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::Logs::Transformer AddKeyEntry
<a name="aws-properties-logs-transformer-addkeyentry"></a>

This object defines one key that will be added with the [ addKeys](https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/CloudWatch-Logs-Transformation-Processors.html#CloudWatch-Logs-Transformation-addKey) processor.

## Syntax
<a name="aws-properties-logs-transformer-addkeyentry-syntax"></a>

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

### JSON
<a name="aws-properties-logs-transformer-addkeyentry-syntax.json"></a>

```
{
  "[Key](#cfn-logs-transformer-addkeyentry-key)" : String,
  "[OverwriteIfExists](#cfn-logs-transformer-addkeyentry-overwriteifexists)" : Boolean,
  "[Value](#cfn-logs-transformer-addkeyentry-value)" : String
}
```

### YAML
<a name="aws-properties-logs-transformer-addkeyentry-syntax.yaml"></a>

```
  [Key](#cfn-logs-transformer-addkeyentry-key): String
  [OverwriteIfExists](#cfn-logs-transformer-addkeyentry-overwriteifexists): Boolean
  [Value](#cfn-logs-transformer-addkeyentry-value): String
```

## Properties
<a name="aws-properties-logs-transformer-addkeyentry-properties"></a>

`Key`  <a name="cfn-logs-transformer-addkeyentry-key"></a>
The key of the new entry to be added to the log event  
*Required*: Yes  
*Type*: String  
*Pattern*: `^.*[a-zA-Z0-9]+.*$`  
*Maximum*: `128`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`OverwriteIfExists`  <a name="cfn-logs-transformer-addkeyentry-overwriteifexists"></a>
Specifies whether to overwrite the value if the key already exists in the log event. If you omit this, the default is `false`.  
*Required*: No  
*Type*: Boolean  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Value`  <a name="cfn-logs-transformer-addkeyentry-value"></a>
The value of the new entry to be added to the log event  
*Required*: Yes  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `256`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)