[Server] Allow overriding the default file name pattern for Discovery (#292)

* Add optional namePatterns capability to discovery so that the default scan for `*.php` files can be overridden.

* add default to namePatterns docs

* add an error check if we manage to pass in an empty list of patterns

* add unit tests (and a static entry to classmap for composer.json so it autoloads from a non .php file for the test)

* run php-cs-fixer

* change how default namePatterns are set and make sure all the annotations are correct

* Fix bad whitespace

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

* switch to a const default instead of nullable with a check in the function to convert null to a default

* make sure we handle empty arrays

* formatting fixes

* Apply suggestion from @chr-hertel

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

* Add changelog entry

---------

Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 All notable changes to `mcp/sdk` will be documented in this file.
 
+0.6.0
+-----
+
+* Allow overriding the default name pattern for Discovery
+
 0.5.0
 -----
 

composer.json

@@ -80,7 +80,10 @@
       "Mcp\\Example\\Server\\OAuthMicrosoft\\": "examples/server/oauth-microsoft/",
       "Mcp\\Example\\Server\\SchemaShowcase\\": "examples/server/schema-showcase/",
       "Mcp\\Tests\\": "tests/"
-    }
+    },
+    "classmap": [
+      "tests/Unit/Capability/Discovery/Fixtures/AlternativeFileNameToolHandler.class.inc"
+    ]
   },
   "config": {
     "allow-plugins": {
@@ -89,4 +92,4 @@
     },
     "sort-packages": true
   }
-}
+}

docs/server-builder.md

@@ -99,8 +99,9 @@ $server = Server::builder()
     ->setDiscovery(
         basePath: __DIR__,
         scanDirs: ['.', 'src', 'lib'],           // Where to look for MCP attributes
-        excludeDirs: ['vendor', 'tests'],        // Where NOT to look 
+        excludeDirs: ['vendor', 'tests'],        // Where NOT to look
-        cache: $cacheInstance                    // Optional: cache discovered elements
+        cache: $cacheInstance,                   // Optional: cache discovered elements
+        namePatterns: ['*.php', '*.inc'],        // Optional: list of filename patterns to match
     );
 ```
 
@@ -109,6 +110,7 @@ $server = Server::builder()
 - `$scanDirs` (array): Directories to recursively scan for `#[McpTool]`, `#[McpResource]`, etc. All subdirectories are included. (default: `['.', 'src']`)
 - `$excludeDirs` (array): Directory names to exclude **within** the scanned directories during recursive scanning
 - `$cache` (CacheInterface|null): Optional PSR-16 cache to store discovered elements for performance
+- `$namePatterns` (array): Optional list of patterns (regexp, glob, or string) for file names (default: `['*.php']`)
 
 **Basic Discovery (scans current directory and `src/`):**
 ```php
@@ -137,7 +139,7 @@ $server = Server::builder()
 
 **How `excludeDirs` works:**
 - If scanning `src/` and there's `src/vendor/`, it will be excluded
-- If scanning `lib/` and there's `lib/tests/`, it will be excluded  
+- If scanning `lib/` and there's `lib/tests/`, it will be excluded
 - But if `vendor/` and `tests/` are at the same level as `src/`, they're not scanned anyway (not in `scanDirs`)
 
 > **Performance**: Always use a cache in production. The first run scans and caches all discovered MCP elements, making
@@ -255,19 +257,19 @@ $server = Server::builder()
         name: 'add_numbers',
         description: 'Adds two numbers together'
     )
-    
+
     // Using class method pair
     ->addTool(
         handler: [Calculator::class, 'multiply'],
         name: 'multiply_numbers'
         // name and description are optional - derived from method name and docblock
     )
-    
+
     // Using instance method
     ->addTool(
         handler: [$calculatorInstance, 'divide']
     )
-    
+
     // Using invokable class
     ->addTool(
         handler: InvokableCalculator::class
@@ -421,17 +423,17 @@ $server = Server::builder()
 individual JSON-RPC messages. They do not receive the builder's registry, container, or discovery output unless you pass
 those dependencies in yourself.
 
-> **Warning**: Custom message handlers bypass discovery, manual capability registration, and container lookups (unless 
+> **Warning**: Custom message handlers bypass discovery, manual capability registration, and container lookups (unless
 > you explicitly pass them). Tools, resources, and prompts you register elsewhere will not show up unless your handler
-> loads and executes them manually. Reach for this API only when you need that level of control and are comfortable 
+> loads and executes them manually. Reach for this API only when you need that level of control and are comfortable
 > taking on the additional plumbing.
 
