feat: Add model selector node (#16371)

cypress/e2e/5-ndv.cy.ts

@@ -565,18 +565,20 @@ describe('NDV', () => {
 				{
 					title: 'Language Models',
 					id: 'ai_languageModel',
+					index: 0,
 				},
 				{
 					title: 'Tools',
 					id: 'ai_tool',
+					index: 0,
 				},
 			];
 
 			workflowPage.actions.addInitialNodeToCanvas('AI Agent', { keepNdvOpen: true });
 
 			connectionGroups.forEach((group) => {
-				cy.getByTestId(`add-subnode-${group.id}`).should('exist');
+				cy.getByTestId(`add-subnode-${group.id}-${group.index}`).should('exist');
-				cy.getByTestId(`add-subnode-${group.id}`).click();
+				cy.getByTestId(`add-subnode-${group.id}-${group.index}`).click();
 
 				cy.getByTestId('nodes-list-header').contains(group.title).should('exist');
 				// Add HTTP Request tool
@@ -585,16 +587,16 @@ describe('NDV', () => {
 				getFloatingNodeByPosition('outputSub').click({ force: true });
 
 				if (group.id === 'ai_languageModel') {
-					cy.getByTestId(`add-subnode-${group.id}`).should('not.exist');
+					cy.getByTestId(`add-subnode-${group.id}-${group.index}`).should('not.exist');
 				} else {
-					cy.getByTestId(`add-subnode-${group.id}`).should('exist');
+					cy.getByTestId(`add-subnode-${group.id}-${group.index}`).should('exist');
 					// Expand the subgroup
-					cy.getByTestId('subnode-connection-group-ai_tool').click();
+					cy.getByTestId('subnode-connection-group-ai_tool-0').click();
-					cy.getByTestId(`add-subnode-${group.id}`).click();
+					cy.getByTestId(`add-subnode-${group.id}-${group.index}`).click();
 					// Add HTTP Request tool
 					nodeCreator.getters.getNthCreatorItem(2).click();
 					getFloatingNodeByPosition('outputSub').click({ force: true });
-					cy.getByTestId('subnode-connection-group-ai_tool')
+					cy.getByTestId('subnode-connection-group-ai_tool-0')
 						.findChildByTestId('floating-subnode')
 						.should('have.length', 2);
 				}

packages/@n8n/nodes-langchain/nodes/ModelSelector/ModelSelector.node.ts

@@ -0,0 +1,204 @@
+/* eslint-disable n8n-nodes-base/node-param-description-wrong-for-dynamic-options */
+/* eslint-disable n8n-nodes-base/node-param-display-name-wrong-for-dynamic-options */
+import type { BaseCallbackHandler, CallbackHandlerMethods } from '@langchain/core/callbacks/base';
+import type { Callbacks } from '@langchain/core/callbacks/manager';
+import type { BaseChatModel } from '@langchain/core/language_models/chat_models';
+import {
+	NodeConnectionTypes,
+	type INodeType,
+	type INodeTypeDescription,
+	type ISupplyDataFunctions,
+	type SupplyData,
+	type ILoadOptionsFunctions,
+	NodeOperationError,
+} from 'n8n-workflow';
+
+import { numberInputsProperty, configuredInputs } from './helpers';
+import { N8nLlmTracing } from '../llms/N8nLlmTracing';
+import { N8nNonEstimatingTracing } from '../llms/N8nNonEstimatingTracing';
+
+interface ModeleSelectionRule {
+	modelIndex: number;
+	conditions: {
+		options: {
+			caseSensitive: boolean;
+			typeValidation: 'strict' | 'loose';
+			leftValue: string;
+			version: 1 | 2;
+		};
+		conditions: Array<{
+			id: string;
+			leftValue: string;
+			rightValue: string;
+			operator: {
+				type: string;
+				operation: string;
+				name: string;
+			};
+		}>;
+		combinator: 'and' | 'or';
+	};
+}
+
+function getCallbacksArray(
+	callbacks: Callbacks | undefined,
+): Array<BaseCallbackHandler | CallbackHandlerMethods> {
+	if (!callbacks) return [];
+
+	if (Array.isArray(callbacks)) {
+		return callbacks;
+	}
+
+	// If it's a CallbackManager, extract its handlers
+	return callbacks.handlers || [];
+}
+
+export class ModelSelector implements INodeType {
+	description: INodeTypeDescription = {
+		displayName: 'Model Selector',
+		name: 'modelSelector',
+		icon: 'fa:map-signs',
+		iconColor: 'green',
+		defaults: {
+			name: 'Model Selector',
+		},
+		version: 1,
+		group: ['transform'],
+		description:
+			'Use this node to select one of the connected models to this node based on workflow data',
+		inputs: `={{
+				((parameters) => {
+					${configuredInputs.toString()};
+					return configuredInputs(parameters)
+				})($parameter)
+			}}`,
+		outputs: [NodeConnectionTypes.AiLanguageModel],
+		requiredInputs: 1,
+		properties: [
+			numberInputsProperty,
+			{
+				displayName: 'Rules',
+				name: 'rules',
+				placeholder: 'Add Rule',
+				type: 'fixedCollection',
+				typeOptions: {
+					multipleValues: true,
+					sortable: true,
+				},
+				description: 'Rules to map workflow data to specific models',
+				default: {},
+				options: [
+					{
+						displayName: 'Rule',
+						name: 'rule',
+						values: [
+							{
+								displayName: 'Model',
+								name: 'modelIndex',
+								type: 'options',
+								description: 'Choose model input from the list',
+								default: 1,
+								required: true,
+								placeholder: 'Choose model input from the list',
+								typeOptions: {
+									loadOptionsMethod: 'getModels',
+								},
+							},
+							{
+								displayName: 'Conditions',
+								name: 'conditions',
+								placeholder: 'Add Condition',
+								type: 'filter',
+								default: {},
+								typeOptions: {
+									filter: {
+										caseSensitive: true,
+										typeValidation: 'strict',
+										version: 2,
+									},
+								},
+								description: 'Conditions that must be met to select this model',
+							},
+						],
+					},
+				],
+			},
+		],
+	};
+
+	methods = {
+		loadOptions: {
+			async getModels(this: ILoadOptionsFunctions) {
+				const numberInputs = this.getCurrentNodeParameter('numberInputs') as number;
+
+				return Array.from({ length: numberInputs ?? 2 }, (_, i) => ({
+					value: i + 1,
+					name: `Model ${(i + 1).toString()}`,
+				}));
+			},
+		},
+	};
+
+	async supplyData(this: ISupplyDataFunctions, itemIndex: number): Promise<SupplyData> {
+		const models = (await this.getInputConnectionData(
+			NodeConnectionTypes.AiLanguageModel,
+			itemIndex,
+		)) as unknown[];
+
+		if (!models || models.length === 0) {
+			throw new NodeOperationError(this.getNode(), 'No models connected', {
+				itemIndex,
+				description: 'No models found in input connections',
+			});
+		}
+		models.reverse();
+
+		const rules = this.getNodeParameter('rules.rule', itemIndex, []) as ModeleSelectionRule[];
+
+		if (!rules || rules.length === 0) {
+			throw new NodeOperationError(this.getNode(), 'No rules defined', {
+				itemIndex,
+				description: 'At least one rule must be defined to select a model',
+			});
+		}
+
+		for (let i = 0; i < rules.length; i++) {
+			const rule = rules[i];
+			const modelIndex = rule.modelIndex;
+
+			if (modelIndex <= 0 || modelIndex > models.length) {
+				throw new NodeOperationError(this.getNode(), `Invalid model index ${modelIndex}`, {
+					itemIndex,
+					description: `Model index must be between 1 and ${models.length}`,
+				});
+			}
+
+			const conditionsMet = this.getNodeParameter(`rules.rule[${i}].conditions`, itemIndex, false, {
+				extractValue: true,
+			}) as boolean;
+
+			if (conditionsMet) {
+				const selectedModel = models[modelIndex - 1] as BaseChatModel;
+
+				const originalCallbacks = getCallbacksArray(selectedModel.callbacks);
+
+				for (const currentCallback of originalCallbacks) {
+					if (currentCallback instanceof N8nLlmTracing) {
+						currentCallback.setParentRunIndex(this.getNextRunIndex());
+					}
+				}
+				const modelSelectorTracing = new N8nNonEstimatingTracing(this);
+				selectedModel.callbacks = [...originalCallbacks, modelSelectorTracing];
+
+				return {
+					response: selectedModel,
+				};
+			}
+		}
+
+		throw new NodeOperationError(this.getNode(), 'No matching rule found', {
+			itemIndex,
+			description: 'None of the defined rules matched the workflow data',
+		});
+	}
+}

packages/@n8n/nodes-langchain/nodes/ModelSelector/helpers.ts

@@ -0,0 +1,59 @@
+import type { INodeInputConfiguration, INodeParameters, INodeProperties } from 'n8n-workflow';
+
+export const numberInputsProperty: INodeProperties = {
+	displayName: 'Number of Inputs',
+	name: 'numberInputs',
+	type: 'options',
+	noDataExpression: true,
+	default: 2,
+	options: [
+		{
+			name: '2',
+			value: 2,
+		},
+		{
+			name: '3',
+			value: 3,
+		},
+		{
+			name: '4',
+			value: 4,
+		},
+		{
+			name: '5',
+			value: 5,
+		},
+		{
+			name: '6',
+			value: 6,
+		},
+		{
+			name: '7',
+			value: 7,
+		},
+		{
+			name: '8',
+			value: 8,
+		},
+		{
+			name: '9',
+			value: 9,
+		},
+		{
+			name: '10',
+			value: 10,
+		},
+	],
+	validateType: 'number',
+	description:
+		'The number of data inputs you want to merge. The node waits for all connected inputs to be executed.',
+};
+
+export function configuredInputs(parameters: INodeParameters): INodeInputConfiguration[] {
+	return Array.from({ length: (parameters.numberInputs as number) || 2 }, (_, i) => ({
+		type: 'ai_languageModel',
+		displayName: `Model ${(i + 1).toString()}`,
+		required: true,
+		maxConnections: 1,
+	}));
+}

packages/@n8n/nodes-langchain/nodes/ModelSelector/test/ModelSelector.node.test.ts

