feat: Add AI tool building capabilities (#7336)

Github issue / Community forum post (link here to close automatically): https://community.n8n.io/t/langchain-memory-chat/23733 --------- Signed-off-by: Oleg Ivaniv <me@olegivaniv.com> Co-authored-by: Oleg Ivaniv <me@olegivaniv.com> Co-authored-by: Val <68596159+valya@users.noreply.github.com> Co-authored-by: Alex Grozav <alex@grozav.com> Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in> Co-authored-by: Deborah <deborah@starfallprojects.co.uk> Co-authored-by: Jesper Bylund <mail@jesperbylund.com> Co-authored-by: Jon <jonathan.bennetts@gmail.com> Co-authored-by: Michael Kret <88898367+michael-radency@users.noreply.github.com> Co-authored-by: Giulio Andreini <andreini@netseven.it> Co-authored-by: Mason Geloso <Mason.geloso@gmail.com> Co-authored-by: Mason Geloso <hone@Masons-Mac-mini.local> Co-authored-by: Mutasem Aldmour <mutasem@n8n.io>
2025-12-23 12:49:09 +00:00 · 2023-11-29 12:13:55 +01:00
parent dbfd617ace
commit 87def60979
243 changed files with 21526 additions and 321 deletions
--- a/packages/@n8n/nodes-langchain/nodes/memory/MemoryBufferWindow/MemoryBufferWindow.node.ts
+++ b/packages/@n8n/nodes-langchain/nodes/memory/MemoryBufferWindow/MemoryBufferWindow.node.ts
@@ -0,0 +1,133 @@
+/* eslint-disable n8n-nodes-base/node-dirname-against-convention */
+import {
+	NodeConnectionType,
+	type IExecuteFunctions,
+	type INodeType,
+	type INodeTypeDescription,
+	type SupplyData,
+} from 'n8n-workflow';
+import type { BufferWindowMemoryInput } from 'langchain/memory';
+import { BufferWindowMemory } from 'langchain/memory';
+import { logWrapper } from '../../../utils/logWrapper';
+import { getConnectionHintNoticeField } from '../../../utils/sharedFields';
+
+class MemoryChatBufferSingleton {
+	private static instance: MemoryChatBufferSingleton;
+
+	private memoryBuffer: Map<
+		string,
+		{ buffer: BufferWindowMemory; created: Date; last_accessed: Date }
+	>;
+
+	private constructor() {
+		this.memoryBuffer = new Map();
+	}
+
+	public static getInstance(): MemoryChatBufferSingleton {
+		if (!MemoryChatBufferSingleton.instance) {
+			MemoryChatBufferSingleton.instance = new MemoryChatBufferSingleton();
+		}
+		return MemoryChatBufferSingleton.instance;
+	}
+
+	public async getMemory(
+		sessionKey: string,
+		memoryParams: BufferWindowMemoryInput,
+	): Promise<BufferWindowMemory> {
+		await this.cleanupStaleBuffers();
+
+		let memoryInstance = this.memoryBuffer.get(sessionKey);
+		if (memoryInstance) {
+			memoryInstance.last_accessed = new Date();
+		} else {
+			const newMemory = new BufferWindowMemory(memoryParams);
+
+			memoryInstance = {
+				buffer: newMemory,
+				created: new Date(),
+				last_accessed: new Date(),
+			};
+			this.memoryBuffer.set(sessionKey, memoryInstance);
+		}
+		return memoryInstance.buffer;
+	}
+
+	private async cleanupStaleBuffers(): Promise<void> {
+		const oneHourAgo = new Date(Date.now() - 60 * 60 * 1000);
+
+		for (const [key, memoryInstance] of this.memoryBuffer.entries()) {
+			if (memoryInstance.last_accessed < oneHourAgo) {
+				await this.memoryBuffer.get(key)?.buffer.clear();
+				this.memoryBuffer.delete(key);
+			}
+		}
+	}
+}
+
+export class MemoryBufferWindow implements INodeType {
+	description: INodeTypeDescription = {
+		displayName: 'Window Buffer Memory (easiest)',
+		name: 'memoryBufferWindow',
+		icon: 'fa:database',
+		group: ['transform'],
+		version: 1,
+		description: 'Stores in n8n memory, so no credentials required',
+		defaults: {
+			name: 'Window Buffer Memory',
+		},
+		codex: {
+			categories: ['AI'],
+			subcategories: {
+				AI: ['Memory'],
+			},
+			resources: {
+				primaryDocumentation: [
+					{
+						url: 'https://docs.n8n.io/integrations/builtin/cluster-nodes/sub-nodes/n8n-nodes-langchain.memorybufferwindow/',
+					},
+				],
+			},
+		},
+		// 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.AiMemory],
+		outputNames: ['Memory'],
+		properties: [
+			getConnectionHintNoticeField([NodeConnectionType.AiAgent]),
+			{
+				displayName: 'Session Key',
+				name: 'sessionKey',
+				type: 'string',
+				default: 'chat_history',
+				description: 'The key to use to store the memory in the workflow data',
+			},
+			{
+				displayName: 'Context Window Length',
+				name: 'contextWindowLength',
+				type: 'number',
+				default: 5,
+				description: 'The number of previous messages to consider for context',
+			},
+		],
+	};
+
+	async supplyData(this: IExecuteFunctions, itemIndex: number): Promise<SupplyData> {
+		const sessionKey = this.getNodeParameter('sessionKey', itemIndex) as string;
+		const contextWindowLength = this.getNodeParameter('contextWindowLength', itemIndex) as number;
+		const workflowId = this.getWorkflow().id;
+		const memoryInstance = MemoryChatBufferSingleton.getInstance();
+
+		const memory = await memoryInstance.getMemory(`${workflowId}__${sessionKey}`, {
+			k: contextWindowLength,
+			inputKey: 'input',
+			memoryKey: 'chat_history',
+			outputKey: 'output',
+			returnMessages: true,
+		});
+
+		return {
+			response: logWrapper(memory, this),
+		};
+	}
+}