 ### Request Handlers
 
-Handle JSON-RPC requests (messages with an `id` that expect a response). Request handlers **must** return either a 
+Handle JSON-RPC requests (messages with an `id` that expect a response). Request handlers **must** return either a
 `Response` or an `Error` object.
 
-Attach request handlers with `addRequestHandler()` (single) or `addRequestHandlers()` (multiple). You can call these 
+Attach request handlers with `addRequestHandler()` (single) or `addRequestHandlers()` (multiple). You can call these
 methods as many times as needed; each call prepends the handlers so they execute before the defaults:
 
 ```php
@@ -508,7 +510,7 @@ interface NotificationHandlerInterface
 
 ### Example
 
-Check out `examples/custom-method-handlers/server.php` for a complete example showing how to implement 
+Check out `examples/custom-method-handlers/server.php` for a complete example showing how to implement
 custom `tools/list` and `tools/call` request handlers independently of the registry.
 
 ## Complete Example
@@ -540,25 +542,25 @@ $container->set(DatabaseService::class, new DatabaseService($container->get(\PDO
 $server = Server::builder()
     // Server identity
     ->setServerInfo('Advanced Calculator', '2.1.0')
-    
+
     // Performance and behavior
     ->setPaginationLimit(100)
     ->setInstructions('Use calculate tool for math operations. Check config resource for current settings.')
-    
+
     // Discovery with caching
     ->setDiscovery(__DIR__, ['src'], ['vendor', 'tests'], $cache)
-    
+
     // Session management
     ->setSession($sessionStore)
-    
+
     // Services
     ->setLogger($logger)
     ->setContainer($container)
-    
+
     // Manual capability registration
     ->addTool([Calculator::class, 'advancedCalculation'], 'advanced_calc')
     ->addResource([Config::class, 'getSettings'], 'config://app/settings', 'app_settings')
-    
+
     // Build the server
     ->build();
 ```

src/Capability/Discovery/CachedDiscoverer.php

@@ -38,11 +38,12 @@ final class CachedDiscoverer implements DiscovererInterface
     /**
      * Discover MCP elements in the specified directories with caching.
      *
-     * @param string        $basePath    the base path for resolving directories
+     * @param string        $basePath     the base path for resolving directories
-     * @param array<string> $directories list of directories (relative to base path) to scan
+     * @param array<string> $directories  list of directories (relative to base path) to scan
-     * @param array<string> $excludeDirs list of directories (relative to base path) to exclude from the scan
+     * @param array<string> $excludeDirs  list of directories (relative to base path) to exclude from the scan
+     * @param array<string> $namePatterns list of file name patterns for the scan. Compatible with Finder->name()
      */
-    public function discover(string $basePath, array $directories, array $excludeDirs = []): DiscoveryState
+    public function discover(string $basePath, array $directories, array $excludeDirs = [], array $namePatterns = self::DEFAULT_NAME_PATERNS): DiscoveryState
     {
         $cacheKey = $this->generateCacheKey($basePath, $directories, $excludeDirs);
 
@@ -63,7 +64,7 @@ final class CachedDiscoverer implements DiscovererInterface
             'directories' => $directories,
         ]);
 
-        $discoveryState = $this->discoverer->discover($basePath, $directories, $excludeDirs);
+        $discoveryState = $this->discoverer->discover($basePath, $directories, $excludeDirs, $namePatterns);
 
         $this->cache->set($cacheKey, $discoveryState);
 

src/Capability/Discovery/Discoverer.php

@@ -65,11 +65,12 @@ final class Discoverer implements DiscovererInterface
     /**
      * Discover MCP elements in the specified directories and return the discovery state.
      *
-     * @param string        $basePath    the base path for resolving directories
+     * @param string        $basePath     the base path for resolving directories
-     * @param array<string> $directories list of directories (relative to base path) to scan
+     * @param array<string> $directories  list of directories (relative to base path) to scan
-     * @param array<string> $excludeDirs list of directories (relative to base path) to exclude from the scan
+     * @param array<string> $excludeDirs  list of directories (relative to base path) to exclude from the scan
+     * @param array<string> $namePatterns list of file name patterns for the scan. Compatible with Finder->name()
      */
-    public function discover(string $basePath, array $directories, array $excludeDirs = []): DiscoveryState
+    public function discover(string $basePath, array $directories, array $excludeDirs = [], array $namePatterns = self::DEFAULT_NAME_PATERNS): DiscoveryState
     {
         $startTime = microtime(true);
         $discoveredCount = [
@@ -79,6 +80,8 @@ final class Discoverer implements DiscovererInterface
             'resourceTemplates' => 0,
         ];
 
