feat: register OAuth MCP server with direct tools

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

src/Plugin.php

@@ -4,6 +4,12 @@ declare(strict_types=1);
 
 namespace LIT\MCP;
 
+use LIT\MCP\Abilities\AbilityRegistrar;
+use LIT\MCP\Guides\InstructionsBuilder;
+use LIT\MCP\Integrations\Core\CoreIntegration;
+use LIT\MCP\Integrations\IntegrationRegistry;
+use LIT\MCP\Server\ServerRegistrar;
+
 /**
  * Wires WP-LIT-MCP into WordPress.
  */
@@ -22,6 +28,15 @@ final class Plugin
         }
 
         (new Access())->register();
+
+        $registry = new IntegrationRegistry(
+            new CoreIntegration(self::pluginDir() . '/docs/guides')
+        );
+
+        (new AbilityRegistrar($registry))->register();
+        (new ServerRegistrar($registry, new InstructionsBuilder($registry)))->register();
+
+        \WPMedia\MCP\OAuth\Bootstrap::instance();
     }
 
     public static function pluginDir(): string

src/Server/ServerRegistrar.php

@@ -0,0 +1,100 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Server;
+
+use LIT\MCP\Guides\InstructionsBuilder;
+use LIT\MCP\Integrations\IntegrationRegistry;
+use WP\MCP\Core\McpAdapter;
+use WP\MCP\Infrastructure\ErrorHandling\ErrorLogMcpErrorHandler;
+use WPMedia\MCP\OAuth\Transport\OAuthHttpTransport;
+
+/**
+ * Registers the OAuth-protected MCP server with our own tool list.
+ *
+ * wp-media/mcp-oauth hardcodes server id/route (token audience) and only three
+ * meta-tools. We register the same server id first (priority 5 < mcp-oauth's 10);
+ * mcp-oauth's later attempt fails with "duplicate server id" (logged via
+ * _doing_it_wrong in debug mode only) – see spec §4.2.
+ */
+final class ServerRegistrar
+{
+    public const SERVER_ID = 'mcp-oauth-server';
+    public const NAMESPACE = 'mcp';
+    public const ROUTE = 'mcp-oauth-server';
+    public const META_TOOLS = [
+        'mcp-adapter/discover-abilities',
+        'mcp-adapter/get-ability-info',
+        'mcp-adapter/execute-ability',
+    ];
+
+    /** @var callable(): bool */
+    private $oauthEnabled;
+
+    public function __construct(
+        private IntegrationRegistry $registry,
+        private InstructionsBuilder $instructions,
+        ?callable $oauthEnabled = null
+    ) {
+        $this->oauthEnabled = $oauthEnabled
+            ?? static fn (): bool => (bool) apply_filters('wpmedia_mcp_oauth_server_enabled', true);
+    }
+
+    public function register(): void
+    {
+        add_action('mcp_adapter_init', [$this, 'createServer'], 5);
+    }
+
+    /** @return array<string, mixed>|null */
+    public function serverArguments(): ?array
+    {
+        if (! ($this->oauthEnabled)()) {
+            return null;
+        }
+
+        return [
+            'id' => self::SERVER_ID,
+            'namespace' => self::NAMESPACE,
+            'route' => self::ROUTE,
+            'name' => 'LIT MCP',
+            'description' => $this->instructions->build(),
+            'version' => '0.1.0',
+            'tools' => array_merge($this->registry->directAbilityNames(), self::META_TOOLS),
+        ];
+    }
+
+    public function createServer(): void
+    {
+        if (
+            ! doing_action('mcp_adapter_init')
+            || ! class_exists(McpAdapter::class)
+            || ! class_exists(OAuthHttpTransport::class)
+        ) {
+            return;
+        }
+
+        $args = $this->serverArguments();
+        if ($args === null) {
+            return;
+        }
+
+        $result = McpAdapter::instance()->create_server(
+            $args['id'],
+            $args['namespace'],
+            $args['route'],
+            $args['name'],
+            $args['description'],
+            $args['version'],
+            [OAuthHttpTransport::class],
+            ErrorLogMcpErrorHandler::class,
+            null,
+            $args['tools']
+        );
+
+        if (is_wp_error($result)) {
+            $message = '[wp-lit-mcp] MCP server registration failed: ' . $result->get_error_message();
+            error_log($message); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
+        }
+    }
+}

tests/Unit/Server/ServerRegistrarTest.php

@@ -0,0 +1,80 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Server;
+
+use Brain\Monkey\Functions;
+use LIT\MCP\Abilities\Ability;
+use LIT\MCP\Guides\InstructionsBuilder;
+use LIT\MCP\Integrations\Integration;
+use LIT\MCP\Integrations\IntegrationRegistry;
+use LIT\MCP\Server\ServerRegistrar;
+use LIT\MCP\Tests\Unit\TestCase;
+use Mockery;
+
+final class ServerRegistrarTest extends TestCase
+{
+    private function registry(): IntegrationRegistry
+    {
+        $direct = Mockery::mock(Ability::class);
+        $direct->allows('name')->andReturn('lit/guide');
+        $direct->allows('isDirect')->andReturn(true);
+        $indirect = Mockery::mock(Ability::class);
+        $indirect->allows('name')->andReturn('lit/rare-tool');
+        $indirect->allows('isDirect')->andReturn(false);
+
+        $core = Mockery::mock(Integration::class);
+        $core->allows('id')->andReturn('core');
+        $core->allows('isAvailable')->andReturn(true);
+        $core->allows('abilities')->andReturn([$direct, $indirect]);
+
+        return new IntegrationRegistry($core);
+    }
+
+    private function instructions(): InstructionsBuilder
+    {
+        // InstructionsBuilder is final (not mockable) and pure – use the real one.
+        return new InstructionsBuilder($this->registry());
+    }
+
+    public function testServerUsesOauthRouteDirectToolsPlusMetaToolsAndInstructions(): void
+    {
+        $args = (new ServerRegistrar($this->registry(), $this->instructions(), static fn () => true))->serverArguments();
+
+        self::assertSame('mcp-oauth-server', $args['id']);
+        self::assertSame('mcp', $args['namespace']);
+        self::assertSame('mcp-oauth-server', $args['route']);
+        self::assertStringContainsString('Aktive Integrationen: core', $args['description']);
+        self::assertSame(
+            ['lit/guide', 'mcp-adapter/discover-abilities', 'mcp-adapter/get-ability-info', 'mcp-adapter/execute-ability'],
+            $args['tools']
+        );
+        self::assertNotContains('lit/rare-tool', $args['tools']);
+    }
+
+    public function testNoServerWhenOauthIsDisabled(): void
+    {
+        $registrar = new ServerRegistrar($this->registry(), $this->instructions(), static fn () => false);
+
+        self::assertNull($registrar->serverArguments());
+    }
+
+    public function testCreateServerOutsideAdapterInitDoesNothing(): void
+    {
+        Functions\when('doing_action')->justReturn(false);
+        $oauthChecked = false;
+        $registrar = new ServerRegistrar(
+            $this->registry(),
+            $this->instructions(),
+            static function () use (&$oauthChecked): bool {
+                $oauthChecked = true;
+                return true;
+            }
+        );
+
+        $registrar->createServer();
+
+        self::assertFalse($oauthChecked, 'createServer must bail out before touching the adapter');
+    }
+}