List JSON object
 List object structure and properties
A JSON response for the Lists API has this structure:
This table summarizes the object properties:
| Property | Description | Constraints | 
|---|---|---|
| idString | A UUIDv4 identifier generated by Cloudflare. | Unique, read only. Length: 32 characters. | 
| nameString | An informative name for the list. | Maximum length: 50 characters. Only alphanumeric and underscore ( A valid name satisfies this regular expression:  | 
| descriptionString | An informative summary of the list. | Maximum length: 500 characters. | 
| kindString | The type of data in the list. | Valid values: ip,hostname,asn,redirect. | 
| num_itemsNumber | The number of items in the list. | Read only. | 
| num_referencing_filtersNumber | The number of filters that reference this list. | Read only. | 
| created_onString | The RFC 3339 timestamp the list was created. | Read only. | 
| modified_onString | The RFC 3339 timestamp when the list was last modified. | Read only. | 
 List item object structure and properties
Each list type (IP address, hostname, ASN, redirects) can only contain items of the same type.
 IP address
A fully populated JSON object for an IP address list item has the following structure:
 Hostname
A fully populated JSON object for a hostname list item has the following structure:
 ASN
A fully populated JSON object for an ASN list item has the following structure:
 URL redirect
A fully populated JSON object for a Bulk Redirect List item has the following structure:
 Properties reference
The JSON object properties for a list item are defined as follows:
| Property | Description | Constraints | 
|---|---|---|
| idString | A UUIDv4 identifier generated by Cloudflare. | Unique, read only. Length: 32 characters. | 
| ipString | An IP address or CIDR range. | Applies only to custom lists with IP addresses (IP lists). Any of these formats can exist in the same custom list with IP addresses: 
 | 
| commentString | An informative summary of the item. | Maximum length: 500 characters. | 
| redirectObject | An object that contains the definition of a URL redirect. Refer to URL redirect parameters for details. | Applies only to Bulk Redirect Lists. | 
| hostnameObject | An object containing a url_hostnameproperty with a hostname value. Refer to Lists with hostnames for details on the supported hostname values. | Applies only to custom lists with hostnames. | 
| asnInteger | An ASN value. | Applies only to custom lists with ASNs. | 
| created_onString | The RFC 3339 timestamp when the list was created. | Read only. | 
| modified_onString | The RFC 3339 timestamp when the item was last modified. | Read only. | 
For a detailed specification, refer to the Lists API documentation.