# CustomResourceProps

Properties to provide a Lambda-backed custom resource.

Extends: CustomResourceProps
Used as props by: CustomResource

- Source: [`core/lib/custom-resource.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/core/lib/custom-resource.ts#L17)
- Type last changed: v2.174.0 · 4 Jan 2025

## Example

```ts
const stack = new Stack();
const durToken = new CfnParameter(stack, 'MyParameter', {
  type: 'Number',
  default: 60,
});
new CustomResource(stack, 'MyCustomResource', {
  serviceToken: 'MyServiceToken',
  serviceTimeout: Duration.seconds(durToken.valueAsNumber),
});
```

## Properties

- `pascalCaseProperties`: boolean = false — Convert all property keys to pascal case.

- `properties`: { [key: string]: any } — Properties to pass to the Lambda.

  **Default:** No properties.

  Values in this `properties` dictionary can possibly overwrite other values in `CustomResourceProps`
  E.g. `ServiceToken` and `ServiceTimeout`
  It is recommended to avoid using same keys that exist in `CustomResourceProps`

- `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 — For custom resources, you can specify AWS::CloudFormation::CustomResource (the default) as the resource type, or you can specify your own resource type name.

  **Default:** AWS::CloudFormation::CustomResource

  For example, you can use "Custom::MyCustomResourceTypeName".

  Custom resource type names must begin with "Custom::" and can include
  alphanumeric characters and the following characters: _@-. You can specify
  a custom resource type name up to a maximum length of 60 characters. You
  cannot change the type during an update.

  Using your own resource type names helps you quickly differentiate the
  types of custom resources in your stack. For example, if you had two custom
  resources that conduct two different ping tests, you could name their type
  as Custom::PingTester to make them easily identifiable as ping testers
  (instead of using AWS::CloudFormation::CustomResource).

- `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.

  The value must be between 1 second and 3600 seconds.

  Maps to [ServiceTimeout](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cloudformation-customresource.html#cfn-cloudformation-customresource-servicetimeout) property for the `AWS::CloudFormation::CustomResource` resource

  A token can be specified for this property, but it must be specified with `Duration.seconds()`.

  ```ts
  const stack = new Stack();
  const durToken = new CfnParameter(stack, 'MyParameter', {
    type: 'Number',
    default: 60,
  });
  new CustomResource(stack, 'MyCustomResource', {
    serviceToken: 'MyServiceToken',
    serviceTimeout: Duration.seconds(durToken.valueAsNumber),
  });
  ```

- `serviceToken`: string (required) — The ARN of the provider which implements this custom resource type.

  You can implement a provider by listening to raw AWS CloudFormation events
  and specify the ARN of an SNS topic (`topic.topicArn`) or the ARN of an AWS
  Lambda function (`lambda.functionArn`) or use the CDK's custom [resource
  provider framework] which makes it easier to implement robust providers.

  [resource provider framework]:
  https://docs.aws.amazon.com/cdk/api/latest/docs/custom-resources-readme.html

  Provider framework:

  ```ts
  // use the provider framework from aws-cdk/custom-resources:
  const provider = new customresources.Provider(this, 'ResourceProvider', {
    onEventHandler,
    isCompleteHandler, // optional
  });

  new CustomResource(this, 'MyResource', {
    serviceToken: provider.serviceToken,
  });
  ```

  AWS Lambda function (not recommended to use AWS Lambda Functions directly,
  see the module README):

  ```ts
  // invoke an AWS Lambda function when a lifecycle event occurs:
  new CustomResource(this, 'MyResource', {
    serviceToken: myFunction.functionArn,
  });
  ```

  SNS topic (not recommended to use AWS Lambda Functions directly, see the
  module README):

  ```ts
  // publish lifecycle events to an SNS topic:
  new CustomResource(this, 'MyResource', {
    serviceToken: myTopic.topicArn,
  });
  ```

  Maps to [ServiceToken](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cloudformation-customresource.html#cfn-cloudformation-customresource-servicetoken) property for the `AWS::CloudFormation::CustomResource` resource