fix(AI Agent Tool Node): Implement version 3 for agent tool node (#22587)

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

@@ -2,6 +2,7 @@ import type { INodeTypeBaseDescription, IVersionedNodeType } from 'n8n-workflow'
 import { VersionedNodeType } from 'n8n-workflow';
 
 import { AgentToolV2 } from './V2/AgentToolV2.node';
+import { AgentToolV3 } from './V3/AgentToolV3.node';
 
 export class AgentTool extends VersionedNodeType {
 	constructor() {
@@ -20,13 +21,14 @@ export class AgentTool extends VersionedNodeType {
 					Tools: ['Other Tools'],
 				},
 			},
-			defaultVersion: 2.2,
+			defaultVersion: 3,
 		};
 
 		const nodeVersions: IVersionedNodeType['nodeVersions'] = {
 			// Should have the same versioning as Agent node
 			// because internal agent logic often checks for node version
 			2.2: new AgentToolV2(baseDescription),
+			3: new AgentToolV3(baseDescription),
 		};
 
 		super(nodeVersions, baseDescription);

packages/@n8n/nodes-langchain/nodes/agents/Agent/V3/AgentToolV3.node.ts

@@ -0,0 +1,91 @@
+import { NodeConnectionTypes } from 'n8n-workflow';
+import type {
+	IExecuteFunctions,
+	INodeExecutionData,
+	INodeType,
+	INodeTypeDescription,
+	INodeTypeBaseDescription,
+	ISupplyDataFunctions,
+	EngineResponse,
+	EngineRequest,
+} from 'n8n-workflow';
+
+import { textInput, toolDescription } from '@utils/descriptions';
+
+import { getInputs } from '../utils';
+import { toolsAgentProperties } from '../agents/ToolsAgent/V3/description';
+import type { RequestResponseMetadata } from '../agents/ToolsAgent/V3/execute';
+import { toolsAgentExecute } from '../agents/ToolsAgent/V3/execute';
+
+export class AgentToolV3 implements INodeType {
+	description: INodeTypeDescription;
+	constructor(baseDescription: INodeTypeBaseDescription) {
+		this.description = {
+			...baseDescription,
+			version: [3],
+			defaults: {
+				name: 'AI Agent Tool',
+				color: '#404040',
+			},
+			inputs: `={{
+				((hasOutputParser, needsFallback) => {
+					${getInputs.toString()};
+					return getInputs(false, hasOutputParser, needsFallback)
+				})($parameter.hasOutputParser === undefined || $parameter.hasOutputParser === true, $parameter.needsFallback !== undefined && $parameter.needsFallback === true)
+			}}`,
+			outputs: [NodeConnectionTypes.AiTool],
+			properties: [
+				toolDescription,
+				{
+					...textInput,
+				},
+				{
+					displayName: 'Require Specific Output Format',
+					name: 'hasOutputParser',
+					type: 'boolean',
+					default: false,
+					noDataExpression: true,
+				},
+				{
+					displayName: `Connect an <a data-action='openSelectiveNodeCreator' data-action-parameter-connectiontype='${NodeConnectionTypes.AiOutputParser}'>output parser</a> on the canvas to specify the output format you require`,
+					name: 'notice',
+					type: 'notice',
+					default: '',
+					displayOptions: {
+						show: {
+							hasOutputParser: [true],
+						},
+					},
+				},
+				{
+					displayName: 'Enable Fallback Model',
+					name: 'needsFallback',
+					type: 'boolean',
+					default: false,
+					noDataExpression: true,
+				},
+				{
+					displayName:
+						'Connect an additional language model on the canvas to use it as a fallback if the main model fails',
+					name: 'fallbackNotice',
+					type: 'notice',
+					default: '',
+					displayOptions: {
+						show: {
+							needsFallback: [true],
+						},
+					},
+				},
+				toolsAgentProperties,
+			],
+		};
+	}
+
+	// Automatically wrapped as a tool
+	async execute(
+		this: IExecuteFunctions | ISupplyDataFunctions,
+		response?: EngineResponse<RequestResponseMetadata>,
+	): Promise<INodeExecutionData[][] | EngineRequest<RequestResponseMetadata>> {
+		return await toolsAgentExecute.call(this, response);
+	}
+}