n8n-io/n8n · error · NodeOperationError

Single document per item expected

Error message

Single document per item expected

What it means

Error "Single document per item expected" thrown in n8n-io/n8n.

Source

Thrown at packages/@n8n/ai-utilities/src/utils/vector-store/createVectorStoreNode/operations/updateOperation.ts:58

		// Get the document ID to update
		const documentId = context.getNodeParameter('id', itemIndex, '', {
			extractValue: true,
		}) as string;

		// Get the vector store client
		const vectorStore = await args.getVectorStoreClient(context, undefined, embeddings, itemIndex);

		try {
			// Process the document from the input
			const { processedDocuments, serializedDocuments } = await processDocument(
				loader,
				itemData,
				itemIndex,
			);

			// Validate that we have exactly one document to update
			if (processedDocuments?.length !== 1) {
				throw new NodeOperationError(context.getNode(), 'Single document per item expected');
			}

			// Add the serialized document to the result
			resultData.push(...serializedDocuments);

			// Use document ID to update the existing document
			await vectorStore.addDocuments(processedDocuments, {
				ids: [documentId],
			});

			// Log the AI event for analytics
			logAiEvent(context, 'ai-vector-store-updated');
		} finally {
			// Release the vector store client if a release method was provided
			args.releaseVectorStoreClient?.(vectorStore);
		}
	}

View on GitHub (pinned to 5ac6606e81)

When it happens

Trigger: Thrown at packages/@n8n/ai-utilities/src/utils/vector-store/createVectorStoreNode/operations/updateOperation.ts:58 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/bd64e2f66a0b1fce. Report an issue: GitHub.