# CreateExtension
<a name="API_CreateExtension"></a>

Creates an Amazon AppConfig extension. An extension augments your ability to inject logic or behavior at different points during the Amazon AppConfig workflow of creating or deploying a configuration.

You can create your own extensions or use the Amazon authored extensions provided by Amazon AppConfig. For an Amazon AppConfig extension that uses Amazon Lambda, you must create a Lambda function to perform any computation and processing defined in the extension. If you plan to create custom versions of the Amazon authored notification extensions, you only need to specify an Amazon Resource Name (ARN) in the `Uri` field for the new extension version.
+ For a custom EventBridge notification extension, enter the ARN of the EventBridge default events in the `Uri` field.
+ For a custom Amazon SNS notification extension, enter the ARN of an Amazon SNS topic in the `Uri` field.
+ For a custom Amazon SQS notification extension, enter the ARN of an Amazon SQS message queue in the `Uri` field. 

For more information about extensions, see [Extending workflows](https://docs.amazonaws.cn/appconfig/latest/userguide/working-with-appconfig-extensions.html) in the * Amazon AppConfig User Guide*.

## Request Syntax
<a name="API_CreateExtension_RequestSyntax"></a>

```
POST /extensions HTTP/1.1
Latest-Version-Number: LatestVersionNumber
Content-type: application/json

{
   "Actions": { 
      "string" : [ 
         { 
            "Description": "string",
            "Name": "string",
            "RoleArn": "string",
            "Uri": "string"
         }
      ]
   },
   "Description": "string",
   "Name": "string",
   "Parameters": { 
      "string" : { 
         "Description": "string",
         "Dynamic": boolean,
         "Required": boolean
      }
   },
   "Tags": { 
      "string" : "string" 
   }
}
```

## URI Request Parameters
<a name="API_CreateExtension_RequestParameters"></a>

The request uses the following URI parameters.

 ** [LatestVersionNumber](#API_CreateExtension_RequestSyntax) **   <a name="appconfig-CreateExtension-request-LatestVersionNumber"></a>
You can omit this field when you create an extension. When you create a new version, specify the most recent current version number. For example, you create version 3, enter 2 for this field.

## Request Body
<a name="API_CreateExtension_RequestBody"></a>

The request accepts the following data in JSON format.

 ** [Actions](#API_CreateExtension_RequestSyntax) **   <a name="appconfig-CreateExtension-request-Actions"></a>
The actions defined in the extension.  
Type: String to array of [Action](API_Action.md) objects map  
Map Entries: Maximum number of 5 items.  
Valid Keys: `PRE_CREATE_HOSTED_CONFIGURATION_VERSION | PRE_START_DEPLOYMENT | AT_DEPLOYMENT_TICK | ON_DEPLOYMENT_START | ON_DEPLOYMENT_STEP | ON_DEPLOYMENT_BAKING | ON_DEPLOYMENT_COMPLETE | ON_DEPLOYMENT_ROLLED_BACK`   
Array Members: Fixed number of 1 item.  
Required: Yes

 ** [Description](#API_CreateExtension_RequestSyntax) **   <a name="appconfig-CreateExtension-request-Description"></a>
Information about the extension.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 1024.  
Required: No

 ** [Name](#API_CreateExtension_RequestSyntax) **   <a name="appconfig-CreateExtension-request-Name"></a>
A name for the extension. Each extension name in your account must be unique. Extension versions use the same name.  
Type: String  
Pattern: `^[^\/#:\n]{1,64}$`   
Required: Yes

 ** [Parameters](#API_CreateExtension_RequestSyntax) **   <a name="appconfig-CreateExtension-request-Parameters"></a>
The parameters accepted by the extension. You specify parameter values when you associate the extension to an Amazon AppConfig resource by using the `CreateExtensionAssociation` API action. For Amazon Lambda extension actions, these parameters are included in the Lambda request object.  
Type: String to [Parameter](API_Parameter.md) object map  
Map Entries: Maximum number of 10 items.  
Key Pattern: `^[^\/#:\n]{1,64}$`   
Required: No

 ** [Tags](#API_CreateExtension_RequestSyntax) **   <a name="appconfig-CreateExtension-request-Tags"></a>
Adds one or more tags for the specified extension. Tags are metadata that help you categorize resources in different ways, for example, by purpose, owner, or environment. Each tag consists of a key and an optional value, both of which you define.   
Type: String to string map  
Map Entries: Minimum number of 0 items. Maximum number of 50 items.  
Key Length Constraints: Minimum length of 1. Maximum length of 128.  
Value Length Constraints: Maximum length of 256.  
Required: No

## Response Syntax
<a name="API_CreateExtension_ResponseSyntax"></a>

```
HTTP/1.1 201
Content-type: application/json

{
   "Actions": { 
      "string" : [ 
         { 
            "Description": "string",
            "Name": "string",
            "RoleArn": "string",
            "Uri": "string"
         }
      ]
   },
   "Arn": "string",
   "Description": "string",
   "Id": "string",
   "Name": "string",
   "Parameters": { 
      "string" : { 
         "Description": "string",
         "Dynamic": boolean,
         "Required": boolean
      }
   },
   "VersionNumber": number
}
```

## Response Elements
<a name="API_CreateExtension_ResponseElements"></a>

If the action is successful, the service sends back an HTTP 201 response.

The following data is returned in JSON format by the service.

