feat: SQL agent improvements (#8709)

Signed-off-by: Oleg Ivaniv <me@olegivaniv.com>
Co-authored-by: Oleg Ivaniv <me@olegivaniv.com>

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

@@ -9,9 +9,9 @@ import type {
 	INodeTypeDescription,
 } from 'n8n-workflow';
 import { getTemplateNoticeField } from '../../../utils/sharedFields';
+import { promptTypeOptions, textInput } from '../../../utils/descriptions';
 import { conversationalAgentProperties } from './agents/ConversationalAgent/description';
 import { conversationalAgentExecute } from './agents/ConversationalAgent/execute';
-
 import { openAiFunctionsAgentProperties } from './agents/OpenAiFunctionsAgent/description';
 import { openAiFunctionsAgentExecute } from './agents/OpenAiFunctionsAgent/execute';
 import { planAndExecuteAgentProperties } from './agents/PlanAndExecuteAgent/description';
@@ -20,6 +20,7 @@ import { reActAgentAgentProperties } from './agents/ReActAgent/description';
 import { reActAgentAgentExecute } from './agents/ReActAgent/execute';
 import { sqlAgentAgentProperties } from './agents/SqlAgent/description';
 import { sqlAgentAgentExecute } from './agents/SqlAgent/execute';
+
 // Function used in the inputs expression to figure out which inputs to
 // display based on the agent type
 function getInputs(
@@ -128,6 +129,9 @@ function getInputs(
 			{
 				type: NodeConnectionType.AiLanguageModel,
 			},
+			{
+				type: NodeConnectionType.AiMemory,
+			},
 		];
 	} else if (agent === 'planAndExecuteAgent') {
 		specialInputs = [
@@ -157,10 +161,10 @@ export class Agent implements INodeType {
 		name: 'agent',
 		icon: 'fa:robot',
 		group: ['transform'],
-		version: [1, 1.1, 1.2, 1.3],
+		version: [1, 1.1, 1.2, 1.3, 1.4],
 		description: 'Generates an action plan and executes it. Can use external tools.',
 		subtitle:
-			"={{ {	conversationalAgent: 'Conversational Agent', openAiFunctionsAgent: 'OpenAI Functions Agent', reactAgent: 'ReAct Agent', sqlAgent: 'SQL Agent' }[$parameter.agent] }}",
+			"={{ {	conversationalAgent: 'Conversational Agent', openAiFunctionsAgent: 'OpenAI Functions Agent', reActAgent: 'ReAct Agent', sqlAgent: 'SQL Agent', planAndExecuteAgent: 'Plan and Execute Agent' }[$parameter.agent] }}",
 		defaults: {
 			name: 'AI Agent',
 			color: '#404040',
@@ -257,45 +261,23 @@ export class Agent implements INodeType {
 				default: 'conversationalAgent',
 			},
 			{
-				displayName: 'Prompt',
-				name: 'promptType',
-				type: 'options',
-				options: [
-					{
-						// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
-						name: 'Take from previous node automatically',
-						value: 'auto',
-						description: 'Looks for an input field called chatInput',
-					},
-					{
-						// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
-						name: 'Define below',
-						value: 'define',
-						description:
-							'Use an expression to reference data in previous nodes or enter static text',
-					},
-				],
+				...promptTypeOptions,
 				displayOptions: {
 					hide: {
 						'@version': [{ _cnd: { lte: 1.2 } }],
+						agent: ['sqlAgent'],
 					},
 				},
-				default: 'auto',
 			},
 			{
-				displayName: 'Text',
-				name: 'text',
-				type: 'string',
-				required: true,
-				default: '',
-				placeholder: 'e.g. Hello, how can you help me?',
-				typeOptions: {
-					rows: 2,
-				},
+				...textInput,
 				displayOptions: {
 					show: {
 						promptType: ['define'],
 					},
+					hide: {
+						agent: ['sqlAgent'],
+					},
 				},
 			},
 			{

packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/SqlAgent/description.ts

@@ -1,35 +1,91 @@
 import type { INodeProperties } from 'n8n-workflow';
+import { promptTypeOptions, textInput } from '../../../../../utils/descriptions';
 import { SQL_PREFIX, SQL_SUFFIX } from './other/prompts';
 
