API Reference


The regular expression pattern that you want AWS WAF to search for in web requests, the location in requests that you want AWS WAF to search, and other settings. Each RegexMatchTuple object contains:

  • The part of a web request that you want AWS WAF to inspect, such as a query string or the value of the User-Agent header.

  • The identifier of the pattern (a regular expression) that you want AWS WAF to look for. For more information, see RegexPatternSet.

  • Whether to perform any conversions on the request, such as converting it to lowercase, before inspecting it for the specified string.



Specifies where in a web request to look for the RegexPatternSet.

Type: FieldToMatch object

Required: Yes


The RegexPatternSetId for a RegexPatternSet. You use RegexPatternSetId to get information about a RegexPatternSet (see GetRegexPatternSet), update a RegexPatternSet (see UpdateRegexPatternSet), insert a RegexPatternSet into a RegexMatchSet or delete one from a RegexMatchSet (see UpdateRegexMatchSet), and delete an RegexPatternSet from AWS WAF (see DeleteRegexPatternSet).

RegexPatternSetId is returned by CreateRegexPatternSet and by ListRegexPatternSets.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 128.

Required: Yes


Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass AWS WAF. If you specify a transformation, AWS WAF performs the transformation on RegexPatternSet before inspecting a request for a match.


When you're concerned that attackers are injecting an operating system commandline command and using unusual formatting to disguise some or all of the command, use this option to perform the following transformations:

  • Delete the following characters: \ " ' ^

  • Delete spaces before the following characters: / (

  • Replace the following characters with a space: , ;

  • Replace multiple spaces with one space

  • Convert uppercase letters (A-Z) to lowercase (a-z)


Use this option to replace the following characters with a space character (decimal 32):

  • \f, formfeed, decimal 12

  • \t, tab, decimal 9

  • \n, newline, decimal 10

  • \r, carriage return, decimal 13

  • \v, vertical tab, decimal 11

  • non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.


Use this option to replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs the following operations:

  • Replaces (ampersand)quot; with "

  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160

  • Replaces (ampersand)lt; with a "less than" symbol

  • Replaces (ampersand)gt; with >

  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh;, with the corresponding characters

  • Replaces characters that are represented in decimal format, (ampersand)#nnnn;, with the corresponding characters


Use this option to convert uppercase letters (A-Z) to lowercase (a-z).


Use this option to decode a URL-encoded value.


Specify NONE if you don't want to perform any text transformations.

Type: String


Required: Yes

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following:

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