fix(core): Fix support for multiple invocation of AI tools

packages/core/src/CreateNodeAsTool.ts

@@ -1,9 +1,11 @@
 import { DynamicStructuredTool } from '@langchain/core/tools';
 import type {
 	IExecuteFunctions,
+	INode,
 	INodeParameters,
 	INodeType,
 	ISupplyDataFunctions,
+	ITaskDataConnections,
 } from 'n8n-workflow';
 import { jsonParse, NodeConnectionType, NodeOperationError } from 'n8n-workflow';
 import { z } from 'zod';
@@ -16,22 +18,25 @@ interface FromAIArgument {
 	defaultValue?: string | number | boolean | Record<string, unknown>;
 }
 
+type ParserOptions = {
+	node: INode;
+	nodeType: INodeType;
+	contextFactory: (runIndex: number, inputData: ITaskDataConnections) => ISupplyDataFunctions;
+};
+
 /**
  * AIParametersParser
  *
  * This class encapsulates the logic for parsing node parameters, extracting $fromAI calls,
  * generating Zod schemas, and creating LangChain tools.
  */
 class AIParametersParser {
-	private ctx: ISupplyDataFunctions;
+	private runIndex = 0;
 
 	/**
 	 * Constructs an instance of AIParametersParser.
-	 * @param ctx The execution context.
 	 */
-	constructor(ctx: ISupplyDataFunctions) {
-		this.ctx = ctx;
-	}
+	constructor(private readonly options: ParserOptions) {}
 
 	/**
 	 * Generates a Zod schema based on the provided FromAIArgument placeholder.
@@ -162,14 +167,14 @@ class AIParametersParser {
 				} catch (error) {
 					// If parsing fails, throw an ApplicationError with details
 					throw new NodeOperationError(
-						this.ctx.getNode(),
+						this.options.node,
 						`Failed to parse $fromAI arguments: ${argsString}: ${error}`,
 					);
 				}
 			} else {
 				// Log an error if parentheses are unbalanced
 				throw new NodeOperationError(
-					this.ctx.getNode(),
+					this.options.node,
 					`Unbalanced parentheses while parsing $fromAI call: ${str.slice(startIndex)}`,
 				);
 			}
@@ -254,7 +259,7 @@ class AIParametersParser {
 		const type = cleanArgs?.[2] || 'string';
 
 		if (!['string', 'number', 'boolean', 'json'].includes(type.toLowerCase())) {
-			throw new NodeOperationError(this.ctx.getNode(), `Invalid type: ${type}`);
+			throw new NodeOperationError(this.options.node, `Invalid type: ${type}`);
 		}
 
 		return {
@@ -315,13 +320,12 @@ class AIParametersParser {
 
 	/**
 	 * Creates a DynamicStructuredTool from a node.
-	 * @param node The node type.
-	 * @param nodeParameters The parameters of the node.
 	 * @returns A DynamicStructuredTool instance.
 	 */
-	public createTool(node: INodeType, nodeParameters: INodeParameters): DynamicStructuredTool {
+	public createTool(): DynamicStructuredTool {
+		const { node, nodeType } = this.options;
 		const collectedArguments: FromAIArgument[] = [];
-		this.traverseNodeParameters(nodeParameters, collectedArguments);
+		this.traverseNodeParameters(node.parameters, collectedArguments);
 
 		// Validate each collected argument
 		const nameValidationRegex = /^[a-zA-Z0-9_-]{1,64}$/;
@@ -331,7 +335,7 @@ class AIParametersParser {
 				const isEmptyError = 'You must specify a key when using $fromAI()';
 				const isInvalidError = `Parameter key \`${argument.key}\` is invalid`;
 				const error = new Error(argument.key.length === 0 ? isEmptyError : isInvalidError);
-				throw new NodeOperationError(this.ctx.getNode(), error, {
+				throw new NodeOperationError(node, error, {
 					description:
 						'Invalid parameter key, must be between 1 and 64 characters long and only contain letters, numbers, underscores, and hyphens',
 				});
@@ -348,7 +352,7 @@ class AIParametersParser {
 				) {
 					// If not, throw an error for inconsistent duplicate keys
 					throw new NodeOperationError(
-						this.ctx.getNode(),
+						node,
 						`Duplicate key '${argument.key}' found with different description or type`,
 						{
 							description:
@@ -378,37 +382,38 @@ class AIParametersParser {
 		}, {});
 
 		const schema = z.object(schemaObj).required();
-		const description = this.getDescription(node, nodeParameters);
-		const nodeName = this.ctx.getNode().name.replace(/ /g, '_');
-		const name = nodeName || node.description.name;
+		const description = this.getDescription(nodeType, node.parameters);
+		const nodeName = node.name.replace(/ /g, '_');
+		const name = nodeName || nodeType.description.name;
 
 		const tool = new DynamicStructuredTool({
 			name,
 			description,
 			schema,
-			func: async (functionArgs: z.infer<typeof schema>) => {
-				const { index } = this.ctx.addInputData(NodeConnectionType.AiTool, [
-					[{ json: functionArgs }],
-				]);
+			func: async (toolArgs: z.infer<typeof schema>) => {
+				const context = this.options.contextFactory(this.runIndex, {});
+				context.addInputData(NodeConnectionType.AiTool, [[{ json: toolArgs }]]);
 
 				try {
 					// Execute the node with the proxied context
-					const result = await node.execute?.bind(this.ctx as IExecuteFunctions)();
+					const result = await nodeType.execute?.call(context as IExecuteFunctions);
 
