# StartSchemaExtension
<a name="API_StartSchemaExtension"></a>

Applies a schema extension to a Microsoft AD directory.

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

```
{
   "CreateSnapshotBeforeSchemaExtension": boolean,
   "Description": "string",
   "DirectoryId": "string",
   "LdifContent": "string"
}
```

## Request Parameters
<a name="API_StartSchemaExtension_RequestParameters"></a>

The request accepts the following data in JSON format.

 ** [CreateSnapshotBeforeSchemaExtension](#API_StartSchemaExtension_RequestSyntax) **   <a name="DirectoryService-StartSchemaExtension-request-CreateSnapshotBeforeSchemaExtension"></a>
If true, creates a snapshot of the directory before applying the schema extension.  
Type: Boolean  
Required: Yes

 ** [Description](#API_StartSchemaExtension_RequestSyntax) **   <a name="DirectoryService-StartSchemaExtension-request-Description"></a>
A description of the schema extension.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 128.  
Pattern: `^([a-zA-Z0-9_])[\\a-zA-Z0-9_@#%*+=:?./!\s-]*$`   
Required: Yes

 ** [DirectoryId](#API_StartSchemaExtension_RequestSyntax) **   <a name="DirectoryService-StartSchemaExtension-request-DirectoryId"></a>
The identifier of the directory for which the schema extension will be applied to.  
Type: String  
Pattern: `^d-[0-9a-f]{10}$`   
Required: Yes

 ** [LdifContent](#API_StartSchemaExtension_RequestSyntax) **   <a name="DirectoryService-StartSchemaExtension-request-LdifContent"></a>
The LDIF file represented as a string. To construct the LdifContent string, precede each line as it would be formatted in an ldif file with \$1n. See the example request below for more details. The file size can be no larger than 1MB.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 500000.  
Required: Yes

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

```
{
   "SchemaExtensionId": "string"
}
```

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

If the action is successful, the service sends back an HTTP 200 response.

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

 ** [SchemaExtensionId](#API_StartSchemaExtension_ResponseSyntax) **   <a name="DirectoryService-StartSchemaExtension-response-SchemaExtensionId"></a>
The identifier of the schema extension that will be applied.  
Type: String  
Pattern: `^e-[0-9a-f]{10}$` 

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

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

 ** ClientException **   
A client exception has occurred.    
 ** Message **   
The descriptive message for the exception.  
 ** RequestId **   
The Amazon request identifier.
HTTP Status Code: 400

 ** DirectoryUnavailableException **   
The specified directory is unavailable.    
 ** Message **   
The descriptive message for the exception.  
 ** RequestId **   
The Amazon request identifier.
HTTP Status Code: 400

 ** EntityDoesNotExistException **   
The specified entity could not be found.    
 ** Message **   
The descriptive message for the exception.  
 ** RequestId **   
The Amazon request identifier.
HTTP Status Code: 400

 ** InvalidParameterException **   
One or more parameters are not valid.    
 ** Message **   
The descriptive message for the exception.  
 ** RequestId **   
The Amazon request identifier.
HTTP Status Code: 400

 ** ServiceException **   
An exception has occurred in Amazon Directory Service.    
 ** Message **   
The descriptive message for the exception.  
 ** RequestId **   
The Amazon request identifier.
HTTP Status Code: 500

 ** SnapshotLimitExceededException **   
The maximum number of manual snapshots for the directory has been reached. You can use the [GetSnapshotLimits](API_GetSnapshotLimits.md) operation to determine the snapshot limits for a directory.    
 ** Message **   
The descriptive message for the exception.  
 ** RequestId **   
The Amazon request identifier.
HTTP Status Code: 400

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

The following examples are formatted for legibility.

### Example Request
<a name="API_StartSchemaExtension_Example_1"></a>

This example illustrates one usage of StartSchemaExtension.

```
POST / HTTP/1.1
Host: ds.us-west-2.amazonaws.com
Accept-Encoding: identity
Content-Length: 320
X-Amz-Target: DirectoryService_20150416.StartSchemaExtension
X-Amz-Date: 20161219T190703Z
User-Agent: aws-cli/1.11.24 Python/2.7.9 Windows/7 botocore/1.4.81
Content-Type: application/x-amz-json-1.1
Authorization: AWS4-HMAC-SHA256 
 Credential=AKIAI7E3BYXS3example/20161219/us-west-2/ds/aws4_request, 
 SignedHeaders=content-type;host;x-amz-date;x-amz-target, 
 Signature=5c1200f494c1771770d7aa964e45ee36d80e724e0d9a8e62ab9822574c8cc915

 {
   "CreateSnapshotBeforeSchemaExtension":true,
   "DirectoryId":"d-926example",
   "LdifContent":"dn: CN=User,CN=Schema,CN=Configuration,DC=sales,DC=example,DC=com\nchangetype: modify\nadd: mayContain\nmayContain: drink\n-\n\nDN:\nchangetype: modify\nreplace: schemaupdatenow\nschemaupdatenow: 1\n-",
   "Description":"Adds may contain attribute to user class. To construct the LdifContent string, precede each line as it would be formatted in an ldif file with \n. For example the LdifContent string above is formatted the following way in an Ldif file:

     dn: CN=User,CN=Schema,CN=Configuration,DC=sales,DC=example,DC=com
     changetype: modify
     add: mayContain
     mayContain: drink
     -

     dn:
     changetype: modify
     replace: schemaupdatenow
     schemaupdatenow: 1
     -"
 }
```

### Example Response
<a name="API_StartSchemaExtension_Example_2"></a>

This example illustrates one usage of StartSchemaExtension.

```
HTTP/1.1 200 OK
x-amzn-RequestId: 54723d00-c61e-11e6-a96d-2b0686697d23
Content-Type: application/x-amz-json-1.1
Content-Length: 36
Date: Mon, 19 Dec 2016 19:07:04 GMT

{
  "SchemaExtensionId": "e-926731dc50"
}
```

## See Also
<a name="API_StartSchemaExtension_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/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for .NET V4](https://docs.amazonaws.cn/goto/DotNetSDKV4/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for Go v2](https://docs.amazonaws.cn/goto/SdkForGoV2/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for JavaScript V3](https://docs.amazonaws.cn/goto/SdkForJavaScriptV3/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for Kotlin](https://docs.amazonaws.cn/goto/SdkForKotlin/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for PHP V3](https://docs.amazonaws.cn/goto/SdkForPHPV3/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for Python](https://docs.amazonaws.cn/goto/boto3/ds-2015-04-16/StartSchemaExtension) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/ds-2015-04-16/StartSchemaExtension)