feat(editor): Auto-add LLM chain for new LLM nodes on empty canvas (#10245)

Co-authored-by: JP van Oosten <jp@n8n.io>

cypress/constants.ts

@@ -37,7 +37,7 @@ export const INSTANCE_MEMBERS = [
 export const MANUAL_TRIGGER_NODE_NAME = 'Manual Trigger';
 export const MANUAL_TRIGGER_NODE_DISPLAY_NAME = 'When clicking ‘Test workflow’';
 export const MANUAL_CHAT_TRIGGER_NODE_NAME = 'Chat Trigger';
-export const MANUAL_CHAT_TRIGGER_NODE_DISPLAY_NAME = 'When chat message received';
+export const CHAT_TRIGGER_NODE_DISPLAY_NAME = 'When chat message received';
 export const SCHEDULE_TRIGGER_NODE_NAME = 'Schedule Trigger';
 export const CODE_NODE_NAME = 'Code';
 export const SET_NODE_NAME = 'Set';

cypress/e2e/233-AI-switch-to-logs-on-error.cy.ts

@@ -13,7 +13,7 @@ import {
 	AI_LANGUAGE_MODEL_OPENAI_CHAT_MODEL_NODE_NAME,
 	AI_MEMORY_POSTGRES_NODE_NAME,
 	AI_TOOL_CALCULATOR_NODE_NAME,
-	MANUAL_CHAT_TRIGGER_NODE_DISPLAY_NAME,
+	CHAT_TRIGGER_NODE_DISPLAY_NAME,
 	MANUAL_CHAT_TRIGGER_NODE_NAME,
 	MANUAL_TRIGGER_NODE_DISPLAY_NAME,
 	MANUAL_TRIGGER_NODE_NAME,
@@ -148,7 +148,7 @@ function setupTestWorkflow(chatTrigger: boolean = false) {
 	if (!chatTrigger) {
 		// Remove chat trigger
 		WorkflowPage.getters
-			.canvasNodeByName(MANUAL_CHAT_TRIGGER_NODE_DISPLAY_NAME)
+			.canvasNodeByName(CHAT_TRIGGER_NODE_DISPLAY_NAME)
 			.find('[data-test-id="delete-node-button"]')
 			.click({ force: true });
 

cypress/e2e/30-langchain.cy.ts

@@ -10,7 +10,9 @@ import {
 	disableNode,
 	getExecuteWorkflowButton,
 	navigateToNewWorkflowPage,
+	getNodes,
 	openNode,
+	getConnectionBySourceAndTarget,
 } from '../composables/workflow';
 import {
 	clickCreateNewCredential,
@@ -41,6 +43,7 @@ import {
 	AI_TOOL_WIKIPEDIA_NODE_NAME,
 	BASIC_LLM_CHAIN_NODE_NAME,
 	EDIT_FIELDS_SET_NODE_NAME,
+	CHAT_TRIGGER_NODE_DISPLAY_NAME,
 } from './../constants';
 
 describe('Langchain Integration', () => {
@@ -331,4 +334,27 @@ describe('Langchain Integration', () => {
 
 		closeManualChatModal();
 	});
+
+	it('should auto-add chat trigger and basic LLM chain when adding LLM node', () => {
+		addNodeToCanvas(AI_LANGUAGE_MODEL_OPENAI_CHAT_MODEL_NODE_NAME, true);
+
+		getConnectionBySourceAndTarget(
+			CHAT_TRIGGER_NODE_DISPLAY_NAME,
+			BASIC_LLM_CHAIN_NODE_NAME,
+		).should('exist');
+
+		getConnectionBySourceAndTarget(
+			AI_LANGUAGE_MODEL_OPENAI_CHAT_MODEL_NODE_NAME,
+			BASIC_LLM_CHAIN_NODE_NAME,
+		).should('exist');
+		getNodes().should('have.length', 3);
+	});
+
+	it('should not auto-add nodes if AI nodes are already present', () => {
+		addNodeToCanvas(AGENT_NODE_NAME, true);
+
+		addNodeToCanvas(AI_LANGUAGE_MODEL_OPENAI_CHAT_MODEL_NODE_NAME, true);
+		getConnectionBySourceAndTarget(CHAT_TRIGGER_NODE_DISPLAY_NAME, AGENT_NODE_NAME).should('exist');
+		getNodes().should('have.length', 3);
+	});
 });