@@ -0,0 +1,298 @@
+/* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-assignment */
+import type { BaseChatModel } from '@langchain/core/language_models/chat_models';
+import { mock } from 'jest-mock-extended';
+import type { ISupplyDataFunctions, INode, ILoadOptionsFunctions } from 'n8n-workflow';
+import { NodeOperationError, NodeConnectionTypes } from 'n8n-workflow';
+
+import { ModelSelector } from '../ModelSelector.node';
+
+// Mock the N8nLlmTracing module completely to avoid module resolution issues
+jest.mock('../../llms/N8nLlmTracing', () => ({
+	N8nLlmTracing: jest.fn().mockImplementation(() => ({
+		handleLLMStart: jest.fn(),
+		handleLLMEnd: jest.fn(),
+	})),
+}));
+
+describe('ModelSelector Node', () => {
+	let node: ModelSelector;
+	let mockSupplyDataFunction: jest.Mocked<ISupplyDataFunctions>;
+	let mockLoadOptionsFunction: jest.Mocked<ILoadOptionsFunctions>;
+
+	beforeEach(() => {
+		node = new ModelSelector();
+		mockSupplyDataFunction = mock<ISupplyDataFunctions>();
+		mockLoadOptionsFunction = mock<ILoadOptionsFunctions>();
+
+		mockSupplyDataFunction.getNode.mockReturnValue({
+			name: 'Model Selector',
+			typeVersion: 1,
+			parameters: {},
+		} as INode);
+
+		jest.clearAllMocks();
+	});
+
+	describe('description', () => {
+		it('should have the expected properties', () => {
+			expect(node.description).toBeDefined();
+			expect(node.description.name).toBe('modelSelector');
+			expect(node.description.displayName).toBe('Model Selector');
+			expect(node.description.version).toBe(1);
+			expect(node.description.group).toEqual(['transform']);
+			expect(node.description.outputs).toEqual([NodeConnectionTypes.AiLanguageModel]);
+			expect(node.description.requiredInputs).toBe(1);
+		});
+
+		it('should have the correct properties defined', () => {
+			expect(node.description.properties).toHaveLength(2);
+			expect(node.description.properties[0].name).toBe('numberInputs');
+			expect(node.description.properties[1].name).toBe('rules');
+		});
+	});
+
+	describe('loadOptions methods', () => {
+		describe('getModels', () => {
+			it('should return correct number of models based on numberInputs parameter', async () => {
+				mockLoadOptionsFunction.getCurrentNodeParameter.mockReturnValue(3);
+
+				const result = await node.methods.loadOptions.getModels.call(mockLoadOptionsFunction);
+
+				expect(result).toEqual([
+					{ value: 1, name: 'Model 1' },
+					{ value: 2, name: 'Model 2' },
+					{ value: 3, name: 'Model 3' },
+				]);
+			});
+
+			it('should default to 2 models when numberInputs is undefined', async () => {
+				mockLoadOptionsFunction.getCurrentNodeParameter.mockReturnValue(undefined);
+
+				const result = await node.methods.loadOptions.getModels.call(mockLoadOptionsFunction);
+
+				expect(result).toEqual([
+					{ value: 1, name: 'Model 1' },
+					{ value: 2, name: 'Model 2' },
+				]);
+			});
+		});
+	});
+
+	describe('supplyData', () => {
+		const mockModel1: Partial<BaseChatModel> = {
+			_llmType: () => 'fake-llm',
+			callbacks: [],
+		};
+		const mockModel2: Partial<BaseChatModel> = {
+			_llmType: () => 'fake-llm-2',
+			callbacks: undefined,
+		};
+		const mockModel3: Partial<BaseChatModel> = {
+			_llmType: () => 'fake-llm-3',
+			callbacks: [{ handleLLMStart: jest.fn() }],
+		};
+
+		beforeEach(() => {
+			// Note: models array gets reversed in supplyData, so [model1, model2, model3] becomes [model3, model2, model1]
+			mockSupplyDataFunction.getInputConnectionData.mockResolvedValue([
+				mockModel1,
+				mockModel2,
+				mockModel3,
+			]);
+		});
+
+		it('should throw error when no models are connected', async () => {
+			mockSupplyDataFunction.getInputConnectionData.mockResolvedValue([]);
+
+			await expect(node.supplyData.call(mockSupplyDataFunction, 0)).rejects.toThrow(
+				NodeOperationError,
+			);
+		});
+
+		it('should throw error when no rules are defined', async () => {
+			mockSupplyDataFunction.getNodeParameter.mockReturnValue([]);
+
+			await expect(node.supplyData.call(mockSupplyDataFunction, 0)).rejects.toThrow(
+				NodeOperationError,
+			);
+		});
+
+		it('should return the correct model when rule conditions are met', async () => {
+			const rules = [
+				{
+					modelIndex: '2',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			const result = await node.supplyData.call(mockSupplyDataFunction, 0);
+
+			// After reverse: [model3, model2, model1], so index 2 (1-based) = model2
+			expect(result.response).toBe(mockModel2);
+		});
+
+		it('should add N8nLlmTracing callback to selected model', async () => {
+			const rules = [
+				{
+					modelIndex: '1',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			const result = await node.supplyData.call(mockSupplyDataFunction, 0);
+
+			// After reverse: [model3, model2, model1], so index 1 (1-based) = model3
+			expect(result.response).toBe(mockModel3);
+			expect((result.response as BaseChatModel).callbacks).toHaveLength(2); // original + N8nLlmTracing
+		});
+
+		it('should handle models with undefined callbacks', async () => {
+			const rules = [
+				{
+					modelIndex: '2',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			const result = await node.supplyData.call(mockSupplyDataFunction, 0);
+
+			// After reverse: [model3, model2, model1], so index 2 (1-based) = model2
+			expect(result.response).toBe(mockModel2);
+			// Should have 1 callback added (N8nLlmTracing)
+			expect(Array.isArray((result.response as BaseChatModel).callbacks)).toBe(true);
+			expect((result.response as BaseChatModel).callbacks).toHaveLength(2);
+		});
+
+		it('should evaluate multiple rules and return first matching model', async () => {
+			const rules = [
+				{
+					modelIndex: '1',
+					conditions: {},
+				},
+				{
+					modelIndex: '3',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(false) // first rule conditions evaluation
+				.mockReturnValueOnce(true); // second rule conditions evaluation
+
+			const result = await node.supplyData.call(mockSupplyDataFunction, 0);
+
+			// After reverse: [model3, model2, model1], so index 3 (1-based) = model1
+			expect(result.response).toBe(mockModel1);
+		});
+
+		it('should throw error when no rules match', async () => {
+			const rules = [
+				{
+					modelIndex: '1',
+					conditions: {},
+				},
+				{
+					modelIndex: '2',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(false) // first rule conditions evaluation
+				.mockReturnValueOnce(false); // second rule conditions evaluation
+
+			await expect(node.supplyData.call(mockSupplyDataFunction, 0)).rejects.toThrow(
+				NodeOperationError,
+			);
+		});
+
+		it('should throw error when model index is invalid (too low)', async () => {
+			const rules = [
+				{
+					modelIndex: '0',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			await expect(node.supplyData.call(mockSupplyDataFunction, 0)).rejects.toThrow(
+				NodeOperationError,
+			);
+		});
+
+		it('should throw error when model index is invalid (too high)', async () => {
+			const rules = [
+				{
+					modelIndex: '5',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			await expect(node.supplyData.call(mockSupplyDataFunction, 0)).rejects.toThrow(
+				NodeOperationError,
+			);
+		});
+
+		it('should handle string model indices correctly', async () => {
+			const rules = [
+				{
+					modelIndex: '3',
+					conditions: {},
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			const result = await node.supplyData.call(mockSupplyDataFunction, 0);
+
+			// After reverse: [model3, model2, model1], so index 3 (1-based) = model1
+			expect(result.response).toBe(mockModel1);
+		});
+
+		it('should call getNodeParameter with correct parameters for condition evaluation', async () => {
+			const rules = [
+				{
+					modelIndex: '1',
+					conditions: { field: 'value' },
+				},
+			];
+
+			mockSupplyDataFunction.getNodeParameter
+				.mockReturnValueOnce(rules) // rules.rule parameter
+				.mockReturnValueOnce(true); // conditions evaluation
+
+			await node.supplyData.call(mockSupplyDataFunction, 0);
+
+			expect(mockSupplyDataFunction.getNodeParameter).toHaveBeenCalledWith(
+				'rules.rule[0].conditions',
+				0,
+				false,
+				{ extractValue: true },
+			);
+		});
+	});
+});

