remotion-dev/remotion · error · TypeError

parameter 'vpcSubnetIds' must either be 'undefined' or a com

Error message

parameter 'vpcSubnetIds' must either be 'undefined' or a comma-separated list of VPC subnet IDs string, but instead got: ${vpcSubnetIds}

What it means

Thrown by validateVpcSubnetIds() in @remotion/lambda when vpcSubnetIds is provided (not undefined) and is not a string. The argument must be a comma-separated string of AWS subnet IDs (e.g. 'subnet-0123456789abcdef0') or undefined. Same caveat as 1111: due to the guard short-circuiting on typeof !== 'string' and a forEach-return bug in isValidVpcSubnetIdList, malformed string IDs are NOT actually caught here; only non-string, non-undefined values are.

Source

Thrown at packages/lambda/src/shared/validate-vpc-subnet-ids.ts:17

const isValidVpcSubnetIdList = (vpcSubnetIds: string) => {
	const subnetIdRegex = /^subnet-[0-9a-f]{17}$/;
	vpcSubnetIds.split(',').forEach((subnetId) => {
		if (!subnetIdRegex.test(subnetId.trim())) {
			return false;
		}
	});
	return true;
};

export const validateVpcSubnetIds = (vpcSubnetIds: unknown) => {
	if (
		typeof vpcSubnetIds !== 'undefined' &&
		typeof vpcSubnetIds !== 'string' &&
		!isValidVpcSubnetIdList(vpcSubnetIds as string)
	) {
		throw new TypeError(
			`parameter 'vpcSubnetIds' must either be 'undefined' or a comma-separated list of VPC subnet IDs string, but instead got: ${vpcSubnetIds}`,
		);
	}
};

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Pass a comma-separated string: vpcSubnetIds: 'subnet-aaaa...,subnet-bbbb...'.
2. Pass undefined when not deploying into a VPC.
3. Convert arrays: subnets.join(',').

Example fix

// before
await deployFunction({ vpcSubnetIds: ['subnet-0123456789abcdef0'] });

// after
await deployFunction({ vpcSubnetIds: ['subnet-0123456789abcdef0'].join(',') });

function toVpcIds(v: unknown): string | undefined {
  if (v === undefined || v === null) return undefined;
  if (Array.isArray(v)) return v.filter(Boolean).join(',');
  return typeof v === 'string' ? v : undefined;
}

const isOptionalSubnetIdString = (v: unknown): v is string | undefined =>
  v === undefined || typeof v === 'string';

When it happens

Trigger: Passing vpcSubnetIds as an array (['subnet-...']), object, number, or null to deployFunction(). Any string value passes the validation regardless of format.

Common situations: Passing an array because AWS SDKs and Terraform represent subnets as lists; passing null meaning 'no VPC'; misreading the docs and supplying an object with {subnets: [...]} structure.

Related errors

• parameter 'vpcSecurityGroupIds' must either be 'undefined' o
• maxRetries must be a number, but is ${JSON.stringify(maxRetr
• parameter 'timeoutInSeconds' must be a number, but got a ${t
• parameter 'timeoutInSeconds' must not be NaN, but is
• parameter 'timeoutInSeconds' must be finite, but is ${timeou

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/d19680afc209694d. Report an issue: GitHub.