commercebird
/
vendor
/
wordpress
/
mcp-adapter
/
includes
/
Transport
/
Infrastructure
/
HttpRequestHandler.php
commercebird
/
vendor
/
wordpress
/
mcp-adapter
/
includes
/
Transport
/
Infrastructure
Last commit date
HttpRequestContext.php
2 months ago
HttpRequestHandler.php
2 months ago
HttpSessionValidator.php
2 months ago
JsonRpcResponseBuilder.php
2 months ago
McpTransportContext.php
2 months ago
McpTransportHelperTrait.php
2 months ago
RequestRouter.php
2 months ago
SessionManager.php
2 months ago
HttpRequestHandler.php
336 lines
| 1 | <?php |
| 2 | /** |
| 3 | * HTTP Request Handler for MCP Transport |
| 4 | * |
| 5 | * @package McpAdapter |
| 6 | */ |
| 7 | |
| 8 | declare( strict_types=1 ); |
| 9 | |
| 10 | namespace WP\MCP\Transport\Infrastructure; |
| 11 | |
| 12 | use WP\MCP\Core\McpVersionNegotiator; |
| 13 | use WP\MCP\Infrastructure\ErrorHandling\McpErrorFactory; |
| 14 | |
| 15 | /** |
| 16 | * Handles HTTP request routing and processing for MCP transports. |
| 17 | * |
| 18 | * Centralizes request routing logic to eliminate duplication and provide |
| 19 | * consistent request handling across transport implementations. |
| 20 | * |
| 21 | * @internal |
| 22 | */ |
| 23 | class HttpRequestHandler { |
| 24 | |
| 25 | /** |
| 26 | * The transport context. |
| 27 | * |
| 28 | * @var \WP\MCP\Transport\Infrastructure\McpTransportContext |
| 29 | */ |
| 30 | public McpTransportContext $transport_context; |
| 31 | |
| 32 | /** |
| 33 | * Constructor. |
| 34 | * |
| 35 | * @param \WP\MCP\Transport\Infrastructure\McpTransportContext $transport_context The transport context. |
| 36 | */ |
| 37 | public function __construct( McpTransportContext $transport_context ) { |
| 38 | $this->transport_context = $transport_context; |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * Get the transport context. |
| 43 | * |
| 44 | * @since 0.5.0 |
| 45 | * |
| 46 | * @return \WP\MCP\Transport\Infrastructure\McpTransportContext |
| 47 | */ |
| 48 | public function get_transport_context(): McpTransportContext { |
| 49 | return $this->transport_context; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Route HTTP request to appropriate handler. |
| 54 | * |
| 55 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 56 | * |
| 57 | * @return \WP_REST_Response HTTP response. |
| 58 | */ |
| 59 | public function handle_request( HttpRequestContext $context ): \WP_REST_Response { |
| 60 | // Handle POST requests (sending MCP messages to server) |
| 61 | if ( 'POST' === $context->method ) { |
| 62 | return $this->handle_mcp_request( $context ); |
| 63 | } |
| 64 | |
| 65 | // Handle GET requests (reserved for SSE streaming; currently not implemented). |
| 66 | if ( 'GET' === $context->method ) { |
| 67 | return $this->handle_sse_request(); |
| 68 | } |
| 69 | |
| 70 | // Handle DELETE requests (session termination) |
| 71 | if ( 'DELETE' === $context->method ) { |
| 72 | return $this->handle_session_termination( $context ); |
| 73 | } |
| 74 | |
| 75 | // Method not allowed |
| 76 | return new \WP_REST_Response( |
| 77 | McpErrorFactory::invalid_request( null, 'Method not allowed' )->toArray(), |
| 78 | 405 |
| 79 | ); |
| 80 | } |
| 81 | |
| 82 | |
| 83 | /** |
| 84 | * Handle MCP POST requests. |
| 85 | * |
| 86 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 87 | * |
| 88 | * @return \WP_REST_Response MCP response. |
| 89 | */ |
| 90 | private function handle_mcp_request( HttpRequestContext $context ): \WP_REST_Response { |
| 91 | try { |
| 92 | // Validate request body |
| 93 | if ( null === $context->body ) { |
| 94 | return new \WP_REST_Response( |
| 95 | McpErrorFactory::parse_error( null, 'Invalid JSON in request body' )->toArray(), |
| 96 | 400 |
| 97 | ); |
| 98 | } |
| 99 | |
| 100 | return $this->process_mcp_messages( $context ); |
| 101 | } catch ( \Throwable $exception ) { |
| 102 | $this->transport_context->mcp_server->get_error_handler()->log( |
| 103 | 'Unexpected error in handle_mcp_request', |
| 104 | array( |
| 105 | 'transport' => static::class, |
| 106 | 'server_id' => $this->transport_context->mcp_server->get_server_id(), |
| 107 | 'error' => $exception->getMessage(), |
| 108 | ) |
| 109 | ); |
| 110 | |
| 111 | return new \WP_REST_Response( |
| 112 | McpErrorFactory::internal_error( null, 'Handler error occurred' )->toArray(), |
| 113 | 500 |
| 114 | ); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Process MCP messages using JsonRpcResponseBuilder. |
