---
title: List JSON object
description: Reference information on the JSON object used in Lists API calls.
image: https://developers.cloudflare.com/core-services-preview.png
---

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### Tags

[ JSON ](https://developers.cloudflare.com/search/?tags=JSON) 

# List JSON object

## List object structure and properties

A JSON response for the [Lists API](https://developers.cloudflare.com/api/resources/rules/subresources/lists/) has this structure:

```

{

  "id": "2c0fc9fa937b11eaa1b71c4d701ab86e",

  "name": "my_list_name",

  "description": "List description.",

  "kind": "(ip|hostname|asn|redirect)",

  "num_items": 10,

  "num_referencing_filters": 2,

  "created_on": "2021-01-01T08:00:00Z",

  "modified_on": "2021-01-10T14:00:00Z"

}


```

This table summarizes the object properties:

| Property                         | Description                                                                                              | Constraints                                                                                                                                                  |
| -------------------------------- | -------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| id String                        | A UUIDv4 identifier generated by Cloudflare.                                                             | Unique, read only.Length: 32 characters.                                                                                                                     |
| name String                      | An informative name for the list.                                                                        | Maximum length: 50 characters.Only alphanumeric and underscore (\_) characters are valid.A valid name satisfies this regular expression: ^\[a-zA-Z0-9\_\]+$. |
| description String               | An informative summary of the list.                                                                      | Maximum length: 500 characters.                                                                                                                              |
| kind String                      | The type of data in the list.                                                                            | Valid values: ip, hostname, asn, redirect.                                                                                                                   |
| num\_items Number                | The number of items in the list.                                                                         | Read only.                                                                                                                                                   |
| num\_referencing\_filters Number | The number of filters that reference this list.                                                          | Read only.                                                                                                                                                   |
| created\_on String               | The [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) timestamp the list was created.            | Read only.                                                                                                                                                   |
| modified\_on String              | The [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) 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:

```

{

  "id": "7c5dae5552338874e5053f2534d2767a",

  "ip": "10.0.0.1/32",

  "comment": "CF DNS server",

  "created_on": "2021-10-01T05:20:00.12345Z",

  "modified_on": "2021-10-01T05:20:00.12345Z"

}


```

### Hostname

A fully populated JSON object for a hostname list item has the following structure:

```

{

  "id": "7c5dae5552338874e5053f2534d2767a",

  "hostname": {

    "url_hostname": "*.example.com"

  },

  "created_on": "2021-10-11T12:39:02Z",

  "modified_on": "2021-10-11T12:39:02Z"

}


```

### ASN

A fully populated JSON object for an ASN list item has the following structure:

```

{

  "id": "7c5dae5552338874e5053f2534d2767a",

  "asn": 13335,

  "comment": "My provider's ASN",

  "created_on": "2021-10-11T12:39:02Z",

  "modified_on": "2021-10-11T12:39:02Z"

}


```

### URL redirect

A fully populated JSON object for a Bulk Redirect List item has the following structure:

```

{

  "id": "7c5dae5552338874e5053f2534d2767a",

  "redirect": {

    "source_url": "https://example.com/blog",

    "target_url": "https://example.com/blog/latest",

    "status_code": 301,

    "include_subdomains": false,

    "subpath_matching": false,

    "preserve_query_string": false,

    "preserve_path_suffix": true

  },

  "created_on": "2021-10-11T12:39:02Z",

  "modified_on": "2021-10-11T12:39:02Z"

}


```

### Properties reference

The JSON object properties for a list item are defined as follows:

| Property            | Description                                                                                                                                                                                                                              | Constraints                                                                                                                                                                                                                         |
| ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| id String           | A UUIDv4 identifier generated by Cloudflare.                                                                                                                                                                                             | Unique, read only.Length: 32 characters.                                                                                                                                                                                            |
| ip String           | 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:IPv4 addressIPv6 addressIPv4 ranges as /8 through /32 CIDRsIPv6 ranges as /12 through /128 CIDRs |
| comment String      | An informative summary of the item.                                                                                                                                                                                                      | Maximum length: 500 characters.                                                                                                                                                                                                     |
| redirect Object     | An object that contains the definition of a URL redirect. Refer to [URL redirect parameters](https://developers.cloudflare.com/rules/url-forwarding/bulk-redirects/reference/parameters/) for details.                                   | Applies only to Bulk Redirect Lists.                                                                                                                                                                                                |
| hostname Object     | An object containing a url\_hostname property with a hostname value. Refer to [Lists with hostnames](https://developers.cloudflare.com/waf/tools/lists/custom-lists/#lists-with-hostnames) for details on the supported hostname values. | Applies only to custom lists with hostnames.                                                                                                                                                                                        |
| asn Integer         | An ASN value.                                                                                                                                                                                                                            | Applies only to custom lists with ASNs.                                                                                                                                                                                             |
| created\_on String  | The [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) timestamp when the list was created.                                                                                                                                       | Read only.                                                                                                                                                                                                                          |
| modified\_on String | The [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) timestamp when the item was last modified.                                                                                                                                 | Read only.                                                                                                                                                                                                                          |

For a detailed specification, refer to the [Lists API](https://developers.cloudflare.com/api/resources/rules/subresources/lists/) documentation.

```json
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/waf/","name":"WAF"}},{"@type":"ListItem","position":3,"item":{"@id":"/waf/tools/","name":"Additional tools"}},{"@type":"ListItem","position":4,"item":{"@id":"/waf/tools/lists/","name":"Lists"}},{"@type":"ListItem","position":5,"item":{"@id":"/waf/tools/lists/lists-api/","name":"Lists API"}},{"@type":"ListItem","position":6,"item":{"@id":"/waf/tools/lists/lists-api/json-object/","name":"List JSON object"}}]}
```
