fix: reset request context after the MCP request, resolve client name

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

src/Server/RequestContext.php

@@ -4,28 +4,32 @@ declare(strict_types=1);
 
 namespace LIT\MCP\Server;
 
+use Throwable;
 use WP_REST_Request;
+use WPMedia\MCP\OAuth\Auth\JWT;
+use WPMedia\MCP\OAuth\Auth\SecretManager;
 
 /**
  * Tracks whether the current REST dispatch is serving our OAuth-protected MCP
- * server route (`/mcp/mcp-oauth-server`).
+ * server route (`/mcp/mcp-oauth-server`) and which OAuth client made it.
  *
- * Abilities must never run outside that route – not through mcp-adapter's
+ * Abilities must never run outside that route. WordPress fires
- * (disabled) default server, not through a differently configured server, and
- * not through any unrelated REST request. WordPress fires
  * `rest_request_before_callbacks` for every matched REST route before any
- * permission_callback runs (see WP_REST_Server::dispatch()), so by the time an
+ * permission_callback runs and `rest_request_after_callbacks` right after the
- * ability's permission_callback executes – itself only reachable from inside
+ * route callback returned (WP_REST_Server::respond_to_request()). The flag is
- * the MCP route's own callback – the flag below is already accurate for the
+ * set in the first and cleared in the second, so persistent PHP workers or a
- * current request.
+ * later `rest_do_request()` in the same process never inherit it.
  */
 final class RequestContext
 {
     private static bool $isOAuthServerRequest = false;
+    private static ?string $bearerToken = null;
+    private static ?string $clientName = null;
 
     public function register(): void
     {
         add_filter('rest_request_before_callbacks', [self::class, 'recordRoute'], 10, 3);
+        add_filter('rest_request_after_callbacks', [self::class, 'clearRoute'], 10, 3);
     }
 
     /**
@@ -37,6 +41,25 @@ final class RequestContext
     {
         if ($request->get_route() === self::route()) {
             self::$isOAuthServerRequest = true;
+            self::$clientName = null;
+            $header = $request->get_header('authorization');
+            self::$bearerToken = is_string($header) && str_starts_with($header, 'Bearer ')
+                ? substr($header, 7)
+                : null;
+        }
+
+        return $response;
+    }
+
+    /**
+     * @param mixed                $response
+     * @param array<string, mixed> $handler
+     * @return mixed
+     */
+    public static function clearRoute(mixed $response, array $handler, WP_REST_Request $request): mixed
+    {
+        if ($request->get_route() === self::route()) {
+            self::reset();
         }
 
         return $response;
@@ -48,11 +71,49 @@ final class RequestContext
     }
 
     /**
-     * Test-only: resets (or forces) the recorded state between unit tests.
+     * Name of the connected OAuth client (the Application Password mcp-oauth created
+     * for it), falling back to the token's client_id; '' when unknown.
      */
-    public static function reset(bool $isOAuthServerRequest = false): void
+    public static function clientName(): string
+    {
+        if (self::$clientName === null) {
+            self::$clientName = self::$bearerToken === null ? '' : self::resolveClientName(self::$bearerToken);
+        }
+
+        return self::$clientName;
+    }
+
+    /**
+     * Resets (or forces) the recorded state – after each request and between unit tests.
+     */
+    public static function reset(bool $isOAuthServerRequest = false, ?string $clientName = null): void
     {
         self::$isOAuthServerRequest = $isOAuthServerRequest;
+        self::$bearerToken = null;
+        self::$clientName = $clientName;
+    }
+
+    private static function resolveClientName(string $token): string
+    {
+        try {
+            $claims = JWT::decode($token, SecretManager::get_secret());
+            if (! is_array($claims)) {
+                return '';
+            }
+
+            $userId = (int) ($claims['sub'] ?? 0);
+            $uuid = (string) ($claims['app_pass_id'] ?? '');
+            if ($userId > 0 && $uuid !== '' && class_exists('WP_Application_Passwords')) {
+                $item = \WP_Application_Passwords::get_user_application_password($userId, $uuid);
+                if (is_array($item) && is_string($item['name'] ?? null) && $item['name'] !== '') {
+                    return $item['name'];
+                }
+            }
+
+            return (string) ($claims['client_id'] ?? '');
+        } catch (Throwable) {
+            return '';
+        }
     }
 
     private static function route(): string

tests/Stubs/WpRestRequest.php

@@ -5,7 +5,8 @@ declare(strict_types=1);
 if (! class_exists('WP_REST_Request')) {
     class WP_REST_Request
     {
-        public function __construct(private string $route = '')
+        /** @param array<string, string> $headers Lower-case header name => value. */
+        public function __construct(private string $route = '', private array $headers = [])
         {
         }
 