packages/@n8n/nodes-langchain/nodes/ModelSelector/test/helpers.test.ts

@@ -0,0 +1,68 @@
+import type { INodeParameters, INodePropertyOptions } from 'n8n-workflow';
+
+// Import the function and property
+import { numberInputsProperty, configuredInputs } from '../helpers';
+
+// We need to extract the configuredInputs function for testing
+// Since it's not exported, we'll test it indirectly through the node's inputs property
+
+describe('ModelSelector Configuration', () => {
+	describe('numberInputsProperty', () => {
+		it('should have correct configuration', () => {
+			expect(numberInputsProperty.displayName).toBe('Number of Inputs');
+			expect(numberInputsProperty.name).toBe('numberInputs');
+			expect(numberInputsProperty.type).toBe('options');
+			expect(numberInputsProperty.default).toBe(2);
+			expect(numberInputsProperty.validateType).toBe('number');
+		});
+
+		it('should have options from 2 to 10', () => {
+			const options = numberInputsProperty.options as INodePropertyOptions[];
+			expect(options).toHaveLength(9);
+			expect(options[0]).toEqual({ name: '2', value: 2 });
+			expect(options[8]).toEqual({ name: '10', value: 10 });
+		});
+
+		it('should have all sequential values from 2 to 10', () => {
+			const expectedValues = [2, 3, 4, 5, 6, 7, 8, 9, 10];
+			const options = numberInputsProperty.options as INodePropertyOptions[];
+			const actualValues = options.map((option) => option.value);
+			expect(actualValues).toEqual(expectedValues);
+		});
+	});
+
+	describe('configuredInputs function', () => {
+		it('should generate correct input configuration for default value', () => {
+			const parameters: INodeParameters = { numberInputs: 2 };
+			const result = configuredInputs(parameters);
+
+			expect(result).toEqual([
+				{ type: 'ai_languageModel', displayName: 'Model 1', required: true, maxConnections: 1 },
+				{ type: 'ai_languageModel', displayName: 'Model 2', required: true, maxConnections: 1 },
+			]);
+		});
+
+		it('should generate correct input configuration for custom value', () => {
+			const parameters: INodeParameters = { numberInputs: 5 };
+			const result = configuredInputs(parameters);
+
+			expect(result).toEqual([
+				{ type: 'ai_languageModel', displayName: 'Model 1', required: true, maxConnections: 1 },
+				{ type: 'ai_languageModel', displayName: 'Model 2', required: true, maxConnections: 1 },
+				{ type: 'ai_languageModel', displayName: 'Model 3', required: true, maxConnections: 1 },
+				{ type: 'ai_languageModel', displayName: 'Model 4', required: true, maxConnections: 1 },
+				{ type: 'ai_languageModel', displayName: 'Model 5', required: true, maxConnections: 1 },
+			]);
+		});
+
+		it('should handle undefined numberInputs parameter', () => {
+			const parameters: INodeParameters = {};
+			const result = configuredInputs(parameters);
+
+			expect(result).toEqual([
+				{ type: 'ai_languageModel', displayName: 'Model 1', required: true, maxConnections: 1 },
+				{ type: 'ai_languageModel', displayName: 'Model 2', required: true, maxConnections: 1 },
+			]);
+		});
+	});
+});

packages/@n8n/nodes-langchain/nodes/agents/Agent/V1/AgentV1.node.ts

@@ -102,6 +102,7 @@ function getInputs(
 						'@n8n/n8n-nodes-langchain.lmChatDeepSeek',
 						'@n8n/n8n-nodes-langchain.lmChatOpenRouter',
 						'@n8n/n8n-nodes-langchain.lmChatXAiGrok',
+						'@n8n/n8n-nodes-langchain.modelSelector',
 					],
 				},
 			},

packages/@n8n/nodes-langchain/nodes/agents/Agent/V2/AgentV2.node.ts

@@ -77,6 +77,7 @@ function getInputs(hasOutputParser?: boolean): Array<NodeConnectionType | INodeI
 					'@n8n/n8n-nodes-langchain.lmChatOpenRouter',
 					'@n8n/n8n-nodes-langchain.lmChatXAiGrok',
 					'@n8n/n8n-nodes-langchain.code',
+					'@n8n/n8n-nodes-langchain.modelSelector',
 				],
 			},
 		},

packages/@n8n/nodes-langchain/nodes/llms/N8nLlmTracing.ts

@@ -41,6 +41,8 @@ export class N8nLlmTracing extends BaseCallbackHandler {
 
 	completionTokensEstimate = 0;
 
+	#parentRunIndex?: number;
+
 	/**
 	 * A map to associate LLM run IDs to run details.
 	 * Key: Unique identifier for each LLM run (run ID)
@@ -141,9 +143,16 @@ export class N8nLlmTracing extends BaseCallbackHandler {
 						return message;
 					});
 
-		this.executionFunctions.addOutputData(this.connectionType, runDetails.index, [
+		const sourceNodeRunIndex =
-			[{ json: { ...response } }],
+			this.#parentRunIndex !== undefined ? this.#parentRunIndex + runDetails.index : undefined;
-		]);
+
+		this.executionFunctions.addOutputData(
+			this.connectionType,
+			runDetails.index,
+			[[{ json: { ...response } }]],
+			undefined,
+			sourceNodeRunIndex,
+		);
 
 		logAiEvent(this.executionFunctions, 'ai-llm-generated-output', {
 			messages: parsedMessages,
@@ -154,19 +163,27 @@ export class N8nLlmTracing extends BaseCallbackHandler {
 
 	async handleLLMStart(llm: Serialized, prompts: string[], runId: string) {
 		const estimatedTokens = await this.estimateTokensFromStringList(prompts);
+		const sourceNodeRunIndex =
+			this.#parentRunIndex !== undefined
+				? this.#parentRunIndex + this.executionFunctions.getNextRunIndex()
+				: undefined;
 
 		const options = llm.type === 'constructor' ? llm.kwargs : llm;
-		const { index } = this.executionFunctions.addInputData(this.connectionType, [
+		const { index } = this.executionFunctions.addInputData(
+			this.connectionType,
 			[
-				{
+				[
-					json: {
+					{
-						messages: prompts,
+						json: {
-						estimatedTokens,
+							messages: prompts,
-						options,
+							estimatedTokens,
+							options,
+						},
 					},
-				},
+				],
 			],
-		]);
+			sourceNodeRunIndex,
+		);
 
 		// Save the run details for later use when processing `handleLLMEnd` event
 		this.runsMap[runId] = {
@@ -218,4 +235,9 @@ export class N8nLlmTracing extends BaseCallbackHandler {
 			parentRunId,
 		});
 	}
+
+	// Used to associate subsequent runs with the correct parent run in subnodes of subnodes
+	setParentRunIndex(runIndex: number) {
+		this.#parentRunIndex = runIndex;
+	}
 }

