| 1 |
<?php |
| 2 |
/** |
| 3 |
* MCP Prompt Validator class for validating MCP prompts according to the specification. |
| 4 |
* |
| 5 |
* @package McpAdapter |
| 6 |
*/ |
| 7 |
|
| 8 |
declare( strict_types=1 ); |
| 9 |
|
| 10 |
namespace WP\MCP\Domain\Prompts; |
| 11 |
|
| 12 |
use WP\MCP\Domain\Resources\McpResourceValidator; |
| 13 |
use WP\MCP\Domain\Utils\McpValidator; |
| 14 |
use WP\McpSchema\Server\Prompts\DTO\Prompt as PromptDto; |
| 15 |
use WP_Error; |
| 16 |
|
| 17 |
/** |
| 18 |
* Validates MCP prompts against the Model Context Protocol specification. |
| 19 |
* |
| 20 |
* Provides minimal, resource-efficient validation to ensure prompts conform |
| 21 |
* to the MCP schema requirements without heavy processing overhead. |
| 22 |
* |
| 23 |
* @link https://modelcontextprotocol.io/specification/2025-11-25/server/prompts |
| 24 |
*/ |
| 25 |
class McpPromptValidator { |
| 26 |
|
| 27 |
/** |
| 28 |
* Validate an MCP prompt data array against the MCP schema. |
| 29 |
* |
| 30 |
* @param array $prompt_data The prompt data to validate. |
| 31 |
* @param string $context Optional context for error messages. |
| 32 |
* |
| 33 |
* @return bool|\WP_Error True if valid, WP_Error if validation fails. |
| 34 |
*/ |
| 35 |
public static function validate_prompt_data( array $prompt_data, string $context = '' ) { |
| 36 |
$validation_errors = self::get_validation_errors( $prompt_data ); |
| 37 |
|
| 38 |
if ( ! empty( $validation_errors ) ) { |
| 39 |
$error_message = $context ? "[{$context}] " : ''; |
| 40 |
$error_message .= sprintf( |
| 41 |
/* translators: %s: comma-separated list of validation errors */ |
| 42 |
__( 'Prompt validation failed: %s', 'mcp-adapter' ), |
| 43 |
implode( ', ', $validation_errors ) |
| 44 |
); |
| 45 |
return new WP_Error( 'mcp_prompt_validation_failed', esc_html( $error_message ) ); |
| 46 |
} |
| 47 |
|
| 48 |
return true; |
| 49 |
} |
| 50 |
|
| 51 |
/** |
| 52 |
* Validate a Prompt DTO against the MCP schema. |
| 53 |
* |
| 54 |
* @param \WP\McpSchema\Server\Prompts\DTO\Prompt $prompt The prompt DTO to validate. |
| 55 |
* |
| 56 |
* @return bool|\WP_Error True if valid, WP_Error otherwise. |
| 57 |
*/ |
| 58 |
public static function validate_prompt_dto( PromptDto $prompt ) { |
| 59 |
$errors = array(); |
| 60 |
|
| 61 |
// Validate name. |
| 62 |
if ( ! McpValidator::validate_name( $prompt->getName() ) ) { |
| 63 |
$errors[] = __( 'Prompt name must be 1-128 characters and contain only [A-Za-z0-9_.-]', 'mcp-adapter' ); |
| 64 |
} |
| 65 |
|
| 66 |
// Validate icons if present. |
| 67 |
$icons = $prompt->getIcons(); |
| 68 |
if ( ! empty( $icons ) ) { |
| 69 |
$icons_array = array_map( static fn( $icon ) => $icon->toArray(), $icons ); |
| 70 |
$icons_result = McpValidator::validate_icons_array( $icons_array ); |
| 71 |
$icons_errors = self::format_icon_validation_errors( $icons_result ); |
| 72 |
$errors = array_merge( $errors, $icons_errors ); |
| 73 |
} |
| 74 |
|
| 75 |
// Validate annotations if present (shared annotations). |
| 76 |
// Currently Prompt DTO doesn't have annotations field in spec, but if it did, we'd validate here. |
| 77 |
// BaseMetadata has title and name, handled separately. |
| 78 |
|
| 79 |
if ( ! empty( $errors ) ) { |
| 80 |
return new WP_Error( |
| 81 |
'mcp_prompt_validation_failed', |
| 82 |
sprintf( |
| 83 |
/* translators: %s: list of validation errors */ |
| 84 |
