Add mcp proxy command (#65)

ai-command.php

@@ -14,4 +14,5 @@ if ( file_exists( __DIR__ . '/vendor/autoload.php' ) ) {
 
 WP_CLI::add_command( 'ai', AiCommand::class );
 WP_CLI::add_command( 'mcp prompt', AiCommand::class );
+WP_CLI::add_command( 'mcp', McpCommand::class );
 WP_CLI::add_command( 'mcp server', McpServerCommand::class );

src/AiCommand.php

@@ -7,7 +7,6 @@ use McpWp\AiCommand\AI\AiClient;
 use McpWp\AiCommand\MCP\Client;
 use McpWp\AiCommand\Utils\CliLogger;
 use McpWp\AiCommand\Utils\McpConfig;
-use McpWp\MCP\Server;
 use McpWp\MCP\Servers\WordPress\WordPress;
 use WP_CLI;
 use WP_CLI\Utils;

src/MCP/ProxySession.php

@@ -0,0 +1,115 @@
+<?php
+
+namespace McpWp\AiCommand\MCP;
+
+use InvalidArgumentException;
+use Mcp\Client\ClientSession;
+use Mcp\Server\InitializationOptions;
+use Mcp\Server\ServerSession;
+use Mcp\Server\Transport\Transport;
+use Mcp\Shared\RequestResponder;
+use Mcp\Types\CallToolRequest;
+use Mcp\Types\CallToolResult;
+use Mcp\Types\ClientRequest;
+use Mcp\Types\CompleteRequest;
+use Mcp\Types\CompleteResult;
+use Mcp\Types\EmptyResult;
+use Mcp\Types\GetPromptRequest;
+use Mcp\Types\GetPromptResult;
+use Mcp\Types\InitializeRequest;
+use Mcp\Types\InitializeResult;
+use Mcp\Types\ListPromptsRequest;
+use Mcp\Types\ListPromptsResult;
+use Mcp\Types\ListResourcesRequest;
+use Mcp\Types\ListResourcesResult;
+use Mcp\Types\ListToolsRequest;
+use Mcp\Types\ListToolsResult;
+use Mcp\Types\PingRequest;
+use Mcp\Types\ReadResourceRequest;
+use Mcp\Types\ReadResourceResult;
+use Mcp\Types\SubscribeRequest;
+use Mcp\Types\UnsubscribeRequest;
+use Psr\Log\LoggerInterface;
+
+
+/**
+ * ProxySession to pass messages from STDIO to an HTTP MCP server.
+ */
+class ProxySession extends ServerSession {
+	protected ?ClientSession $client_session;
+
+	public function __construct(
+		protected readonly string $url,
+		Transport $transport,
+		InitializationOptions $init_options,
+		?LoggerInterface $logger = null
+	) {
+		parent::__construct(
+			$transport,
+			$init_options,
+			$logger
+		);
+	}
+
+	/**
+	 * Handle incoming requests. If it's the initialize request, handle it specially.
+	 * Otherwise, ensure initialization is complete before handling other requests.
+	 *
+	 * @param ClientRequest $request The incoming client request.
+	 * @param callable $respond The responder callable.
+	 */
+	public function handleRequest( RequestResponder $responder ): void {
+		$request        = $responder->getRequest();
+		$actual_request = $request->getRequest();
+		$method         = $actual_request->method;
+
+		$this->logger->info( 'Proxying request: ' . json_encode( $actual_request ) );
+
+		$result = null;
+
+		if ( ! isset( $this->client_session ) ) {
+			$client               = new Client( $this->logger );
+			$this->client_session = $client->connect(
+				$this->url
+			);
+		}
+
+		switch ( get_class( $actual_request ) ) {
+			case InitializeRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, InitializeResult::class );
+				break;
+			case SubscribeRequest::class:
+			case UnsubscribeRequest::class:
+			case PingRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, EmptyResult::class );
+				break;
+			case ListResourcesRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, ListResourcesResult::class );
+				break;
+			case ListToolsRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, ListToolsResult::class );
+				break;
+			case CallToolRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, CallToolResult::class );
+				break;
+			case ReadResourceRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, ReadResourceResult::class );
+				break;
+			case ListPromptsRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, ListPromptsResult::class );
+				break;
+			case GetPromptRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, GetPromptResult::class );
+				break;
+			case CompleteRequest::class:
+				$result = $this->client_session->sendRequest( $actual_request, CompleteResult::class );
+				break;
+		}
+
+		if ( null === $result ) {
+			throw new InvalidArgumentException( "Unhandled proxied request for method: $method / " . get_class( $actual_request ) );
+		}
+
+		$responder->sendResponse( $result );
+	}
+}

src/McpCommand.php

@@ -0,0 +1,99 @@
+<?php
+
+namespace McpWp\AiCommand;
+
+use Exception;
+use Mcp\Server\Server;
+use Mcp\Server\Transport\StdioServerTransport;
+use McpWp\AiCommand\MCP\ProxySession;
+use McpWp\AiCommand\Utils\CliLogger;
+use McpWp\AiCommand\Utils\McpConfig;
+use WP_CLI;
+use WP_CLI_Command;
+
+/**
+ * MCP command.
+ *
+ * Manage MCP servers for use with WP-CLI and proxy requests to servers using the HTTP transport.
+ */
+class McpCommand extends WP_CLI_Command {
+	/**
+	 * Proxy MCP requests to a given server.
+	 *
+	 * ## OPTIONS
+	 *
+	 * <server>
+	 * : Name of an existing server to proxy requests to.
+	 *
+	 * ## EXAMPLES
+	 *
+	 *     # Add server from URL.
+	 *     $ wp mcp server add "mywpserver" "https://example.com/wp-json/mcp/v1/mcp"
+	 *     Success: Server added.
+	 *
+	 *     # Proxy requests to server
+	 *     $ wp mcp proxy "mywpserver"
+	 *
+	 * @when before_wp_load
+	 *
+	 * @param string[] $args Indexed array of positional arguments.
+	 */
+	public function proxy( $args ): void {
+		$server = $this->get_config()->get_server( $args[0] );
+
+		if ( null === $server ) {
+			WP_CLI::error( 'Server does not exist.' );
+			return;
+		}
+
+		$url = $server['server'];
+
+		if ( ! str_starts_with( $url, 'http://' ) && ! str_starts_with( $url, 'https://' ) ) {
+			WP_CLI::error( 'Server is not using HTTP transport.' );
+			return;
+		}
+
+		$logger = new CliLogger();
+
+		$server = new Server( $args[0], $logger );
+
+		try {
+			$transport = StdioServerTransport::create();
+
+			$proxy_session = new ProxySession(
+				$url,
+				$transport,
+				$server->createInitializationOptions(),
+				$logger
+			);
+
+			$server->setSession( $proxy_session );
+
+			$proxy_session->registerHandlers( $server->getHandlers() );
+			$proxy_session->registerNotificationHandlers( $server->getNotificationHandlers() );
+
+			$proxy_session->start();
+
+			$logger->info( 'Server started' );
+
+		} catch ( Exception $e ) {
+			$logger->error( 'Proxy error: ' . $e->getMessage() );
+		} finally {
+			if ( isset( $proxy_session ) ) {
+				$proxy_session->stop();
+			}
+			if ( isset( $transport ) ) {
+				$transport->stop();
+			}
+		}
+	}
+
+	/**
+	 * Returns an McpConfig instance.
+	 *
+	 * @return McpConfig Config instance.
+	 */
+	protected function get_config(): McpConfig {
+		return new McpConfig();
+	}
+}