+        $namePatterns = !empty($namePatterns) ? $namePatterns : self::DEFAULT_NAME_PATERNS;
+
         $tools = [];
         $resources = [];
         $prompts = [];
@@ -106,7 +109,7 @@ final class Discoverer implements DiscovererInterface
             $finder->files()
                 ->in($absolutePaths)
                 ->exclude($excludeDirs)
-                ->name('*.php');
+                ->name($namePatterns);
 
             foreach ($finder as $file) {
                 $this->processFile($file, $discoveredCount, $tools, $resources, $prompts, $resourceTemplates);

src/Capability/Discovery/DiscovererInterface.php

@@ -20,12 +20,15 @@ namespace Mcp\Capability\Discovery;
  */
 interface DiscovererInterface
 {
+    public const DEFAULT_NAME_PATERNS = ['*.php'];
+
     /**
      * Discover MCP elements in the specified directories and return the discovery state.
      *
-     * @param string        $basePath    the base path for resolving directories
+     * @param string        $basePath     the base path for resolving directories
-     * @param array<string> $directories list of directories (relative to base path) to scan
+     * @param array<string> $directories  list of directories (relative to base path) to scan
-     * @param array<string> $excludeDirs list of directories (relative to base path) to exclude from the scan
+     * @param array<string> $excludeDirs  list of directories (relative to base path) to exclude from the scan
+     * @param array<string> $namePatterns list of file name patterns for the scan. Compatible with Finder->name()
      */
-    public function discover(string $basePath, array $directories, array $excludeDirs = []): DiscoveryState;
+    public function discover(string $basePath, array $directories, array $excludeDirs = [], array $namePatterns = self::DEFAULT_NAME_PATERNS): DiscoveryState;
 }

src/Capability/Registry/Loader/DiscoveryLoader.php

@@ -24,18 +24,20 @@ final class DiscoveryLoader implements LoaderInterface
     /**
      * @param string[]       $scanDirs
      * @param array|string[] $excludeDirs
+     * @param string[]       $namePatterns
      */
     public function __construct(
         private string $basePath,
         private array $scanDirs,
         private array $excludeDirs,
         private DiscovererInterface $discoverer,
+        private array $namePatterns = DiscovererInterface::DEFAULT_NAME_PATERNS,
     ) {
     }
 
     public function load(RegistryInterface $registry): void
     {
-        $discoveryState = $this->discoverer->discover($this->basePath, $this->scanDirs, $this->excludeDirs);
+        $discoveryState = $this->discoverer->discover($this->basePath, $this->scanDirs, $this->excludeDirs, $this->namePatterns);
 
         $registry->setDiscoveryState($discoveryState);
     }

src/Server/Builder.php

@@ -160,6 +160,11 @@ final class Builder
      */
     private array $discoveryExcludeDirs = [];
 
+    /**
+     * @var string[]|null
+     */
+    private ?array $discoveryNamePatterns = null;
+
     private ?ServerCapabilities $serverCapabilities = null;
 
     /**
@@ -348,17 +353,20 @@ final class Builder
     /**
      * @param string[] $scanDirs
      * @param string[] $excludeDirs
+     * @param string[] $namePatterns
      */
     public function setDiscovery(
         string $basePath,
         array $scanDirs = ['.', 'src'],
         array $excludeDirs = [],
         ?CacheInterface $cache = null,
+        array $namePatterns = DiscovererInterface::DEFAULT_NAME_PATERNS,
     ): self {
         $this->discoveryBasePath = $basePath;
         $this->discoveryScanDirs = $scanDirs;
         $this->discoveryExcludeDirs = $excludeDirs;
         $this->discoveryCache = $cache;
+        $this->discoveryNamePatterns = $namePatterns;
 
         return $this;
     }
@@ -531,7 +539,7 @@ final class Builder
         if (null !== $this->discoveryBasePath) {
             if (null !== $this->discoverer || class_exists(Finder::class)) {
                 $discoverer = $this->discoverer ?? $this->createDiscoverer($logger);
-                $loaders[] = new DiscoveryLoader($this->discoveryBasePath, $this->discoveryScanDirs, $this->discoveryExcludeDirs, $discoverer);
+                $loaders[] = new DiscoveryLoader($this->discoveryBasePath, $this->discoveryScanDirs, $this->discoveryExcludeDirs, $discoverer, $this->discoveryNamePatterns);
             } else {
                 $logger->warning('File-based discovery requires symfony/finder. Skipping automatic discovery. Run: composer require symfony/finder');
             }