__( 'Prompt validation failed: %s', 'mcp-adapter' ), |
| 85 |
implode( '; ', $errors ) |
| 86 |
) |
| 87 |
); |
| 88 |
} |
| 89 |
|
| 90 |
return true; |
| 91 |
} |
| 92 |
|
| 93 |
/** |
| 94 |
* Validate an McpPrompt instance against the MCP schema. |
| 95 |
* |
| 96 |
* @param \WP\MCP\Domain\Prompts\McpPrompt $prompt The prompt instance to validate. |
| 97 |
* |
| 98 |
* @return bool|\WP_Error True if valid, WP_Error if validation fails. |
| 99 |
*/ |
| 100 |
public static function validate_prompt_instance( McpPrompt $prompt ) { |
| 101 |
return self::validate_prompt_dto( $prompt->get_protocol_dto() ); |
| 102 |
} |
| 103 |
|
| 104 |
|
| 105 |
/** |
| 106 |
* Get validation error details for debugging purposes. |
| 107 |
* This is the core validation method - all other validation methods use this. |
| 108 |
* |
| 109 |
* @param array $prompt_data The prompt data to validate. |
| 110 |
* |
| 111 |
* @return array Array of validation errors, empty if valid. |
| 112 |
*/ |
| 113 |
public static function get_validation_errors( array $prompt_data ): array { |
| 114 |
$errors = array(); |
| 115 |
|
| 116 |
// Check required fields |
| 117 |
if ( empty( $prompt_data['name'] ) || ! is_string( $prompt_data['name'] ) || ! McpValidator::validate_name( $prompt_data['name'] ) ) { |
| 118 |
$errors[] = __( 'Prompt name is required and must be 1-128 characters and contain only [A-Za-z0-9_.-]', 'mcp-adapter' ); |
| 119 |
} |
| 120 |
|
| 121 |
// Check optional fields if present |
| 122 |
if ( isset( $prompt_data['title'] ) && ! is_string( $prompt_data['title'] ) ) { |
| 123 |
$errors[] = __( 'Prompt title must be a string if provided', 'mcp-adapter' ); |
| 124 |
} |
| 125 |
|
| 126 |
if ( isset( $prompt_data['description'] ) && ! is_string( $prompt_data['description'] ) ) { |
| 127 |
$errors[] = __( 'Prompt description must be a string if provided', 'mcp-adapter' ); |
| 128 |
} |
| 129 |
|
| 130 |
// Validate arguments (optional field) |
| 131 |
if ( isset( $prompt_data['arguments'] ) ) { |
| 132 |
$arguments_errors = self::get_arguments_validation_errors( $prompt_data['arguments'] ); |
| 133 |
if ( ! empty( $arguments_errors ) ) { |
| 134 |
$errors = array_merge( $errors, $arguments_errors ); |
| 135 |
} |
| 136 |
} |
| 137 |
|
| 138 |
return $errors; |
| 139 |
} |
| 140 |
|
| 141 |
/** |
| 142 |
* Get detailed validation errors for prompt arguments. |
| 143 |
* |
| 144 |
* @param array|mixed $arguments The arguments to validate. |
| 145 |
* |
| 146 |
* @return array Array of validation errors, empty if valid. |
| 147 |
*/ |
| 148 |
private static function get_arguments_validation_errors( $arguments ): array { |
| 149 |
$errors = array(); |
| 150 |
|
| 151 |
// Arguments must be an array |
| 152 |
if ( ! is_array( $arguments ) ) { |
| 153 |
return array( __( 'Prompt arguments must be an array if provided', 'mcp-adapter' ) ); |
| 154 |
} |
| 155 |
|
| 156 |
// Validate each argument |
| 157 |
foreach ( $arguments as $index => $argument ) { |
| 158 |
if ( ! is_array( $argument ) ) { |
| 159 |
$errors[] = sprintf( |
| 160 |
/* translators: %d: argument index */ |
| 161 |
__( 'Prompt argument at index %d must be an object', 'mcp-adapter' ), |
| 162 |
$index |
| 163 |
); |
| 164 |
continue; |
| 165 |
} |
| 166 |
|
| 167 |
// Check required name field |
| 168 |
if ( empty( $argument['name'] ) || ! is_string( $argument['name'] ) ) { |
| 169 |
