Fix missing instructions from builder to handler

Author: chr-hertel

examples/01-discovery-stdio-calculator/server.php

@@ -20,6 +20,7 @@
 
 $server = Server::builder()
     ->setServerInfo('Stdio Calculator', '1.1.0', 'Basic Calculator over STDIO transport.')
+    ->setInstructions('This server supports basic arithmetic operations: add, subtract, multiply, and divide. Send JSON-RPC requests to perform calculations.')
     ->setContainer(container())
     ->setLogger(logger())
     ->setDiscovery(__DIR__, ['.'])

phpstan-baseline.neon

@@ -78,12 +78,6 @@ parameters:
 			count: 1
 			path: src/Server/Builder.php
 
-		-
-			message: '#^Property Mcp\\Server\\Builder\:\:\$instructions is never read, only written\.$#'
-			identifier: property.onlyWritten
-			count: 1
-			path: src/Server/Builder.php
-
 		-
 			message: '#^Property Mcp\\Server\\Builder\:\:\$prompts type has no value type specified in iterable type array\.$#'
 			identifier: missingType.iterableValue

src/Server/Builder.php

@@ -337,14 +337,17 @@ public function build(): Server
             jsonRpcHandler: JsonRpcHandler::make(
                 registry: $registry,
                 referenceProvider: $registry,
-                implementation: $this->serverInfo,
+                configuration: new Configuration(
+                    $this->serverInfo,
+                    $registry->getCapabilities(),
+                    $this->paginationLimit, $this->instructions,
+                ),
                 toolCaller: $toolCaller,
                 resourceReader: $resourceReader,
                 promptGetter: $promptGetter,
                 sessionStore: $sessionStore,
                 sessionFactory: $sessionFactory,
                 logger: $logger,
-                paginationLimit: $this->paginationLimit,
             ),
             logger: $logger,
         );

src/Server/Handler/JsonRpcHandler.php

@@ -21,12 +21,12 @@
 use Mcp\Exception\InvalidInputMessageException;
 use Mcp\Exception\NotFoundExceptionInterface;
 use Mcp\JsonRpc\MessageFactory;
-use Mcp\Schema\Implementation;
 use Mcp\Schema\JsonRpc\Error;
 use Mcp\Schema\JsonRpc\HasMethodInterface;
 use Mcp\Schema\JsonRpc\Request;
 use Mcp\Schema\JsonRpc\Response;
 use Mcp\Schema\Request\InitializeRequest;
+use Mcp\Server\Configuration;
 use Mcp\Server\Handler;
 use Mcp\Server\Session\SessionFactoryInterface;
 use Mcp\Server\Session\SessionInterface;
@@ -65,7 +65,7 @@ public function __construct(
     public static function make(
         ReferenceRegistryInterface $registry,
         ReferenceProviderInterface $referenceProvider,
-        Implementation $implementation,
+        Configuration $configuration,
         ToolCallerInterface $toolCaller,
         ResourceReaderInterface $resourceReader,
         PromptGetterInterface $promptGetter,
@@ -80,7 +80,7 @@ public static function make(
             sessionStore: $sessionStore,
             methodHandlers: [
                 new Notification\InitializedHandler(),
-                new Handler\Request\InitializeHandler($registry->getCapabilities(), $implementation),
+                new Handler\Request\InitializeHandler($configuration),
                 new Handler\Request\PingHandler(),
                 new Handler\Request\ListPromptsHandler($referenceProvider, $paginationLimit),
                 new Handler\Request\GetPromptHandler($promptGetter),

src/Server/Handler/Request/InitializeHandler.php

@@ -17,6 +17,7 @@
 use Mcp\Schema\Request\InitializeRequest;
 use Mcp\Schema\Result\InitializeResult;
 use Mcp\Schema\ServerCapabilities;
+use Mcp\Server\Configuration;
 use Mcp\Server\Handler\MethodHandlerInterface;
 use Mcp\Server\Session\SessionInterface;
 
@@ -26,8 +27,7 @@
 final class InitializeHandler implements MethodHandlerInterface
 {
     public function __construct(
-        public readonly ?ServerCapabilities $capabilities = new ServerCapabilities(),
-        public readonly ?Implementation $serverInfo = new Implementation(),
+        public readonly ?Configuration $configuration = null,
     ) {
     }
 
@@ -44,7 +44,11 @@ public function handle(InitializeRequest|HasMethodInterface $message, SessionInt
 
         return new Response(
             $message->getId(),
-            new InitializeResult($this->capabilities, $this->serverInfo),
+            new InitializeResult(
+                $this->configuration->capabilities ?? new ServerCapabilities(),
+                $this->configuration->serverInfo ?? new Implementation(),
+                $this->configuration?->instructions,
+            ),
         );
     }
 }