for deleting a recipient from RapidMail
+ *
+ * Example usage:
+ *
+ * $request = new DeleteRecipientApiRequest(
+ *     config: $rapidMailConfig,
+ *     recipientId: '12345'
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class DeleteRecipientApiRequest implements ApiRequest
+{
+    public function __construct(
+        private RapidMailConfig $config,
+        private string $recipientId
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        $url = rtrim($this->config->baseUrl, '/') . '/recipients/' . $this->recipientId;
+
+        return ApiEndpoint::fromUrl(Url::parse($url));
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::DELETE;
+    }
+
+    public function getTimeout(): Duration
+    {
+        return Duration::fromSeconds((int) $this->config->timeout);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        // Exponential backoff: 1s, 2s, 4s
+        return new ExponentialBackoffStrategy(
+            maxAttempts: 3,
+            baseDelaySeconds: 1,
+            maxDelaySeconds: 10
+        );
+    }
+
+    public function getHeaders(): Headers
+    {
+        // Basic Auth
+        $credentials = base64_encode("{$this->config->username}:{$this->config->password}");
+
+        return new Headers([
+            'Authorization' => "Basic {$credentials}",
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'rapidmail.delete_recipient';
+    }
+}

src/Infrastructure/Api/RapidMail/ApiRequests/GetRecipientApiRequest.php

@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ApiRequests;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\ExponentialBackoffStrategy;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\RapidMail\RapidMailConfig;
+
+/**
+ * Domain-specific API request for retrieving a recipient from RapidMail
+ *
+ * Example usage:
+ *
+ * $request = new GetRecipientApiRequest(
+ *     config: $rapidMailConfig,
+ *     recipientId: '12345'
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class GetRecipientApiRequest implements ApiRequest
+{
+    public function __construct(
+        private RapidMailConfig $config,
+        private string $recipientId
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        $url = rtrim($this->config->baseUrl, '/') . '/recipients/' . $this->recipientId;
+
+        return ApiEndpoint::fromUrl(Url::parse($url));
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::GET;
+    }
+
+    public function getTimeout(): Duration
+    {
+        return Duration::fromSeconds((int) $this->config->timeout);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        // Exponential backoff: 1s, 2s, 4s
+        return new ExponentialBackoffStrategy(
+            maxAttempts: 3,
+            baseDelaySeconds: 1,
+            maxDelaySeconds: 10
+        );
+    }
+
+    public function getHeaders(): Headers
+    {
+        // Basic Auth
+        $credentials = base64_encode("{$this->config->username}:{$this->config->password}");
+
+        return new Headers([
+            'Authorization' => "Basic {$credentials}",
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'rapidmail.get_recipient';
+    }
+}

src/Infrastructure/Api/RapidMail/ApiRequests/SearchRecipientsApiRequest.php

@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ApiRequests;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\ExponentialBackoffStrategy;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\RapidMail\RapidMailConfig;
+
+/**
+ * Domain-specific API request for searching recipients in RapidMail
+ *
+ * Example usage:
+ *
+ * $request = new SearchRecipientsApiRequest(
+ *     config: $rapidMailConfig,
+ *     filter: ['email' => 'user@example.com'],
+ *     page: 1,
+ *     perPage: 50
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class SearchRecipientsApiRequest implements ApiRequest
+{
+    public function __construct(
+        private RapidMailConfig $config,
+        private array $filter = [],
+        private int $page = 1,
+        private int $perPage = 50
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        $baseUrl = rtrim($this->config->baseUrl, '/') . '/recipients';
+
+        // Build query parameters
+        $queryParams = [
+            'page' => (string) $this->page,
+            'per_page' => (string) $this->perPage,
+        ];
+
+        // Merge filter parameters
+        if (!empty($this->filter)) {
+            foreach ($this->filter as $key => $value) {
+                $queryParams[$key] = is_array($value) ? json_encode($value) : (string) $value;
+            }
+        }
+
+        // Build query string
+        $queryString = http_build_query($queryParams);
+
+        // Create URL with query parameters
+        $url = Url::parse($baseUrl)->withQuery($queryString);
+
+        return ApiEndpoint::fromUrl($url);
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::GET;
+    }
+
+    public function getTimeout(): Duration
+    {
+        return Duration::fromSeconds((int) $this->config->timeout);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        // Exponential backoff: 1s, 2s, 4s
+        return new ExponentialBackoffStrategy(
+            maxAttempts: 3,
+            baseDelaySeconds: 1,
+            maxDelaySeconds: 10
+        );
+    }
+
+    public function getHeaders(): Headers
+    {
+        // Basic Auth
+        $credentials = base64_encode("{$this->config->username}:{$this->config->password}");
+
+        return new Headers([
+            'Authorization' => "Basic {$credentials}",
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'rapidmail.search_recipients';
+    }
+}