packages/@n8n/nodes-langchain/nodes/llms/N8nNonEstimatingTracing.ts

@@ -0,0 +1,185 @@
+import { BaseCallbackHandler } from '@langchain/core/callbacks/base';
+import type { SerializedFields } from '@langchain/core/dist/load/map_keys';
+import type {
+	Serialized,
+	SerializedNotImplemented,
+	SerializedSecret,
+} from '@langchain/core/load/serializable';
+import type { BaseMessage } from '@langchain/core/messages';
+import type { LLMResult } from '@langchain/core/outputs';
+import pick from 'lodash/pick';
+import type { IDataObject, ISupplyDataFunctions, JsonObject } from 'n8n-workflow';
+import { NodeConnectionTypes, NodeError, NodeOperationError } from 'n8n-workflow';
+
+import { logAiEvent } from '@utils/helpers';
+
+type RunDetail = {
+	index: number;
+	messages: BaseMessage[] | string[] | string;
+	options: SerializedSecret | SerializedNotImplemented | SerializedFields;
+};
+
+export class N8nNonEstimatingTracing extends BaseCallbackHandler {
+	name = 'N8nNonEstimatingTracing';
+
+	// This flag makes sure that LangChain will wait for the handlers to finish before continuing
+	// This is crucial for the handleLLMError handler to work correctly (it should be called before the error is propagated to the root node)
+	awaitHandlers = true;
+
+	connectionType = NodeConnectionTypes.AiLanguageModel;
+
+	#parentRunIndex?: number;
+
+	/**
+	 * A map to associate LLM run IDs to run details.
+	 * Key: Unique identifier for each LLM run (run ID)
+	 * Value: RunDetails object
+	 *
+	 */
+	runsMap: Record<string, RunDetail> = {};
+
+	options = {
+		// Default(OpenAI format) parser
+		errorDescriptionMapper: (error: NodeError) => error.description,
+	};
+
+	constructor(
+		private executionFunctions: ISupplyDataFunctions,
+		options?: {
+			errorDescriptionMapper?: (error: NodeError) => string;
+		},
+	) {
+		super();
+		this.options = { ...this.options, ...options };
+	}
+
+	async handleLLMEnd(output: LLMResult, runId: string) {
+		// The fallback should never happen since handleLLMStart should always set the run details
+		// but just in case, we set the index to the length of the runsMap
+		const runDetails = this.runsMap[runId] ?? { index: Object.keys(this.runsMap).length };
+
+		output.generations = output.generations.map((gen) =>
+			gen.map((g) => pick(g, ['text', 'generationInfo'])),
+		);
+
+		const tokenUsageEstimate = {
+			completionTokens: 0,
+			promptTokens: 0,
+			totalTokens: 0,
+		};
+		const response: {
+			response: { generations: LLMResult['generations'] };
+			tokenUsageEstimate?: typeof tokenUsageEstimate;
+		} = {
+			response: { generations: output.generations },
+		};
+
+		response.tokenUsageEstimate = tokenUsageEstimate;
+
+		const parsedMessages =
+			typeof runDetails.messages === 'string'
+				? runDetails.messages
+				: runDetails.messages.map((message) => {
+						if (typeof message === 'string') return message;
+						if (typeof message?.toJSON === 'function') return message.toJSON();
+
+						return message;
+					});
+
+		const sourceNodeRunIndex =
+			this.#parentRunIndex !== undefined ? this.#parentRunIndex + runDetails.index : undefined;
+
+		this.executionFunctions.addOutputData(
+			this.connectionType,
+			runDetails.index,
+			[[{ json: { ...response } }]],
+			undefined,
+			sourceNodeRunIndex,
+		);
+
+		logAiEvent(this.executionFunctions, 'ai-llm-generated-output', {
+			messages: parsedMessages,
+			options: runDetails.options,
+			response,
+		});
+	}
+
+	async handleLLMStart(llm: Serialized, prompts: string[], runId: string) {
+		const estimatedTokens = 0;
+		const sourceNodeRunIndex =
+			this.#parentRunIndex !== undefined
+				? this.#parentRunIndex + this.executionFunctions.getNextRunIndex()
+				: undefined;
+
+		const options = llm.type === 'constructor' ? llm.kwargs : llm;
+		const { index } = this.executionFunctions.addInputData(
+			this.connectionType,
+			[
+				[
+					{
+						json: {
+							messages: prompts,
+							estimatedTokens,
+							options,
+						},
+					},
+				],
+			],
+			sourceNodeRunIndex,
+		);
+
+		// Save the run details for later use when processing `handleLLMEnd` event
+		this.runsMap[runId] = {
+			index,
+			options,
+			messages: prompts,
+		};
+	}
+
+	async handleLLMError(
+		error: IDataObject | Error,
+		runId: string,
+		parentRunId?: string | undefined,
+	) {
+		const runDetails = this.runsMap[runId] ?? { index: Object.keys(this.runsMap).length };
+
+		// Filter out non-x- headers to avoid leaking sensitive information in logs
+		if (typeof error === 'object' && error?.hasOwnProperty('headers')) {
+			const errorWithHeaders = error as { headers: Record<string, unknown> };
+
+			Object.keys(errorWithHeaders.headers).forEach((key) => {
+				if (!key.startsWith('x-')) {
+					delete errorWithHeaders.headers[key];
+				}
+			});
+		}
+
+		if (error instanceof NodeError) {
+			if (this.options.errorDescriptionMapper) {
+				error.description = this.options.errorDescriptionMapper(error);
+			}
+
+			this.executionFunctions.addOutputData(this.connectionType, runDetails.index, error);
+		} else {
+			// If the error is not a NodeError, we wrap it in a NodeOperationError
+			this.executionFunctions.addOutputData(
+				this.connectionType,
+				runDetails.index,
+				new NodeOperationError(this.executionFunctions.getNode(), error as JsonObject, {
+					functionality: 'configuration-node',
+				}),
+			);
+		}
+
+		logAiEvent(this.executionFunctions, 'ai-llm-errored', {
+			error: Object.keys(error).length === 0 ? error.toString() : error,
+			runId,
+			parentRunId,
+		});
+	}
+
+	// Used to associate subsequent runs with the correct parent run in subnodes of subnodes
+	setParentRunIndex(runIndex: number) {
+		this.#parentRunIndex = runIndex;
+	}
+}

packages/@n8n/nodes-langchain/package.json

@@ -135,7 +135,8 @@
       "dist/nodes/vector_store/VectorStoreZep/VectorStoreZep.node.js",
       "dist/nodes/vector_store/VectorStoreZepInsert/VectorStoreZepInsert.node.js",
       "dist/nodes/vector_store/VectorStoreZepLoad/VectorStoreZepLoad.node.js",
-      "dist/nodes/ToolExecutor/ToolExecutor.node.js"
+      "dist/nodes/ToolExecutor/ToolExecutor.node.js",
+      "dist/nodes/ModelSelector/ModelSelector.node.js"
     ]
   },
   "devDependencies": {

packages/core/src/execution-engine/node-execution-context/node-execution-context.ts

@@ -17,6 +17,7 @@ import type {
 	IRunExecutionData,
 	IWorkflowExecuteAdditionalData,
 	NodeConnectionType,
+	NodeInputConnections,
 	NodeParameterValueType,
 	NodeTypeAndVersion,
 	Workflow,
@@ -153,6 +154,10 @@ export abstract class NodeExecutionContext implements Omit<FunctionsBase, 'getCr
 			.filter((node) => node.disabled !== true);
 	}
 
+	getConnections(destination: INode, connectionType: NodeConnectionType): NodeInputConnections {
+		return this.workflow.connectionsByDestinationNode[destination.name]?.[connectionType] ?? [];
+	}
+
 	getNodeOutputs(): INodeOutputConfiguration[] {
 		return this.nodeOutputs;
 	}

packages/core/src/execution-engine/node-execution-context/supply-data-context.ts

@@ -176,6 +176,7 @@ export class SupplyDataContext extends BaseExecuteContext implements ISupplyData
 	addInputData(
 		connectionType: AINodeConnectionType,
 		data: INodeExecutionData[][],
+		runIndex?: number,
 	): { index: number } {
 		const nodeName = this.node.name;
 		const currentNodeRunIndex = this.getNextRunIndex();
@@ -186,6 +187,8 @@ export class SupplyDataContext extends BaseExecuteContext implements ISupplyData
 			connectionType,
 			nodeName,
 			currentNodeRunIndex,
+			undefined,
+			runIndex,
 		).catch((error) => {
 			this.logger.warn(
 				`There was a problem logging input data of node "${nodeName}": ${
@@ -204,6 +207,7 @@ export class SupplyDataContext extends BaseExecuteContext implements ISupplyData
 		currentNodeRunIndex: number,
 		data: INodeExecutionData[][] | ExecutionBaseError,
 		metadata?: ITaskMetadata,
+		sourceNodeRunIndex?: number,
 	): void {
 		const nodeName = this.node.name;
 		this.addExecutionDataFunctions(
@@ -213,6 +217,7 @@ export class SupplyDataContext extends BaseExecuteContext implements ISupplyData
 			nodeName,
 			currentNodeRunIndex,
 			metadata,
+			sourceNodeRunIndex,
 		).catch((error) => {
 			this.logger.warn(
 				`There was a problem logging output data of node "${nodeName}": ${
@@ -230,17 +235,23 @@ export class SupplyDataContext extends BaseExecuteContext implements ISupplyData
 		sourceNodeName: string,
 		currentNodeRunIndex: number,
 		metadata?: ITaskMetadata,
+		sourceNodeRunIndex?: number,
 	): Promise<void> {
 		const {
 			additionalData,
 			runExecutionData,
-			runIndex: sourceNodeRunIndex,
+			runIndex: currentRunIndex,
 			node: { name: nodeName },
 		} = this;
 
 		let taskData: ITaskData | undefined;
 		const source: ISourceData[] = this.parentNode
-			? [{ previousNode: this.parentNode.name, previousNodeRun: sourceNodeRunIndex }]
+			? [
+					{
+						previousNode: this.parentNode.name,
+						previousNodeRun: sourceNodeRunIndex ?? currentRunIndex,
+					},
+				]
 			: [];
 
 		if (type === 'input') {
@@ -313,14 +324,13 @@ export class SupplyDataContext extends BaseExecuteContext implements ISupplyData
 				runExecutionData.executionData!.metadata[sourceNodeName] = [];
 				sourceTaskData = runExecutionData.executionData!.metadata[sourceNodeName];
 			}
-
+			if (!sourceTaskData[currentNodeRunIndex]) {
-			if (!sourceTaskData[sourceNodeRunIndex]) {
+				sourceTaskData[currentNodeRunIndex] = {
-				sourceTaskData[sourceNodeRunIndex] = {
 					subRun: [],
 				};
 			}
 
-			sourceTaskData[sourceNodeRunIndex].subRun!.push({
+			sourceTaskData[currentNodeRunIndex].subRun!.push({
 				node: nodeName,
 				runIndex: currentNodeRunIndex,
 			});

packages/core/src/execution-engine/node-execution-context/utils/__tests__/get-input-connection-data.test.ts

