New array and map operation functions in Rulesets

New functions for array and map operations

Cloudflare Rulesets now include new functions that enable advanced expression logic for evaluating arrays and maps. These functions allow you to build rules that match against lists of values in request or response headers, enabling use cases like country-based blocking using custom headers.

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New functions

Function	Description
split(source, delimiter)	Splits a string into an array of strings using the specified delimiter.
join(array, delimiter)	Joins an array of strings into a single string using the specified delimiter.
has_key(map, key)	Returns true if the specified key exists in the map.
has_value(map, value)	Returns true if the specified value exists in the map.

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Example use cases

Check if a country code exists in a header list:

has_value(split(http.response.headers["x-allow-country"][0], ","), ip.src.country)

Check if a specific header key exists:

has_key(http.request.headers, "x-custom-header")

Join array values for logging or comparison:

join(http.request.headers.names, ", ")

For more information, refer to the Functions reference.