n8n-io/n8n · error · Error

Failed to generate valid workflow after

Error message

Failed to generate valid workflow after ${MAX_VALIDATE_ATTEMPTS} validate attempts.

What it means

Inside the agentic loop's tool-call handler, the model kept invoking validate_workflow without the workflow ever becoming ready. Each failed validation increments textEditorValidateAttempts; once it reaches MAX_VALIDATE_ATTEMPTS the loop is aborted. This means the model repeatedly produced code that fails validation and exhausted its repair budget.

Solutions

  1. Inspect the validation feedback returned by validate_workflow on the final attempts to find the recurring defect
  2. Retry with a fresh session — sometimes the model escapes a bad self-repair loop on restart
  3. Increase MAX_VALIDATE_ATTEMPTS if workflows are consistently complex enough to need more repair rounds
  4. Use a stronger build model or provide a more detailed plan so the first code generation is closer to valid
Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at packages/@n8n/ai-workflow-builder.ee/src/code-builder/code-builder-agent.ts:657 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/2c0e0ab6862e603c. Report an issue: GitHub.

Appendix: source

Thrown at packages/@n8n/ai-workflow-builder.ee/src/code-builder/code-builder-agent.ts:657

		}
		if (dispatchResult.parseDuration !== undefined) {
			state.parseDuration = dispatchResult.parseDuration;
		}
		if (dispatchResult.workflowReady) {
			state.sourceCode = dispatchResult.sourceCode ?? null;
			state.textEditorValidateAttempts = 0;
			return { shouldBreak: true };
		}

		// Increment validate attempts counter when validate_workflow was called but failed
		const hadValidateCall = toolCalls.some((tc) => tc.name === 'validate_workflow');
		if (hadValidateCall && !dispatchResult.workflowReady) {
			state.textEditorValidateAttempts++;
		}

		// Check for too many validate failures
		if (textEditorEnabled && state.textEditorValidateAttempts >= MAX_VALIDATE_ATTEMPTS) {
			throw new Error(
				`Failed to generate valid workflow after ${MAX_VALIDATE_ATTEMPTS} validate attempts.`,
			);
		}

		return { shouldBreak: false };
	}

	/**
	 * Handle text editor auto-finalize when no tool calls
	 */
	private async *handleTextEditorAutoFinalize(params: {
		textEditorHandler: TextEditorHandler;
		currentWorkflow?: WorkflowJSON;
		messages: BaseMessage[];
		state: AgenticLoopState;
	}): AsyncGenerator<StreamOutput, { shouldBreak: boolean }, unknown> {
		const { textEditorHandler, currentWorkflow, messages, state } = params;

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