@@ -68,6 +68,10 @@ describe('getInputConnectionData', () => {
 		nodeTypes.getByNameAndVersion
 			.calledWith(agentNode.type, expect.anything())
 			.mockReturnValue(agentNodeType);
+
+		// Mock getConnections method used by validateInputConfiguration
+		// This will be overridden in individual tests as needed
+		jest.spyOn(executeContext, 'getConnections').mockReturnValue([]);
 	});
 
 	describe.each([
@@ -88,7 +92,7 @@ describe('getInputConnectionData', () => {
 			type: 'test.type',
 			disabled: false,
 		});
-		const secondNode = mock<INode>({ name: 'Second Node', disabled: false });
+		const secondNode = mock<INode>({ name: 'Second Node', type: 'test.type', disabled: false });
 		const supplyData = jest.fn().mockResolvedValue({ response });
 		const nodeType = mock<INodeType>({ supplyData });
 
@@ -121,6 +125,7 @@ describe('getInputConnectionData', () => {
 				},
 			];
 			workflow.getParentNodes.mockReturnValueOnce([]);
+			(executeContext.getConnections as jest.Mock).mockReturnValueOnce([]);
 
 			const result = await executeContext.getInputConnectionData(connectionType, 0);
 			expect(result).toBeUndefined();
@@ -136,6 +141,12 @@ describe('getInputConnectionData', () => {
 				},
 			];
 			workflow.getParentNodes.mockReturnValueOnce([node.name, secondNode.name]);
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: node.name, type: connectionType, index: 0 }],
+					[{ node: secondNode.name, type: connectionType, index: 0 }],
+				]);
 
 			await expect(executeContext.getInputConnectionData(connectionType, 0)).rejects.toThrow(
 				`Only 1 ${connectionType} sub-nodes are/is allowed to be connected`,
@@ -151,6 +162,7 @@ describe('getInputConnectionData', () => {
 				},
 			];
 			workflow.getParentNodes.mockReturnValueOnce([]);
+			jest.spyOn(executeContext, 'getConnections').mockReturnValueOnce([]);
 
 			await expect(executeContext.getInputConnectionData(connectionType, 0)).rejects.toThrow(
 				'must be connected and enabled',
@@ -173,6 +185,10 @@ describe('getInputConnectionData', () => {
 			});
 			workflow.getParentNodes.mockReturnValueOnce([disabledNode.name]);
 			workflow.getNode.calledWith(disabledNode.name).mockReturnValue(disabledNode);
+			// Mock connections that include the disabled node, but getConnectedNodes will filter it out
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([[{ node: disabledNode.name, type: connectionType, index: 0 }]]);
 
 			await expect(executeContext.getInputConnectionData(connectionType, 0)).rejects.toThrow(
 				'must be connected and enabled',
@@ -187,6 +203,9 @@ describe('getInputConnectionData', () => {
 					required: true,
 				},
 			];
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([[{ node: node.name, type: connectionType, index: 0 }]]);
 
 			supplyData.mockRejectedValueOnce(new Error('supplyData error'));
 
@@ -203,6 +222,9 @@ describe('getInputConnectionData', () => {
 					required: true,
 				},
 			];
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([[{ node: node.name, type: connectionType, index: 0 }]]);
 
 			const configError = new NodeOperationError(node, 'Config Error in node', {
 				functionality: 'configuration-node',
@@ -223,6 +245,9 @@ describe('getInputConnectionData', () => {
 					required: true,
 				},
 			];
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([[{ node: node.name, type: connectionType, index: 0 }]]);
 
 			const closeFunction = jest.fn();
 			supplyData.mockResolvedValueOnce({ response, closeFunction });
@@ -233,6 +258,127 @@ describe('getInputConnectionData', () => {
 			// @ts-expect-error private property
 			expect(executeContext.closeFunctions).toContain(closeFunction);
 		});
+
+		it('should handle multiple input configurations of the same type with different max connections', async () => {
+			agentNodeType.description.inputs = [
+				{
+					type: connectionType,
+					maxConnections: 2,
+					required: true,
+				},
+				{
+					type: connectionType,
+					maxConnections: 1,
+					required: false,
+				},
+			];
+
+			const thirdNode = mock<INode>({ name: 'Third Node', type: 'test.type', disabled: false });
+
+			// Mock node types for all connected nodes
+			nodeTypes.getByNameAndVersion
+				.calledWith(secondNode.type, expect.anything())
+				.mockReturnValue(nodeType);
+			nodeTypes.getByNameAndVersion
+				.calledWith(thirdNode.type, expect.anything())
+				.mockReturnValue(nodeType);
+
+			workflow.getParentNodes.mockReturnValueOnce([node.name, secondNode.name, thirdNode.name]);
+			workflow.getNode.calledWith(thirdNode.name).mockReturnValue(thirdNode);
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: node.name, type: connectionType, index: 0 }],
+					[{ node: secondNode.name, type: connectionType, index: 0 }],
+					[{ node: thirdNode.name, type: connectionType, index: 0 }],
+				]);
+
+			const result = await executeContext.getInputConnectionData(connectionType, 0);
+			expect(result).toEqual([response, response, response]);
+			expect(supplyData).toHaveBeenCalledTimes(3);
+		});
+
+		it('should throw when exceeding total max connections across multiple input configurations', async () => {
+			agentNodeType.description.inputs = [
+				{
+					type: connectionType,
+					maxConnections: 1,
+					required: true,
+				},
+				{
+					type: connectionType,
+					maxConnections: 1,
+					required: false,
+				},
+			];
+
+			const thirdNode = mock<INode>({ name: 'Third Node', type: 'test.type', disabled: false });
+
+			// Mock node types for all connected nodes
+			nodeTypes.getByNameAndVersion
+				.calledWith(secondNode.type, expect.anything())
+				.mockReturnValue(nodeType);
+			nodeTypes.getByNameAndVersion
+				.calledWith(thirdNode.type, expect.anything())
+				.mockReturnValue(nodeType);
+
+			workflow.getParentNodes.mockReturnValueOnce([node.name, secondNode.name, thirdNode.name]);
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: node.name, type: connectionType, index: 0 }],
+					[{ node: secondNode.name, type: connectionType, index: 0 }],
+					[{ node: thirdNode.name, type: connectionType, index: 0 }],
+				]);
+
+			await expect(executeContext.getInputConnectionData(connectionType, 0)).rejects.toThrow(
+				`Only 2 ${connectionType} sub-nodes are/is allowed to be connected`,
+			);
+			expect(supplyData).not.toHaveBeenCalled();
+		});
+
+		it('should return array when multiple input configurations exist even with single connection', async () => {
+			agentNodeType.description.inputs = [
+				{
+					type: connectionType,
+					maxConnections: 1,
+					required: true,
+				},
+				{
+					type: connectionType,
+					maxConnections: 2,
+					required: false,
+				},
+			];
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([[{ node: node.name, type: connectionType, index: 0 }]]);
+
+			const result = await executeContext.getInputConnectionData(connectionType, 0);
+			expect(result).toEqual([response]);
+			expect(supplyData).toHaveBeenCalledTimes(1);
+		});
+
+		it('should return empty array when no connections and multiple optional inputs', async () => {
+			agentNodeType.description.inputs = [
+				{
+					type: connectionType,
+					maxConnections: 1,
+					required: false,
+				},
+				{
+					type: connectionType,
+					maxConnections: 1,
+					required: false,
+				},
+			];
+			workflow.getParentNodes.mockReturnValueOnce([]);
+			jest.spyOn(executeContext, 'getConnections').mockReturnValueOnce([]);
+
+			const result = await executeContext.getInputConnectionData(connectionType, 0);
+			expect(result).toEqual([]);
+			expect(supplyData).not.toHaveBeenCalled();
+		});
 	});
 
 	describe(NodeConnectionTypes.AiTool, () => {
@@ -270,6 +416,7 @@ describe('getInputConnectionData', () => {
 				},
 			];
 			workflow.getParentNodes.mockReturnValueOnce([]);
+			jest.spyOn(executeContext, 'getConnections').mockReturnValueOnce([]);
 
 			const result = await executeContext.getInputConnectionData(NodeConnectionTypes.AiTool, 0);
 			expect(result).toEqual([]);
@@ -284,6 +431,7 @@ describe('getInputConnectionData', () => {
 				},
 			];
 			workflow.getParentNodes.mockReturnValueOnce([]);
+			jest.spyOn(executeContext, 'getConnections').mockReturnValueOnce([]);
 
 			await expect(
 				executeContext.getInputConnectionData(NodeConnectionTypes.AiTool, 0),
@@ -309,6 +457,11 @@ describe('getInputConnectionData', () => {
 				.calledWith(agentNode.name, NodeConnectionTypes.AiTool)
 				.mockReturnValue([disabledToolNode.name]);
 			workflow.getNode.calledWith(disabledToolNode.name).mockReturnValue(disabledToolNode);
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: disabledToolNode.name, type: NodeConnectionTypes.AiTool, index: 0 }],
+				]);
 
 			await expect(
 				executeContext.getInputConnectionData(NodeConnectionTypes.AiTool, 0),
@@ -331,6 +484,12 @@ describe('getInputConnectionData', () => {
 			workflow.getParentNodes
 				.calledWith(agentNode.name, NodeConnectionTypes.AiTool)
 				.mockReturnValue([toolNode.name, secondToolNode.name]);
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: toolNode.name, type: NodeConnectionTypes.AiTool, index: 0 }],
+					[{ node: secondToolNode.name, type: NodeConnectionTypes.AiTool, index: 0 }],
+				]);
 
 			const result = await executeContext.getInputConnectionData(NodeConnectionTypes.AiTool, 0);
 			expect(result).toEqual([mockTool, secondMockTool]);
@@ -347,6 +506,11 @@ describe('getInputConnectionData', () => {
 					required: true,
 				},
 			];
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: toolNode.name, type: NodeConnectionTypes.AiTool, index: 0 }],
+				]);
 
 			await expect(
 				executeContext.getInputConnectionData(NodeConnectionTypes.AiTool, 0),
@@ -361,6 +525,11 @@ describe('getInputConnectionData', () => {
 					required: true,
 				},
 			];
+			jest
+				.spyOn(executeContext, 'getConnections')
+				.mockReturnValueOnce([
+					[{ node: toolNode.name, type: NodeConnectionTypes.AiTool, index: 0 }],
+				]);
 
 			const result = await executeContext.getInputConnectionData(NodeConnectionTypes.AiTool, 0);
 			expect(result).toEqual([mockTool]);

packages/core/src/execution-engine/node-execution-context/utils/get-input-connection-data.ts

