[FEAT] dynamic stdio connection for mcp client

Signed-off-by: Changue Lim <[email protected]>

Author: baekgol

auto-configurations/mcp/spring-ai-autoconfigure-mcp-client/src/main/java/org/springframework/ai/mcp/client/autoconfigure/McpClientStdioUtils.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright 2025-2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.mcp.client.autoconfigure;
+
+import io.modelcontextprotocol.client.McpAsyncClient;
+import io.modelcontextprotocol.client.McpClient;
+import io.modelcontextprotocol.client.McpSyncClient;
+import io.modelcontextprotocol.client.transport.ServerParameters;
+import io.modelcontextprotocol.client.transport.StdioClientTransport;
+import io.modelcontextprotocol.spec.McpSchema;
+import org.springframework.ai.mcp.client.autoconfigure.properties.McpClientCommonProperties;
+
+import java.util.List;
+
+/**
+ * Utility class for managing MCP (Model Context Protocol) clients using stdio transports.
+ * <p>
+ * This utility class provides methods to dynamically create and add MCP clients to existing
+ * client collections at runtime. It supports both synchronous and asynchronous client creation
+ * through the appropriate helper methods.
+ * <p>
+ * Key features:
+ * <ul>
+ *   <li>Dynamic creation of MCP clients with stdio transport</li>
+ *   <li>Support for both synchronous and asynchronous client types</li>
+ *   <li>Consistent configuration using common properties</li>
+ *   <li>Runtime management of client connections</li>
+ * </ul>
+ * <p>
+ * Example usage: <pre>{@code
+ * // Obtain common properties and client lists
+ * McpClientCommonProperties properties = // obtain properties
+ * List<McpSyncClient> syncClients = // obtain sync client list
+ *
+ * // Add a new stdio connection
+ * McpStdioUtils.addConnectionSync(properties, syncClients,
+ *                               "search-service",
+ *                               "/path/to/executable",
+ *                               "--arg1", "--arg2");
+ * }</pre>
+ *
+ * @author Changue Lim
+ * @see McpSyncClient
+ * @see McpAsyncClient
+ * @see StdioClientTransport
+ * @see ServerParameters
+ */
+public class McpClientStdioUtils {
+	/**
+	 * Adds a new MCP Sync Client connection to the existing list of clients.
+	 * This method dynamically creates and configures a synchronous MCP client
+	 * using a stdio transport, making it possible to add new connections at runtime.
+	 *
+	 * <p>The newly created client is configured with:
+	 * <ul>
+	 *   <li>A stdio transport using the specified command and arguments</li>
+	 *   <li>Client information derived from common properties and the connection name</li>
+	 *   <li>Request timeout from common properties</li>
+	 * </ul>
+	 *
+	 * <p>If initialization is enabled in the common properties, the client will be initialized
+	 * immediately before being added to the client list.
+	 *
+	 * @param mcpClientCommonProperties common MCP client configuration properties
+	 *                                 used for timeout, name, version, and initialization settings
+	 * @param mcpSyncClients the list of existing clients to which the new client will be added
+	 * @param name a unique identifier for this connection (used as part of the client info name)
+	 * @param command the command to execute for the stdio transport (e.g., path to executable)
+	 * @param args variable number of command-line arguments to pass to the command
+	 *
+	 * @see McpSyncClient
+	 * @see StdioClientTransport
+	 * @see ServerParameters
+	 */
+	private static void addConnectionSync(McpClientCommonProperties mcpClientCommonProperties,
+										  List<McpSyncClient> mcpSyncClients,
+										  String name,
+										  String command,
+										  String... args) {
+		final McpSyncClient syncClient = McpClient.sync(new StdioClientTransport(ServerParameters.builder(command).args(args).build()))
+				.clientInfo(new McpSchema.Implementation(mcpClientCommonProperties.getName() + "-" + name, mcpClientCommonProperties.getVersion()))
+				.requestTimeout(mcpClientCommonProperties.getRequestTimeout())
+				.build();
+
+		if(mcpClientCommonProperties.isInitialized())
+			syncClient.initialize();
+
+		mcpSyncClients.add(syncClient);
+	}
+
+	/**
+	 * Adds a new MCP Async Client connection to the existing list of clients.
+	 * This method dynamically creates and configures an asynchronous MCP client
+	 * using a stdio transport, making it possible to add new connections at runtime.
+	 *
+	 * <p>The newly created client is configured with:
+	 * <ul>
+	 *   <li>A stdio transport using the specified command and arguments</li>
+	 *   <li>Client information derived from common properties and the connection name</li>
+	 *   <li>Request timeout from common properties</li>
+	 * </ul>
+	 *
+	 * <p>If initialization is enabled in the common properties, the client will be initialized
+	 * immediately before being added to the client list. For async clients, the initialization
+	 * is performed by blocking on the Mono completion.
+	 *
+	 * @param mcpClientCommonProperties common MCP client configuration properties
+	 *                                 used for timeout, name, version, and initialization settings
+	 * @param mcpAsyncClients the list of existing clients to which the new client will be added
+	 * @param name a unique identifier for this connection (used as part of the client info name)
+	 * @param command the command to execute for the stdio transport (e.g., path to executable)
+	 * @param args variable number of command-line arguments to pass to the command
+	 *
+	 * @see McpAsyncClient
+	 * @see StdioClientTransport
+	 * @see ServerParameters
+	 */
+	private static void addConnectionAsync(McpClientCommonProperties mcpClientCommonProperties,
+										   List<McpAsyncClient> mcpAsyncClients,
+										   String name,
+										   String command,
+										   String... args) {
+		final McpAsyncClient asyncClient = McpClient.async(new StdioClientTransport(ServerParameters.builder(command).args(args).build()))
+				.clientInfo(new McpSchema.Implementation(mcpClientCommonProperties.getName() + "-" + name, mcpClientCommonProperties.getVersion()))
+				.requestTimeout(mcpClientCommonProperties.getRequestTimeout())
+				.build();
+
+		if(mcpClientCommonProperties.isInitialized())
+			asyncClient.initialize().block();
+
+		mcpAsyncClients.add(asyncClient);
+	}
+}