 ** [Actions](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-Actions"></a>
The actions defined in the extension.  
Type: String to array of [Action](API_Action.md) objects map  
Map Entries: Maximum number of 5 items.  
Valid Keys: `PRE_CREATE_HOSTED_CONFIGURATION_VERSION | PRE_START_DEPLOYMENT | AT_DEPLOYMENT_TICK | ON_DEPLOYMENT_START | ON_DEPLOYMENT_STEP | ON_DEPLOYMENT_BAKING | ON_DEPLOYMENT_COMPLETE | ON_DEPLOYMENT_ROLLED_BACK`   
Array Members: Fixed number of 1 item.

 ** [Arn](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-Arn"></a>
The system-generated Amazon Resource Name (ARN) for the extension.  
Type: String  
Length Constraints: Minimum length of 20. Maximum length of 2048.  
Pattern: `arn:(aws[a-zA-Z-]*)?:[a-z]+:((eusc-)?[a-z]{2}((-gov)|(-iso([a-z]?)))?-[a-z]+-\d{1})?:(\d{12})?:[a-zA-Z0-9-_/:.]+` 

 ** [Description](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-Description"></a>
Information about the extension.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 1024.

 ** [Id](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-Id"></a>
The system-generated ID of the extension.  
Type: String  
Pattern: `[a-z0-9]{4,7}` 

 ** [Name](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-Name"></a>
The extension name.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 64.

 ** [Parameters](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-Parameters"></a>
The parameters accepted by the extension. You specify parameter values when you associate the extension to an Amazon AppConfig resource by using the `CreateExtensionAssociation` API action. For Amazon Lambda extension actions, these parameters are included in the Lambda request object.  
Type: String to [Parameter](API_Parameter.md) object map  
Map Entries: Maximum number of 10 items.  
Key Pattern: `^[^\/#:\n]{1,64}$` 

 ** [VersionNumber](#API_CreateExtension_ResponseSyntax) **   <a name="appconfig-CreateExtension-response-VersionNumber"></a>
The extension version number.  
Type: Integer

## Errors
<a name="API_CreateExtension_Errors"></a>

For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).

 ** BadRequestException **   
The input fails to satisfy the constraints specified by an Amazon service.    
 ** Details **   
Detailed information about the input that failed to satisfy the constraints specified by a call.
HTTP Status Code: 400

 ** ConflictException **   
The request could not be processed because of conflict in the current state of the resource.  
HTTP Status Code: 409

 ** InternalServerException **   
There was an internal failure in the Amazon AppConfig service.  
HTTP Status Code: 500

 ** ServiceQuotaExceededException **   
The number of one more Amazon AppConfig resources exceeds the maximum allowed. Verify that your environment doesn't exceed the following service quotas:  
Applications: 100 max  
Deployment strategies: 20 max  
Configuration profiles: 100 max per application  
Environments: 20 max per application  
To resolve this issue, you can delete one or more resources and try again. Or, you can request a quota increase. For more information about quotas and to request an increase, see [Service quotas for Amazon AppConfig](https://docs.amazonaws.cn/general/latest/gr/appconfig.html#limits_appconfig) in the Amazon Web Services General Reference.  
HTTP Status Code: 402

## Examples
<a name="API_CreateExtension_Examples"></a>

### Example
<a name="API_CreateExtension_Example_1"></a>

This example illustrates one usage of CreateExtension.

#### Sample Request
<a name="API_CreateExtension_Example_1_Request"></a>

```
POST /extensions HTTP/1.1
Host: appconfig.us-west-2.amazonaws.com
Accept-Encoding: identity
Content-Type: application/json
User-Agent: aws-cli/2.7.19 Python/3.9.11 Windows/10 exe/AMD64 prompt/off command/appconfig.create-extension
X-Amz-Date: 20220803T202954Z
Authorization: AWS4-HMAC-SHA256 Credential=AKIAIOSFODNN7EXAMPLE/20220803/us-west-2/appconfig/aws4_request, SignedHeaders=content-type;host;x-amz-date, Signature=39c3b3042cd2aEXAMPLE
Content-Length: 304

{
	"Name": "my-test-extension",
	"Actions": {
		"PRE_CREATE_HOSTED_CONFIGURATION_VERSION": [{
			"Name": "S3backup",
			"Uri": "arn:aws:lambda:us-west-2:111122223333:function:mytestfunction",
			"RoleArn": "arn:aws:iam::111122223333:role/mytestextensionrole"
		}]
	},
	"Parameters": {
		"MyParamKey": {
			"Required": true
		}
	}
}
```

#### Sample Response
<a name="API_CreateExtension_Example_1_Response"></a>

```
{
	"Actions": {
		"PRE_CREATE_HOSTED_CONFIGURATION_VERSION": [{
			"Description": null,
			"Name": "S3backup",
			"RoleArn": "arn:aws:iam::111122223333:role/mytestextensionrole",
			"Uri": "arn:aws:lambda:us-west-2:111122223333:function:mytestfunction"
		}]
	}
```

## See Also
<a name="API_CreateExtension_SeeAlso"></a>

For more information about using this API in one of the language-specific Amazon SDKs, see the following:
+  [Amazon Command Line Interface V2](https://docs.amazonaws.cn/goto/cli2/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for .NET V4](https://docs.amazonaws.cn/goto/DotNetSDKV4/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for Go v2](https://docs.amazonaws.cn/goto/SdkForGoV2/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for JavaScript V3](https://docs.amazonaws.cn/goto/SdkForJavaScriptV3/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for Kotlin](https://docs.amazonaws.cn/goto/SdkForKotlin/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for PHP V3](https://docs.amazonaws.cn/goto/SdkForPHPV3/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for Python](https://docs.amazonaws.cn/goto/boto3/appconfig-2019-10-09/CreateExtension) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/appconfig-2019-10-09/CreateExtension)