Add possibility to set custom ServerCapabilities. (#95)

src/Capability/Registry.php

@@ -63,6 +63,8 @@ final class Registry implements ReferenceProviderInterface, ReferenceRegistryInt
      */
     private array $resourceTemplates = [];
 
+    private ServerCapabilities $serverCapabilities;
+
     public function __construct(
         private readonly ?EventDispatcherInterface $eventDispatcher = null,
         private readonly LoggerInterface $logger = new NullLogger(),
@@ -75,7 +77,7 @@ final class Registry implements ReferenceProviderInterface, ReferenceRegistryInt
             $this->logger->info('No capabilities registered on server.');
         }
 
-        return new ServerCapabilities(
+        return $this->serverCapabilities ?? new ServerCapabilities(
             tools: [] !== $this->tools,
             toolsListChanged: $this->eventDispatcher instanceof EventDispatcherInterface,
             resources: [] !== $this->resources || [] !== $this->resourceTemplates,
@@ -453,4 +455,9 @@ final class Registry implements ReferenceProviderInterface, ReferenceRegistryInt
 
         return array_values(\array_slice($items, $offset, $limit));
     }
+
+    public function setServerCapabilities(ServerCapabilities $serverCapabilities): void
+    {
+        $this->serverCapabilities = $serverCapabilities;
+    }
 }

src/Server/Builder.php

@@ -138,6 +138,8 @@ final class Builder
      */
     private array $discoveryExcludeDirs = [];
 
+    private ?ServerCapabilities $serverCapabilities = null;
+
     /**
      * Sets the server's identity. Required.
      */
@@ -264,6 +266,13 @@ final class Builder
         return $this;
     }
 
+    public function setServerCapabilities(ServerCapabilities $serverCapabilities): self
+    {
+        $this->serverCapabilities = $serverCapabilities;
+
+        return $this;
+    }
+
     /**
      * Manually registers a tool handler.
      *
@@ -348,6 +357,9 @@ final class Builder
         $registry = new Registry($this->eventDispatcher, $logger);
 
         $this->registerCapabilities($registry, $logger);
+        if ($this->serverCapabilities) {
+            $registry->setServerCapabilities($this->serverCapabilities);
+        }
 
         if (null !== $this->discoveryBasePath) {
             $this->performDiscovery($registry, $logger);