fix(AI Agent Node): Fix tool calling when tools run in a loop (#15250)

Co-authored-by: JP van Oosten <jp@n8n.io>
Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/@n8n/nodes-langchain/nodes/tools/ToolWorkflow/v2/ToolWorkflowV2.node.ts

@@ -39,6 +39,7 @@ export class ToolWorkflowV2 implements INodeType {
 		const description = this.getNodeParameter('description', itemIndex) as string;
 
 		const tool = await workflowToolService.createTool({
+			ctx: this,
 			name,
 			description,
 			itemIndex,

packages/@n8n/nodes-langchain/nodes/tools/ToolWorkflow/v2/ToolWorkflowV2.test.ts

@@ -13,6 +13,10 @@ import { WorkflowToolService } from './utils/WorkflowToolService';
 
 // Mock ISupplyDataFunctions interface
 function createMockContext(overrides?: Partial<ISupplyDataFunctions>): ISupplyDataFunctions {
+	let runIndex = 0;
+	const getNextRunIndex = jest.fn(() => {
+		return runIndex++;
+	});
 	return {
 		runIndex: 0,
 		getNodeParameter: jest.fn(),
@@ -26,6 +30,7 @@ function createMockContext(overrides?: Partial<ISupplyDataFunctions>): ISupplyDa
 		getInputData: jest.fn(),
 		getMode: jest.fn(),
 		getRestApiUrl: jest.fn(),
+		getNextRunIndex,
 		getTimezone: jest.fn(),
 		getWorkflow: jest.fn(),
 		getWorkflowStaticData: jest.fn(),
@@ -56,6 +61,7 @@ describe('WorkflowTool::WorkflowToolService', () => {
 	describe('createTool', () => {
 		it('should create a basic dynamic tool when schema is not used', async () => {
 			const toolParams = {
+				ctx: context,
 				name: 'TestTool',
 				description: 'Test Description',
 				itemIndex: 0,
@@ -70,6 +76,7 @@ describe('WorkflowTool::WorkflowToolService', () => {
 
 		it('should create a tool that can handle successful execution', async () => {
 			const toolParams = {
+				ctx: context,
 				name: 'TestTool',
 				description: 'Test Description',
 				itemIndex: 0,
@@ -112,6 +119,7 @@ describe('WorkflowTool::WorkflowToolService', () => {
 
 		it('should handle errors during tool execution', async () => {
 			const toolParams = {
+				ctx: context,
 				name: 'TestTool',
 				description: 'Test Description',
 				itemIndex: 0,

packages/@n8n/nodes-langchain/nodes/tools/ToolWorkflow/v2/utils/WorkflowToolService.ts

@@ -60,17 +60,21 @@ export class WorkflowToolService {
 
 	// Creates the tool based on the provided parameters
 	async createTool({
+		ctx,
 		name,
 		description,
 		itemIndex,
 	}: {
+		ctx: ISupplyDataFunctions;
 		name: string;
 		description: string;
 		itemIndex: number;
 	}): Promise<DynamicTool | DynamicStructuredTool> {
-		let runIndex = 0;
 		// Handler for the tool execution, will be called when the tool is executed
 		// This function will execute the sub-workflow and return the response
+		// We get the runIndex from the context to handle multiple executions
+		// of the same tool when the tool is used in a loop or in a parallel execution.
+		let runIndex: number = ctx.getNextRunIndex();
 		const toolHandler = async (
 			query: string | IDataObject,
 			runManager?: CallbackManagerForToolRun,