[Schema] Drop SDK-only name pattern on resources and resource templates (#430)

* [Schema] Drop SDK-only name pattern on resources and resource templates

* Update src/Schema/ResourceDefinition.php

* Update src/Schema/ResourceTemplate.php

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to `mcp/sdk` will be documented in this file.
 0.8.0
 -----
 
+* [BC Break] Drop the SDK-only `[a-zA-Z0-9_-]+` restriction on `ResourceDefinition::$name` and `ResourceTemplate::$name`: the specification puts no pattern on `name` (its own examples use `main.rs` and `Project Files`), and the classes also parse what a peer sent, so the rule rejected conformant servers. Any string is now accepted; the URI / URI template validation is unchanged.
 * Add `ClientGateway::supportsExtension()` to check whether the client negotiated a protocol extension (e.g. `McpApps::EXTENSION_ID`) before offering UI-linked tools, plus `Client\Builder::enableExtension()` and `ClientCapabilities::withExtensions()` so hosts advertise extensions the same way servers do. [BC Break] `ServerExtensionInterface` is replaced by the side-agnostic `Mcp\Schema\Extension\ExtensionInterface`.
 * Deprecate the Roots, Sampling and Logging features per SEP-2577 (protocol revision `2026-07-28`, earliest removal `2027-07-28`): the schema, client and server classes that make them up are marked `@deprecated` with the suggested migration (tool arguments or resource URIs instead of roots; an LLM provider's API instead of sampling; stderr or OpenTelemetry instead of logging), and exercising them — `ClientGateway::log()` / `sample()` / `listRoots()`, or registering a client-side `SamplingRequestHandler`, `ListRootsRequestHandler` or `LoggingNotificationHandler` — triggers a silenced `E_USER_DEPRECATED` via `symfony/deprecation-contracts`. Everything remains fully functional until removal.
 * Always emit `{}` for empty tool schemas: `Tool` recursively normalizes every empty sub-schema — `properties`, `items`, `additionalProperties`, `$defs`, combinators and the other draft-07 to 2020-12 schema keywords — in the constructor, for both `inputSchema` and `outputSchema`, so an object position is never serialized as `[]`.

src/Schema/ResourceDefinition.php

@@ -35,11 +35,6 @@ use Mcp\Exception\InvalidArgumentException;
  */
 class ResourceDefinition implements \JsonSerializable
 {
-    /**
-     * Resource name pattern regex - must contain only alphanumeric characters, underscores, and hyphens.
-     */
-    private const RESOURCE_NAME_PATTERN = '/^[a-zA-Z0-9_-]+$/';
-
     /**
      * URI pattern regex - requires a valid scheme followed by colon and optional path (RFC 3986).
      * Example patterns: file://path, db://table, urn:isbn:123, config:key, etc.
@@ -68,9 +63,6 @@ class ResourceDefinition implements \JsonSerializable
         public readonly ?array $icons = null,
         public readonly ?array $meta = null,
     ) {
-        if (!preg_match(self::RESOURCE_NAME_PATTERN, $name)) {
-            throw new InvalidArgumentException(\sprintf('Invalid resource name "%s": must contain only alphanumeric characters, underscores, and hyphens.', $name));
-        }
         if (!preg_match(self::URI_PATTERN, $uri)) {
             throw new InvalidArgumentException(\sprintf('Invalid resource URI: "%s" must be a valid URI with a scheme and optional path.', $uri));
         }

src/Schema/ResourceTemplate.php

@@ -32,11 +32,6 @@ use Mcp\Exception\InvalidArgumentException;
  */
 class ResourceTemplate implements \JsonSerializable
 {
-    /**
-     * Resource name pattern regex - must contain only alphanumeric characters, underscores, and hyphens.
-     */
-    private const RESOURCE_NAME_PATTERN = '/^[a-zA-Z0-9_-]+$/';
-
     /**
      * URI Template pattern regex - requires a valid scheme followed by colon and path with at least one placeholder (RFC 3986).
      * Example patterns: file://{path}/contents.txt, db://{table}/{id}, config:{key}, etc.
@@ -61,9 +56,6 @@ class ResourceTemplate implements \JsonSerializable
         public readonly ?Annotations $annotations = null,
         public readonly ?array $meta = null,
     ) {
-        if (!preg_match(self::RESOURCE_NAME_PATTERN, $name)) {
-            throw new InvalidArgumentException(\sprintf('Invalid resource name "%s": must contain only alphanumeric characters, underscores, and hyphens.', $name));
-        }
         if (!preg_match(self::URI_TEMPLATE_PATTERN, $uriTemplate)) {
             throw new InvalidArgumentException(\sprintf('Invalid URI template : "%s" must be a valid URI template with at least one placeholder.', $uriTemplate));
         }

tests/Unit/Schema/ResourceDefinitionTest.php

@@ -116,6 +116,30 @@ class ResourceDefinitionTest extends TestCase
         $this->assertArrayNotHasKey('title', $data);
     }
 
+    /**
+     * The specification puts no pattern on `name`; its own examples use
+     * names such as "main.rs" and "Project Files".
+     */
+    #[DataProvider('provideSpecExampleNames')]
+    public function testConstructorAcceptsAnyName(string $name): void
+    {
+        $resource = new ResourceDefinition(
+            uri: self::VALID_URI,
+            name: $name,
+        );
+
+        $this->assertSame($name, $resource->name);
+    }
+
+    public static function provideSpecExampleNames(): iterable
+    {
+        yield 'file name with dot' => ['main.rs'];
+        yield 'display name with space' => ['Project Files'];
+        yield 'uppercase file name' => ['README.md'];
+        yield 'namespaced' => ['acme/reports:quarterly'];
+        yield 'unicode' => ['Ünïcödé 名前'];
+    }
+
     #[DataProvider('provideInvalidResources')]
     public function testFromArrayInvalid(array $input, string $expectedExceptionMessage): void
     {

tests/Unit/Schema/ResourceTemplateTest.php

@@ -114,6 +114,30 @@ class ResourceTemplateTest extends TestCase
         $this->assertArrayNotHasKey('title', $data);
     }
 
+    /**
+     * The specification puts no pattern on `name`; its own examples use
+     * names such as "main.rs" and "Project Files".
+     */
+    #[DataProvider('provideSpecExampleNames')]
+    public function testConstructorAcceptsAnyName(string $name): void
+    {
+        $resource = new ResourceTemplate(
+            uriTemplate: self::VALID_URI,
+            name: $name,
+        );
+
+        $this->assertSame($name, $resource->name);
+    }
+
+    public static function provideSpecExampleNames(): iterable
+    {
+        yield 'file name with dot' => ['main.rs'];
+        yield 'display name with space' => ['Project Files'];
+        yield 'uppercase file name' => ['README.md'];
+        yield 'namespaced' => ['acme/reports:quarterly'];
+        yield 'unicode' => ['Ünïcödé 名前'];
+    }
+
     #[DataProvider('provideInvalidResources')]
     public function testFromArrayInvalid(array $input, string $expectedExceptionMessage): void
     {