src/Infrastructure/Api/RapidMail/ApiRequests/UpdateRecipientApiRequest.php

@@ -0,0 +1,91 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ApiRequests;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\HasPayload;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\ExponentialBackoffStrategy;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\RapidMail\RapidMailConfig;
+
+/**
+ * Domain-specific API request for updating a recipient in RapidMail
+ *
+ * Example usage:
+ *
+ * $request = new UpdateRecipientApiRequest(
+ *     config: $rapidMailConfig,
+ *     recipientId: '12345',
+ *     recipientData: [
+ *         'firstname' => 'Jane',
+ *         'lastname' => 'Doe'
+ *     ]
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class UpdateRecipientApiRequest implements ApiRequest, HasPayload
+{
+    public function __construct(
+        private RapidMailConfig $config,
+        private string $recipientId,
+        private array $recipientData
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        $url = rtrim($this->config->baseUrl, '/') . '/recipients/' . $this->recipientId;
+
+        return ApiEndpoint::fromUrl(Url::parse($url));
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::PATCH;
+    }
+
+    public function getPayload(): array
+    {
+        return $this->recipientData;
+    }
+
+    public function getTimeout(): Duration
+    {
+        return Duration::fromSeconds((int) $this->config->timeout);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        // Exponential backoff: 1s, 2s, 4s
+        return new ExponentialBackoffStrategy(
+            maxAttempts: 3,
+            baseDelaySeconds: 1,
+            maxDelaySeconds: 10
+        );
+    }
+
+    public function getHeaders(): Headers
+    {
+        // Basic Auth
+        $credentials = base64_encode("{$this->config->username}:{$this->config->password}");
+
+        return new Headers([
+            'Authorization' => "Basic {$credentials}",
+            'Content-Type' => 'application/json',
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'rapidmail.update_recipient';
+    }
+}

src/Infrastructure/Api/RapidMail/SendEmailApiRequest.php

@@ -0,0 +1,86 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\RapidMail\ValueObjects\{EmailAddress, EmailTemplate, RapidMailApiKey};
+
+/**
+ * Domain-specific API request for sending emails via RapidMail
+ *
+ * Example usage:
+ *
+ * $request = new SendEmailApiRequest(
+ *     apiKey: $apiKey,
+ *     to: EmailAddress::fromString('user@example.com'),
+ *     template: EmailTemplate::fromString('welcome'),
+ *     data: ['name' => 'John Doe']
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class SendEmailApiRequest implements ApiRequest
+{
+    public function __construct(
+        private RapidMailApiKey $apiKey,
+        private EmailAddress $to,
+        private EmailTemplate $template,
+        private array $data = [],
+        private ?RetryStrategy $retryStrategy = null
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        return ApiEndpoint::fromUrl(
+            Url::parse('https://api.rapidmail.com/v1/send')
+        );
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::POST;
+    }
+
+    public function getPayload(): array
+    {
+        return [
+            'to' => $this->to->value,
+            'template' => $this->template->value,
+            'data' => $this->data,
+        ];
+    }
+
+    public function getTimeout(): Duration
+    {
+        // Email sending can take a bit longer
+        return Duration::fromSeconds(15);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        return $this->retryStrategy;
+    }
+
+    public function getHeaders(): Headers
+    {
+        return new Headers([
+            'Authorization' => "Bearer {$this->apiKey->value}",
+            'Content-Type' => 'application/json',
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'rapidmail.send_email';
+    }
+}

src/Infrastructure/Api/RapidMail/ValueObjects/EmailAddress.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ValueObjects;
+
+use InvalidArgumentException;
+
+/**
+ * Value object for email address
+ */
+final readonly class EmailAddress
+{
+    public function __construct(
+        public string $value
+    ) {
+        if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
+            throw new InvalidArgumentException("Invalid email address: {$value}");
+        }
+    }
+
+    public static function fromString(string $value): self
+    {
+        return new self($value);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+
+    public function __toString(): string
+    {
+        return $this->toString();
+    }
+}

src/Infrastructure/Api/RapidMail/ValueObjects/EmailTemplate.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ValueObjects;
+
+use InvalidArgumentException;
+
+/**
+ * Value object for email template identifier
+ */
+final readonly class EmailTemplate
+{
+    public function __construct(
+        public string $value
+    ) {
+        if (empty($value)) {
+            throw new InvalidArgumentException('Email template identifier cannot be empty');
+        }
+
+        if (!preg_match('/^[a-z0-9_-]+$/', $value)) {
+            throw new InvalidArgumentException(
+                'Email template identifier must contain only lowercase letters, numbers, hyphens and underscores'
+            );
+        }
+    }
+
+    public static function fromString(string $value): self
+    {
+        return new self($value);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+
+    public function __toString(): string
+    {
+        return $this->toString();
+    }
+}