| 120 | * |
| 121 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 122 | * |
| 123 | * @return \WP_REST_Response MCP response. |
| 124 | */ |
| 125 | private function process_mcp_messages( HttpRequestContext $context ): \WP_REST_Response { |
| 126 | $is_batch_request = JsonRpcResponseBuilder::is_batch_request( $context->body ); |
| 127 | $messages = JsonRpcResponseBuilder::normalize_messages( $context->body ); |
| 128 | |
| 129 | $response_body = JsonRpcResponseBuilder::process_messages( |
| 130 | $messages, |
| 131 | $is_batch_request, |
| 132 | function ( array $message ) use ( $context ) { |
| 133 | return $this->process_single_message( $message, $context ); |
| 134 | } |
| 135 | ); |
| 136 | |
| 137 | // Per MCP spec 2025-06-18: Notifications return HTTP 202 Accepted with no body. |
| 138 | // A null response_body indicates only notifications were processed (no requests with IDs). |
| 139 | if ( null === $response_body ) { |
| 140 | return new \WP_REST_Response( null, 202 ); |
| 141 | } |
| 142 | |
| 143 | // Determine HTTP status code based on error type |
| 144 | if ( ! $is_batch_request && isset( $response_body['error'] ) ) { |
| 145 | $http_status = McpErrorFactory::get_http_status_for_error( $response_body ); |
| 146 | |
| 147 | return new \WP_REST_Response( $response_body, $http_status ); |
| 148 | } |
| 149 | |
| 150 | return new \WP_REST_Response( $response_body, 200 ); |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Process a single MCP message. |
| 155 | * |
| 156 | * @param array $message The MCP JSON-RPC message. |
| 157 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 158 | * |
| 159 | * @return array|null JSON-RPC response or null for notifications. |
| 160 | */ |
| 161 | private function process_single_message( array $message, HttpRequestContext $context ): ?array { |
| 162 | // Validate JSON-RPC message format |
| 163 | $validation = McpErrorFactory::validate_jsonrpc_message( $message ); |
| 164 | if ( true !== $validation ) { |
| 165 | return $validation->toArray(); |
| 166 | } |
| 167 | |
| 168 | // Handle notifications (no response required) |
| 169 | if ( isset( $message['method'] ) && ! isset( $message['id'] ) ) { |
| 170 | return null; // Notifications don't get a response |
| 171 | } |
| 172 | |
| 173 | // Process requests with IDs |
| 174 | if ( isset( $message['method'] ) && isset( $message['id'] ) ) { |
| 175 | return $this->process_jsonrpc_request( $message, $context ); |
| 176 | } |
| 177 | |
| 178 | // JSON-RPC responses from client (has result/error, no method) also return null. |
| 179 | // Per MCP spec: client responses get HTTP 202 Accepted with no body, same as notifications. |
| 180 | return null; |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * Process a JSON-RPC request message. |
| 185 | * |
| 186 | * @param array $message The JSON-RPC message. |
| 187 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 188 | * |
| 189 | * @return array JSON-RPC response. |
| 190 | */ |
| 191 | private function process_jsonrpc_request( array $message, HttpRequestContext $context ): array { |
| 192 | $request_id = $message['id']; // Preserve original scalar ID (string, number, or null) |
| 193 | $method = $message['method']; |
| 194 | $params = $message['params'] ?? array(); |
| 195 | |
| 196 | // Validate session for all requests except initialize (router will handle initialize session creation) |
| 197 | if ( 'initialize' !== $method ) { |
| 198 | $session_validation = HttpSessionValidator::validate_session( $context ); |
| 199 | if ( true !== $session_validation ) { |
| 200 | return JsonRpcResponseBuilder::create_error_response( $request_id, $session_validation['error'] ?? $session_validation ); |
| 201 | } |
| 202 | |
| 203 | // Validate MCP-Protocol-Version header for non-initialize requests. |
| 204 | $protocol_version_error = $this->validate_protocol_version_header( $context ); |
| 205 | if ( null !== $protocol_version_error ) { |
| 206 | return JsonRpcResponseBuilder::create_error_response( $request_id, $protocol_version_error ); |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | // Route the request through the transport context |
| 211 | $result = $this->transport_context->request_router->route_request( |
| 212 | $method, |
| 213 | $params, |
| 214 | $request_id, |
| 215 | $this->get_transport_name(), |
| 216 | $context |
