ameliabooking
/
vendor
/
wordpress
/
mcp-adapter
/
includes
/
Handlers
/
Initialize
/
InitializeHandler.php
ameliabooking
/
vendor
/
wordpress
/
mcp-adapter
/
includes
/
Handlers
/
Initialize
Last commit date
InitializeHandler.php
1 month ago
InitializeHandler.php
101 lines
| 1 | <?php |
| 2 | /** |
| 3 | * Initialize method handler for MCP requests. |
| 4 | * |
| 5 | * @package McpAdapter |
| 6 | */ |
| 7 | |
| 8 | declare( strict_types=1 ); |
| 9 | |
| 10 | namespace WP\MCP\Handlers\Initialize; |
| 11 | |
| 12 | use WP\MCP\Core\McpServer; |
| 13 | use WP\MCP\Core\McpVersionNegotiator; |
| 14 | use WP\McpSchema\Common\Lifecycle\DTO\Implementation; |
| 15 | use WP\McpSchema\Common\Protocol\DTO\InitializeResult; |
| 16 | use WP\McpSchema\Server\Lifecycle\DTO\ServerCapabilities; |
| 17 | |
| 18 | /** |
| 19 | * Handles the initialize MCP method. |
| 20 | */ |
| 21 | class InitializeHandler { |
| 22 | /** |
| 23 | * The WordPress MCP instance. |
| 24 | * |
| 25 | * @var \WP\MCP\Core\McpServer |
| 26 | */ |
| 27 | private McpServer $mcp; |
| 28 | |
| 29 | /** |
| 30 | * Constructor. |
| 31 | * |
| 32 | * @param \WP\MCP\Core\McpServer $mcp The WordPress MCP instance. |
| 33 | */ |
| 34 | public function __construct( McpServer $mcp ) { |
| 35 | $this->mcp = $mcp; |
| 36 | } |
| 37 | |
| 38 | /** |
| 39 | * Handles the initialize request. |
| 40 | * |
| 41 | * Negotiates the protocol version with the client using McpVersionNegotiator. |
| 42 | * If the client requests a supported version, that version is used. Otherwise |
| 43 | * the server falls back to the latest supported version. |
| 44 | * |
| 45 | * @since 0.5.0 |
| 46 | * |
| 47 | * @param string $client_protocol_version The protocol version requested by the client. |
| 48 | * |
| 49 | * @return \WP\McpSchema\Common\Protocol\DTO\InitializeResult Response with server capabilities and information. |
| 50 | */ |
| 51 | public function handle( string $client_protocol_version ): InitializeResult { |
| 52 | $negotiated_version = McpVersionNegotiator::negotiate( $client_protocol_version ); |
| 53 | |
| 54 | $server_info = Implementation::fromArray( |
| 55 | array( |
| 56 | 'name' => $this->mcp->get_server_name(), |
| 57 | 'version' => $this->mcp->get_server_version(), |
| 58 | ) |
| 59 | ); |
| 60 | |
| 61 | // Capabilities should only be advertised if they are implemented end-to-end. |
| 62 | // IMPORTANT: We set explicit boolean values (not empty arrays) to ensure proper JSON serialization. |
| 63 | // Empty arrays `[]` serialize as JSON arrays `[]`, but MCP spec requires JSON objects `{}`. |
| 64 | // Setting explicit values like `listChanged: false` produces associative arrays that serialize correctly. |
| 65 | $capabilities = ServerCapabilities::fromArray( |
| 66 | array( |
| 67 | 'prompts' => array( 'listChanged' => false ), |
| 68 | 'resources' => array( |
| 69 | 'subscribe' => false, |
| 70 | 'listChanged' => false, |
| 71 | ), |
| 72 | 'tools' => array( 'listChanged' => false ), |
| 73 | ) |
| 74 | ); |
| 75 | |
| 76 | $result = InitializeResult::fromArray( |
| 77 | array( |
| 78 | 'protocolVersion' => $negotiated_version, |
| 79 | 'capabilities' => $capabilities, |
| 80 | 'serverInfo' => $server_info, |
| 81 | 'instructions' => $this->mcp->get_server_description(), |
| 82 | ) |
| 83 | ); |
| 84 | |
| 85 | /** |
| 86 | * Filters the initialize response before returning to the client. |
| 87 | * |
| 88 | * Use this filter to modify server capabilities, instructions, or |
| 89 | * other initialization data dynamically. To modify the result, call |
| 90 | * `$result->toArray()`, change the data, and return |
| 91 | * `InitializeResult::fromArray( $modified_data )`. |
| 92 | * |
| 93 | * @since 0.5.0 |
| 94 | * |
| 95 | * @param \WP\McpSchema\Common\Protocol\DTO\InitializeResult $result The initialize result DTO. |
| 96 | * @param \WP\MCP\Core\McpServer $server The MCP server instance. |
| 97 | */ |
| 98 | return apply_filters( 'mcp_adapter_initialize_response', $result, $this->mcp ); |
| 99 | } |
| 100 | } |
| 101 |