# AwsCustomResourceProps

Properties for AwsCustomResource.

Note that at least onCreate, onUpdate or onDelete must be specified.

Extends: AwsCustomResourceProps
Used as props by: AwsCustomResource

- Source: [`custom-resources/lib/aws-custom-resource/aws-custom-resource.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0/packages/aws-cdk-lib/custom-resources/lib/aws-custom-resource/aws-custom-resource.ts#L294)
- Type last changed: v2.235.0 · 15 Jan 2026

## Example

```ts
const crossAccountRoleArn = 'arn:aws:iam::OTHERACCOUNT:role/CrossAccountRoleName'; // arn of role deployed in separate account

const callRegion = 'us-west-1'; // sdk call to be made in specified region (optional)

new cr.AwsCustomResource(this, 'CrossAccount', {
  onCreate: {
    assumedRoleArn: crossAccountRoleArn,
    region: callRegion, // optional
    service: 'sts',
    action: 'GetCallerIdentity',
    physicalResourceId: cr.PhysicalResourceId.of('id'),
  },
  policy: cr.AwsCustomResourcePolicy.fromStatements([iam.PolicyStatement.fromJson({
    Effect: "Allow",
    Action: "sts:AssumeRole",
    Resource: crossAccountRoleArn,
  })]),
});
```

## Properties

- `functionName`: string — A name for the singleton Lambda function implementing this custom resource.

  **Default:** AWS CloudFormation generates a unique physical ID and uses that ID for the function's name. For more information, see Name Type.

  The function name will remain the same after the first AwsCustomResource is created in a stack.

- `installLatestAwsSdk`: boolean — Whether to install the latest AWS SDK v3.

  **Default:** The value of `@aws-cdk/customresources:installLatestAwsSdkDefault`, otherwise `true`

  If not specified, this uses whatever JavaScript SDK version is the default in
  AWS Lambda at the time of execution.

  Otherwise, installs the latest version from 'npmjs.com'. The installation takes
  around 60 seconds and requires internet connectivity.

  The default can be controlled using the context key
  `@aws-cdk/customresources:installLatestAwsSdkDefault` is.

- `logGroup`: [ILogGroupRef](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_logs.ILogGroupRef.html) — The Log Group used for logging of events emitted by the custom resource's lambda function.

  **Default:** a default log group created by AWS Lambda

  Providing a user-controlled log group was rolled out to commercial regions on 2023-11-16.
  If you are deploying to another type of region, please check regional availability first.

- `logRetention`: [RetentionDays](/cdk/api/v2/docs/aws-cdk-lib.aws_logs.RetentionDays.html) = logs.RetentionDays.INFINITE — The number of days log events of the singleton Lambda function implementing this custom resource are kept in CloudWatch Logs.

  This is a legacy API and we strongly recommend you migrate to `logGroup` if you can.
  `logGroup` allows you to create a fully customizable log group and instruct the Lambda function to send logs to it.

- `memorySize`: number — The memory size for the singleton Lambda function implementing this custom resource.

  **Default:** 512 mega in case if installLatestAwsSdk is false.

- `onCreate`: [AwsSdkCall](/cdk/api/v2/docs/aws-cdk-lib.custom_resources.AwsSdkCall.html) — The AWS SDK call to make when the resource is created.

  **Default:** the call when the resource is updated

- `onDelete`: [AwsSdkCall](/cdk/api/v2/docs/aws-cdk-lib.custom_resources.AwsSdkCall.html) — The AWS SDK call to make when the resource is deleted.

  **Default:** no call

- `onUpdate`: [AwsSdkCall](/cdk/api/v2/docs/aws-cdk-lib.custom_resources.AwsSdkCall.html) — The AWS SDK call to make when the resource is updated.

  **Default:** no call

- `policy`: [AwsCustomResourcePolicy](/cdk/api/v2/docs/aws-cdk-lib.custom_resources.AwsCustomResourcePolicy.html) — The policy that will be added to the execution role of the Lambda function implementing this custom resource provider.

  **Default:** no policy added

  The custom resource also implements `iam.IGrantable`, making it possible
  to use the `grantXxx()` methods.

  As this custom resource uses a singleton Lambda function, it's important
  to note the that function's role will eventually accumulate the
  permissions/grants from all resources.

  Note that a policy must be specified if `role` is not provided, as
  by default a new role is created which requires policy changes to access
  resources.

- `removalPolicy`: [RemovalPolicy](/cdk/api/v2/docs/aws-cdk-lib.RemovalPolicy.html) = cdk.RemovalPolicy.Destroy — The policy to apply when this resource is removed from the application.

- `resourceType`: string = Custom::AWS — Cloudformation Resource type.

- `role`: [IRole](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IRole.html) — The execution role for the singleton Lambda function implementing this custom resource provider.

  **Default:** a new role is created

  This role will apply to all `AwsCustomResource`
  instances in the stack. The role must be assumable by the
  `lambda.amazonaws.com` service principal.

- `serviceTimeout`: [Duration](/cdk/api/v2/docs/aws-cdk-lib.Duration.html) = Duration.seconds(3600) — The maximum time that can elapse before a custom resource operation times out.

  You should not need to set this property. It is intended to allow quick turnaround
  even if the implementor of the custom resource forgets to include a `try/catch`.
  We have included the `try/catch`, and AWS service calls usually do not take an hour
  to complete.

  The value must be between 1 second and 3600 seconds.

- `timeout`: [Duration](/cdk/api/v2/docs/aws-cdk-lib.Duration.html) = Duration.minutes(2) — The timeout for the singleton Lambda function implementing this custom resource.

- `vpc`: [IVpc](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.IVpc.html) — The vpc to provision the lambda function in.

  **Default:** the function is not provisioned inside a vpc.

- `vpcSubnets`: [SubnetSelection](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.SubnetSelection.html) — Which subnets from the VPC to place the lambda function in.

  **Default:** the Vpc default strategy if not specified

  Only used if 'vpc' is supplied. Note: internet access for Lambdas
  requires a NAT gateway, so picking Public subnets is not allowed.