packages/@n8n/nodes-langchain/nodes/llms/LMChatAnthropic/LmChatAnthropic.node.ts

@@ -74,7 +74,7 @@ export class LmChatAnthropic implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

packages/@n8n/nodes-langchain/nodes/llms/LMChatOllama/LmChatOllama.node.ts

@@ -28,7 +28,7 @@ export class LmChatOllama implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

packages/@n8n/nodes-langchain/nodes/llms/LMChatOpenAi/LmChatOpenAi.node.ts

@@ -26,7 +26,7 @@ export class LmChatOpenAi implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

packages/@n8n/nodes-langchain/nodes/llms/LMCohere/LmCohere.node.ts

@@ -26,7 +26,7 @@ export class LmCohere implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Text Completion Models'],
 			},
 			resources: {

packages/@n8n/nodes-langchain/nodes/llms/LMOllama/LmOllama.node.ts

@@ -27,7 +27,7 @@ export class LmOllama implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Text Completion Models'],
 			},
 			resources: {

packages/@n8n/nodes-langchain/nodes/llms/LMOpenAi/LmOpenAi.node.ts

@@ -38,7 +38,7 @@ export class LmOpenAi implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Text Completion Models'],
 			},
 			resources: {

packages/@n8n/nodes-langchain/nodes/llms/LMOpenHuggingFaceInference/LmOpenHuggingFaceInference.node.ts

@@ -26,7 +26,7 @@ export class LmOpenHuggingFaceInference implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Text Completion Models'],
 			},
 			resources: {

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

@@ -29,7 +29,7 @@ export class LmChatAwsBedrock implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -27,7 +27,7 @@ export class LmChatAzureOpenAi implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -27,7 +27,7 @@ export class LmChatGoogleGemini implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -25,7 +25,7 @@ export class LmChatGooglePalm implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -32,7 +32,7 @@ export class LmChatGoogleVertex implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -26,7 +26,7 @@ export class LmChatGroq implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -27,7 +27,7 @@ export class LmChatMistralCloud implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Chat Models (Recommended)'],
 			},
 			resources: {

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

@@ -25,7 +25,7 @@ export class LmGooglePalm implements INodeType {
 		codex: {
 			categories: ['AI'],
 			subcategories: {
-				AI: ['Language Models'],
+				AI: ['Language Models', 'Root Nodes'],
 				'Language Models': ['Text Completion Models'],
 			},
 			resources: {

packages/editor-ui/src/Interface.ts

@@ -1808,8 +1808,8 @@ export type AddedNode = {
 } & Partial<INodeUi>;
 
 export type AddedNodeConnection = {
-	from: { nodeIndex: number; outputIndex?: number };
+	from: { nodeIndex: number; outputIndex?: number; type?: NodeConnectionType };
-	to: { nodeIndex: number; inputIndex?: number };
+	to: { nodeIndex: number; inputIndex?: number; type?: NodeConnectionType };
 };
 
 export type AddedNodesAndConnections = {

packages/editor-ui/src/components/Node/NodeCreator/composables/useActions.ts

@@ -1,5 +1,10 @@
 import { computed } from 'vue';
-import type { IDataObject, INodeParameters } from 'n8n-workflow';
+import {
+	CHAIN_LLM_LANGCHAIN_NODE_TYPE,
+	NodeConnectionType,
+	type IDataObject,
+	type INodeParameters,
+} from 'n8n-workflow';
 import type {
 	ActionTypeDescription,
 	AddedNode,
@@ -11,6 +16,7 @@ import type {
 } from '@/Interface';
 import {
 	AGENT_NODE_TYPE,
+	AI_CATEGORY_LANGUAGE_MODELS,
 	BASIC_CHAIN_NODE_TYPE,
 	CHAT_TRIGGER_NODE_TYPE,
 	MANUAL_CHAT_TRIGGER_NODE_TYPE,
@@ -37,11 +43,12 @@ import { useExternalHooks } from '@/composables/useExternalHooks';
 
