Enable servers to send sampling messages to clients (#101)

examples/stdio-client-communication/ClientAwareService.php

@@ -0,0 +1,71 @@
+<?php
+
+/*
+ * This file is part of the official PHP MCP SDK.
+ *
+ * A collaboration between Symfony and the PHP Foundation.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Mcp\Example\StdioClientCommunication;
+
+use Mcp\Capability\Attribute\McpTool;
+use Mcp\Schema\Content\TextContent;
+use Mcp\Schema\Enum\LoggingLevel;
+use Mcp\Server\ClientAwareInterface;
+use Mcp\Server\ClientAwareTrait;
+use Psr\Log\LoggerInterface;
+
+final class ClientAwareService implements ClientAwareInterface
+{
+    use ClientAwareTrait;
+
+    public function __construct(
+        private readonly LoggerInterface $logger,
+    ) {
+        $this->logger->info('SamplingTool instantiated for sampling example.');
+    }
+
+    /**
+     * @return array{incident: string, recommended_actions: string, model: string}
+     */
+    #[McpTool('coordinate_incident_response', 'Coordinate an incident response with logging, progress, and sampling.')]
+    public function coordinateIncident(string $incidentTitle): array
+    {
+        $this->log(LoggingLevel::Warning, \sprintf('Incident triage started: %s', $incidentTitle));
+
+        $steps = [
+            'Collecting telemetry',
+            'Assessing scope',
+            'Coordinating responders',
+        ];
+
+        foreach ($steps as $index => $step) {
+            $progress = ($index + 1) / \count($steps);
+
+            $this->progress($progress, 1, $step);
+
+            usleep(180_000); // Simulate work being done
+        }
+
+        $prompt = \sprintf(
+            'Provide a concise response strategy for incident "%s" based on the steps completed: %s.',
+            $incidentTitle,
+            implode(', ', $steps)
+        );
+
+        $result = $this->sample($prompt, 350, 90, ['temperature' => 0.5]);
+
+        $recommendation = $result->content instanceof TextContent ? trim((string) $result->content->text) : '';
+
+        $this->log(LoggingLevel::Info, \sprintf('Incident triage completed for %s', $incidentTitle));
+
+        return [
+            'incident' => $incidentTitle,
+            'recommended_actions' => $recommendation,
+            'model' => $result->model,
+        ];
+    }
+}