src/Infrastructure/Api/RapidMail/ValueObjects/RapidMailApiKey.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\RapidMail\ValueObjects;
+
+use InvalidArgumentException;
+
+/**
+ * Value object for RapidMail API key
+ */
+final readonly class RapidMailApiKey
+{
+    public function __construct(
+        public string $value
+    ) {
+        if (empty($value)) {
+            throw new InvalidArgumentException('RapidMail API key cannot be empty');
+        }
+
+        if (strlen($value) < 32) {
+            throw new InvalidArgumentException('RapidMail API key appears invalid (too short)');
+        }
+    }
+
+    public static function fromString(string $value): self
+    {
+        return new self($value);
+    }
+}

src/Infrastructure/Api/Shopify/CreateOrderApiRequest.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\Shopify;
+
+use App\Framework\ApiGateway\ApiRequest;
+use App\Framework\ApiGateway\ValueObjects\ApiEndpoint;
+use App\Framework\Core\ValueObjects\Duration;
+use App\Framework\Http\Headers;
+use App\Framework\Http\Method as HttpMethod;
+use App\Framework\Http\Url\Url;
+use App\Framework\Retry\RetryStrategy;
+use App\Infrastructure\Api\Shopify\ValueObjects\{ShopifyApiKey, ShopifyStore};
+
+/**
+ * Domain-specific API request for creating orders in Shopify
+ *
+ * Example usage:
+ *
+ * $request = new CreateOrderApiRequest(
+ *     apiKey: $apiKey,
+ *     store: ShopifyStore::fromString('mystore'),
+ *     orderData: [
+ *         'line_items' => [
+ *             ['variant_id' => 123, 'quantity' => 2]
+ *         ],
+ *         'customer' => ['email' => 'customer@example.com']
+ *     ]
+ * );
+ *
+ * $response = $apiGateway->send($request);
+ */
+final readonly class CreateOrderApiRequest implements ApiRequest
+{
+    public function __construct(
+        private ShopifyApiKey $apiKey,
+        private ShopifyStore $store,
+        private array $orderData,
+        private ?RetryStrategy $retryStrategy = null
+    ) {
+    }
+
+    public function getEndpoint(): ApiEndpoint
+    {
+        $shopUrl = "https://{$this->store->value}.myshopify.com/admin/api/2024-01/orders.json";
+
+        return ApiEndpoint::fromUrl(
+            Url::parse($shopUrl)
+        );
+    }
+
+    public function getMethod(): HttpMethod
+    {
+        return HttpMethod::POST;
+    }
+
+    public function getPayload(): array
+    {
+        return [
+            'order' => $this->orderData,
+        ];
+    }
+
+    public function getTimeout(): Duration
+    {
+        // Order creation should be quick
+        return Duration::fromSeconds(10);
+    }
+
+    public function getRetryStrategy(): ?RetryStrategy
+    {
+        return $this->retryStrategy;
+    }
+
+    public function getHeaders(): Headers
+    {
+        return new Headers([
+            'X-Shopify-Access-Token' => $this->apiKey->value,
+            'Content-Type' => 'application/json',
+            'Accept' => 'application/json',
+        ]);
+    }
+
+    public function getRequestName(): string
+    {
+        return 'shopify.create_order';
+    }
+}

src/Infrastructure/Api/Shopify/ValueObjects/ShopifyApiKey.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\Shopify\ValueObjects;
+
+use InvalidArgumentException;
+
+/**
+ * Value object for Shopify API access token
+ */
+final readonly class ShopifyApiKey
+{
+    public function __construct(
+        public string $value
+    ) {
+        if (empty($value)) {
+            throw new InvalidArgumentException('Shopify API key cannot be empty');
+        }
+
+        // Shopify access tokens are typically 32+ characters
+        if (strlen($value) < 32) {
+            throw new InvalidArgumentException('Shopify API key appears invalid (too short)');
+        }
+    }
+
+    public static function fromString(string $value): self
+    {
+        return new self($value);
+    }
+}

src/Infrastructure/Api/Shopify/ValueObjects/ShopifyStore.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Infrastructure\Api\Shopify\ValueObjects;
+
+use InvalidArgumentException;
+
+/**
+ * Value object for Shopify store identifier
+ */
+final readonly class ShopifyStore
+{
+    public function __construct(
+        public string $value
+    ) {
+        if (empty($value)) {
+            throw new InvalidArgumentException('Shopify store identifier cannot be empty');
+        }
+
+        // Shopify store names are lowercase alphanumeric with hyphens
+        if (!preg_match('/^[a-z0-9][a-z0-9-]*[a-z0-9]$/', $value)) {
+            throw new InvalidArgumentException(
+                'Shopify store identifier must be lowercase alphanumeric with hyphens'
+            );
+        }
+    }
+
+    public static function fromString(string $value): self
+    {
+        return new self($value);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+
+    public function __toString(): string
+    {
+        return $this->toString();
+    }
+
+    /**
+     * Get the full Shopify URL for this store
+     */
+    public function getShopifyUrl(): string
+    {
+        return "https://{$this->value}.myshopify.com";
+    }
+}