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

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# List JSON object

Last updated Aug 25, 2026|Copy as Markdown| [View as Markdown](https://d1-custom-bindings-docs.previews.developers.cloudflare.com/waf/tools/lists/lists-api/json-object/index.md)| [Agent setup](https://d1-custom-bindings-docs.previews.developers.cloudflare.com/agent-setup/)

## List object structure and properties

A JSON response for the [Lists API](https://d1-custom-bindings-docs.previews.developers.cloudflare.com/api/resources/rules/subresources/lists/) has this structure:

```json
{
	"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`<br>`String` | A UUIDv4 identifier generated by Cloudflare. | Unique, read only. Length: 32 characters. |
| `name`<br>`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`<br>`String` | An informative summary of the list. | Maximum length: 500 characters. |
| `kind`<br>`String` | The type of data in the list. | Valid values: `ip`, `hostname`, `asn`, `redirect`. |
| `num_items`<br>`Number` | The number of items in the list. | Read only. |
| `num_referencing_filters`<br>`Number` | The number of filters that reference this list. | Read only. |
| `created_on`<br>`String` | The [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) timestamp the list was created. | Read only. |
| `modified_on`<br>`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:

```json
{
	"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:

```json
{
	"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:

```json
{
	"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:

```json
{
	"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`<br>`String` | A UUIDv4 identifier generated by Cloudflare. | Unique, read only. Length: 32 characters. |
| `ip`<br>`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:<ul><li>IPv4 address</li><li>IPv6 address</li><li>IPv4 ranges as `/8` through `/32` CIDRs</li><li>IPv6 ranges as `/12` through `/128` CIDRs</li></ul> |
| `comment`<br>`String` | An informative summary of the item. | Maximum length: 500 characters. |
| `redirect`<br>`Object` | An object that contains the definition of a URL redirect. Refer to [URL redirect parameters](https://d1-custom-bindings-docs.previews.developers.cloudflare.com/rules/url-forwarding/bulk-redirects/reference/parameters/) for details. | Applies only to Bulk Redirect Lists. |
| `hostname`<br>`Object` | An object containing a `url_hostname` property with a hostname value. Refer to [Lists with hostnames](https://d1-custom-bindings-docs.previews.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`<br>`Integer` | An ASN value. | Applies only to custom lists with ASNs. |
| `created_on`<br>`String` | The [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339) timestamp when the list was created. | Read only. |
| `modified_on`<br>`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://d1-custom-bindings-docs.previews.developers.cloudflare.com/api/resources/rules/subresources/lists/) documentation.

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