n8n-io/n8n · error · NodeOperationError

An assistant with the same name '${name}' already exists

Error message

An assistant with the same name '${name}' already exists

What it means

Before creating a new OpenAI assistant, the code paginates through all existing assistants (following has_more/last_id pagination) and collects their names. If the requested assistant name already exists on the account, it throws a NodeOperationError to prevent a duplicate. This is a client-side pre-validation check before the POST to /v1/assistants.

Source

Thrown at packages/@n8n/nodes-langchain/nodes/vendors/OpenAi/v1/actions/assistant/create.operation.ts:220

					after,
				},
			})) as { data: IDataObject[]; has_more: boolean; last_id: string };

			for (const assistant of response.data || []) {
				assistants.push(assistant.name as string);
			}

			has_more = response.has_more;

			if (has_more) {
				after = response.last_id;
			} else {
				break;
			}
		} while (has_more);

		if (assistants.includes(name)) {
			throw new NodeOperationError(
				this.getNode(),
				`An assistant with the same name '${name}' already exists`,
				{ itemIndex: i },
			);
		}
	}

	if (file_ids.length > 20) {
		throw new NodeOperationError(
			this.getNode(),
			'The maximum number of files that can be attached to the assistant is 20',
			{ itemIndex: i },
		);
	}

	const body: IDataObject = {
		model,
		name,

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Use a unique assistant name, or append a timestamp/UUID to the name
2. Delete the existing assistant with the same name from the OpenAI dashboard before re-running
3. Switch to an 'Update Assistant' operation if the intent is to modify an existing one

Example fix

// before — name: 'My Assistant'
// after  — name: `My Assistant ${Date.now()}`

// Check for existing assistant name before creating
const existingNames = await listExistingAssistantNames(this);
if (existingNames.includes(name)) {
  // Use a unique name or update instead
  name = `${name}-${Date.now()}`;
}

try {
  await createAssistant(this, i);
} catch (error) {
  if (error instanceof NodeOperationError && error.message.includes('already exists')) {
    // Retry with a unique name or switch to update
    name = `${name}-${Date.now()}`;
    await createAssistant(this, i);
  }
  throw error;
}

When it happens

Trigger: The 'Create Assistant' operation is called with a name that matches an existing assistant on the OpenAI account. The code lists all assistants via paginated GET requests, and if the name is found in the list, it aborts before creating.

Common situations: Running the same create-assistant workflow multiple times without changing the name; migrating or replaying workflows that create named assistants; accidental duplicate workflow executions.

Related errors

• The maximum number of files that can be attached to the assi
• The maximum number of files that can be attached to the assi
• ${error.message}
• Invalid file_ids type
• The file content is not in JSONL format

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/d5336cce2049f35a. Report an issue: GitHub.