tests/Unit/Capability/Discovery/DiscoveryTest.php

@@ -16,6 +16,7 @@ use Mcp\Capability\Completion\ListCompletionProvider;
 use Mcp\Capability\Discovery\Discoverer;
 use Mcp\Capability\Registry\ToolReference;
 use Mcp\Tests\Unit\Capability\Attribute\CompletionProviderFixture;
+use Mcp\Tests\Unit\Capability\Discovery\Fixtures\AlternativeFileNameToolHandler;
 use Mcp\Tests\Unit\Capability\Discovery\Fixtures\DiscoverableToolHandler;
 use Mcp\Tests\Unit\Capability\Discovery\Fixtures\InvocablePromptFixture;
 use Mcp\Tests\Unit\Capability\Discovery\Fixtures\InvocableResourceFixture;
@@ -34,10 +35,10 @@ class DiscoveryTest extends TestCase
 
     public function testDiscoversAllElementTypesCorrectlyFromFixtureFiles(): void
     {
-        $discovery = $this->discoverer->discover(__DIR__, ['Fixtures']);
+        $discovery = $this->discoverer->discover(__DIR__, ['Fixtures'], [], ['*.php', '*.inc']);
 
         $tools = $discovery->getTools();
-        $this->assertCount(4, $tools);
+        $this->assertCount(5, $tools);
 
         $this->assertArrayHasKey('greet_user', $tools);
         $this->assertFalse($tools['greet_user']->isManual);
@@ -56,6 +57,9 @@ class DiscoveryTest extends TestCase
         $this->assertFalse($tools['InvokableCalculator']->isManual);
         $this->assertEquals([InvocableToolFixture::class, '__invoke'], $tools['InvokableCalculator']->handler);
 
+        $this->assertArrayHasKey('inc_file_name_tool', $tools);
+        $this->assertEquals([AlternativeFileNameToolHandler::class, 'run'], $tools['inc_file_name_tool']->handler);
+
         $this->assertArrayNotHasKey('private_tool_should_be_ignored', $tools);
         $this->assertArrayNotHasKey('protected_tool_should_be_ignored', $tools);
         $this->assertArrayNotHasKey('static_tool_should_be_ignored', $tools);
@@ -121,6 +125,25 @@ class DiscoveryTest extends TestCase
         $this->assertTrue($discovery->isEmpty());
     }
 
+    public function testHandlesDefaultAndOverriddenFileNamePatterns(): void
+    {
+        $discovery = $this->discoverer->discover(__DIR__, ['Fixtures']);
+        $this->assertArrayHasKey('greet_user', $discovery->getTools());
+        $this->assertArrayNotHasKey('inc_file_name_tool', $discovery->getTools());
+
+        $discovery = $this->discoverer->discover(__DIR__, ['Fixtures'], [], []);
+        $this->assertArrayHasKey('greet_user', $discovery->getTools());
+        $this->assertArrayNotHasKey('inc_file_name_tool', $discovery->getTools());
+
+        $discovery = $this->discoverer->discover(__DIR__, ['Fixtures'], [], ['*.php', '*.inc']);
+        $this->assertArrayHasKey('greet_user', $discovery->getTools());
+        $this->assertArrayHasKey('inc_file_name_tool', $discovery->getTools());
+
+        $discovery = $this->discoverer->discover(__DIR__, ['Fixtures'], [], ['*.inc']);
+        $this->assertArrayNotHasKey('greet_user', $discovery->getTools());
+        $this->assertArrayHasKey('inc_file_name_tool', $discovery->getTools());
+    }
+
     public function testCorrectlyInfersNamesAndDescriptionsFromMethodsOrClassesIfNotSetInAttribute(): void
     {
         $discovery = $this->discoverer->discover(__DIR__, ['Fixtures']);

tests/Unit/Capability/Discovery/Fixtures/AlternativeFileNameToolHandler.class.inc

@@ -0,0 +1,22 @@
+<?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\Tests\Unit\Capability\Discovery\Fixtures;
+
+use Mcp\Capability\Attribute\McpTool;
+
+class AlternativeFileNameToolHandler
+{
+    #[McpTool(name: 'inc_file_name_tool')]
+    public function run(): void
+    {
+    }
+}