---
title: Rules · Cloudflare Zero Trust docs
description: DEX rules allow you to create and manage testing policies for
  targeted user groups within your fleet. After creating a rule, you can use it
  to define the scope of a test to specific groups such as departments (like
  finance or sales), devices, and/or users. You can apply and reuse rules on
  your desired tests.
lastUpdated: 2025-05-05T21:54:16.000Z
chatbotDeprioritize: false
source_url:
  html: https://developers.cloudflare.com/cloudflare-one/insights/dex/rules/
  md: https://developers.cloudflare.com/cloudflare-one/insights/dex/rules/index.md
---

DEX rules allow you to create and manage testing policies for targeted user groups within your [fleet](https://developers.cloudflare.com/cloudflare-one/insights/dex/tests/). After creating a rule, you can use it to define the scope of a [test](https://developers.cloudflare.com/cloudflare-one/insights/dex/tests/) to specific groups such as departments (like finance or sales), devices, and/or users. You can apply and reuse rules on your desired tests.

DEX rules are ideal for admins who want to define the scope of a test to a specific group within their fleet to allow for more precise problem detection and resolution.

## Create a rule

To create a rule:

1. In [Zero Trust](https://one.dash.cloudflare.com/), go to **DEX** > **Rules**.
2. Select **Add a rule**.
3. Give your rule a name and build your desired expressions.
4. Select **Create rule** to finalize your rule.

### Selectors

Selectors are required categories in a DEX rule expression that define a group within a fleet. The selector(s) you have defined in a rule will determine which group a test will impact.

Review the available selectors and their scope in the following list.

| Selector | Description |
| - | - |
| **User email** | For specifying [user emails](https://developers.cloudflare.com/cloudflare-one/policies/gateway/identity-selectors/#user-email). |
| **User group emails** | For specifying [group emails](https://developers.cloudflare.com/cloudflare-one/policies/gateway/identity-selectors/#user-group-email). |
| **User group IDs** | For specifying [group IDs](https://developers.cloudflare.com/cloudflare-one/policies/gateway/identity-selectors/#user-group-ids). |
| **User group names** | For specifying a [group name](https://developers.cloudflare.com/cloudflare-one/policies/gateway/identity-selectors/#user-group-names). |
| **Operating systems** | For specifying operating systems. |
| **Operating system version** | For specifying an operating system version (use Operator `in`) or versions (use Operator `is`). |
| **Managed network** | For specifying users accessing the network from the office (managed network) compared to those accessing remotely. |
| **SAML attributes** | For specifying a value from the [SAML Attribute Assertion](https://developers.cloudflare.com/cloudflare-one/policies/gateway/identity-selectors/#saml-attributes). |
| **Colos** | For specifying a Cloudflare data center location users are connected to. |

## Add a rule to a test

After you have created a rule, you can add it to a test. If you do not add a rule to a test, the test will run on your entire device fleet.

To add a rule to a test:

1. In [Zero Trust](https://one.dash.cloudflare.com/), go to **DEX** > **Tests**.
2. Choose an existing test and select **Edit**, or select **Add a test** to make a new test.
3. Under **Select DEX rules**, select the rule you would like to apply.
4. Select **Save test** for an existing rule or **Add rule** for the new test.

Note

It may take up to 10 minutes for newly updated settings to propagate to devices.

To view which tests a rule is being applied to:

1. In [Zero Trust](https://one.dash.cloudflare.com/), go to **DEX** > **Rules**.
2. Select a rule > **Edit**.
3. Select the **DEX tests** tab and review the list of tests that include your selected rule.

## Create a test using a rule

You can create a new test from the [DEX test dashboard as described above](https://developers.cloudflare.com/cloudflare-one/insights/dex/rules/#add-a-rule-to-a-test) or directly from the DEX rules dashboard.

To create a new test using a rule from DEX rules:

1. In [Zero Trust](https://one.dash.cloudflare.com/), go to **DEX** > **Rules**.
2. Select a rule > **Edit**.
3. Select the **DEX tests** tab.
4. You will be able to review all the tests that currently include this rule. To create a new test, select **Create a test using this rule**.
5. Enter all required information, making sure that the box next to your rule name is checked.
6. Select **Add test**.

## Related resources

* [DEX HTTP test](https://developers.cloudflare.com/cloudflare-one/insights/dex/tests/http/) - Assess the accessibility of a web application.
* [DEX Traceroute test](https://developers.cloudflare.com/cloudflare-one/insights/dex/tests/traceroute/) - Measure the network path of an IP packet from an end-user device to a server.
