# Manage time-based events with EventBridge Scheduler in AWS SAM
<a name="using-eventbridge-scheduler"></a>

The content in this topic provides details on what Amazon EventBridge Scheduler is, what support AWS SAM offers, how you can create Scheduler events, and examples you can reference when creating Scheduler events.

## What is Amazon EventBridge Scheduler?
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Use EventBridge Scheduler to schedule events in your AWS SAM templates. Amazon EventBridge Scheduler is a scheduling service that lets you create, initiate, and manage tens of millions of events and tasks across all AWS services. This service is particularly useful for time-related events. You can use it to schedule events and recurring time-based invocations. It also supports one-time events as well as rate and chron expressions with a start and end time.

To learn more about Amazon EventBridge Scheduler, see [What is Amazon EventBridge Scheduler?](https://docs.aws.amazon.com/scheduler/latest/UserGuide/what-is-scheduler.html) in the *EventBridge Scheduler User Guide*.

**Topics**
+ [What is Amazon EventBridge Scheduler?](#using-eventbridge-scheduler-intro)
+ [EventBridge Scheduler support in AWS SAM](#using-eventbridge-scheduler-sam-support)
+ [Creating EventBridge Scheduler events in AWS SAM](#using-eventbridge-scheduler-sam-create)
+ [Examples](#using-eventbridge-scheduler-examples)
+ [Learn more](#using-eventbridge-scheduler-learn)

## EventBridge Scheduler support in AWS SAM
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The AWS Serverless Application Model (AWS SAM) template specification provides a simple, short-hand syntax that you can use to schedule events with EventBridge Scheduler for AWS Lambda and AWS Step Functions.

## Creating EventBridge Scheduler events in AWS SAM
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Set the `ScheduleV2` property as the event type in your AWS SAM template to define your EventBridge Scheduler event. This property supports the `AWS::Serverless::Function` and `AWS::Serverless::StateMachine` resource types.

```
MyFunction:
  Type: AWS::Serverless::Function
  Properties:
    Events:
      CWSchedule:
        Type: ScheduleV2
        Properties:
          ScheduleExpression: 'rate(1 minute)'
          Name: TestScheduleV2Function
          Description: Test schedule event
                    
MyStateMachine:
  Type: AWS::Serverless::StateMachine
  Properties:
    Events:
      CWSchedule:
        Type: ScheduleV2
        Properties:
          ScheduleExpression: 'rate(1 minute)'
          Name: TestScheduleV2StateMachine
          Description: Test schedule event
```

EventBridge Scheduler event scheduling also supports *dead-letter queues (DLQ)* for unprocessed events. For more information on dead-letter queues, see [Configuring a dead-letter queue for EventBridge Scheduler](https://docs.aws.amazon.com/scheduler/latest/UserGuide/configuring-schedule-dlq.html) in the *EventBridge Scheduler User Guide*.

When a DLQ ARN is specified, AWS SAM configures permissions for the Scheduler schedule to send messages to the DLQ. When a DLQ ARN is not specified, AWS SAM will create the DLQ resource.

## Examples
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### Basic example of defining an EventBridge Scheduler event with AWS SAM
<a name="using-eventbridge-scheduler-examples-example1"></a>

```
Transform: AWS::Serverless-2016-10-31
Resources:
  MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: python3.8
      InlineCode: |
        def handler(event, context):
            print(event)
            return {'body': 'Hello World!', 'statusCode': 200}
      MemorySize: 128
      Events:
        Schedule:
          Type: ScheduleV2
          Properties:
            ScheduleExpression: rate(1 minute)
            Input: '{"hello": "simple"}'
 
  MySFNFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: python3.8
      InlineCode: |
        def handler(event, context):
            print(event)
            return {'body': 'Hello World!', 'statusCode': 200}
      MemorySize: 128
 
  StateMachine:
    Type: AWS::Serverless::StateMachine
    Properties:
      Type: STANDARD
      Definition:
        StartAt: MyLambdaState
        States:
          MyLambdaState:
            Type: Task
            Resource: !GetAtt MySFNFunction.Arn
            End: true
      Policies:
        - LambdaInvokePolicy:
            FunctionName: !Ref MySFNFunction
      Events:
        Schedule:
          Type: ScheduleV2
          Properties:
            ScheduleExpression: rate(1 minute)
            Input: '{"hello": "simple"}'
```

## Learn more
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To learn more about defining the `ScheduleV2` EventBridge Scheduler property, see:
+ [ScheduleV2](sam-property-function-schedulev2.md) for `AWS::Serverless::Function`.
+ [ScheduleV2](sam-property-statemachine-statemachineschedulev2.md) for `AWS::Serverless::StateMachine`.