This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::Greengrass::SubscriptionDefinitionVersion
<a name="aws-resource-greengrass-subscriptiondefinitionversion"></a>

The `AWS::Greengrass::SubscriptionDefinitionVersion` resource represents a subscription definition version for AWS IoT Greengrass. A subscription definition version contains a list of subscriptions.

**Note**  
To create a subscription definition version, you must specify the ID of the subscription definition that you want to associate with the version. For information about creating a subscription definition, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-greengrass-subscriptiondefinition.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-greengrass-subscriptiondefinition.html).  
After you create a subscription definition version that contains the subscriptions you want to deploy, you must add it to your group version. For more information, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-greengrass-group.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-greengrass-group.html).

## Syntax
<a name="aws-resource-greengrass-subscriptiondefinitionversion-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-greengrass-subscriptiondefinitionversion-syntax.json"></a>

```
{
  "Type" : "AWS::Greengrass::SubscriptionDefinitionVersion",
  "Properties" : {
      "[SubscriptionDefinitionId](#cfn-greengrass-subscriptiondefinitionversion-subscriptiondefinitionid)" : String,
      "[Subscriptions](#cfn-greengrass-subscriptiondefinitionversion-subscriptions)" : [ Subscription, ... ]
    }
}
```

### YAML
<a name="aws-resource-greengrass-subscriptiondefinitionversion-syntax.yaml"></a>

```
Type: AWS::Greengrass::SubscriptionDefinitionVersion
Properties:
  [SubscriptionDefinitionId](#cfn-greengrass-subscriptiondefinitionversion-subscriptiondefinitionid): String
  [Subscriptions](#cfn-greengrass-subscriptiondefinitionversion-subscriptions): 
    - Subscription
```

## Properties
<a name="aws-resource-greengrass-subscriptiondefinitionversion-properties"></a>

`SubscriptionDefinitionId`  <a name="cfn-greengrass-subscriptiondefinitionversion-subscriptiondefinitionid"></a>
The ID of the subscription definition associated with this version. This value is a GUID.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Subscriptions`  <a name="cfn-greengrass-subscriptiondefinitionversion-subscriptions"></a>
The subscriptions in this version.  
*Required*: Yes  
*Type*: Array of [Subscription](aws-properties-greengrass-subscriptiondefinitionversion-subscription.md)  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

## Return values
<a name="aws-resource-greengrass-subscriptiondefinitionversion-return-values"></a>

### Ref
<a name="aws-resource-greengrass-subscriptiondefinitionversion-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the Amazon Resource Name (ARN) of the subscription definition version, such as `arn:aws:greengrass:us-east-1:123456789012:/greengrass/definition/subscriptions/1234a5b6-78cd-901e-2fgh-3i45j6k178l9/versions/9876ac30-4bdb-4f9d-95af-b5fdb66be1a2`. 

For more information about using the `Ref` function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).

### Fn::GetAtt
<a name="aws-resource-greengrass-subscriptiondefinitionversion-return-values-fn--getatt"></a>

## Examples
<a name="aws-resource-greengrass-subscriptiondefinitionversion--examples"></a>



### Subscription Definition Version Snippet
<a name="aws-resource-greengrass-subscriptiondefinitionversion--examples--Subscription_Definition_Version_Snippet"></a>

The following snippet defines subscription definition and subscription definition version subscriptions. The subscription definition version references the subscription definition and contains a subscription. In this example, the subscription source is an existing device in the group. The target is a function in the group that was created in another stack and is referenced using the `ImportValue` function.

For an example of a complete template, see the [https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-subscription-greengrass-group.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-subscription-greengrass-group.html) subscription.

#### JSON
<a name="aws-resource-greengrass-subscriptiondefinitionversion--examples--Subscription_Definition_Version_Snippet--json"></a>

```
"TestSubscriptionDefinition": {
    "Type": "AWS::Greengrass::SubscriptionDefinition",
    "Properties": {
        "Name": "DemoTestSubscriptionDefinition"
    }
},
"TestSubscriptionDefinitionVersion": {
    "Type": "AWS::Greengrass::SubscriptionDefinitionVersion",
    "Properties": {
        "SubscriptionDefinitionId": {
            "Ref": "TestSubscriptionDefinition"
        },
        "Subscriptions": [
            {
                "Id": "TestSubscription1",
                "Source": {
                    "Fn::Join": [
                        ":",
                        [
                            "arn:aws:iot",
                            {
                                "Ref": "AWS::Region"
                            },
                            {
                                "Ref": "AWS::AccountId"
                            },
                            "thing/TestDevice1"
                        ]
                    ]
                },
                "Subject": "some/topic",
                "Target": {
                    "Fn::ImportValue": "TestCanaryLambdaVersionArn"
                }
            }
        ]
    }
}
```