 import { sortNodeCreateElements, transformNodeType } from '../utils';
 import { useI18n } from '@/composables/useI18n';
+import { useCanvasStore } from '@/stores/canvas.store';
 
 export const useActions = () => {
 	const nodeCreatorStore = useNodeCreatorStore();
+	const nodeTypesStore = useNodeTypesStore();
 	const i18n = useI18n();
-
 	const singleNodeOpenSources = [
 		NODE_CREATOR_OPEN_SOURCES.PLUS_ENDPOINT,
 		NODE_CREATOR_OPEN_SOURCES.NODE_CONNECTION_ACTION,
@@ -216,6 +223,19 @@ export const useActions = () => {
 		return isCompatibleNode && isChatTriggerMissing;
 	}
 
+	// AI-226: Prepend LLM Chain node when adding a language model
+	function shouldPrependLLMChain(addedNodes: AddedNode[]): boolean {
+		const canvasHasAINodes = useCanvasStore().aiNodes.length > 0;
+		if (canvasHasAINodes) return false;
+
+		return addedNodes.some((node) => {
+			const nodeType = nodeTypesStore.getNodeType(node.type);
+			return Object.keys(nodeType?.codex?.subcategories ?? {}).includes(
+				AI_CATEGORY_LANGUAGE_MODELS,
+			);
+		});
+	}
+
 	function getAddedNodesAndConnections(addedNodes: AddedNode[]): AddedNodesAndConnections {
 		if (addedNodes.length === 0) {
 			return { nodes: [], connections: [] };
@@ -230,7 +250,14 @@ export const useActions = () => {
 			nodeToAutoOpen.openDetail = true;
 		}
 
-		if (shouldPrependChatTrigger(addedNodes)) {
+		if (shouldPrependLLMChain(addedNodes) || shouldPrependChatTrigger(addedNodes)) {
+			if (shouldPrependLLMChain(addedNodes)) {
+				addedNodes.unshift({ type: CHAIN_LLM_LANGCHAIN_NODE_TYPE, isAutoAdd: true });
+				connections.push({
+					from: { nodeIndex: 2, type: NodeConnectionType.AiLanguageModel },
+					to: { nodeIndex: 1 },
+				});
+			}
 			addedNodes.unshift({ type: CHAT_TRIGGER_NODE_TYPE, isAutoAdd: true });
 			connections.push({
 				from: { nodeIndex: 0 },

packages/editor-ui/src/views/NodeView.vue

@@ -610,7 +610,7 @@ export default defineComponent({
 			return this.workflowsStore.getWorkflowExecution;
 		},
 		workflowRunning(): boolean {
-			return this.uiStore.isActionActive['workflowRunning'];
+			return this.uiStore.isActionActive.workflowRunning;
 		},
 		currentWorkflow(): string {
 			return this.$route.params.name?.toString() || this.workflowsStore.workflowId;
@@ -4428,7 +4428,7 @@ export default defineComponent({
 					from.outputIndex ?? 0,
 					toNode.name,
 					to.inputIndex ?? 0,
-					NodeConnectionType.Main,
+					from.type ?? NodeConnectionType.Main,
 				);
 			}
 
@@ -4449,6 +4449,22 @@ export default defineComponent({
 				});
 			}
 
+			const lastNodeType = this.nodeTypesStore.getNodeType(lastAddedNode.type);
+			const isSubNode = NodeHelpers.isSubNodeType(lastNodeType);
+
+			// When adding a sub-node and there's more than one node added at the time, it must mean that it's
+			// connected to a root node, so we adjust the position of the sub-node to make it appear in the correct
+			// in relation to the root node
+			if (isSubNode && nodes.length > 1) {
+				this.onMoveNode({
+					nodeName: lastAddedNode.name,
+					position: [
+						lastAddedNode.position[0] - NodeViewUtils.NODE_SIZE * 2.5,
+						lastAddedNode.position[1] + NodeViewUtils.NODE_SIZE * 1.5,
+					],
+				});
+			}
+
 			this.nodeHelpers.addPinDataConnections(this.workflowsStore.pinnedWorkflowData);
 		},