+const dataSourceOptions: INodeProperties = {
+	displayName: 'Data Source',
+	name: 'dataSource',
+	type: 'options',
+	displayOptions: {
+		show: {
+			agent: ['sqlAgent'],
+		},
+	},
+	default: 'sqlite',
+	description: 'SQL database to connect to',
+	options: [
+		{
+			name: 'MySQL',
+			value: 'mysql',
+			description: 'Connect to a MySQL database',
+		},
+		{
+			name: 'Postgres',
+			value: 'postgres',
+			description: 'Connect to a Postgres database',
+		},
+		{
+			name: 'SQLite',
+			value: 'sqlite',
+			description: 'Use SQLite by connecting a database file as binary input',
+		},
+	],
+};
+
 export const sqlAgentAgentProperties: INodeProperties[] = [
 	{
-		displayName: 'Data Source',
-		name: 'dataSource',
-		type: 'options',
+		...dataSourceOptions,
 		displayOptions: {
 			show: {
 				agent: ['sqlAgent'],
+				'@version': [{ _cnd: { lt: 1.4 } }],
 			},
 		},
-		default: 'sqlite',
-		description: 'SQL database to connect to',
-		options: [
-			{
-				name: 'MySQL',
-				value: 'mysql',
-				description: 'Connect to a MySQL database',
+	},
+	{
+		...dataSourceOptions,
+		default: 'postgres',
+		displayOptions: {
+			show: {
+				agent: ['sqlAgent'],
+				'@version': [{ _cnd: { gte: 1.4 } }],
 			},
-			{
-				name: 'Postgres',
-				value: 'postgres',
-				description: 'Connect to a Postgres database',
+		},
+	},
+	{
+		displayName: 'Credentials',
+		name: 'credentials',
+		type: 'credentials',
+		default: '',
+	},
+	{
+		// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
+		displayName:
+			"Pass the SQLite database into this node as binary data, e.g. by inserting a 'Read/Write Files from Disk' node beforehand",
+		name: 'sqLiteFileNotice',
+		type: 'notice',
+		default: '',
+		displayOptions: {
+			show: {
+				agent: ['sqlAgent'],
+				dataSource: ['sqlite'],
 			},
-			{
-				name: 'SQLite',
-				value: 'sqlite',
-				description: 'Use SQLite by connecting a database file as binary input',
+		},
+	},
+	{
+		displayName: 'Input Binary Field',
+		name: 'binaryPropertyName',
+		type: 'string',
+		default: 'data',
+		required: true,
+		placeholder: 'e.g data',
+		hint: 'The name of the input binary field containing the file to be extracted',
+		displayOptions: {
+			show: {
+				agent: ['sqlAgent'],
+				dataSource: ['sqlite'],
 			},
-		],
+		},
 	},
 	{
 		displayName: 'Prompt',
@@ -47,6 +103,26 @@ export const sqlAgentAgentProperties: INodeProperties[] = [
 			rows: 5,
 		},
 	},
+	{
+		...promptTypeOptions,
+		displayOptions: {
+			hide: {
+				'@version': [{ _cnd: { lte: 1.2 } }],
+			},
+			show: {
+				agent: ['sqlAgent'],
+			},
+		},
+	},
+	{
+		...textInput,
+		displayOptions: {
+			show: {
+				promptType: ['define'],
+				agent: ['sqlAgent'],
+			},
+		},
+	},
 	{
 		displayName: 'Options',
 		name: 'options',

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

@@ -9,9 +9,10 @@ import { SqlDatabase } from 'langchain/sql_db';
 import type { SqlCreatePromptArgs } from 'langchain/agents/toolkits/sql';
 import { SqlToolkit, createSqlAgent } from 'langchain/agents/toolkits/sql';
 import type { BaseLanguageModel } from 'langchain/dist/base_language';
+import type { BaseChatMemory } from 'langchain/memory';
 import type { DataSource } from '@n8n/typeorm';
 