$errors[] = sprintf( |
| 170 |
/* translators: %d: argument index */ |
| 171 |
__( 'Prompt argument at index %d must have a non-empty name string', 'mcp-adapter' ), |
| 172 |
$index |
| 173 |
); |
| 174 |
continue; |
| 175 |
} |
| 176 |
|
| 177 |
// Validate argument name format (uses standard 128-char limit per MCP spec). |
| 178 |
if ( ! McpValidator::validate_name( $argument['name'] ) ) { |
| 179 |
$errors[] = sprintf( |
| 180 |
/* translators: %s: argument name */ |
| 181 |
__( 'Prompt argument \'%s\' name must only contain letters, numbers, hyphens (-), underscores (_), and dots (.), and be 128 characters or less', 'mcp-adapter' ), |
| 182 |
$argument['name'] |
| 183 |
); |
| 184 |
} |
| 185 |
|
| 186 |
// Check optional description field |
| 187 |
if ( isset( $argument['description'] ) && ! is_string( $argument['description'] ) ) { |
| 188 |
$errors[] = sprintf( |
| 189 |
/* translators: %s: argument name */ |
| 190 |
__( 'Prompt argument \'%s\' description must be a string if provided', 'mcp-adapter' ), |
| 191 |
$argument['name'] |
| 192 |
); |
| 193 |
} |
| 194 |
|
| 195 |
// Check optional required field |
| 196 |
if ( ! isset( $argument['required'] ) || is_bool( $argument['required'] ) ) { |
| 197 |
continue; |
| 198 |
} |
| 199 |
|
| 200 |
$errors[] = sprintf( |
| 201 |
/* translators: %s: argument name */ |
| 202 |
__( 'Prompt argument \'%s\' required field must be a boolean if provided', 'mcp-adapter' ), |
| 203 |
$argument['name'] |
| 204 |
); |
| 205 |
} |
| 206 |
|
| 207 |
return $errors; |
| 208 |
} |
| 209 |
|
| 210 |
/** |
| 211 |
* Validate prompt messages array (used when getting a prompt with messages). |
| 212 |
* |
| 213 |
* @param array $messages The messages to validate. |
| 214 |
* |
| 215 |
* @return array Array of validation errors, empty if valid. |
| 216 |
*/ |
| 217 |
public static function validate_prompt_messages( array $messages ): array { |
| 218 |
$errors = array(); |
| 219 |
|
| 220 |
foreach ( $messages as $index => $message ) { |
| 221 |
if ( ! is_array( $message ) ) { |
| 222 |
$errors[] = sprintf( |
| 223 |
/* translators: %d: message index */ |
| 224 |
__( 'Message at index %d must be an object', 'mcp-adapter' ), |
| 225 |
$index |
| 226 |
); |
| 227 |
continue; |
| 228 |
} |
| 229 |
|
| 230 |
// Check the required role field |
| 231 |
if ( empty( $message['role'] ) || ! is_string( $message['role'] ) ) { |
| 232 |
$errors[] = sprintf( |
| 233 |
/* translators: %d: message index */ |
| 234 |
__( 'Message at index %d must have a role field', 'mcp-adapter' ), |
| 235 |
$index |
| 236 |
); |
| 237 |
continue; |
| 238 |
} |
| 239 |
|
| 240 |
// Validate role value |
| 241 |
if ( ! in_array( $message['role'], array( 'user', 'assistant' ), true ) ) { |
| 242 |
$errors[] = sprintf( |
| 243 |
/* translators: %d: message index */ |
| 244 |
__( 'Message at index %d role must be either \'user\' or \'assistant\'', 'mcp-adapter' ), |
| 245 |
$index |
| 246 |
); |
| 247 |
} |
| 248 |
|
| 249 |
// Check the required content field |
| 250 |
if ( empty( $message['content'] ) || ! is_array( $message['content'] ) ) { |
| 251 |
$errors[] = sprintf( |
| 252 |
/* translators: %d: message index */ |
| 253 |
__( 'Message at index %d must have a content object', 'mcp-adapter' ), |
| 254 |
$index |
| 255 |
); |
| 256 |
continue; |
| 257 |
} |
| 258 |
|
| 259 |
// Validate content |
| 260 |
