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

# AWS::GreengrassV2::ComponentVersion LambdaEventSource
<a name="aws-properties-greengrassv2-componentversion-lambdaeventsource"></a>

Contains information about an event source for an Amazon Lambda function. The event source defines the topics on which this Lambda function subscribes to receive messages that run the function.

## Syntax
<a name="aws-properties-greengrassv2-componentversion-lambdaeventsource-syntax"></a>

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

### JSON
<a name="aws-properties-greengrassv2-componentversion-lambdaeventsource-syntax.json"></a>

```
{
  "[Topic](#cfn-greengrassv2-componentversion-lambdaeventsource-topic)" : String,
  "[Type](#cfn-greengrassv2-componentversion-lambdaeventsource-type)" : String
}
```

### YAML
<a name="aws-properties-greengrassv2-componentversion-lambdaeventsource-syntax.yaml"></a>

```
  [Topic](#cfn-greengrassv2-componentversion-lambdaeventsource-topic): String
  [Type](#cfn-greengrassv2-componentversion-lambdaeventsource-type): String
```

## Properties
<a name="aws-properties-greengrassv2-componentversion-lambdaeventsource-properties"></a>

`Topic`  <a name="cfn-greengrassv2-componentversion-lambdaeventsource-topic"></a>
The topic to which to subscribe to receive event messages.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Type`  <a name="cfn-greengrassv2-componentversion-lambdaeventsource-type"></a>
The type of event source. Choose from the following options:  
+ `PUB_SUB` – Subscribe to local publish/subscribe messages. This event source type doesn't support MQTT wildcards (`+` and `#`) in the event source topic.
+ `IOT_CORE` – Subscribe to Amazon IoT Core MQTT messages. This event source type supports MQTT wildcards (`+` and `#`) in the event source topic.
*Required*: No  
*Type*: String  
*Allowed values*: `PUB_SUB | IOT_CORE`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)