 					// Process and map the results
 					const mappedResults = result?.[0]?.flatMap((item) => item.json);
 
 					// Add output data to the context
-					this.ctx.addOutputData(NodeConnectionType.AiTool, index, [
+					context.addOutputData(NodeConnectionType.AiTool, this.runIndex, [
 						[{ json: { response: mappedResults } }],
 					]);
 
 					// Return the stringified results
 					return JSON.stringify(mappedResults);
 				} catch (error) {
-					const nodeError = new NodeOperationError(this.ctx.getNode(), error as Error);
-					this.ctx.addOutputData(NodeConnectionType.AiTool, index, nodeError);
+					const nodeError = new NodeOperationError(this.options.node, error as Error);
+					context.addOutputData(NodeConnectionType.AiTool, this.runIndex, nodeError);
 					return 'Error during node execution: ' + nodeError.description;
+				} finally {
+					this.runIndex++;
 				}
 			},
 		});
@@ -421,20 +426,8 @@ class AIParametersParser {
  * Converts node into LangChain tool by analyzing node parameters,
  * identifying placeholders using the $fromAI function, and generating a Zod schema. It then creates
  * a DynamicStructuredTool that can be used in LangChain workflows.
- *
- * @param ctx The execution context.
- * @param node The node type.
- * @param nodeParameters The parameters of the node.
- * @returns An object containing the DynamicStructuredTool instance.
  */
-export function createNodeAsTool(
-	ctx: ISupplyDataFunctions,
-	node: INodeType,
-	nodeParameters: INodeParameters,
-) {
-	const parser = new AIParametersParser(ctx);
-
-	return {
-		response: parser.createTool(node, nodeParameters),
-	};
+export function createNodeAsTool(options: ParserOptions) {
+	const parser = new AIParametersParser(options);
+	return { response: parser.createTool() };
 }

packages/core/src/NodeExecuteFunctions.ts

@@ -77,9 +77,9 @@ import type {
 	DeduplicationScope,
 	DeduplicationItemTypes,
 	ICheckProcessedContextData,
-	ISupplyDataFunctions,
 	WebhookType,
 	SchedulingFunctions,
+	SupplyData,
 } from 'n8n-workflow';
 import {
 	NodeConnectionType,
@@ -2023,9 +2023,9 @@ export async function getInputConnectionData(
 	this: IAllExecuteFunctions,
 	workflow: Workflow,
 	runExecutionData: IRunExecutionData,
-	runIndex: number,
+	parentRunIndex: number,
 	connectionInputData: INodeExecutionData[],
-	inputData: ITaskDataConnections,
+	parentInputData: ITaskDataConnections,
 	additionalData: IWorkflowExecuteAdditionalData,
 	executeData: IExecuteData,
 	mode: WorkflowExecuteMode,
@@ -2034,10 +2034,13 @@ export async function getInputConnectionData(
 	itemIndex: number,
 	abortSignal?: AbortSignal,
 ): Promise<unknown> {
-	const node = this.getNode();
-	const nodeType = workflow.nodeTypes.getByNameAndVersion(node.type, node.typeVersion);
+	const parentNode = this.getNode();
+	const parentNodeType = workflow.nodeTypes.getByNameAndVersion(
+		parentNode.type,
+		parentNode.typeVersion,
+	);
 
-	const inputs = NodeHelpers.getNodeInputs(workflow, node, nodeType.description);
+	const inputs = NodeHelpers.getNodeInputs(workflow, parentNode, parentNodeType.description);
 
 	let inputConfiguration = inputs.find((input) => {
 		if (typeof input === 'string') {
@@ -2048,7 +2051,7 @@ export async function getInputConnectionData(
 
 	if (inputConfiguration === undefined) {
 		throw new ApplicationError('Node does not have input of type', {
-			extra: { nodeName: node.name, connectionType },
+			extra: { nodeName: parentNode.name, connectionType },
 		});
 	}
 
@@ -2059,14 +2062,14 @@ export async function getInputConnectionData(
 	}
 
 	const connectedNodes = workflow
-		.getParentNodes(node.name, connectionType, 1)
+		.getParentNodes(parentNode.name, connectionType, 1)
 		.map((nodeName) => workflow.getNode(nodeName) as INode)
 		.filter((connectedNode) => connectedNode.disabled !== true);
 
 	if (connectedNodes.length === 0) {
 		if (inputConfiguration.required) {
 			throw new NodeOperationError(
-				node,
+				parentNode,
 				`A ${inputConfiguration?.displayName ?? connectionType} sub-node must be connected and enabled`,
 			);
 		}
@@ -2078,82 +2081,86 @@ export async function getInputConnectionData(
 		connectedNodes.length > inputConfiguration.maxConnections
 	) {
 		throw new NodeOperationError(
-			node,
+			parentNode,
 			`Only ${inputConfiguration.maxConnections} ${connectionType} sub-nodes are/is allowed to be connected`,
 		);
 	}
 