@@ -15,12 +15,15 @@ import type {
 	ISupplyDataFunctions,
 	INodeType,
 	INode,
+	INodeInputConfiguration,
+	NodeConnectionType,
 } from 'n8n-workflow';
 import {
 	NodeConnectionTypes,
 	NodeOperationError,
 	ExecutionBaseError,
 	ApplicationError,
+	UserError,
 } from 'n8n-workflow';
 
 import { createNodeAsTool } from './create-node-as-tool';
@@ -85,6 +88,42 @@ export function makeHandleToolInvocation(
 	};
 }
 
+function validateInputConfiguration(
+	context: ExecuteContext | WebhookContext | SupplyDataContext,
+	connectionType: NodeConnectionType,
+	nodeInputs: INodeInputConfiguration[],
+	connectedNodes: INode[],
+) {
+	const parentNode = context.getNode();
+
+	const connections = context.getConnections(parentNode, connectionType);
+
+	// Validate missing required connections
+	for (let index = 0; index < nodeInputs.length; index++) {
+		const inputConfiguration = nodeInputs[index];
+
+		if (inputConfiguration.required) {
+			// For required inputs, we need at least one enabled connected node
+			if (
+				connections.length === 0 ||
+				connections.length <= index ||
+				connections.at(index)?.length === 0 ||
+				!connectedNodes.find((node) =>
+					connections
+						.at(index)
+						?.map((value) => value.node)
+						.includes(node.name),
+				)
+			) {
+				throw new NodeOperationError(
+					parentNode,
+					`A ${inputConfiguration?.displayName ?? connectionType} sub-node must be connected and enabled`,
+				);
+			}
+		}
+	}
+}
+
 export async function getInputConnectionData(
 	this: ExecuteContext | WebhookContext | SupplyDataContext,
 	workflow: Workflow,
@@ -101,32 +140,37 @@ export async function getInputConnectionData(
 	abortSignal?: AbortSignal,
 ): Promise<unknown> {
 	const parentNode = this.getNode();
+	const inputConfigurations = this.nodeInputs.filter((input) => input.type === connectionType);
 
-	const inputConfiguration = this.nodeInputs.find((input) => input.type === connectionType);
+	if (inputConfigurations === undefined || inputConfigurations.length === 0) {
-	if (inputConfiguration === undefined) {
+		throw new UserError('Node does not have input of type', {
-		throw new ApplicationError('Node does not have input of type', {
 			extra: { nodeName: parentNode.name, connectionType },
 		});
 	}
 
+	const maxConnections = inputConfigurations.reduce(
+		(acc, currentItem) =>
+			currentItem.maxConnections !== undefined ? acc + currentItem.maxConnections : acc,
+		0,
+	);
+
 	const connectedNodes = this.getConnectedNodes(connectionType);
+	validateInputConfiguration(this, connectionType, inputConfigurations, connectedNodes);
+
+	// Nothing is connected or required
 	if (connectedNodes.length === 0) {
-		if (inputConfiguration.required) {
+		return maxConnections === 1 ? undefined : [];
-			throw new NodeOperationError(
-				parentNode,
-				`A ${inputConfiguration?.displayName ?? connectionType} sub-node must be connected and enabled`,
-			);
-		}
-		return inputConfiguration.maxConnections === 1 ? undefined : [];
 	}
 
+	// Too many connections
 	if (
-		inputConfiguration.maxConnections !== undefined &&
+		maxConnections !== undefined &&
-		connectedNodes.length > inputConfiguration.maxConnections
+		maxConnections !== 0 &&
+		connectedNodes.length > maxConnections
 	) {
 		throw new NodeOperationError(
 			parentNode,
-			`Only ${inputConfiguration.maxConnections} ${connectionType} sub-nodes are/is allowed to be connected`,
+			`Only ${maxConnections} ${connectionType} sub-nodes are/is allowed to be connected`,
 		);
 	}
 
@@ -214,7 +258,5 @@ export async function getInputConnectionData(
 		}
 	}
 
-	return inputConfiguration.maxConnections === 1
+	return maxConnections === 1 ? (nodes || [])[0]?.response : nodes.map((node) => node.response);
-		? (nodes || [])[0]?.response
-		: nodes.map((node) => node.response);
 }

packages/core/src/execution-engine/partial-execution-utils/get-source-data-groups.ts

@@ -1,4 +1,4 @@
-import { type INode, type IPinData, type IRunData } from 'n8n-workflow';
+import { NodeConnectionTypes, type INode, type IPinData, type IRunData } from 'n8n-workflow';
 
 import type { GraphConnection, DirectedGraph } from './directed-graph';
 
@@ -99,7 +99,7 @@ export function getSourceDataGroups(
 
 		if (hasData) {
 			sortedConnectionsWithData.push(connection);
-		} else {
+		} else if (connection.type === NodeConnectionTypes.Main) {
 			sortedConnectionsWithoutData.push(connection);
 		}
 	}

packages/frontend/editor-ui/src/components/NDVSubConnections.test.ts

@@ -5,6 +5,7 @@ import { createTestingPinia } from '@pinia/testing';
 import type { INodeUi } from '@/Interface';
 import type { INodeTypeDescription, WorkflowParameters } from 'n8n-workflow';
 import { NodeConnectionTypes, Workflow } from 'n8n-workflow';
+import { nextTick } from 'vue';
 
 const nodeType: INodeTypeDescription = {
 	displayName: 'OpenAI',
@@ -57,6 +58,8 @@ const workflow: WorkflowParameters = {
 };
 
 const getNodeType = vi.fn();
+let mockWorkflowData = workflow;
+let mockGetNodeByName = vi.fn(() => node);
 
 vi.mock('@/stores/nodeTypes.store', () => ({
 	useNodeTypesStore: vi.fn(() => ({
@@ -66,8 +69,8 @@ vi.mock('@/stores/nodeTypes.store', () => ({
 
 vi.mock('@/stores/workflows.store', () => ({
 	useWorkflowsStore: vi.fn(() => ({
-		getCurrentWorkflow: vi.fn(() => new Workflow(workflow)),
+		getCurrentWorkflow: vi.fn(() => new Workflow(mockWorkflowData)),
-		getNodeByName: vi.fn(() => node),
+		getNodeByName: mockGetNodeByName,
 	})),
 }));
 
@@ -88,17 +91,17 @@ describe('NDVSubConnections', () => {
 		vi.advanceTimersByTime(1000); // Event debounce time
 
