n8n-io/n8n · error · WorkflowGenerationError

CodeWorkflowBuilder did not produce a workflow

Error message

CodeWorkflowBuilder did not produce a workflow

What it means

Post-run invariant error in createCodeWorkflowBuilderGenerator, raised as WorkflowGenerationError. It fires when the CodeWorkflowBuilder chat stream completed (including timeout cleanup) but no workflow message was ever captured in streamState — the builder streamed output without producing a workflow.

Solutions

1. Inspect the streamed builder messages for errors or refusals; the run ended without emitting a workflow.
2. Re-run the case; LLM non-determinism can produce a chat-only reply with no workflow.
3. Check the prompt and feature flags — a prompt that only asks questions yields no workflow.

When it happens

Trigger: Thrown at packages/@n8n/ai-workflow-builder.ee/evaluations/cli/index.ts:400 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/a8a428f3a0fd4603. Report an issue: GitHub.

Appendix: source

Thrown at packages/@n8n/ai-workflow-builder.ee/evaluations/cli/index.ts:400

		try {
			for await (const output of builder.chat(
				payload,
				EVAL_USERS.LANGSMITH,
				abortController.signal,
				historyContext,
			)) {
				for (const message of output.messages) {
					processCodeBuilderMessage(message, streamState);
				}
			}
		} finally {
			if (timeoutId !== undefined) {
				clearTimeout(timeoutId);
			}
		}

		if (!streamState.workflow) {
			throw new WorkflowGenerationError('CodeWorkflowBuilder did not produce a workflow');
		}

		// Report accumulated token usage
		if (collectors?.tokenUsage && (totalInputTokens > 0 || totalOutputTokens > 0)) {
			collectors.tokenUsage({ inputTokens: totalInputTokens, outputTokens: totalOutputTokens });
		}

		return {
			workflow: streamState.workflow,
			generatedCode: streamState.generatedCode,
			agentTextResponse: streamState.textParts.join('') || undefined,
		};
	};
}

/**
 * Load test cases from various sources.
 */

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