From f0cf6dcbcdfaae86233c6fdac8795bd7f2111d3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Iv=C3=A1n=20Ovejero?= <ivov.src@gmail.com>
Date: Wed, 11 Jun 2025 13:11:13 +0200
Subject: [PATCH] perf(core): Lazyload AI workflow builder's langchain
 dependencies (#16178)

---
 .../src/ai-workflow-builder.service.ts        |  8 +++----
 .../ai-workflow-builder/src/llm-config.ts     | 21 +++++++++++--------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/packages/@n8n/ai-workflow-builder/src/ai-workflow-builder.service.ts b/packages/@n8n/ai-workflow-builder/src/ai-workflow-builder.service.ts
index d72c0d6b8a..c1686ab5e1 100644
--- a/packages/@n8n/ai-workflow-builder/src/ai-workflow-builder.service.ts
+++ b/packages/@n8n/ai-workflow-builder/src/ai-workflow-builder.service.ts
@@ -60,7 +60,7 @@ export class AiWorkflowBuilderService {
 			assert(this.client, 'Client not setup');
 
 			const authHeaders = await this.client.generateApiProxyCredentials(user);
-			this.llmSimpleTask = gpt41mini({
+			this.llmSimpleTask = await gpt41mini({
 				baseUrl: baseUrl + '/v1/api-proxy/openai',
 				// When using api-proxy the key will be populated automatically, we just need to pass a placeholder
 				apiKey: '-',
@@ -68,7 +68,7 @@ export class AiWorkflowBuilderService {
 					Authorization: authHeaders.apiKey,
 				},
 			});
-			this.llmComplexTask = anthropicClaude37Sonnet({
+			this.llmComplexTask = await anthropicClaude37Sonnet({
 				baseUrl: baseUrl + '/v1/api-proxy/anthropic',
 				apiKey: '-',
 				headers: {
@@ -78,10 +78,10 @@ export class AiWorkflowBuilderService {
 			return;
 		}
 		// If base URL is not set, use environment variables
-		this.llmSimpleTask = gpt41mini({
+		this.llmSimpleTask = await gpt41mini({
 			apiKey: process.env.N8N_AI_OPENAI_API_KEY ?? '',
 		});
-		this.llmComplexTask = anthropicClaude37Sonnet({
+		this.llmComplexTask = await anthropicClaude37Sonnet({
 			apiKey: process.env.N8N_AI_ANTHROPIC_KEY ?? '',
 		});
 	}
diff --git a/packages/@n8n/ai-workflow-builder/src/llm-config.ts b/packages/@n8n/ai-workflow-builder/src/llm-config.ts
index f50073ad70..c89defba37 100644
--- a/packages/@n8n/ai-workflow-builder/src/llm-config.ts
+++ b/packages/@n8n/ai-workflow-builder/src/llm-config.ts
@@ -1,14 +1,12 @@
-import { ChatAnthropic } from '@langchain/anthropic';
-import { ChatOpenAI } from '@langchain/openai';
-
 type LLMConfig = {
 	apiKey: string;
 	baseUrl?: string;
 	headers?: Record<string, string>;
 };
 
-export const o4mini = (config: LLMConfig) =>
-	new ChatOpenAI({
+export const o4mini = async (config: LLMConfig) => {
+	const { ChatOpenAI } = await import('@langchain/openai');
+	return new ChatOpenAI({
 		modelName: 'o4-mini-2025-04-16',
 		apiKey: config.apiKey,
 		configuration: {
@@ -16,9 +14,11 @@ export const o4mini = (config: LLMConfig) =>
 			defaultHeaders: config.headers,
 		},
 	});
+};
 
-export const gpt41mini = (config: LLMConfig) =>
-	new ChatOpenAI({
+export const gpt41mini = async (config: LLMConfig) => {
+	const { ChatOpenAI } = await import('@langchain/openai');
+	return new ChatOpenAI({
 		modelName: 'gpt-4.1-mini-2025-04-14',
 		apiKey: config.apiKey,
 		temperature: 0,
@@ -27,9 +27,11 @@ export const gpt41mini = (config: LLMConfig) =>
 			defaultHeaders: config.headers,
 		},
 	});
+};
 
-export const anthropicClaude37Sonnet = (config: LLMConfig) =>
-	new ChatAnthropic({
+export const anthropicClaude37Sonnet = async (config: LLMConfig) => {
+	const { ChatAnthropic } = await import('@langchain/anthropic');
+	return new ChatAnthropic({
 		modelName: 'claude-3-7-sonnet-20250219',
 		apiKey: config.apiKey,
 		temperature: 0,
@@ -39,3 +41,4 @@ export const anthropicClaude37Sonnet = (config: LLMConfig) =>
 			defaultHeaders: config.headers,
 		},
 	});
+};