#### YAML
<a name="aws-resource-greengrass-subscriptiondefinitionversion--examples--Subscription_Definition_Version_Snippet--yaml"></a>

```
TestSubscriptionDefinition:
  Type: 'AWS::Greengrass::SubscriptionDefinition'
  Properties:
    Name: DemoTestSubscriptionDefinition
TestSubscriptionDefinitionVersion:
  Type: 'AWS::Greengrass::SubscriptionDefinitionVersion'
  Properties:
    SubscriptionDefinitionId: !Ref TestSubscriptionDefinition
    Subscriptions:
      - Id: TestSubscription1
        Source: !Join 
          - ':'
          - - 'arn:aws:iot'
            - !Ref 'AWS::Region'
            - !Ref 'AWS::AccountId'
            - thing/TestDevice1
        Subject: some/topic
        Target: !ImportValue TestCanaryLambdaVersionArn
```

## See also
<a name="aws-resource-greengrass-subscriptiondefinitionversion--seealso"></a>
+ [CreateSubscriptionDefinitionVersion](https://docs.aws.amazon.com/greengrass/v1/apireference/createsubscriptiondefinitionversion-post.html) in the * AWS IoT Greengrass Version 1 API Reference *
+  [AWS IoT Greengrass Version 1 Developer Guide](https://docs.aws.amazon.com/greengrass/v1/developerguide/) 

# AWS::Greengrass::SubscriptionDefinitionVersion Subscription
<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription"></a>

<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription-description"></a>Subscriptions define how MQTT messages can be exchanged between devices, functions, and connectors in the group, and with AWS IoT or the local shadow service. A subscription defines a message source, message target, and a topic (or subject) that's used to route messages from the source to the target. A subscription defines the message flow in one direction, from the source to the target. For two-way communication, you must set up two subscriptions, one for each direction.

<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription-inheritance"></a> In an CloudFormation template, the `Subscriptions` property of the [https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-greengrass-subscriptiondefinitionversion.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-greengrass-subscriptiondefinitionversion.html) resource contains a list of `Subscription` property types.

## Syntax
<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription-syntax.json"></a>

```
{
  "[Id](#cfn-greengrass-subscriptiondefinitionversion-subscription-id)" : String,
  "[Source](#cfn-greengrass-subscriptiondefinitionversion-subscription-source)" : String,
  "[Subject](#cfn-greengrass-subscriptiondefinitionversion-subscription-subject)" : String,
  "[Target](#cfn-greengrass-subscriptiondefinitionversion-subscription-target)" : String
}
```

### YAML
<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription-syntax.yaml"></a>

```
  [Id](#cfn-greengrass-subscriptiondefinitionversion-subscription-id): String
  [Source](#cfn-greengrass-subscriptiondefinitionversion-subscription-source): String
  [Subject](#cfn-greengrass-subscriptiondefinitionversion-subscription-subject): String
  [Target](#cfn-greengrass-subscriptiondefinitionversion-subscription-target): String
```

## Properties
<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription-properties"></a>

`Id`  <a name="cfn-greengrass-subscriptiondefinitionversion-subscription-id"></a>
A descriptive or arbitrary ID for the subscription. This value must be unique within the subscription definition version. Maximum length is 128 characters with pattern `[a-zA-Z0-9:_-]+`.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Source`  <a name="cfn-greengrass-subscriptiondefinitionversion-subscription-source"></a>
The originator of the message. The value can be a thing ARN, the ARN of a Lambda function alias (recommended) or version, a connector ARN, `cloud` (which represents the AWS IoT cloud), or `GGShadowService`.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Subject`  <a name="cfn-greengrass-subscriptiondefinitionversion-subscription-subject"></a>
The MQTT topic used to route the message.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Target`  <a name="cfn-greengrass-subscriptiondefinitionversion-subscription-target"></a>
The destination of the message. The value can be a thing ARN, the ARN of a Lambda function alias (recommended) or version, a connector ARN, `cloud` (which represents the AWS IoT cloud), or `GGShadowService`.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

## See also
<a name="aws-properties-greengrass-subscriptiondefinitionversion-subscription--seealso"></a>
+ [Subscription](https://docs.aws.amazon.com/greengrass/v1/apireference/definitions-subscription.html) in the * AWS IoT Greengrass Version 1 API Reference *
+  [AWS IoT Greengrass Version 1 Developer Guide](https://docs.aws.amazon.com/greengrass/v1/developerguide/)