feat(MCP Client Tool Node): Add Timeout config for the MCP Client tool (#15886)

Co-authored-by: Shireen Missi <94372015+ShireenMissi@users.noreply.github.com>

Author: jreyesr

packages/@n8n/nodes-langchain/nodes/mcp/McpClientTool/McpClientTool.node.test.ts

@@ -1,5 +1,6 @@
 import { Client } from '@modelcontextprotocol/sdk/client/index.js';
 import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js';
+import { McpError, ErrorCode } from '@modelcontextprotocol/sdk/types.js';
 import { mock } from 'jest-mock-extended';
 import {
 	NodeConnectionTypes,
@@ -358,5 +359,50 @@ describe('McpClientTool', () => {
 				new NodeOperationError(supplyDataFunctions.getNode(), 'Weather unknown at location'),
 			);
 		});
+
+		it('should support setting a timeout', async () => {
+			jest.spyOn(Client.prototype, 'connect').mockResolvedValue();
+			const callToolSpy = jest
+				.spyOn(Client.prototype, 'callTool')
+				.mockRejectedValue(
+					new McpError(ErrorCode.RequestTimeout, 'Request timed out', { timeout: 200 }),
+				);
+			jest.spyOn(Client.prototype, 'listTools').mockResolvedValue({
+				tools: [
+					{
+						name: 'SlowTool',
+						description: 'SlowTool throws a timeout',
+						inputSchema: { type: 'object', properties: { input: { type: 'string' } } },
+					},
+				],
+			});
+
+			const mockNode = mock<INode>({ typeVersion: 1 });
+			const supplyDataResult = await new McpClientTool().supplyData.call(
+				mock<ISupplyDataFunctions>({
+					getNode: jest.fn(() => mockNode),
+					getNodeParameter: jest.fn((key, _index) => {
+						const parameters: Record<string, any> = {
+							'options.timeout': 200,
+						};
+						return parameters[key];
+					}),
+					logger: { debug: jest.fn(), error: jest.fn() },
+					addInputData: jest.fn(() => ({ index: 0 })),
+				}),
+				0,
+			);
+
+			const tools = (supplyDataResult.response as McpToolkit).getTools();
+
+			await expect(tools[0].invoke({ input: 'foo' })).resolves.toEqual(
+				'MCP error -32001: Request timed out',
+			);
+			expect(callToolSpy).toHaveBeenCalledWith(
+				expect.any(Object), // params
+				expect.any(Object), // schema
+				expect.objectContaining({ timeout: 200 }),
+			); // options
+		});
 	});
 });

packages/@n8n/nodes-langchain/nodes/mcp/McpClientTool/McpClientTool.node.ts

@@ -213,6 +213,26 @@ export class McpClientTool implements INodeType {
 					},
 				},
 			},
+			{
+				displayName: 'Options',
+				name: 'options',
+				placeholder: 'Add Option',
+				description: 'Additional options to add',
+				type: 'collection',
+				default: {},
+				options: [
+					{
+						displayName: 'Timeout',
+						name: 'timeout',
+						type: 'number',
+						typeOptions: {
+							minValue: 1,
+						},
+						default: 60000,
+						description: 'Time in ms to wait for tool calls to finish',
+					},
+				],
+			},
 		],
 	};
 
@@ -228,6 +248,7 @@ export class McpClientTool implements INodeType {
 			itemIndex,
 		) as McpAuthenticationOption;
 		const node = this.getNode();
+		const timeout = this.getNodeParameter('options.timeout', itemIndex, 60000) as number;
 
 		let serverTransport: McpServerTransport;
 		let endpointUrl: string;
@@ -293,7 +314,7 @@ export class McpClientTool implements INodeType {
 			logWrapper(
 				mcpToolToDynamicTool(
 					tool,
-					createCallTool(tool.name, client.result, (errorMessage) => {
+					createCallTool(tool.name, client.result, timeout, (errorMessage) => {
 						const error = new NodeOperationError(node, errorMessage, { itemIndex });
 						void this.addOutputData(NodeConnectionTypes.AiTool, itemIndex, error);
 						this.logger.error(`McpClientTool: Tool "${tool.name}" failed to execute`, { error });

packages/@n8n/nodes-langchain/nodes/mcp/McpClientTool/utils.ts

@@ -77,7 +77,8 @@ export const getErrorDescriptionFromToolCall = (result: unknown): string | undef
 };
 
 export const createCallTool =
-	(name: string, client: Client, onError: (error: string) => void) => async (args: IDataObject) => {
+	(name: string, client: Client, timeout: number, onError: (error: string) => void) =>
+	async (args: IDataObject) => {
 		let result: Awaited<ReturnType<Client['callTool']>>;
 
 		function handleError(error: unknown) {
@@ -88,7 +89,9 @@ export const createCallTool =
 		}
 
 		try {
-			result = await client.callTool({ name, arguments: args }, CompatibilityCallToolResultSchema);
+			result = await client.callTool({ name, arguments: args }, CompatibilityCallToolResultSchema, {
+				timeout,
+			});
 		} catch (error) {
 			return handleError(error);
 		}