-import { getPromptInputByType } from '../../../../../utils/helpers';
+import { getPromptInputByType, serializeChatHistory } from '../../../../../utils/helpers';
 import { getSqliteDataSource } from './other/handlers/sqlite';
 import { getPostgresDataSource } from './other/handlers/postgres';
 import { SQL_PREFIX, SQL_SUFFIX } from './other/prompts';
@@ -73,7 +74,8 @@ export async function sqlAgentAgentExecute(
 				);
 			}
 
-			dataSource = getSqliteDataSource.call(this, item.binary);
+			const binaryPropertyName = this.getNodeParameter('binaryPropertyName', i, 'data');
+			dataSource = await getSqliteDataSource.call(this, item.binary, binaryPropertyName);
 		}
 
 		if (selectedDataSource === 'postgres') {
@@ -95,6 +97,7 @@ export async function sqlAgentAgentExecute(
 			topK: (options.topK as number) ?? 10,
 			prefix: (options.prefixPrompt as string) ?? SQL_PREFIX,
 			suffix: (options.suffixPrompt as string) ?? SQL_SUFFIX,
+			inputVariables: ['chatHistory', 'input', 'agent_scratchpad'],
 		};
 
 		const dbInstance = await SqlDatabase.fromDataSourceParams({
@@ -107,7 +110,32 @@ export async function sqlAgentAgentExecute(
 		const toolkit = new SqlToolkit(dbInstance, model);
 		const agentExecutor = createSqlAgent(model, toolkit, agentOptions);
 
-		const response = await agentExecutor.call({ input, signal: this.getExecutionCancelSignal() });
+		const memory = (await this.getInputConnectionData(NodeConnectionType.AiMemory, 0)) as
+			| BaseChatMemory
+			| undefined;
+
+		agentExecutor.memory = memory;
+
+		let chatHistory = '';
+		if (memory) {
+			const messages = await memory.chatHistory.getMessages();
+			chatHistory = serializeChatHistory(messages);
+		}
+
+		let response;
+		try {
+			response = await agentExecutor.call({
+				input,
+				signal: this.getExecutionCancelSignal(),
+				chatHistory,
+			});
+		} catch (error) {
+			if (error.message?.output) {
+				response = error.message;
+			} else {
+				throw new NodeOperationError(this.getNode(), error.message, { itemIndex: i });
+			}
+		}
 
 		returnData.push({ json: response });
 	}

packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/SqlAgent/other/handlers/sqlite.ts

@@ -5,17 +5,28 @@ import * as temp from 'temp';
 import * as sqlite3 from 'sqlite3';
 import { DataSource } from '@n8n/typeorm';
 
-export function getSqliteDataSource(
+export async function getSqliteDataSource(
 	this: IExecuteFunctions,
 	binary: INodeExecutionData['binary'],
-): DataSource {
-	const binaryData = binary?.data;
+	binaryPropertyName = 'data',
+): Promise<DataSource> {
+	const binaryData = binary?.[binaryPropertyName];
 
 	if (!binaryData) {
 		throw new NodeOperationError(this.getNode(), 'No binary data received.');
 	}
 
-	const bufferString = Buffer.from(binaryData.data, BINARY_ENCODING);
+	let fileBase64;
+	if (binaryData.id) {
+		const chunkSize = 256 * 1024;
+		const stream = await this.helpers.getBinaryStream(binaryData.id, chunkSize);
+		const buffer = await this.helpers.binaryToBuffer(stream);
+		fileBase64 = buffer.toString('base64');
+	} else {
+		fileBase64 = binaryData.data;
+	}
+
+	const bufferString = Buffer.from(fileBase64, BINARY_ENCODING);
 
 	// Track and cleanup temp files at exit
 	temp.track();

packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/SqlAgent/other/prompts.ts

@@ -12,6 +12,8 @@ DO NOT make any DML statements (INSERT, UPDATE, DELETE, DROP etc.) to the databa
 If the question does not seem related to the database, just return "I don't know" as the answer.`;
 
 export const SQL_SUFFIX = `Begin!
+Chat History:
+{chatHistory}
 
 Question: {input}
 Thought: I should look at the tables in the database to see what I can query.

packages/@n8n/nodes-langchain/nodes/vendors/OpenAi/actions/file/upload.operation.ts