$content_errors = self::get_content_validation_errors( $message['content'], $index ); |
| 261 |
if ( empty( $content_errors ) ) { |
| 262 |
continue; |
| 263 |
} |
| 264 |
|
| 265 |
$errors = array_merge( $errors, $content_errors ); |
| 266 |
} |
| 267 |
|
| 268 |
return $errors; |
| 269 |
} |
| 270 |
|
| 271 |
/** |
| 272 |
* Format icon validation errors from the validation result. |
| 273 |
* |
| 274 |
* @param array{valid: array, errors: array} $icons_result The result from validate_icons_array. |
| 275 |
* |
| 276 |
* @return array Array of formatted error messages. |
| 277 |
*/ |
| 278 |
private static function format_icon_validation_errors( array $icons_result ): array { |
| 279 |
$errors = array(); |
| 280 |
|
| 281 |
if ( ! empty( $icons_result['errors'] ) ) { |
| 282 |
foreach ( $icons_result['errors'] as $error_group ) { |
| 283 |
foreach ( $error_group['errors'] as $error ) { |
| 284 |
$errors[] = sprintf( |
| 285 |
/* translators: 1: icon index, 2: error message */ |
| 286 |
__( 'Icon at index %1$d: %2$s', 'mcp-adapter' ), |
| 287 |
$error_group['index'], |
| 288 |
$error |
| 289 |
); |
| 290 |
} |
| 291 |
} |
| 292 |
} |
| 293 |
|
| 294 |
return $errors; |
| 295 |
} |
| 296 |
|
| 297 |
/** |
| 298 |
* Get validation errors for message content. |
| 299 |
* |
| 300 |
* @param array $content The content to validate. |
| 301 |
* @param int $message_index The message index for error reporting. |
| 302 |
* |
| 303 |
* @return array Array of validation errors, empty if valid. |
| 304 |
*/ |
| 305 |
private static function get_content_validation_errors( array $content, int $message_index ): array { |
| 306 |
$errors = array(); |
| 307 |
|
| 308 |
// Check the required type field |
| 309 |
if ( empty( $content['type'] ) || ! is_string( $content['type'] ) ) { |
| 310 |
return array( |
| 311 |
sprintf( |
| 312 |
/* translators: %d: message index */ |
| 313 |
__( 'Message %d content must have a type field', 'mcp-adapter' ), |
| 314 |
$message_index |
| 315 |
), |
| 316 |
); |
| 317 |
} |
| 318 |
|
| 319 |
$type = $content['type']; |
| 320 |
|
| 321 |
switch ( $type ) { |
| 322 |
case 'text': |
| 323 |
if ( ! isset( $content['text'] ) || ! is_string( $content['text'] ) ) { |
| 324 |
$errors[] = sprintf( |
| 325 |
/* translators: %d: message index */ |
| 326 |
__( 'Message %d text content must have a text field', 'mcp-adapter' ), |
| 327 |
$message_index |
| 328 |
); |
| 329 |
} |
| 330 |
break; |
| 331 |
|
| 332 |
case 'image': |
| 333 |
if ( empty( $content['data'] ) || ! is_string( $content['data'] ) ) { |
| 334 |
$errors[] = sprintf( |
| 335 |
/* translators: %d: message index */ |
| 336 |
__( 'Message %d image content must have a data field with base64-encoded image', 'mcp-adapter' ), |
| 337 |
$message_index |
| 338 |
); |
| 339 |
} elseif ( ! McpValidator::validate_base64( $content['data'] ) ) { |
| 340 |
$errors[] = sprintf( |
| 341 |
/* translators: %d: message index */ |
| 342 |
__( 'Message %d image content data must be valid base64', 'mcp-adapter' ), |
| 343 |
$message_index |
| 344 |
); |
| 345 |
} |
| 346 |
|
| 347 |
if ( empty( $content['mimeType'] ) || ! is_string( $content['mimeType'] ) ) { |
| 348 |
$errors[] = sprintf( |
| 349 |
/* translators: %d: message index */ |
| 350 |
__( 'Message %d image content must have a mimeType field', 'mcp-adapter' ), |
| 351 |
$message_index |
| 352 |
); |
| 353 |
