feat(Google Vertex Chat Model Node): Add support for Google Vertex AI Chat models (#9970)

Co-authored-by: oleg <oleg@n8n.io>

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

@@ -80,6 +80,7 @@ function getInputs(
 						'@n8n/n8n-nodes-langchain.lmChatOpenAi',
 						'@n8n/n8n-nodes-langchain.lmChatGooglePalm',
 						'@n8n/n8n-nodes-langchain.lmChatGoogleGemini',
+						'@n8n/n8n-nodes-langchain.lmChatGoogleVertex',
 						'@n8n/n8n-nodes-langchain.lmChatMistralCloud',
 						'@n8n/n8n-nodes-langchain.lmChatAzureOpenAi',
 					],
@@ -106,6 +107,7 @@ function getInputs(
 						'@n8n/n8n-nodes-langchain.lmChatMistralCloud',
 						'@n8n/n8n-nodes-langchain.lmChatOpenAi',
 						'@n8n/n8n-nodes-langchain.lmChatGroq',
+						'@n8n/n8n-nodes-langchain.lmChatGoogleVertex',
 					],
 				},
 			},

packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/execute.ts

@@ -226,7 +226,10 @@ export async function toolsAgentExecute(this: IExecuteFunctions): Promise<INodeE
 			});
 		} catch (error) {
 			if (this.continueOnFail(error)) {
-				returnData.push({ json: { error: error.message }, pairedItem: { item: itemIndex } });
+				returnData.push({
+					json: { error: error.message },
+					pairedItem: { item: itemIndex },
+				});
 				continue;
 			}
 

packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleGemini/LmChatGoogleGemini.node.ts

@@ -7,10 +7,10 @@ import {
 	type SupplyData,
 } from 'n8n-workflow';
 import { ChatGoogleGenerativeAI } from '@langchain/google-genai';
-import type { HarmBlockThreshold, HarmCategory, SafetySetting } from '@google/generative-ai';
+import type { SafetySetting } from '@google/generative-ai';
 import { getConnectionHintNoticeField } from '../../../utils/sharedFields';
 import { N8nLlmTracing } from '../N8nLlmTracing';
-import { harmCategories, harmThresholds } from './options';
+import { additionalOptions } from '../gemini-common/additional-options';
 
 export class LmChatGoogleGemini implements INodeType {
 	description: INodeTypeDescription = {
@@ -108,89 +108,7 @@ export class LmChatGoogleGemini implements INodeType {
 				},
 				default: 'models/gemini-1.0-pro',
 			},
-			{
+			additionalOptions,
-				displayName: 'Options',
-				name: 'options',
-				placeholder: 'Add Option',
-				description: 'Additional options to add',
-				type: 'collection',
-				default: {},
-				options: [
-					{
-						displayName: 'Maximum Number of Tokens',
-						name: 'maxOutputTokens',
-						default: 2048,
-						description: 'The maximum number of tokens to generate in the completion',
-						type: 'number',
-					},
-					{
-						displayName: 'Sampling Temperature',
-						name: 'temperature',
-						default: 0.4,
-						typeOptions: { maxValue: 1, minValue: 0, numberPrecision: 1 },
-						description:
-							'Controls randomness: Lowering results in less random completions. As the temperature approaches zero, the model will become deterministic and repetitive.',
-						type: 'number',
-					},
-					{
-						displayName: 'Top K',
-						name: 'topK',
-						default: 32,
-						typeOptions: { maxValue: 40, minValue: -1, numberPrecision: 1 },
-						description:
-							'Used to remove "long tail" low probability responses. Defaults to -1, which disables it.',
-						type: 'number',
-					},
-					{
-						displayName: 'Top P',
-						name: 'topP',
-						default: 1,
-						typeOptions: { maxValue: 1, minValue: 0, numberPrecision: 1 },
-						description:
-							'Controls diversity via nucleus sampling: 0.5 means half of all likelihood-weighted options are considered. We generally recommend altering this or temperature but not both.',
-						type: 'number',
-					},
-
-					// Safety Settings
-					{
-						displayName: 'Safety Settings',
-						name: 'safetySettings',
-						type: 'fixedCollection',
-						typeOptions: { multipleValues: true },
-						default: {
-							values: {
-								category: harmCategories[0].name as HarmCategory,
-								threshold: harmThresholds[0].name as HarmBlockThreshold,
-							},
-						},
-						placeholder: 'Add Option',
-						options: [
-							{
-								name: 'values',
-								displayName: 'Values',
-								values: [
-									{
-										displayName: 'Safety Category',
-										name: 'category',
-										type: 'options',
-										description: 'The category of harmful content to block',
-										default: 'HARM_CATEGORY_UNSPECIFIED',
-										options: harmCategories,
-									},
-									{
-										displayName: 'Safety Threshold',
-										name: 'threshold',
-										type: 'options',
-										description: 'The threshold of harmful content to block',
-										default: 'HARM_BLOCK_THRESHOLD_UNSPECIFIED',
-										options: harmThresholds,
-									},
-								],
-							},
-						],
-					},
-				],
-			},
 		],
 	};
 

packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleVertex/LmChatGoogleVertex.node.ts

@@ -0,0 +1,200 @@
+/* eslint-disable n8n-nodes-base/node-dirname-against-convention */
+import {
+	NodeConnectionType,
+	type IExecuteFunctions,
+	type INodeType,
+	type INodeTypeDescription,
+	type SupplyData,
+	type ILoadOptionsFunctions,
+	type JsonObject,
+	NodeOperationError,
+} from 'n8n-workflow';
+import { ChatVertexAI } from '@langchain/google-vertexai';
+import type { SafetySetting } from '@google/generative-ai';
+import { ProjectsClient } from '@google-cloud/resource-manager';
+import { getConnectionHintNoticeField } from '../../../utils/sharedFields';
+import { N8nLlmTracing } from '../N8nLlmTracing';
+import { makeErrorFromStatus } from './error-handling';
+import { additionalOptions } from '../gemini-common/additional-options';
+
+export class LmChatGoogleVertex implements INodeType {
+	description: INodeTypeDescription = {
+		displayName: 'Google Vertex Chat Model',
+		// eslint-disable-next-line n8n-nodes-base/node-class-description-name-miscased
+		name: 'lmChatGoogleVertex',
+		icon: 'file:google.svg',
+		group: ['transform'],
+		version: 1,
+		description: 'Chat Model Google Vertex',
+		defaults: {
+			name: 'Google Vertex Chat Model',
+		},
+		codex: {
+			categories: ['AI'],
+			subcategories: {
+				AI: ['Language Models'],
+			},
+			resources: {
+				primaryDocumentation: [
+					{
+						url: 'https://docs.n8n.io/integrations/builtin/cluster-nodes/sub-nodes/n8n-nodes-langchain.lmchatgooglevertex/',
+					},
+				],
+			},
+		},
+		// eslint-disable-next-line n8n-nodes-base/node-class-description-inputs-wrong-regular-node
+		inputs: [],
+		// eslint-disable-next-line n8n-nodes-base/node-class-description-outputs-wrong
+		outputs: [NodeConnectionType.AiLanguageModel],
+		outputNames: ['Model'],
+		credentials: [
+			{
+				name: 'googleApi',
+				required: true,
+			},
+		],
+		properties: [
+			getConnectionHintNoticeField([NodeConnectionType.AiChain, NodeConnectionType.AiAgent]),
+			{
+				displayName: 'Project ID',
+				name: 'projectId',
+				type: 'resourceLocator',
+				default: { mode: 'list', value: '' },
+				required: true,
+				description: 'Select or enter your Google Cloud project ID',
+				modes: [
+					{
+						displayName: 'From List',
+						name: 'list',
+						type: 'list',
+						typeOptions: {
+							searchListMethod: 'gcpProjectsList',
+						},
+					},
+					{
+						displayName: 'ID',
+						name: 'id',
+						type: 'string',
+					},
+				],
+			},
+			{
+				displayName: 'Model Name',
+				name: 'modelName',
+				type: 'string',
+				description:
+					'The model which will generate the completion. <a href="https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models">Learn more</a>.',
+				default: 'gemini-1.5-flash',
+			},
+			additionalOptions,
+		],
+	};
+
+	methods = {
+		listSearch: {
+			async gcpProjectsList(this: ILoadOptionsFunctions) {
+				const results: Array<{ name: string; value: string }> = [];
+
