n8n-io/n8n · error · Error

Failed to read prebuilt-workflows manifest at

Error message

Failed to read prebuilt-workflows manifest at ${path}: ${msg}

What it means

Thrown by loadPrebuiltManifest when readFileSync or JSON.parse fails on the manifest path — the file is missing, unreadable, or not valid JSON. The error wraps the underlying filesystem/parse error message so the caller can see the exact OS/parse cause.

Solutions

1. Check the underlying error message embedded in the thrown string (e.g. ENOENT, EACCES, Unexpected token) to classify the cause.
2. Verify the path exists and is a file: `fs.statSync(path).isFile()`.
3. If missing, generate or regenerate the manifest (run the project's manifest-generation step).
4. If malformed, validate the JSON with a linter/editor and fix the syntax error.

Example fix

// before
loadPrebuiltManifest('./prebuilt-workflows.json');

// after — verify existence and provide a clear fallback path
const path = './prebuilt-workflows.json';
if (!fs.existsSync(path)) throw new Error(`manifest missing at ${path}; run the generator first`);
loadPrebuiltManifest(path);

import { existsSync, statSync } from 'node:fs';

function manifestReadable(path: string): boolean {
  try {
    return existsSync(path) && statSync(path).isFile();
  } catch {
    return false;
  }
}

if (!manifestReadable(path)) {
  throw new Error(`manifest not readable at ${path}; generate it first`);
}

function isManifestReadError(e: unknown): boolean {
  return e instanceof Error && e.message.startsWith('Failed to read prebuilt-workflows manifest at ');
}

try {
  loadPrebuiltManifest(path);
} catch (e) {
  if (e instanceof Error && e.message.startsWith('Failed to read prebuilt-workflows manifest')) {
    // regenerate or fall back to a known-good path
  }
  throw e;
}

When it happens

Trigger: The manifest path does not exist; the path points at a directory; insufficient read permissions; the file exists but contains malformed JSON (trailing comma, unquoted keys, BOM issues).

Common situations: CI checkout missing the generated manifest file; relative path resolved against an unexpected cwd; the manifest was hand-edited and broke JSON syntax; the file was gitignored and not committed.

Related errors

• Existing manifest at
• Additional Model Request Fields must be a JSON object
• Additional Model Request Fields must be valid JSON
• Additional Model Request Fields must be valid JSON
• Could not read node catalogue at

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/8b046baa41d3f290. Report an issue: GitHub.

Appendix: source

Thrown at packages/@n8n/instance-ai/evaluations/harness/prebuilt-workflows.ts:39

import { z } from 'zod';

import type { BuildResult } from './build-workflow';
import type { EvalLogger } from './logger';
import type { N8nClient } from '../clients/n8n-client';

export const prebuiltManifestSchema = z
	.record(z.string().min(1), z.array(z.string().min(1)).min(1))
	.refine((v) => Object.keys(v).length > 0, { message: 'manifest must not be empty' });

export type PrebuiltManifest = z.infer<typeof prebuiltManifestSchema>;

export function loadPrebuiltManifest(path: string): PrebuiltManifest {
	let raw: unknown;
	try {
		raw = JSON.parse(readFileSync(path, 'utf-8'));
	} catch (error) {
		const msg = error instanceof Error ? error.message : String(error);
		throw new Error(`Failed to read prebuilt-workflows manifest at ${path}: ${msg}`);
	}
	const result = prebuiltManifestSchema.safeParse(raw);
	if (!result.success) {
		throw new Error(
			`Invalid prebuilt-workflows manifest at ${path}: ${result.error.issues
				.map((i) => `${i.path.join('.')}: ${i.message}`)
				.join('; ')}`,
		);
	}
	return result.data;
}

/**
 * Look up the workflow ID for a given test-case file slug + iteration.
 *
 * Returns `undefined` in two cases — callers cannot distinguish them and
 * shouldn't need to:
 *   • the manifest argument itself is undefined (no `--prebuilt-workflows`)

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