} elseif ( ! McpValidator::validate_image_mime_type( $content['mimeType'] ) ) { |
| 354 |
$errors[] = sprintf( |
| 355 |
/* translators: %d: message index */ |
| 356 |
__( 'Message %d image content must have a valid image MIME type', 'mcp-adapter' ), |
| 357 |
$message_index |
| 358 |
); |
| 359 |
} |
| 360 |
break; |
| 361 |
|
| 362 |
case 'audio': |
| 363 |
if ( empty( $content['data'] ) || ! is_string( $content['data'] ) ) { |
| 364 |
$errors[] = sprintf( |
| 365 |
/* translators: %d: message index */ |
| 366 |
__( 'Message %d audio content must have a data field with base64-encoded audio', 'mcp-adapter' ), |
| 367 |
$message_index |
| 368 |
); |
| 369 |
} elseif ( ! McpValidator::validate_base64( $content['data'] ) ) { |
| 370 |
$errors[] = sprintf( |
| 371 |
/* translators: %d: message index */ |
| 372 |
__( 'Message %d audio content data must be valid base64', 'mcp-adapter' ), |
| 373 |
$message_index |
| 374 |
); |
| 375 |
} |
| 376 |
|
| 377 |
if ( empty( $content['mimeType'] ) || ! is_string( $content['mimeType'] ) ) { |
| 378 |
$errors[] = sprintf( |
| 379 |
/* translators: %d: message index */ |
| 380 |
__( 'Message %d audio content must have a mimeType field', 'mcp-adapter' ), |
| 381 |
$message_index |
| 382 |
); |
| 383 |
} elseif ( ! McpValidator::validate_audio_mime_type( $content['mimeType'] ) ) { |
| 384 |
$errors[] = sprintf( |
| 385 |
/* translators: %d: message index */ |
| 386 |
__( 'Message %d audio content must have a valid audio MIME type', 'mcp-adapter' ), |
| 387 |
$message_index |
| 388 |
); |
| 389 |
} |
| 390 |
break; |
| 391 |
|
| 392 |
case 'resource_link': |
| 393 |
// ResourceLink is a metadata-only reference (same shape as Resource + type discriminator). |
| 394 |
if ( empty( $content['name'] ) || ! is_string( $content['name'] ) ) { |
| 395 |
$errors[] = sprintf( |
| 396 |
/* translators: %d: message index */ |
| 397 |
__( 'Message %d resource_link content must have a name field', 'mcp-adapter' ), |
| 398 |
$message_index |
| 399 |
); |
| 400 |
} |
| 401 |
|
| 402 |
if ( empty( $content['uri'] ) || ! is_string( $content['uri'] ) ) { |
| 403 |
$errors[] = sprintf( |
| 404 |
/* translators: %d: message index */ |
| 405 |
__( 'Message %d resource_link content must have a uri field', 'mcp-adapter' ), |
| 406 |
$message_index |
| 407 |
); |
| 408 |
} elseif ( ! McpValidator::validate_resource_uri( $content['uri'] ) ) { |
| 409 |
$errors[] = sprintf( |
| 410 |
/* translators: %d: message index */ |
| 411 |
__( 'Message %d resource_link content uri must be a valid URI format', 'mcp-adapter' ), |
| 412 |
$message_index |
| 413 |
); |
| 414 |
} |
| 415 |
|
| 416 |
if ( isset( $content['mimeType'] ) ) { |
| 417 |
if ( ! is_string( $content['mimeType'] ) ) { |
| 418 |
$errors[] = sprintf( |
| 419 |
/* translators: %d: message index */ |
| 420 |
__( 'Message %d resource_link content mimeType must be a string if provided', 'mcp-adapter' ), |
| 421 |
$message_index |
| 422 |
); |
| 423 |
} elseif ( ! McpValidator::validate_mime_type( $content['mimeType'] ) ) { |
| 424 |
$errors[] = sprintf( |
| 425 |
/* translators: %d: message index */ |
| 426 |
__( 'Message %d resource_link content mimeType must be a valid MIME type format', 'mcp-adapter' ), |
| 427 |
$message_index |
| 428 |
); |
| 429 |
} |
| 430 |
} |
| 431 |
|
| 432 |
if ( isset( $content['size'] ) && ! is_int( $content['size'] ) ) { |
| 433 |
$errors[] = sprintf( |
| 434 |
