fix(AI Agent Node): Preserve intermediateSteps when using output parser with non-tool agent (#11363)

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

@@ -251,7 +251,7 @@ export class Agent implements INodeType {
 		icon: 'fa:robot',
 		iconColor: 'black',
 		group: ['transform'],
-		version: [1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6],
+		version: [1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7],
 		description: 'Generates an action plan and executes it. Can use external tools.',
 		subtitle:
 			"={{ {	toolsAgent: 'Tools Agent', conversationalAgent: 'Conversational Agent', openAiFunctionsAgent: 'OpenAI Functions Agent', reActAgent: 'ReAct Agent', sqlAgent: 'SQL Agent', planAndExecuteAgent: 'Plan and Execute Agent' }[$parameter.agent] }}",

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

@@ -14,6 +14,7 @@ import {
 import { getOptionalOutputParsers } from '../../../../../utils/output_parsers/N8nOutputParser';
 import { throwIfToolSchema } from '../../../../../utils/schemaParsing';
 import { getTracingConfig } from '../../../../../utils/tracing';
+import { extractParsedOutput } from '../utils';
 
 export async function conversationalAgentExecute(
 	this: IExecuteFunctions,
@@ -102,12 +103,12 @@ export async function conversationalAgentExecute(
 				input = (await prompt.invoke({ input })).value;
 			}
 
-			let response = await agentExecutor
+			const response = await agentExecutor
 				.withConfig(getTracingConfig(this))
 				.invoke({ input, outputParsers });
 
 			if (outputParser) {
-				response = { output: await outputParser.parse(response.output as string) };
+				response.output = await extractParsedOutput(this, outputParser, response.output as string);
 			}
 
 			returnData.push({ json: response });

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

@@ -15,6 +15,7 @@ import {
 import { getConnectedTools, getPromptInputByType } from '../../../../../utils/helpers';
 import { getOptionalOutputParsers } from '../../../../../utils/output_parsers/N8nOutputParser';
 import { getTracingConfig } from '../../../../../utils/tracing';
+import { extractParsedOutput } from '../utils';
 
 export async function openAiFunctionsAgentExecute(
 	this: IExecuteFunctions,
@@ -103,12 +104,12 @@ export async function openAiFunctionsAgentExecute(
 				input = (await prompt.invoke({ input })).value;
 			}
 
-			let response = await agentExecutor
+			const response = await agentExecutor
 				.withConfig(getTracingConfig(this))
 				.invoke({ input, outputParsers });
 
 			if (outputParser) {
-				response = { output: await outputParser.parse(response.output as string) };
+				response.output = await extractParsedOutput(this, outputParser, response.output as string);
 			}
 
 			returnData.push({ json: response });

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

@@ -14,6 +14,7 @@ import { getConnectedTools, getPromptInputByType } from '../../../../../utils/he
 import { getOptionalOutputParsers } from '../../../../../utils/output_parsers/N8nOutputParser';
 import { throwIfToolSchema } from '../../../../../utils/schemaParsing';
 import { getTracingConfig } from '../../../../../utils/tracing';
+import { extractParsedOutput } from '../utils';
 
 export async function planAndExecuteAgentExecute(
 	this: IExecuteFunctions,
@@ -79,12 +80,12 @@ export async function planAndExecuteAgentExecute(
 				input = (await prompt.invoke({ input })).value;
 			}
 
-			let response = await agentExecutor
+			const response = await agentExecutor
 				.withConfig(getTracingConfig(this))
 				.invoke({ input, outputParsers });
 
 			if (outputParser) {
-				response = { output: await outputParser.parse(response.output as string) };
+				response.output = await extractParsedOutput(this, outputParser, response.output as string);
 			}
 
 			returnData.push({ json: response });

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

@@ -19,6 +19,7 @@ import {
 import { getOptionalOutputParsers } from '../../../../../utils/output_parsers/N8nOutputParser';
 import { throwIfToolSchema } from '../../../../../utils/schemaParsing';
 import { getTracingConfig } from '../../../../../utils/tracing';
+import { extractParsedOutput } from '../utils';
 
 export async function reActAgentAgentExecute(
 	this: IExecuteFunctions,
@@ -103,12 +104,12 @@ export async function reActAgentAgentExecute(
 				input = (await prompt.invoke({ input })).value;
 			}
 
-			let response = await agentExecutor
+			const response = await agentExecutor
 				.withConfig(getTracingConfig(this))
 				.invoke({ input, outputParsers });
 
 			if (outputParser) {
-				response = { output: await outputParser.parse(response.output as string) };
+				response.output = await extractParsedOutput(this, outputParser, response.output as string);
 			}
 
 			returnData.push({ json: response });

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

@@ -0,0 +1,19 @@
+import type { BaseOutputParser } from '@langchain/core/output_parsers';
+import type { IExecuteFunctions } from 'n8n-workflow';
+
+export async function extractParsedOutput(
+	ctx: IExecuteFunctions,
+	outputParser: BaseOutputParser<unknown>,
+	output: string,
+): Promise<Record<string, unknown> | undefined> {
+	const parsedOutput = (await outputParser.parse(output)) as {
+		output: Record<string, unknown>;
+	};
+
+	if (ctx.getNode().typeVersion <= 1.6) {
+		return parsedOutput;
+	}
+	// For 1.7 and above, we try to extract the output from the parsed output
+	// with fallback to the original output if it's not present
+	return parsedOutput?.output ?? parsedOutput;
+}