+				const credentials = await this.getCredentials('googleApi');
+
+				const client = new ProjectsClient({
+					credentials: {
+						client_email: credentials.email as string,
+						private_key: credentials.privateKey as string,
+					},
+				});
+
+				const [projects] = await client.searchProjects();
+
+				for (const project of projects) {
+					if (project.projectId) {
+						results.push({
+							name: project.displayName ?? project.projectId,
+							value: project.projectId,
+						});
+					}
+				}
+
+				return { results };
+			},
+		},
+	};
+
+	async supplyData(this: IExecuteFunctions, itemIndex: number): Promise<SupplyData> {
+		const credentials = await this.getCredentials('googleApi');
+
+		const modelName = this.getNodeParameter('modelName', itemIndex) as string;
+
+		const projectId = this.getNodeParameter('projectId', itemIndex, '', {
+			extractValue: true,
+		}) as string;
+
+		const options = this.getNodeParameter('options', itemIndex, {
+			maxOutputTokens: 2048,
+			temperature: 0.4,
+			topK: 40,
+			topP: 0.9,
+		}) as {
+			maxOutputTokens: number;
+			temperature: number;
+			topK: number;
+			topP: number;
+		};
+
+		const safetySettings = this.getNodeParameter(
+			'options.safetySettings.values',
+			itemIndex,
+			null,
+		) as SafetySetting[];
+
+		try {
+			const model = new ChatVertexAI({
+				authOptions: {
+					projectId,
+					credentials: {
+						client_email: credentials.email as string,
+						private_key: credentials.privateKey as string,
+					},
+				},
+				model: modelName,
+				topK: options.topK,
+				topP: options.topP,
+				temperature: options.temperature,
+				maxOutputTokens: options.maxOutputTokens,
+				safetySettings,
+				callbacks: [new N8nLlmTracing(this)],
+				// Handle ChatVertexAI invocation errors to provide better error messages
+				onFailedAttempt: (error: any) => {
+					const customError = makeErrorFromStatus(Number(error?.response?.status), {
+						modelName,
+					});
+
+					if (customError) {
+						throw new NodeOperationError(this.getNode(), error as JsonObject, customError);
+					}
+
+					throw error;
+				},
+			});
+
+			return {
+				response: model,
+			};
+		} catch (e) {
+			// Catch model name validation error from LangChain (https://github.com/langchain-ai/langchainjs/blob/ef201d0ee85ee4049078270a0cfd7a1767e624f8/libs/langchain-google-common/src/utils/common.ts#L124)
+			// to show more helpful error message
+			if (e?.message?.startsWith('Unable to verify model params')) {
+				throw new NodeOperationError(this.getNode(), e as JsonObject, {
+					message: 'Unsupported model',
+					description: "Only models starting with 'gemini' are supported.",
+				});
+			}
+
+			// Assume all other exceptions while creating a new ChatVertexAI instance are parameter validation errors
+			throw new NodeOperationError(this.getNode(), e as JsonObject, {
+				message: 'Invalid options',
+				description: e.message,
+			});
+		}
+	}
+}

packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleVertex/error-handling.ts

