From 231e4eff57efe2a9ff11f4e5bcbd36c252e8006f Mon Sep 17 00:00:00 2001
From: Michael Drury <me@michaeldrury.co.uk>
Date: Fri, 21 Nov 2025 09:01:25 +0000
Subject: [PATCH] fix(Agent Node): Thinking model issue - undefined `.map`
 error (#22046)

---
 .../agents/Agent/agents/ToolsAgent/common.ts  | 29 +++++++++---
 .../Agent/test/ToolsAgent/commons.test.ts     | 45 +++++++++++++++++++
 2 files changed, 68 insertions(+), 6 deletions(-)

diff --git a/packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/common.ts b/packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/common.ts
index 88d1d4ad4d8..5f43ba958fc 100644
--- a/packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/common.ts
+++ b/packages/@n8n/nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/common.ts
@@ -206,18 +206,35 @@ export function handleAgentFinishOutput(
 	if (agentFinishSteps.returnValues) {
 		const isMultiOutput = Array.isArray(agentFinishSteps.returnValues?.output);
 		if (isMultiOutput) {
-			// If all items in the multi-output array are of type 'text', merge them into a single string
 			const multiOutputSteps = agentFinishSteps.returnValues.output as Array<{
 				index: number;
 				type: string;
-				text: string;
+				text?: string;
+				thinking?: string;
 			}>;
-			const isTextOnly = multiOutputSteps.every((output) => 'text' in output);
-			if (isTextOnly) {
-				agentFinishSteps.returnValues.output = multiOutputSteps
-					.map((output) => output.text)
+
+			// Filter out thinking blocks and join text blocks
+			const textOutputs = multiOutputSteps
+				.filter((output) => output.type === 'text' && output.text)
+				.map((output) => output.text)
+				.join('\n')
+				.trim();
+
+			if (textOutputs) {
+				agentFinishSteps.returnValues.output = textOutputs;
+			} else {
+				const thinkingOutputs = multiOutputSteps
+					.filter((output) => output.type === 'thinking' && output.thinking)
+					.map((output) => output.thinking)
 					.join('\n')
 					.trim();
+
+				if (thinkingOutputs) {
+					agentFinishSteps.returnValues.output = thinkingOutputs;
+				} else {
+					// no output was found
+					agentFinishSteps.returnValues.output = '';
+				}
 			}
 			return agentFinishSteps;
 		}
diff --git a/packages/@n8n/nodes-langchain/nodes/agents/Agent/test/ToolsAgent/commons.test.ts b/packages/@n8n/nodes-langchain/nodes/agents/Agent/test/ToolsAgent/commons.test.ts
index a6a6977577d..f953f45e24d 100644
--- a/packages/@n8n/nodes-langchain/nodes/agents/Agent/test/ToolsAgent/commons.test.ts
+++ b/packages/@n8n/nodes-langchain/nodes/agents/Agent/test/ToolsAgent/commons.test.ts
@@ -831,4 +831,49 @@ describe('handleAgentFinishOutput', () => {
 
 		expect(result).toEqual(steps);
 	});
+
+	it('should filter out thinking blocks and return only text blocks', () => {
+		const steps: AgentFinish = {
+			returnValues: {
+				output: [
+					{ index: 0, type: 'thinking', thinking: 'Internal reasoning...' },
+					{ index: 1, type: 'text', text: 'User-facing output' },
+				],
+			},
+			log: '',
+		};
+
+		const result = handleAgentFinishOutput(steps) as AgentFinish;
+
+		expect(result.returnValues.output).toBe('User-facing output');
+	});
+
+	it('should return thinking content when no text blocks exist', () => {
+		const steps: AgentFinish = {
+			returnValues: {
+				output: [
+					{ index: 0, type: 'thinking', thinking: 'Only thinking content' },
+					{ index: 1, type: 'thinking', thinking: 'More thinking' },
+				],
+			},
+			log: '',
+		};
+
+		const result = handleAgentFinishOutput(steps) as AgentFinish;
+
+		expect(result.returnValues.output).toBe('Only thinking content\nMore thinking');
+	});
+
+	it('should return empty string when no text or thinking blocks exist', () => {
+		const steps: AgentFinish = {
+			returnValues: {
+				output: [{ index: 0, type: 'unknown' }],
+			},
+			log: '',
+		};
+
+		const result = handleAgentFinishOutput(steps) as AgentFinish;
+
+		expect(result.returnValues.output).toBe('');
+	});
 });