@@ -85,8 +85,7 @@ export async function execute(this: IExecuteFunctions, i: number): Promise<INode
 	} catch (error) {
 		if (
 			error.message.includes('Bad request') &&
-			error.description &&
-			error.description.includes('Expected file to have JSONL format')
+			error.description?.includes('Expected file to have JSONL format')
 		) {
 			throw new NodeOperationError(this.getNode(), 'The file content is not in JSONL format', {
 				description:

packages/@n8n/nodes-langchain/nodes/vendors/OpenAi/test/OpenAi.node.test.ts

@@ -1,14 +1,13 @@
+import type { IDataObject, IExecuteFunctions } from 'n8n-workflow';
+import get from 'lodash/get';
 import * as assistant from '../actions/assistant';
 import * as audio from '../actions/audio';
 import * as file from '../actions/file';
 import * as image from '../actions/image';
 import * as text from '../actions/text';
 
-import type { IDataObject, IExecuteFunctions } from 'n8n-workflow';
 import * as transport from '../transport';
 
-import get from 'lodash/get';
-
 const createExecuteFunctionsMock = (parameters: IDataObject) => {
 	const nodeParameters = parameters;
 	return {

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

@@ -0,0 +1,34 @@
+import type { INodeProperties } from 'n8n-workflow';
+
+export const promptTypeOptions: INodeProperties = {
+	displayName: 'Prompt',
+	name: 'promptType',
+	type: 'options',
+	options: [
+		{
+			// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
+			name: 'Take from previous node automatically',
+			value: 'auto',
+			description: 'Looks for an input field called chatInput',
+		},
+		{
+			// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
+			name: 'Define below',
+			value: 'define',
+			description: 'Use an expression to reference data in previous nodes or enter static text',
+		},
+	],
+	default: 'auto',
+};
+
+export const textInput: INodeProperties = {
+	displayName: 'Text',
+	name: 'text',
+	type: 'string',
+	required: true,
+	default: '',
+	placeholder: 'e.g. Hello, how can you help me?',
+	typeOptions: {
+		rows: 2,
+	},
+};

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

@@ -3,6 +3,7 @@ import type { EventNamesAiNodesType, IDataObject, IExecuteFunctions } from 'n8n-
 import { BaseChatModel } from 'langchain/chat_models/base';
 import { BaseChatModel as BaseChatModelCore } from '@langchain/core/language_models/chat_models';
 import type { BaseOutputParser } from '@langchain/core/output_parsers';
+import { BaseMessage } from 'langchain/schema';
 
 export function getMetadataFiltersValues(
 	ctx: IExecuteFunctions,
@@ -77,3 +78,17 @@ export async function logAiEvent(
 		executeFunctions.logger.debug(`Error logging AI event: ${event}`);
 	}
 }
+
+export function serializeChatHistory (chatHistory: Array<BaseMessage>): string {
+	return chatHistory
+		.map((chatMessage) => {
+			if (chatMessage._getType() === 'human') {
+				return `Human: ${chatMessage.content}`;
+			} else if (chatMessage._getType() === 'ai') {
+				return `Assistant: ${chatMessage.content}`;
+			} else {
+				return `${chatMessage.content}`;
+			}
+		})
+		.join('\n');
+}

packages/workflow/src/Interfaces.ts

@@ -2237,6 +2237,7 @@ export interface INodeGraphItem {
 	method?: string; // HTTP Request node v2
 	src_node_id?: string;
 	src_instance_id?: string;
+	agent?: string; //@n8n/n8n-nodes-langchain.agent
 }
 
 export interface INodeNameIndex {

packages/workflow/src/TelemetryHelpers.ts

@@ -158,7 +158,9 @@ export function generateNodesGraph(
 			nodeItem.src_node_id = options.nodeIdMap[node.id];
 		}
 
-		if (node.type === 'n8n-nodes-base.httpRequest' && node.typeVersion === 1) {
+		if (node.type === '@n8n/n8n-nodes-langchain.agent') {
+			nodeItem.agent = (node.parameters.agent as string) || 'conversationalAgent';
+		} else if (node.type === 'n8n-nodes-base.httpRequest' && node.typeVersion === 1) {
 			try {
 				nodeItem.domain = new URL(node.parameters.url as string).hostname;
 			} catch {