-	const constParentNodes = connectedNodes.map(async (connectedNode) => {
-		const nodeType = workflow.nodeTypes.getByNameAndVersion(
+	const nodes: SupplyData[] = [];
+	for (const connectedNode of connectedNodes) {
+		const connectedNodeType = workflow.nodeTypes.getByNameAndVersion(
 			connectedNode.type,
 			connectedNode.typeVersion,
 		);
-		const context = new SupplyDataContext(
-			workflow,
-			connectedNode,
-			additionalData,
-			mode,
-			runExecutionData,
-			runIndex,
-			connectionInputData,
-			inputData,
-			executeData,
-			closeFunctions,
-			abortSignal,
-		);
+		const contextFactory = (runIndex: number, inputData: ITaskDataConnections) =>
+			new SupplyDataContext(
+				workflow,
+				connectedNode,
+				additionalData,
+				mode,
+				runExecutionData,
+				runIndex,
+				connectionInputData,
+				inputData,
+				connectionType,
+				executeData,
+				closeFunctions,
+				abortSignal,
+			);
 
-		if (!nodeType.supplyData) {
-			if (nodeType.description.outputs.includes(NodeConnectionType.AiTool)) {
-				nodeType.supplyData = async function (this: ISupplyDataFunctions) {
-					return createNodeAsTool(this, nodeType, this.getNode().parameters);
-				};
+		if (!connectedNodeType.supplyData) {
+			if (connectedNodeType.description.outputs.includes(NodeConnectionType.AiTool)) {
+				const supplyData = createNodeAsTool({
+					node: connectedNode,
+					nodeType: connectedNodeType,
+					contextFactory,
+				});
+				nodes.push(supplyData);
 			} else {
 				throw new ApplicationError('Node does not have a `supplyData` method defined', {
 					extra: { nodeName: connectedNode.name },
 				});
 			}
-		}
+		} else {
+			const context = contextFactory(parentRunIndex, parentInputData);
+			try {
+				const supplyData = await connectedNodeType.supplyData.call(context, itemIndex);
+				if (supplyData.closeFunction) {
+					closeFunctions.push(supplyData.closeFunction);
+				}
+				nodes.push(supplyData);
+			} catch (error) {
+				// Propagate errors from sub-nodes
+				if (error.functionality === 'configuration-node') throw error;
+				if (!(error instanceof ExecutionBaseError)) {
+					error = new NodeOperationError(connectedNode, error, {
+						itemIndex,
+					});
+				}
 
-		try {
-			const response = await nodeType.supplyData.call(context, itemIndex);
-			if (response.closeFunction) {
-				closeFunctions.push(response.closeFunction);
-			}
-			return response;
-		} catch (error) {
-			// Propagate errors from sub-nodes
-			if (error.functionality === 'configuration-node') throw error;
-			if (!(error instanceof ExecutionBaseError)) {
-				error = new NodeOperationError(connectedNode, error, {
+				let currentNodeRunIndex = 0;
+				if (runExecutionData.resultData.runData.hasOwnProperty(parentNode.name)) {
+					currentNodeRunIndex = runExecutionData.resultData.runData[parentNode.name].length;
+				}
+
+				// Display the error on the node which is causing it
+				await context.addExecutionDataFunctions(
+					'input',
+					error,
+					connectionType,
+					parentNode.name,
+					currentNodeRunIndex,
+				);
+
+				// Display on the calling node which node has the error
+				throw new NodeOperationError(connectedNode, `Error in sub-node ${connectedNode.name}`, {
 					itemIndex,
+					functionality: 'configuration-node',
+					description: error.message,
 				});
 			}
-
-			let currentNodeRunIndex = 0;
-			if (runExecutionData.resultData.runData.hasOwnProperty(node.name)) {
-				currentNodeRunIndex = runExecutionData.resultData.runData[node.name].length;
-			}
-
-			// Display the error on the node which is causing it
-			await context.addExecutionDataFunctions(
-				'input',
-				error,
-				connectionType,
-				node.name,
-				currentNodeRunIndex,
-			);
-
-			// Display on the calling node which node has the error
-			throw new NodeOperationError(connectedNode, `Error in sub-node ${connectedNode.name}`, {
-				itemIndex,
-				functionality: 'configuration-node',
-				description: error.message,
-			});
 		}
-	});
-
-	// Validate the inputs
-	const nodes = await Promise.all(constParentNodes);
+	}
 
 	return inputConfiguration.maxConnections === 1
 		? (nodes || [])[0]?.response

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

@@ -72,6 +72,7 @@ describe('SupplyDataContext', () => {
 		runIndex,
 		connectionInputData,
 		inputData,
+		connectionType,
 		executeData,
 		[closeFn],
 		abortSignal,