fix(core): Skip disabled tool nodes when mapping AI Agent tool sources (#29460)

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

@@ -200,13 +200,17 @@ export const getConnectedTools = async (
 		0,
 	)) as SupplyDataToolResponse[];
 
-	// Get parent nodes to map toolkits to their source nodes
+	// Get parent nodes to map toolkits to their source nodes.
+	// getInputConnectionData filters out disabled nodes, so parents must be filtered
+	// the same way to keep the index alignment between toolkitConnections and parentNodes.
 	const parentNodes =
 		'getParentNodes' in ctx
-			? ctx.getParentNodes(ctx.getNode().name, {
-					connectionType: NodeConnectionTypes.AiTool,
-					depth: 1,
-				})
+			? ctx
+					.getParentNodes(ctx.getNode().name, {
+						connectionType: NodeConnectionTypes.AiTool,
+						depth: 1,
+					})
+					.filter((node) => !node.disabled)
 			: [];
 
 	const connectedTools = (toolkitConnections ?? [])

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

@@ -341,6 +341,38 @@ describe('getConnectedTools', () => {
 			sourceNodeName: 'MCP Client Tool',
 		});
 	});
+
+	it('should map source node names correctly when a disabled tool node is still connected', async () => {
+		// getParentNodes returns ALL parents including disabled ones,
+		// while getInputConnectionData filters disabled nodes out.
+		// getConnectedTools must skip disabled parents to keep the index in sync.
+		const mockParentNodes = [
+			{ name: 'Tool Alpha', disabled: false },
+			{ name: 'Tool Bravo', disabled: true },
+			{ name: 'Tool Charlie', disabled: false },
+		];
+		const mockTools = [
+			{ name: 'alpha', description: 'desc-alpha' },
+			{ name: 'charlie', description: 'desc-charlie' },
+		];
+
+		mockExecuteFunctions.getInputConnectionData = jest.fn().mockResolvedValue(mockTools);
+		mockExecuteFunctions.getParentNodes = jest.fn().mockReturnValue(mockParentNodes);
+
+		const tools = await getConnectedTools(mockExecuteFunctions, false);
+
+		expect(tools).toHaveLength(2);
+		expect(tools[0].name).toBe('alpha');
+		expect(tools[0].metadata).toEqual({
+			isFromToolkit: false,
+			sourceNodeName: 'Tool Alpha',
+		});
+		expect(tools[1].name).toBe('charlie');
+		expect(tools[1].metadata).toEqual({
+			isFromToolkit: false,
+			sourceNodeName: 'Tool Charlie',
+		});
+	});
 });
 
 describe('unwrapNestedOutput', () => {