/* translators: %d: message index */ |
| 435 |
__( 'Message %d resource_link content size must be an integer if provided', 'mcp-adapter' ), |
| 436 |
$message_index |
| 437 |
); |
| 438 |
} |
| 439 |
|
| 440 |
if ( isset( $content['title'] ) && ! is_string( $content['title'] ) ) { |
| 441 |
$errors[] = sprintf( |
| 442 |
/* translators: %d: message index */ |
| 443 |
__( 'Message %d resource_link content title must be a string if provided', 'mcp-adapter' ), |
| 444 |
$message_index |
| 445 |
); |
| 446 |
} |
| 447 |
|
| 448 |
if ( isset( $content['description'] ) && ! is_string( $content['description'] ) ) { |
| 449 |
$errors[] = sprintf( |
| 450 |
/* translators: %d: message index */ |
| 451 |
__( 'Message %d resource_link content description must be a string if provided', 'mcp-adapter' ), |
| 452 |
$message_index |
| 453 |
); |
| 454 |
} |
| 455 |
|
| 456 |
if ( isset( $content['icons'] ) ) { |
| 457 |
if ( ! is_array( $content['icons'] ) ) { |
| 458 |
$errors[] = sprintf( |
| 459 |
/* translators: %d: message index */ |
| 460 |
__( 'Message %d resource_link content icons must be an array if provided', 'mcp-adapter' ), |
| 461 |
$message_index |
| 462 |
); |
| 463 |
} else { |
| 464 |
$icons_result = McpValidator::validate_icons_array( $content['icons'], false ); |
| 465 |
$errors = array_merge( $errors, self::format_icon_validation_errors( $icons_result ) ); |
| 466 |
} |
| 467 |
} |
| 468 |
|
| 469 |
break; |
| 470 |
|
| 471 |
case 'resource': |
| 472 |
if ( empty( $content['resource'] ) || ! is_array( $content['resource'] ) ) { |
| 473 |
$errors[] = sprintf( |
| 474 |
/* translators: %d: message index */ |
| 475 |
__( 'Message %d resource content must have a resource object', 'mcp-adapter' ), |
| 476 |
$message_index |
| 477 |
); |
| 478 |
} else { |
| 479 |
// Validate embedded resource using the resource validator for strict MCP compliance. |
| 480 |
$resource_errors = McpResourceValidator::get_validation_errors( $content['resource'] ); |
| 481 |
foreach ( $resource_errors as $resource_error ) { |
| 482 |
$errors[] = sprintf( |
| 483 |
/* translators: %1$d: message index, %2$s: resource error */ |
| 484 |
__( 'Message %1$d embedded resource: %2$s', 'mcp-adapter' ), |
| 485 |
$message_index, |
| 486 |
$resource_error |
| 487 |
); |
| 488 |
} |
| 489 |
} |
| 490 |
break; |
| 491 |
|
| 492 |
default: |
| 493 |
$errors[] = sprintf( |
| 494 |
/* translators: %1$d: message index, %2$s: content type */ |
| 495 |
__( 'Message %1$d content type \'%2$s\' is not supported. Must be \'text\', \'image\', \'audio\', \'resource\', or \'resource_link\'', 'mcp-adapter' ), |
| 496 |
$message_index, |
| 497 |
$type |
| 498 |
); |
| 499 |
break; |
| 500 |
} |
| 501 |
|
| 502 |
// Check optional annotations |
| 503 |
if ( isset( $content['annotations'] ) ) { |
| 504 |
if ( ! is_array( $content['annotations'] ) ) { |
| 505 |
$errors[] = sprintf( |
| 506 |
/* translators: %d: message index */ |
| 507 |
__( 'Message %d content annotations must be an array if provided', 'mcp-adapter' ), |
| 508 |
$message_index |
| 509 |
); |
| 510 |
} else { |
| 511 |
$annotation_errors = McpValidator::get_annotation_validation_errors( $content['annotations'] ); |
| 512 |
if ( ! empty( $annotation_errors ) ) { |
| 513 |
$errors = array_merge( $errors, $annotation_errors ); |
| 514 |
} |
| 515 |
} |
| 516 |
} |
| 517 |
|
| 518 |
return $errors; |
| 519 |
} |
| 520 |
} |
| 521 |
|
