HttpTransport.php
152 lines
| 1 | <?php |
| 2 | /** |
| 3 | * MCP HTTP Transport for WordPress (MCP 2025-11-25 baseline) |
| 4 | * |
| 5 | * This transport implements the MCP HTTP transport surface used by this plugin. |
| 6 | * It can work both with and without the mcp-wordpress-remote proxy. |
| 7 | * |
| 8 | * Note: SSE (GET streaming) is not yet implemented; GET currently returns 405. |
| 9 | * |
| 10 | * @package McpAdapter |
| 11 | */ |
| 12 | |
| 13 | declare( strict_types=1 ); |
| 14 | |
| 15 | namespace WP\MCP\Transport; |
| 16 | |
| 17 | use WP\MCP\Transport\Contracts\McpRestTransportInterface; |
| 18 | use WP\MCP\Transport\Infrastructure\HttpRequestContext; |
| 19 | use WP\MCP\Transport\Infrastructure\HttpRequestHandler; |
| 20 | use WP\MCP\Transport\Infrastructure\McpTransportContext; |
| 21 | use WP\MCP\Transport\Infrastructure\McpTransportHelperTrait; |
| 22 | |
| 23 | /** |
| 24 | * MCP HTTP Transport - Unified transport for both proxy and direct clients |
| 25 | * |
| 26 | * Implements the MCP 2025-11-25 HTTP transport shape used by this adapter (POST + sessions). |
| 27 | * |
| 28 | * Note: SSE (GET streaming) is not yet implemented; GET currently returns 405. |
| 29 | */ |
| 30 | class HttpTransport implements McpRestTransportInterface { |
| 31 | use McpTransportHelperTrait; |
| 32 | |
| 33 | /** |
| 34 | * The HTTP request handler. |
| 35 | * |
| 36 | * @var \WP\MCP\Transport\Infrastructure\HttpRequestHandler |
| 37 | */ |
| 38 | protected HttpRequestHandler $request_handler; |
| 39 | |
| 40 | /** |
| 41 | * Initialize the class and register routes |
| 42 | * |
| 43 | * @param \WP\MCP\Transport\Infrastructure\McpTransportContext $transport_context The transport context. |
| 44 | */ |
| 45 | public function __construct( McpTransportContext $transport_context ) { |
| 46 | $this->request_handler = new HttpRequestHandler( $transport_context ); |
| 47 | add_action( 'rest_api_init', array( $this, 'register_routes' ), 16 ); |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * Register MCP HTTP routes |
| 52 | */ |
| 53 | public function register_routes(): void { |
| 54 | // Get server info from request handler's transport context |
| 55 | $server = $this->request_handler->get_transport_context()->mcp_server; |
| 56 | |
| 57 | // Single endpoint for MCP communication (POST, GET reserved for SSE, DELETE for session termination). |
| 58 | // Do not remove GET: it is part of the MCP HTTP transport shape and will be implemented (SSE) in a future iteration. |
| 59 | register_rest_route( |
| 60 | $server->get_server_route_namespace(), |
| 61 | $server->get_server_route(), |
| 62 | array( |
| 63 | 'methods' => array( 'POST', 'GET', 'DELETE' ), |
| 64 | 'callback' => array( $this, 'handle_request' ), |
| 65 | 'permission_callback' => array( $this, 'check_permission' ), |
| 66 | ) |
| 67 | ); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Check if the user has permission to access the MCP API |
| 72 | * |
| 73 | * @param \WP_REST_Request<array<string, mixed>> $request The request object. |
| 74 | * |
| 75 | * @return bool True if the user has permission, false otherwise. |
| 76 | */ |
| 77 | public function check_permission( \WP_REST_Request $request ) { |
| 78 | $context = new HttpRequestContext( $request ); |
| 79 | |
| 80 | // Check permission using callback or default |
| 81 | $transport_context = $this->request_handler->get_transport_context(); |
| 82 | |
| 83 | if ( null !== $transport_context->transport_permission_callback ) { |
| 84 | try { |
| 85 | $result = call_user_func( $transport_context->transport_permission_callback, $context->request ); |
| 86 | |
| 87 | // Handle WP_Error returns |
| 88 | if ( ! is_wp_error( $result ) ) { |
| 89 | // Cast to bool to match return type while preserving truthy/falsy semantics. |
| 90 | return (bool) $result; |
| 91 | } |
| 92 | |
| 93 | // Log the error and deny access (fail-closed) |
| 94 | $this->request_handler->get_transport_context()->error_handler->log( |
| 95 | 'Permission callback returned WP_Error: ' . $result->get_error_message(), |
| 96 | array( 'HttpTransport::check_permission' ) |
| 97 | ); |
| 98 | |
| 99 | return false; |
| 100 | } catch ( \Throwable $e ) { |
| 101 | // Log the error and deny access (fail-closed) |
| 102 | $this->request_handler->get_transport_context()->error_handler->log( 'Error in transport permission callback: ' . $e->getMessage(), array( 'HttpTransport::check_permission' ) ); |
| 103 | |
| 104 | return false; |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * Filters the default user capability required for MCP transport access. |
| 110 | * |
| 111 | * This filter is only applied when no custom transport permission callback |
| 112 | * is provided. The capability is checked using current_user_can(). |
| 113 | * |
| 114 | * @since 0.3.0 |
| 115 | * |
| 116 | * @param string $capability The required capability. Default 'read'. |
| 117 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 118 | */ |
| 119 | $user_capability = apply_filters( 'mcp_adapter_default_transport_permission_user_capability', 'read', $context ); |
| 120 | |
| 121 | // Validate that the filtered capability is a non-empty string |
| 122 | if ( ! is_string( $user_capability ) || empty( $user_capability ) ) { |
| 123 | $user_capability = 'read'; |
| 124 | } |
| 125 | |
| 126 | $user_has_capability = current_user_can( $user_capability ); // phpcs:ignore WordPress.WP.Capabilities.Undetermined -- Capability is filtered and defaults to 'read' |
| 127 | |
| 128 | if ( ! $user_has_capability ) { |
| 129 | $user_id = get_current_user_id(); |
| 130 | $this->request_handler->get_transport_context()->error_handler->log( |
| 131 | sprintf( 'Permission denied for MCP API access. User ID %d does not have capability "%s"', $user_id, $user_capability ), |
| 132 | array( 'HttpTransport::check_permission' ) |
| 133 | ); |
| 134 | } |
| 135 | |
| 136 | return $user_has_capability; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Handle HTTP requests according to MCP 2025-11-25 specification |
| 141 | * |
| 142 | * @param \WP_REST_Request<array<string, mixed>> $request The request object. |
| 143 | * |
| 144 | * @return \WP_REST_Response |
| 145 | */ |
| 146 | public function handle_request( \WP_REST_Request $request ): \WP_REST_Response { |
| 147 | $context = new HttpRequestContext( $request ); |
| 148 | |
| 149 | return $this->request_handler->handle_request( $context ); |
| 150 | } |
| 151 | } |
| 152 |