@@ -13,5 +14,10 @@ if (! class_exists('WP_REST_Request')) {
         {
             return $this->route;
         }
+
+        public function get_header(string $key): ?string
+        {
+            return $this->headers[strtolower($key)] ?? null;
+        }
     }
 }

tests/Unit/Server/RequestContextTest.php

@@ -7,10 +7,14 @@ namespace LIT\MCP\Tests\Unit\Server;
 use Brain\Monkey\Functions;
 use LIT\MCP\Server\RequestContext;
 use LIT\MCP\Tests\Unit\TestCase;
+use stdClass;
 use WP_REST_Request;
+use WPMedia\MCP\OAuth\Auth\JWT;
 
 final class RequestContextTest extends TestCase
 {
+    private const ROUTE = '/mcp/mcp-oauth-server';
+
     protected function tearDown(): void
     {
         RequestContext::reset();
@@ -24,37 +28,90 @@ final class RequestContextTest extends TestCase
 
     public function testRecordRouteMarksTheOAuthServerRoute(): void
     {
-        $request = new WP_REST_Request('/mcp/mcp-oauth-server');
+        RequestContext::recordRoute(null, [], new WP_REST_Request(self::ROUTE));
-
-        RequestContext::recordRoute(null, [], $request);
 
         self::assertTrue(RequestContext::isOAuthServerRequest());
     }
 
     public function testRecordRouteIgnoresOtherRoutes(): void
     {
-        $request = new WP_REST_Request('/wp/v2/users/me');
+        RequestContext::recordRoute(null, [], new WP_REST_Request('/wp/v2/users/me'));
-
-        RequestContext::recordRoute(null, [], $request);
 
         self::assertFalse(RequestContext::isOAuthServerRequest());
     }
 
     public function testRecordRouteReturnsResponseUnchanged(): void
     {
-        $response = new \stdClass();
+        $response = new stdClass();
-        $request = new WP_REST_Request('/mcp/mcp-oauth-server');
 
-        $result = RequestContext::recordRoute($response, [], $request);
+        self::assertSame($response, RequestContext::recordRoute($response, [], new WP_REST_Request(self::ROUTE)));
-
-        self::assertSame($response, $result);
     }
 
-    public function testRegisterHooksRecordRouteOnRestRequestBeforeCallbacks(): void
+    public function testClearRouteResetsTheFlagAfterOurRequest(): void
+    {
+        $request = new WP_REST_Request(self::ROUTE);
+        RequestContext::recordRoute(null, [], $request);
+        $response = new stdClass();
+
+        $result = RequestContext::clearRoute($response, [], $request);
+
+        self::assertSame($response, $result);
+        self::assertFalse(RequestContext::isOAuthServerRequest());
+    }
+
+    public function testClearRouteIgnoresNestedRequestsToOtherRoutes(): void
+    {
+        RequestContext::recordRoute(null, [], new WP_REST_Request(self::ROUTE));
+
+        RequestContext::clearRoute(null, [], new WP_REST_Request('/wp/v2/posts'));
+
+        self::assertTrue(RequestContext::isOAuthServerRequest());
+    }
+
+    public function testClientNameFallsBackToTheClientIdClaim(): void
+    {
+        Functions\when('get_option')->justReturn('test-secret');
+        $token = JWT::encode([
+            'sub' => '3',
+            'app_pass_id' => 'uuid-unknown',
+            'client_id' => 'https://claude.ai/oauth/mcp-oauth-client-metadata',
+            'exp' => time() + 60,
+        ], 'test-secret');
+
+        RequestContext::recordRoute(
+            null,
+            [],
+            new WP_REST_Request(self::ROUTE, ['authorization' => 'Bearer ' . $token])
+        );
+
+        self::assertSame('https://claude.ai/oauth/mcp-oauth-client-metadata', RequestContext::clientName());
+    }
+
+    public function testClientNameIsEmptyForAnInvalidToken(): void
+    {
+        Functions\when('get_option')->justReturn('test-secret');
+
+        RequestContext::recordRoute(null, [], new WP_REST_Request(self::ROUTE, ['authorization' => 'Bearer garbage']));
+
+        self::assertSame('', RequestContext::clientName());
+    }
+
+    public function testResetCanForceAClientName(): void
+    {
+        RequestContext::reset(true, 'Claude');
+
+        self::assertTrue(RequestContext::isOAuthServerRequest());
+        self::assertSame('Claude', RequestContext::clientName());
+    }
+
+    public function testRegisterHooksBeforeAndAfterCallbacks(): void
     {
         Functions\expect('add_filter')
             ->once()
             ->with('rest_request_before_callbacks', [RequestContext::class, 'recordRoute'], 10, 3);
+        Functions\expect('add_filter')
+            ->once()
+            ->with('rest_request_after_callbacks', [RequestContext::class, 'clearRoute'], 10, 3);
 
         (new RequestContext())->register();
     }