# CreateRegexPatternSet
<a name="API_waf_CreateRegexPatternSet"></a>

**Note**  
 Amazon WAF Classic support will end on September 30, 2025.   
This is ** Amazon WAF Classic** documentation. For more information, see [Amazon WAF Classic](https://docs.amazonaws.cn/waf/latest/developerguide/classic-waf-chapter.html) in the developer guide.  
 **For the latest version of Amazon WAF **, use the Amazon WAFV2 API and see the [Amazon WAF Developer Guide](https://docs.amazonaws.cn/waf/latest/developerguide/waf-chapter.html). With the latest version, Amazon WAF has a single set of endpoints for regional and global use. 

Creates a `RegexPatternSet`. You then use [UpdateRegexPatternSet](API_waf_UpdateRegexPatternSet.md) to specify the regular expression (regex) pattern that you want Amazon WAF to search for, such as `B[a@]dB[o0]t`. You can then configure Amazon WAF to reject those requests.

To create and configure a `RegexPatternSet`, perform the following steps:

1. Use [GetChangeToken](API_waf_GetChangeToken.md) to get the change token that you provide in the `ChangeToken` parameter of a `CreateRegexPatternSet` request.

1. Submit a `CreateRegexPatternSet` request.

1. Use `GetChangeToken` to get the change token that you provide in the `ChangeToken` parameter of an `UpdateRegexPatternSet` request.

1. Submit an [UpdateRegexPatternSet](API_waf_UpdateRegexPatternSet.md) request to specify the string that you want Amazon WAF to watch for.

For more information about how to use the Amazon WAF API to allow or block HTTP requests, see the [Amazon WAF Developer Guide](https://docs.amazonaws.cn/waf/latest/developerguide/).

## Request Syntax
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```
{
   "ChangeToken": "string",
   "Name": "string"
}
```

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

For information about the parameters that are common to all actions, see [Common Parameters](CommonParameters.md).

The request accepts the following data in JSON format.

 ** [ChangeToken](#API_waf_CreateRegexPatternSet_RequestSyntax) **   <a name="WAF-waf_CreateRegexPatternSet-request-ChangeToken"></a>
The value returned by the most recent call to [GetChangeToken](API_waf_GetChangeToken.md).  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `.*\S.*`   
Required: Yes

 ** [Name](#API_waf_CreateRegexPatternSet_RequestSyntax) **   <a name="WAF-waf_CreateRegexPatternSet-request-Name"></a>
A friendly name or description of the [RegexPatternSet](API_waf_RegexPatternSet.md). You can't change `Name` after you create a `RegexPatternSet`.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `.*\S.*`   
Required: Yes

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

```
{
   "ChangeToken": "string",
   "RegexPatternSet": { 
      "Name": "string",
      "RegexPatternSetId": "string",
      "RegexPatternStrings": [ "string" ]
   }
}
```

## Response Elements
<a name="API_waf_CreateRegexPatternSet_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.

 ** [ChangeToken](#API_waf_CreateRegexPatternSet_ResponseSyntax) **   <a name="WAF-waf_CreateRegexPatternSet-response-ChangeToken"></a>
The `ChangeToken` that you used to submit the `CreateRegexPatternSet` request. You can also use this value to query the status of the request. For more information, see [GetChangeTokenStatus](API_waf_GetChangeTokenStatus.md).  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `.*\S.*` 

 ** [RegexPatternSet](#API_waf_CreateRegexPatternSet_ResponseSyntax) **   <a name="WAF-waf_CreateRegexPatternSet-response-RegexPatternSet"></a>
A [RegexPatternSet](API_waf_RegexPatternSet.md) that contains no objects.  
Type: [RegexPatternSet](API_waf_RegexPatternSet.md) object

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

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

 ** WAFDisallowedNameException **   
The name specified is invalid.  
HTTP Status Code: 400

 ** WAFInternalErrorException **   
The operation failed because of a system problem, even though the request was valid. Retry your request.  
HTTP Status Code: 500

 ** WAFLimitsExceededException **   
The operation exceeds a resource limit, for example, the maximum number of `WebACL` objects that you can create for an Amazon Web Services account. For more information, see [Amazon WAF Classic quotas](https://docs.amazonaws.cn/waf/latest/developerguide/classic-limits.html) in the * Amazon WAF Developer Guide*.  
HTTP Status Code: 400

 ** WAFStaleDataException **   
The operation failed because you tried to create, update, or delete an object by using a change token that has already been used.  
HTTP Status Code: 400

## See Also
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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/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for .NET V4](https://docs.amazonaws.cn/goto/DotNetSDKV4/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for Go v2](https://docs.amazonaws.cn/goto/SdkForGoV2/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for JavaScript V3](https://docs.amazonaws.cn/goto/SdkForJavaScriptV3/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for Kotlin](https://docs.amazonaws.cn/goto/SdkForKotlin/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for PHP V3](https://docs.amazonaws.cn/goto/SdkForPHPV3/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for Python](https://docs.amazonaws.cn/goto/boto3/waf-2015-08-24/CreateRegexPatternSet) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/waf-2015-08-24/CreateRegexPatternSet)