n8n-io/n8n · error · NodeOperationError

Missing search query input at itemIndex ${itemIndex}

Error message

Missing search query input at itemIndex ${itemIndex}

What it means

Thrown by the deprecated SerpApi tool's execute() when item.input is not a non-empty string. Identical contract to other search tools: a search query string must be supplied per input item.

Source

Thrown at packages/@n8n/nodes-langchain/nodes/tools/ToolSerpApi/ToolSerpApi.node.ts:148

			},
		],
	};

	async supplyData(this: ISupplyDataFunctions, itemIndex: number): Promise<SupplyData> {
		return {
			response: logWrapper(await getTool(this, itemIndex), this),
		};
	}

	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
		const inputData = this.getInputData();
		const returnData: INodeExecutionData[] = [];
		for (let itemIndex = 0; itemIndex < inputData.length; itemIndex++) {
			const tool = await getTool(this, itemIndex);
			const item = inputData[itemIndex].json;

			if (typeof item.input !== 'string' || !item.input) {
				throw new NodeOperationError(
					this.getNode(),
					`Missing search query input at itemIndex ${itemIndex}`,
				);
			}

			const result = (await tool.invoke(item)) as string;

			returnData.push({
				json: {
					response: result,
				},
				pairedItem: { item: itemIndex },
			});
		}

		return [returnData];
	}
}

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Map the upstream query field to 'input' for every item.
2. Add a Set/Edit Fields node to guarantee a non-empty 'input' string.
3. Migrate to the official verified community SerpApi node (the node description recommends this).
4. Drop empty items before they reach the tool.

Example fix

// before: item { json: { q: 'weather' } } → throws
// after:
{ json: { input: 'weather' } }

const q = item.input;
if (typeof q !== 'string' || !q) {
  throw new Error(`Item ${itemIndex} is missing a non-empty 'input' string`);
}

function isSearchQuery(v: unknown): v is string { return typeof v === 'string' && v.length > 0; }

When it happens

Trigger: Input items lacking an 'input' field; input present but empty or non-string; an upstream node emitting items shaped differently than expected.

Common situations: This node is deprecated (the description says so), so a stale workflow referencing it may have drifted from its input contract; field-name mismatches after refactoring upstream nodes.

Related errors

• Input item is missing
• Message exceeds maximum length of ${MAX_AI_BUILDER_PROMPT_LE
• The type ${genericType} is not supported
• The response type must be a string. Received: ${typeof respo
• The response type must be an object or an array of objects

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/618c8339ffb68a11. Report an issue: GitHub.