How to use [validators.regex]

The reference page of validators.regex has its arguments, constraints and declaration.

This validator requires a [regex] argument, that is a regular expression that must match the argument specified. Usage can be found below.

.arguments
   foo:howdy world
validators.regex:x:@.arguments/*/foo
   regex:howdy

If you remove the “howdy” parts of your above argument, an exception will be thrown.