| 217 | ); |
| 218 | |
| 219 | // Handle session header if provided by router |
| 220 | if ( isset( $result['_session_id'] ) ) { |
| 221 | $this->add_session_header_to_response( $result['_session_id'] ); |
| 222 | unset( $result['_session_id'] ); // Remove from actual response data |
| 223 | } |
| 224 | |
| 225 | // Format response based on result |
| 226 | if ( isset( $result['error'] ) ) { |
| 227 | return JsonRpcResponseBuilder::create_error_response( $request_id, $result['error'] ); |
| 228 | } |
| 229 | |
| 230 | return JsonRpcResponseBuilder::create_success_response( $request_id, $result ); |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * Get transport name for observability. |
| 235 | * |
| 236 | * @return string Transport name. |
| 237 | */ |
| 238 | private function get_transport_name(): string { |
| 239 | return 'HTTP'; |
| 240 | } |
| 241 | |
| 242 | /** |
| 243 | * Validate the MCP-Protocol-Version header on non-initialize requests. |
| 244 | * |
| 245 | * A missing header is accepted (returns null). A header containing a supported |
| 246 | * version is also accepted. An unsupported version returns a JSON-RPC |
| 247 | * invalid-request error payload. |
| 248 | * |
| 249 | * @since 0.5.0 |
| 250 | * |
| 251 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 252 | * |
| 253 | * @return array|null Null when the header is absent or valid, error payload otherwise. |
| 254 | */ |
| 255 | private function validate_protocol_version_header( HttpRequestContext $context ): ?array { |
| 256 | if ( null === $context->protocol_version ) { |
| 257 | return null; |
| 258 | } |
| 259 | |
| 260 | if ( McpVersionNegotiator::is_supported( $context->protocol_version ) ) { |
| 261 | return null; |
| 262 | } |
| 263 | |
| 264 | return McpErrorFactory::create_error( |
| 265 | McpErrorFactory::INVALID_REQUEST, |
| 266 | sprintf( |
| 267 | 'Bad Request: Unsupported protocol version: %s (supported versions: %s)', |
| 268 | $context->protocol_version, |
| 269 | implode( ', ', McpVersionNegotiator::SUPPORTED_PROTOCOL_VERSIONS ) |
| 270 | ) |
| 271 | )->toArray(); |
| 272 | } |
| 273 | |
| 274 | /** |
| 275 | * Add session header to the REST response. |
| 276 | * |
| 277 | * Uses a static flag to prevent multiple filters from being added |
| 278 | * if this method is called multiple times during a single request |
| 279 | * (e.g., during batch JSON-RPC processing). |
| 280 | * |
| 281 | * @param string $session_id The session ID to add to the response header. |
| 282 | * |
| 283 | * @return void |
| 284 | */ |
| 285 | private function add_session_header_to_response( string $session_id ): void { |
| 286 | static $current_session_id = null; |
| 287 | |
| 288 | // Only add filter once per request, or if session ID changes |
| 289 | if ( null !== $current_session_id && $current_session_id === $session_id ) { |
| 290 | return; |
| 291 | } |
| 292 | |
| 293 | add_filter( |
| 294 | 'rest_post_dispatch', |
| 295 | static function ( $response ) use ( $session_id ) { |
| 296 | if ( $response instanceof \WP_REST_Response ) { |
| 297 | $response->header( 'Mcp-Session-Id', $session_id ); |
| 298 | } |
| 299 | |
| 300 | return $response; |
| 301 | } |
| 302 | ); |
| 303 | |
| 304 | $current_session_id = $session_id; |
| 305 | } |
| 306 | |
| 307 | /** |
| 308 | * Handle GET requests (SSE streaming). |
| 309 | * |
| 310 | * @return \WP_REST_Response SSE response. |
| 311 | */ |
| 312 | private function handle_sse_request(): \WP_REST_Response { |
| 313 | // SSE streaming not yet implemented - return HTTP 405 with no body |
| 314 | return new \WP_REST_Response( null, 405 ); |
| 315 | } |
| 316 | |
| 317 | /** |
| 318 | * Handle DELETE requests (session termination). |
| 319 | * |
| 320 | * @param \WP\MCP\Transport\Infrastructure\HttpRequestContext $context The HTTP request context. |
| 321 | * |
| 322 | * @return \WP_REST_Response Termination response. |
| 323 | */ |
| 324 | private function handle_session_termination( HttpRequestContext $context ): \WP_REST_Response { |
| 325 | $result = HttpSessionValidator::terminate_session( $context ); |
| 326 | |
| 327 | if ( true !== $result ) { |
| 328 | $http_status = McpErrorFactory::get_http_status_for_error( $result ); |
| 329 | |
| 330 | return new \WP_REST_Response( $result, $http_status ); |
| 331 | } |
| 332 | |
| 333 | return new \WP_REST_Response( null, 200 ); |
| 334 | } |
| 335 | } |
| 336 |