@@ -0,0 +1,25 @@
+export interface ErrorLike {
+	message?: string;
+	description?: string;
+}
+
+export interface ErrorContext {
+	modelName?: string;
+}
+
+export function makeErrorFromStatus(statusCode: number, context?: ErrorContext): ErrorLike {
+	const errorMessages: Record<number, ErrorLike> = {
+		403: {
+			message: 'Unauthorized for this project',
+			description:
+				'Check your Google Cloud project ID, and that your credential has access to that project',
+		},
+		404: {
+			message: context?.modelName
+				? `No model found called '${context.modelName}'`
+				: 'No model found',
+		},
+	};
+
+	return errorMessages[statusCode];
+}

packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleVertex/google.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 48 48"><defs><path id="a" d="M44.5 20H24v8.5h11.8C34.7 33.9 30.1 37 24 37c-7.2 0-13-5.8-13-13s5.8-13 13-13c3.1 0 5.9 1.1 8.1 2.9l6.4-6.4C34.6 4.1 29.6 2 24 2 11.8 2 2 11.8 2 24s9.8 22 22 22c11 0 21-8 21-22 0-1.3-.2-2.7-.5-4"/></defs><clipPath id="b"><use xlink:href="#a" overflow="visible"/></clipPath><path fill="#FBBC05" d="M0 37V11l17 13z" clip-path="url(#b)"/><path fill="#EA4335" d="m0 11 17 13 7-6.1L48 14V0H0z" clip-path="url(#b)"/><path fill="#34A853" d="m0 37 30-23 7.9 1L48 0v48H0z" clip-path="url(#b)"/><path fill="#4285F4" d="M48 48 17 24l-4-3 35-10z" clip-path="url(#b)"/></svg>

packages/@n8n/nodes-langchain/nodes/llms/gemini-common/additional-options.ts

@@ -0,0 +1,87 @@
+import type { HarmBlockThreshold, HarmCategory } from '@google/generative-ai';
+import type { INodeProperties } from 'n8n-workflow';
+import { harmCategories, harmThresholds } from './safety-options';
+
+export const additionalOptions: INodeProperties = {
+	displayName: 'Options',
+	name: 'options',
+	placeholder: 'Add Option',
+	description: 'Additional options to add',
+	type: 'collection',
+	default: {},
+	options: [
+		{
+			displayName: 'Maximum Number of Tokens',
+			name: 'maxOutputTokens',
+			default: 2048,
+			description: 'The maximum number of tokens to generate in the completion',
+			type: 'number',
+		},
+		{
+			displayName: 'Sampling Temperature',
+			name: 'temperature',
+			default: 0.4,
+			typeOptions: { maxValue: 1, minValue: 0, numberPrecision: 1 },
+			description:
+				'Controls randomness: Lowering results in less random completions. As the temperature approaches zero, the model will become deterministic and repetitive.',
+			type: 'number',
+		},
+		{
+			displayName: 'Top K',
+			name: 'topK',
+			default: 32,
+			typeOptions: { maxValue: 40, minValue: -1, numberPrecision: 1 },
+			description:
+				'Used to remove "long tail" low probability responses. Defaults to -1, which disables it.',
+			type: 'number',
+		},
+		{
+			displayName: 'Top P',
+			name: 'topP',
+			default: 1,
+			typeOptions: { maxValue: 1, minValue: 0, numberPrecision: 1 },
+			description:
+				'Controls diversity via nucleus sampling: 0.5 means half of all likelihood-weighted options are considered. We generally recommend altering this or temperature but not both.',
+			type: 'number',
+		},
+
+		// Safety Settings
+		{
+			displayName: 'Safety Settings',
+			name: 'safetySettings',
+			type: 'fixedCollection',
+			typeOptions: { multipleValues: true },
+			default: {
+				values: {
+					category: harmCategories[0].name as HarmCategory,
+					threshold: harmThresholds[0].name as HarmBlockThreshold,
+				},
+			},
+			placeholder: 'Add Option',
+			options: [
+				{
+					name: 'values',
+					displayName: 'Values',
+					values: [
+						{
+							displayName: 'Safety Category',
+							name: 'category',
+							type: 'options',
+							description: 'The category of harmful content to block',
+							default: 'HARM_CATEGORY_UNSPECIFIED',
+							options: harmCategories,
+						},
+						{
+							displayName: 'Safety Threshold',
+							name: 'threshold',
+							type: 'options',
+							description: 'The threshold of harmful content to block',
+							default: 'HARM_BLOCK_THRESHOLD_UNSPECIFIED',
+							options: harmThresholds,
+						},
+					],
+				},
+			],
+		},
+	],
+};