 		await waitFor(() => {});
-		expect(getByTestId('subnode-connection-group-ai_tool')).toBeVisible();
+		expect(getByTestId('subnode-connection-group-ai_tool-0')).toBeVisible();
 		expect(html()).toEqual(
 			`<div class="container">
   <div class="connections" style="--possible-connections: 1;">
-    <div data-test-id="subnode-connection-group-ai_tool">
+    <div data-test-id="subnode-connection-group-ai_tool-0">
       <div class="connectionType"><span class="connectionLabel">Tools</span>
         <div>
           <div class="connectedNodesWrapper" style="--nodes-length: 0;">
             <div class="plusButton">
               <n8n-tooltip placement="top" teleported="true" offset="10" show-after="300" disabled="false">
-                <n8n-icon-button size="medium" icon="plus" type="tertiary" data-test-id="add-subnode-ai_tool"></n8n-icon-button>
+                <n8n-icon-button size="medium" icon="plus" type="tertiary" data-test-id="add-subnode-ai_tool-0"></n8n-icon-button>
               </n8n-tooltip>
             </div>
             <!--v-if-->
@@ -123,4 +126,101 @@ describe('NDVSubConnections', () => {
 		await waitFor(() => {});
 		expect(component.html()).toEqual('<!--v-if-->');
 	});
+
+	it('should render multiple connections of the same type separately', async () => {
+		// Mock a ModelSelector-like node with multiple ai_languageModel connections
+		const multiConnectionNodeType: INodeTypeDescription = {
+			displayName: 'Model Selector',
+			name: 'modelSelector',
+			version: [1],
+			inputs: [
+				{ type: NodeConnectionTypes.Main },
+				{
+					type: NodeConnectionTypes.AiLanguageModel,
+					displayName: 'Model 1',
+					required: true,
+					maxConnections: 1,
+				},
+				{
+					type: NodeConnectionTypes.AiLanguageModel,
+					displayName: 'Model 2',
+					required: true,
+					maxConnections: 1,
+				},
+				{
+					type: NodeConnectionTypes.AiLanguageModel,
+					displayName: 'Model 3',
+					required: true,
+					maxConnections: 1,
+				},
+			],
+			outputs: [NodeConnectionTypes.AiLanguageModel],
+			properties: [],
+			defaults: { color: '', name: '' },
+			group: [],
+			description: '',
+		};
+
+		const multiConnectionNode: INodeUi = {
+			...node,
+			name: 'ModelSelector',
+			type: 'modelSelector',
+		};
+
+		// Mock connected nodes
+		const mockWorkflow = {
+			...workflow,
+			nodes: [multiConnectionNode],
+			connectionsByDestinationNode: {
+				ModelSelector: {
+					[NodeConnectionTypes.AiLanguageModel]: [
+						null, // Main input (index 0) - no ai_languageModel connection
+						[{ node: 'OpenAI1', type: NodeConnectionTypes.AiLanguageModel, index: 0 }], // Model 1 (index 1)
+						[{ node: 'Claude', type: NodeConnectionTypes.AiLanguageModel, index: 0 }], // Model 2 (index 2)
+						[], // Model 3 (index 3) - no connection
+					],
+				},
+			},
+		};
+
+		// Mock additional nodes
+		const openAI1Node: INodeUi = {
+			...node,
+			name: 'OpenAI1',
+			type: '@n8n/n8n-nodes-langchain.openAi',
+		};
+		const claudeNode: INodeUi = {
+			...node,
+			name: 'Claude',
+			type: '@n8n/n8n-nodes-langchain.claude',
+		};
+
+		getNodeType.mockReturnValue(multiConnectionNodeType);
+
+		// Update mock data for this test
+		mockWorkflowData = mockWorkflow;
+		mockGetNodeByName = vi.fn((name: string) => {
+			if (name === 'ModelSelector') return multiConnectionNode;
+			if (name === 'OpenAI1') return openAI1Node;
+			if (name === 'Claude') return claudeNode;
+			return null;
+		});
+
+		const { getByTestId } = render(NDVSubConnections, {
+			props: {
+				rootNode: multiConnectionNode,
+			},
+		});
+		vi.advanceTimersByTime(1);
+
+		await nextTick();
+
+		expect(getByTestId('subnode-connection-group-ai_languageModel-0')).toBeVisible(); // Model 1
+		expect(getByTestId('subnode-connection-group-ai_languageModel-1')).toBeVisible(); // Model 2
+		expect(getByTestId('subnode-connection-group-ai_languageModel-2')).toBeVisible(); // Model 3
+
+		expect(getByTestId('add-subnode-ai_languageModel-0')).toBeVisible();
+		expect(getByTestId('add-subnode-ai_languageModel-1')).toBeVisible();
+		expect(getByTestId('add-subnode-ai_languageModel-2')).toBeVisible();
+	});
 });

packages/frontend/editor-ui/src/components/NDVSubConnections.vue

@@ -40,7 +40,7 @@ interface NodeConfig {
 
 const possibleConnections = ref<INodeInputConfiguration[]>([]);
 
-const expandedGroups = ref<NodeConnectionType[]>([]);
+const expandedGroups = ref<string[]>([]);
 const shouldShowNodeInputIssues = ref(false);
 
 const nodeType = computed(() =>
@@ -61,41 +61,79 @@ const nodeInputIssues = computed(() => {
 	return issues?.input ?? {};
 });
 
-const connectedNodes = computed<Record<NodeConnectionType, NodeConfig[]>>(() => {
+const connectedNodes = computed<Record<string, NodeConfig[]>>(() => {
+	const typeIndexCounters: Record<string, number> = {};
+
 	return possibleConnections.value.reduce(
 		(acc, connection) => {
-			const nodes = getINodesFromNames(
+			// Track index per connection type
-				workflow.value.getParentNodes(props.rootNode.name, connection.type),
+			const typeIndex = typeIndexCounters[connection.type] ?? 0;
-			);
+			typeIndexCounters[connection.type] = typeIndex + 1;
-			return { ...acc, [connection.type]: nodes };
+
+			// Get input-index-specific connections using the per-type index
+			const nodeConnections =
+				workflow.value.connectionsByDestinationNode[props.rootNode.name]?.[connection.type] ?? [];
+			const inputConnections = nodeConnections[typeIndex] ?? [];
+			const nodeNames = inputConnections.map((conn) => conn.node);
+			const nodes = getINodesFromNames(nodeNames);
+
+			// Use a unique key that combines connection type and per-type index
+			const connectionKey = `${connection.type}-${typeIndex}`;
+			return { ...acc, [connectionKey]: nodes };
 		},
-		{} as Record<NodeConnectionType, NodeConfig[]>,
+		{} as Record<string, NodeConfig[]>,
 	);
 });
 
-function getConnectionConfig(connectionType: NodeConnectionType) {
+function getConnectionKey(connection: INodeInputConfiguration, globalIndex: number): string {
-	return possibleConnections.value.find((c) => c.type === connectionType);
+	// Calculate the per-type index for this connection
+	let typeIndex = 0;
+	for (let i = 0; i < globalIndex; i++) {
+		if (possibleConnections.value[i].type === connection.type) {
+			typeIndex++;
+		}
+	}
+	return `${connection.type}-${typeIndex}`;
 }
 
-function isMultiConnection(connectionType: NodeConnectionType) {
+function getConnectionConfig(connectionKey: string) {
-	const connectionConfig = getConnectionConfig(connectionType);
+	const [type, indexStr] = connectionKey.split('-');
+	const typeIndex = parseInt(indexStr, 10);
+
+	// Find the connection config by type and type-specific index
+	let currentTypeIndex = 0;
+	for (const connection of possibleConnections.value) {
+		if (connection.type === type) {
+			if (currentTypeIndex === typeIndex) {
+				return connection;
+			}
+			currentTypeIndex++;
+		}
+	}
+	return undefined;
+}
+
+function isMultiConnection(connectionKey: string) {
+	const connectionConfig = getConnectionConfig(connectionKey);
 	return connectionConfig?.maxConnections !== 1;
 }
 
-function shouldShowConnectionTooltip(connectionType: NodeConnectionType) {
+function shouldShowConnectionTooltip(connectionKey: string) {
-	return isMultiConnection(connectionType) && !expandedGroups.value.includes(connectionType);
+	const [type] = connectionKey.split('-');
+	return isMultiConnection(connectionKey) && !expandedGroups.value.includes(type);
 }
 
-function expandConnectionGroup(connectionType: NodeConnectionType, isExpanded: boolean) {
+function expandConnectionGroup(connectionKey: string, isExpanded: boolean) {
+	const [type] = connectionKey.split('-');
 	// If the connection is a single connection, we don't need to expand the group
-	if (!isMultiConnection(connectionType)) {
+	if (!isMultiConnection(connectionKey)) {
 		return;
 	}
 
 	if (isExpanded) {
-		expandedGroups.value = [...expandedGroups.value, connectionType];
+		expandedGroups.value = [...expandedGroups.value, type];
 	} else {
-		expandedGroups.value = expandedGroups.value.filter((g) => g !== connectionType);
+		expandedGroups.value = expandedGroups.value.filter((g) => g !== type);
 	}
 }
 
@@ -116,10 +154,9 @@ function getINodesFromNames(names: string[]): NodeConfig[] {
 		.filter((n): n is NodeConfig => n !== null);
 }
 
-function hasInputIssues(connectionType: NodeConnectionType) {
+function hasInputIssues(connectionKey: string) {
-	return (
+	const [type] = connectionKey.split('-');
-		shouldShowNodeInputIssues.value && (nodeInputIssues.value[connectionType] ?? []).length > 0
+	return shouldShowNodeInputIssues.value && (nodeInputIssues.value[type] ?? []).length > 0;
-	);
 }
 
 function isNodeInputConfiguration(
@@ -144,27 +181,29 @@ function getPossibleSubInputConnections(): INodeInputConfiguration[] {
 	return nonMainInputs;
 }
 
-function onNodeClick(nodeName: string, connectionType: NodeConnectionType) {
+function onNodeClick(nodeName: string, connectionKey: string) {
-	if (isMultiConnection(connectionType) && !expandedGroups.value.includes(connectionType)) {
+	const [type] = connectionKey.split('-');
-		expandConnectionGroup(connectionType, true);
+	if (isMultiConnection(connectionKey) && !expandedGroups.value.includes(type)) {
+		expandConnectionGroup(connectionKey, true);
 		return;
 	}
 
 	emit('switchSelectedNode', nodeName);
 }
 
-function onPlusClick(connectionType: NodeConnectionType) {
+function onPlusClick(connectionKey: string) {
-	const connectionNodes = connectedNodes.value[connectionType];
+	const [type] = connectionKey.split('-');
+	const connectionNodes = connectedNodes.value[connectionKey];
 	if (
-		isMultiConnection(connectionType) &&
+		isMultiConnection(connectionKey) &&
-		!expandedGroups.value.includes(connectionType) &&
+		!expandedGroups.value.includes(type) &&
 		connectionNodes.length >= 1
 	) {
-		expandConnectionGroup(connectionType, true);
+		expandConnectionGroup(connectionKey, true);
 		return;
 	}
 
