n8n-io/n8n · error

invalid_request

invalid_request

Error message

invalid_request

What it means

Returned as HTTP 400 {error:'invalid_request', details:...} when Zod's StartExecutionBody.safeParse(req.body) fails on POST /workflow-executions. The body schema requires workflowId (non-empty string), graph (nodes + edges matching GraphNodeSchema/GraphEdgeSchema), optional triggerPayload (JSON object or null), and optional mode ('production'|'manual'). details carries parsed.error.flatten() with field-level validation errors. This is a transport-layer rejection before any execution logic runs.

Source

Thrown at packages/@n8n/engine/src/server/routes/workflow-executions.ts:59

const WorkflowGraphSchema = z.object({
	nodes: z.array(GraphNodeSchema),
	edges: z.array(GraphEdgeSchema),
});

const StartExecutionBody = z.object({
	workflowId: z.string().min(1),
	graph: WorkflowGraphSchema,
	triggerPayload: jsonObjectSchema.nullable().optional(),
	mode: z.enum(['production', 'manual']).optional(),
});

export function createWorkflowExecutionsRouter(startExecution: StartExecutionService): RouterType {
	const router = Router();

	router.post('/', async (req, res) => {
		const parsed = StartExecutionBody.safeParse(req.body);
		if (!parsed.success) {
			res.status(400).json({
				error: 'invalid_request',
				details: parsed.error.flatten(),
			});
			return;
		}

		try {
			const result = await startExecution.start(parsed.data);
			res.status(201).json(result);
		} catch (error) {
			if (error instanceof AdmittanceRejectedError) {
				res.status(429).json({ error: 'admittance_rejected', reason: error.reason });
				return;
			}
			if (error instanceof GraphValidationError) {
				res.status(400).json({ error: 'invalid_graph', reason: error.message });
				return;
			}

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Inspect response.body.details.fieldErrors — Zod reports the exact failing field and rule.
2. Validate the payload against StartExecutionBody on the client before POSTing (mirror the Zod schema).
3. Ensure workflowId is a non-empty string and graph has both nodes and edges arrays.
4. Confirm every node.type is in ['trigger','v1-node','wait','subworkflow','batch'] and every edge index is a non-negative integer.
5. If triggerPayload is present, make it a JSON object (z.record) or null, never a primitive.

Example fix

// before — missing workflowId, bad node type
const body = { graph: { nodes: [{ id: 'n1', type: 'httpRequest' }], edges: [] } };
// after — valid shape
const body = {
  workflowId: 'wf-123',
  graph: {
    nodes: [{ id: 'n1', name: 'Start', type: 'trigger' }],
    edges: []
  }
};

import { z } from 'zod';
const StepType = z.enum(['trigger','v1-node','wait','subworkflow','batch']);
const Edge = z.object({
  from: z.string(), to: z.string(),
  outputIndex: z.number().int().nonnegative().default(0),
  inputIndex: z.number().int().nonnegative().default(0),
  isBackEdge: z.boolean().optional(),
});
const Graph = z.object({
  nodes: z.array(z.object({ id: z.string(), name: z.string(), type: StepType, config: z.unknown().optional() })),
  edges: z.array(Edge),
});
const Body = z.object({
  workflowId: z.string().min(1),
  graph: Graph,
  triggerPayload: z.record(z.unknown()).nullable().optional(),
  mode: z.enum(['production','manual']).optional(),
});
// run before POST
const parsed = Body.safeParse(payload);
if (!parsed.success) console.error(parsed.error.flatten());

function isValidStartBody(body) {
  return typeof body?.workflowId === 'string' && body.workflowId.length > 0
    && Array.isArray(body?.graph?.nodes) && Array.isArray(body?.graph?.edges)
    && body.graph.nodes.every(n => ['trigger','v1-node','wait','subworkflow','batch'].includes(n.type));
}

const res = await fetch('/workflow-executions', { method: 'POST', body: JSON.stringify(payload) });
if (res.status === 400) {
  const body = await res.json();
  if (body.error === 'invalid_request') {
    // body.details.fieldErrors pinpoints each failing field; fix and retry
  }
}

When it happens

Trigger: POST /workflow-executions with: missing or empty workflowId; graph missing nodes or edges arrays; a node whose type is not one of 'trigger'|'v1-node'|'wait'|'subworkflow'|'batch'; an edge with a negative or non-integer outputIndex/inputIndex; mode set to an invalid enum value; triggerPayload that is a primitive instead of an object.

Common situations: Client sends a partially-built graph during development. A field rename (workflowId vs workflow_id) after an API version bump. Sending triggerPayload as a raw string instead of a JSON object. Copy-pasting a v1 workflow JSON whose shape doesn't match the new engine schema.

Related errors

• invalid_graph
• Tool "${this.name}" requires an input schema
• VALIDATION_ERROR
• VALIDATION_ERROR
• VALIDATION_ERROR

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/c89729004b1cda70. Report an issue: GitHub.