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

@@ -65,6 +65,7 @@
       "dist/nodes/llms/LmChatAwsBedrock/LmChatAwsBedrock.node.js",
       "dist/nodes/llms/LmChatGooglePalm/LmChatGooglePalm.node.js",
       "dist/nodes/llms/LmChatGoogleGemini/LmChatGoogleGemini.node.js",
+      "dist/nodes/llms/LmChatGoogleVertex/LmChatGoogleVertex.node.js",
       "dist/nodes/llms/LmChatGroq/LmChatGroq.node.js",
       "dist/nodes/llms/LmChatMistralCloud/LmChatMistralCloud.node.js",
       "dist/nodes/llms/LMChatOllama/LmChatOllama.node.js",
@@ -129,6 +130,7 @@
     "@getzep/zep-cloud": "1.0.6",
     "@getzep/zep-js": "0.9.0",
     "@google-ai/generativelanguage": "2.5.0",
+    "@google-cloud/resource-manager": "5.3.0",
     "@google/generative-ai": "0.11.4",
     "@huggingface/inference": "2.7.0",
     "@langchain/anthropic": "0.1.21",
@@ -136,6 +138,7 @@
     "@langchain/community": "0.2.13",
     "@langchain/core": "0.2.9",
     "@langchain/google-genai": "0.0.16",
+    "@langchain/google-vertexai": "0.0.19",
     "@langchain/groq": "0.0.12",
     "@langchain/mistralai": "0.0.22",
     "@langchain/openai": "0.0.33",

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

@@ -44,6 +44,12 @@ export function isChatInstance(model: unknown): model is BaseChatModel {
 	return namespace.includes('chat_models');
 }
 
+export function isToolsInstance(model: unknown): model is Tool {
+	const namespace = (model as Tool)?.lc_namespace ?? [];
+
+	return namespace.includes('tools');
+}
+
 export async function getOptionalOutputParsers(
 	ctx: IExecuteFunctions,
 ): Promise<Array<BaseOutputParser<unknown>>> {

packages/@n8n/nodes-langchain/utils/logWrapper.ts

@@ -1,7 +1,7 @@
 import { NodeOperationError, NodeConnectionType } from 'n8n-workflow';
 import type { ConnectionTypes, IExecuteFunctions, INodeExecutionData } from 'n8n-workflow';
 
-import { Tool } from '@langchain/core/tools';
+import type { Tool } from '@langchain/core/tools';
 import type { BaseMessage } from '@langchain/core/messages';
 import type { InputValues, MemoryVariables, OutputValues } from '@langchain/core/memory';
 import { BaseChatMessageHistory } from '@langchain/core/chat_history';
@@ -18,7 +18,7 @@ import { isObject } from 'lodash';
 import type { BaseDocumentLoader } from 'langchain/dist/document_loaders/base';
 import { N8nJsonLoader } from './N8nJsonLoader';
 import { N8nBinaryLoader } from './N8nBinaryLoader';
-import { logAiEvent } from './helpers';
+import { logAiEvent, isToolsInstance } from './helpers';
 
 const errorsMap: { [key: string]: { message: string; description: string } } = {
 	'You exceeded your current quota, please check your plan and billing details.': {
@@ -401,7 +401,7 @@ export function logWrapper(
 			}
 
 			// ========== Tool ==========
-			if (originalInstance instanceof Tool) {
+			if (isToolsInstance(originalInstance)) {
 				if (prop === '_call' && '_call' in target) {
 					return async (query: string): Promise<string> => {
 						connectionType = NodeConnectionType.AiTool;

packages/nodes-base/nodes/Google/GenericFunctions.ts

@@ -56,6 +56,7 @@ const googleServiceAccountScopes = {
 		'https://www.googleapis.com/auth/datastore',
 		'https://www.googleapis.com/auth/firebase',
 	],
+	vertex: ['https://www.googleapis.com/auth/cloud-platform'],
 };
 
 type GoogleServiceAccount = keyof typeof googleServiceAccountScopes;