-	emit('openConnectionNodeCreator', props.rootNode.name, connectionType);
+	emit('openConnectionNodeCreator', props.rootNode.name, type as NodeConnectionType);
 }
 
 function showNodeInputsIssues() {
@@ -200,39 +239,41 @@ defineExpose({
 			:style="`--possible-connections: ${possibleConnections.length}`"
 		>
 			<div
-				v-for="connection in possibleConnections"
+				v-for="(connection, index) in possibleConnections"
-				:key="connection.type"
+				:key="getConnectionKey(connection, index)"
-				:data-test-id="`subnode-connection-group-${connection.type}`"
+				:data-test-id="`subnode-connection-group-${getConnectionKey(connection, index)}`"
 			>
 				<div :class="$style.connectionType">
 					<span
 						:class="{
 							[$style.connectionLabel]: true,
-							[$style.hasIssues]: hasInputIssues(connection.type),
+							[$style.hasIssues]: hasInputIssues(getConnectionKey(connection, index)),
 						}"
 						v-text="`${connection.displayName}${connection.required ? ' *' : ''}`"
 					/>
-					<OnClickOutside @trigger="expandConnectionGroup(connection.type, false)">
+					<OnClickOutside
+						@trigger="expandConnectionGroup(getConnectionKey(connection, index), false)"
+					>
 						<div
 							ref="connectedNodesWrapper"
 							:class="{
 								[$style.connectedNodesWrapper]: true,
 								[$style.connectedNodesWrapperExpanded]: expandedGroups.includes(connection.type),
 							}"
-							:style="`--nodes-length: ${connectedNodes[connection.type].length}`"
+							:style="`--nodes-length: ${connectedNodes[getConnectionKey(connection, index)].length}`"
-							@click="expandConnectionGroup(connection.type, true)"
+							@click="expandConnectionGroup(getConnectionKey(connection, index), true)"
 						>
 							<div
 								v-if="
-									connectedNodes[connection.type].length >= 1
+									connectedNodes[getConnectionKey(connection, index)].length >= 1
 										? connection.maxConnections !== 1
 										: true
 								"
 								:class="{
 									[$style.plusButton]: true,
-									[$style.hasIssues]: hasInputIssues(connection.type),
+									[$style.hasIssues]: hasInputIssues(getConnectionKey(connection, index)),
 								}"
-								@click="onPlusClick(connection.type)"
+								@click="onPlusClick(getConnectionKey(connection, index))"
 							>
 								<n8n-tooltip
 									placement="top"
@@ -240,13 +281,13 @@ defineExpose({
 									:offset="10"
 									:show-after="300"
 									:disabled="
-										shouldShowConnectionTooltip(connection.type) &&
+										shouldShowConnectionTooltip(getConnectionKey(connection, index)) &&
-										connectedNodes[connection.type].length >= 1
+										connectedNodes[getConnectionKey(connection, index)].length >= 1
 									"
 								>
 									<template #content>
 										Add {{ connection.displayName }}
-										<template v-if="hasInputIssues(connection.type)">
+										<template v-if="hasInputIssues(getConnectionKey(connection, index))">
 											<TitledList
 												:title="`${i18n.baseText('node.issues')}:`"
 												:items="nodeInputIssues[connection.type]"
@@ -257,24 +298,25 @@ defineExpose({
 										size="medium"
 										icon="plus"
 										type="tertiary"
-										:data-test-id="`add-subnode-${connection.type}`"
+										:data-test-id="`add-subnode-${getConnectionKey(connection, index)}`"
 									/>
 								</n8n-tooltip>
 							</div>
 							<div
-								v-if="connectedNodes[connection.type].length > 0"
+								v-if="connectedNodes[getConnectionKey(connection, index)].length > 0"
 								:class="{
 									[$style.connectedNodes]: true,
-									[$style.connectedNodesMultiple]: connectedNodes[connection.type].length > 1,
+									[$style.connectedNodesMultiple]:
+										connectedNodes[getConnectionKey(connection, index)].length > 1,
 								}"
 							>
 								<div
-									v-for="(node, index) in connectedNodes[connection.type]"
+									v-for="(node, nodeIndex) in connectedNodes[getConnectionKey(connection, index)]"
 									:key="node.node.name"
 									:class="{ [$style.nodeWrapper]: true, [$style.hasIssues]: node.issues }"
 									data-test-id="floating-subnode"
 									:data-node-name="node.node.name"
-									:style="`--node-index: ${index}`"
+									:style="`--node-index: ${nodeIndex}`"
 								>
 									<n8n-tooltip
 										:key="node.node.name"
@@ -282,7 +324,7 @@ defineExpose({
 										:teleported="true"
 										:offset="10"
 										:show-after="300"
-										:disabled="shouldShowConnectionTooltip(connection.type)"
+										:disabled="shouldShowConnectionTooltip(getConnectionKey(connection, index))"
 									>
 										<template #content>
 											{{ node.node.name }}
@@ -296,7 +338,7 @@ defineExpose({
 
 										<div
 											:class="$style.connectedNode"
-											@click="onNodeClick(node.node.name, connection.type)"
+											@click="onNodeClick(node.node.name, getConnectionKey(connection, index))"
 										>
 											<NodeIcon
 												:node-type="node.nodeType"

packages/frontend/editor-ui/src/features/logs/logs.utils.test.ts

@@ -394,13 +394,13 @@ describe(getTreeNodeData, () => {
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:02.000Z'),
 					executionIndex: 2,
-					source: [{ previousNode: 'RootNode1' }],
+					source: [{ previousNode: 'RootNode1', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from RootNode1' } }]] },
 				}),
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:03.000Z'),
 					executionIndex: 3,
-					source: [{ previousNode: 'RootNode2' }],
+					source: [{ previousNode: 'RootNode2', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from RootNode2' } }]] },
 				}),
 			],
@@ -408,13 +408,13 @@ describe(getTreeNodeData, () => {
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:04.000Z'),
 					executionIndex: 4,
-					source: [{ previousNode: 'SharedSubNode' }],
+					source: [{ previousNode: 'SharedSubNode', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from SharedSubNode run 0' } }]] },
 				}),
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:05.000Z'),
 					executionIndex: 5,
-					source: [{ previousNode: 'SharedSubNode' }],
+					source: [{ previousNode: 'SharedSubNode', previousNodeRun: 1 }],
 					data: { main: [[{ json: { result: 'from SharedSubNode run 1' } }]] },
 				}),
 			],
@@ -494,7 +494,7 @@ describe(getTreeNodeData, () => {
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:02.000Z'),
 					executionIndex: 2,
-					source: [{ previousNode: 'RootNode1' }],
+					source: [{ previousNode: 'RootNode1', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from RootNode1' } }]] },
 				}),
 			],
@@ -502,7 +502,7 @@ describe(getTreeNodeData, () => {
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:03.000Z'),
 					executionIndex: 3,
-					source: [{ previousNode: 'RootNode2' }],
+					source: [{ previousNode: 'RootNode2', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from RootNode2' } }]] },
 				}),
 			],
@@ -510,13 +510,13 @@ describe(getTreeNodeData, () => {
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:04.000Z'),
 					executionIndex: 4,
-					source: [{ previousNode: 'SubNodeA' }],
+					source: [{ previousNode: 'SubNodeA', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from SubNodeA' } }]] },
 				}),
 				createTestTaskData({
 					startTime: Date.parse('2025-02-26T00:00:05.000Z'),
 					executionIndex: 5,
-					source: [{ previousNode: 'SubNodeB' }],
+					source: [{ previousNode: 'SubNodeB', previousNodeRun: 0 }],
 					data: { main: [[{ json: { result: 'from SubNodeB' } }]] },
 				}),
 			],

packages/frontend/editor-ui/src/features/logs/logs.utils.ts

@@ -94,7 +94,6 @@ function getChildNodes(
 
 	// Get the first level of children
 	const connectedSubNodes = context.workflow.getParentNodes(node.name, 'ALL_NON_MAIN', 1);
-	const isExecutionRoot = !isSubNodeLog(treeNode);
 
 	function isMatchedSource(source: ISourceData | null): boolean {
 		return (
@@ -106,13 +105,12 @@ function getChildNodes(
 
 	return connectedSubNodes.flatMap((subNodeName) =>
 		(context.data.resultData.runData[subNodeName] ?? []).flatMap((t, index) => {
-			// At root depth, filter out node executions that weren't triggered by this node
+			// Filter out node executions that weren't triggered by this node
 			// This prevents showing duplicate executions when a sub-node is connected to multiple parents
 			// Only filter nodes that have source information with valid previousNode references
-			const isMatched =
+			const isMatched = t.source.some((source) => source !== null)
-				isExecutionRoot && t.source.some((source) => source !== null)
+				? t.source.some(isMatchedSource)
-					? t.source.some(isMatchedSource)
+				: runIndex === undefined || index === runIndex;
-					: runIndex === undefined || index === runIndex;
 
 			if (!isMatched) {
 				return [];

packages/workflow/src/interfaces.ts

@@ -931,6 +931,7 @@ export type IExecuteFunctions = ExecuteFunctions.GetNodeParameterFn &
 			currentNodeRunIndex: number,
 			data: INodeExecutionData[][] | ExecutionError,
 			metadata?: ITaskMetadata,
+			sourceNodeRunIndex?: number,
 		): void;
 
 		addExecutionHints(...hints: NodeExecutionHint[]): void;