Targeting

Using this feature you will be able to set different setting values for different users in your application. Let's say you would like to enable a feature only for the users within your company or only to a small percentage of your users before releasing it to the entire world.

Targeting specific users

Enable feature

1. Log in to access the *Dashboard*
2. Go to Feature Flags & Settings
3. Select TARGET SPECIFIC USERS after clicking the actions icon.

Anatomy of a Targeting Rule

By adding a rule, you specify a group of your users and what feature flag or setting value they should get. A rule consists of an Attribute of a user in your application (e.g. email address), a Comparison value (e.g. a list of email addresses), and a Comparator (e.g. IS ONE OF). ConfigCat evaluates the targeting rule every time your application requires and decides what value to serve.

Attribute

A property of your user (e.g. email address, geographic location). Your application should pass the attribute values (e.g. [email protected], Europe) to ConfigCat for comparison.

There are 3 predefined attributes. Additionally, you can define your custom attributes as well:

Attribute Name	Description
Email	The e-mail address of your user.
Identifier	Usually a unique user identifier in your application.
Country	Might come useful for testing a new feature only in one country.
Custom	Define any attribute (e.g. OS version), by typing its name to the textbox.

Comparison value

Any string, number, or comma-separated list. Will be compared to the selected Attribute using the Comparator. Max Length: 65535 chars.

Comparator

Text comparators

The following comparators assume that Attribute and Comparison value contain string/text.

In case attribute is not passed to the SDK or it's value is falsy (unknown, null, ""), targeting rule evaluation will be skipped.

caution

Consider using Sensitive text comparators if you are planning to target users by their sensitive information e.g: email address or company domain!

Comparator	Description
IS ONE OF	Checks if the Attribute is listed in the Comparison value. Comparison value should be a comma-separated list.
IS NOT ONE OF	True if the Attribute is not listed in the Comparison value.
CONTAINS	True if the Attribute contains the Comparison value.
DOES NOT CONTAIN	True if the Attribute doesn't contain the Comparison value.

Sensitive text comparators

We recommend sensitive text comparators in case of frontend applications targeting users based on sensitive data (like email addresses, names, etc). In this case, the feature flag evaluation is based on the secure hashes of the comparison values.

Comparator	Description
IS ONE OF (Sensitive)	Checks if the Attribute is listed in the Comparison value. Comparison value should be a comma-separated list.
IS NOT ONE OF (Sensitive)	True if the Attribute is not listed in the Comparison value.

Since sensitive text comparators don't support CONTAINS or DOES NOT CONTAIN comparisons, here is an example of how to target users from the same company. Which used to be handled by a rule like:

You can add a custom attribute called domain and use only sensitive comparators in the targeting rule.

On the Dashboard:

In your code:

const userDomain = userEmail.split('@').pop();
const userObject = {
    identifier: '<SOME USER ID>',
    email: userEmail,
    custom: { domain: userDomain }
}
const value = configCatClient.getValue(key, defaultValue, callback, userObject);

Sensitive comparators are supported from these SDK versions:

SDK	Version
JS	v3.0.0
Node	v4.0.0
PHP	v3.0.2
Python	v3.0.2
Ruby	v2.0.3
Go	v4.0.2
Java	v4.0.1
Android	v4.0.0
.NET	v4.0.0
Swift	v4.0.0

Semantic version comparators

The following comparators assume that Attribute and Comparison value contain semantic versions. Evaluation is based on the SemVer Semantic Version Specification.

Comparator	Description
IS ONE OF (Semver)	True if Attribute is listed in the Comparison value. Comparison value should be a comma-separated list of semantic versions.
IS NOT ONE OF (Semver)	True if the Attribute is not listed in the Comparison value.
< (Semver)	True if Attribute is a smaller version number than Comparison value.
<= (Semver)	True if Attribute is smaller than or equals Comparison value.
> (Semver)	True if Attribute is a larger version number than Comparison value.
>= (Semver)	True if Attribute is larger than or equals Comparison value.

All semantic version comparators return false if either Attribute or Comparison value is not a valid semantic version.

Number comparators

The following comparators assume that Attribute and Comparison value contain numbers.

Comparator	Description
= (Number)	True if Attribute equals Comparison value.
<​> (Number)	True if Attribute does not equal Comparison value.
< (Number)	True if Attribute is less than Comparison value.
<= (Number)	True if Attribute is less than or equals Comparison value.
> (Number)	True if Attribute is a larger than Comparison value.
>= (Number)	True if Attribute is larger than or equals Comparison value.

All number comparators return false if either Attribute or Comparison value is not a valid number.

Served value

The exact value that will be served to the users who match the targeting rule. Depending on the kind of your setting this could be:

Setting Kind	Setting Type	Description
On/Off Toggle	Boolean	true/false, usually the state of a feature flag
Text	String	any string, max. 65535 characters
Whole Number	Integer	any whole number within the range of int32
Decimal Number	Double	any decimal number within the range of double

Multiple targeting rules and ordering

Add new rule by clicking on the Actions icon.

By adding multiple targeting rules you can create more complex rule sets.

Rule sets are evaluated one by one, from top to bottom direction.

Change the order of targeting rules by drag n' drop.

Example

Enable a feature only to users within your company except for the sales team (Susan and Simon) by adding two targeting rules:

#	Attribute	Comparator	Comparison value	Served value
1	Email	CONTAINS	[email protected], [email protected]	OFF
2	Email	CONTAINS	@mycompany.com	ON

All other cases: OFF

To all other users, serve

This value will be served as a fallback if none of the above rules apply or a User Object is not passed to the ConfigCat SDK correctly within your application.

Targeting a percentage of users

With percentage-based user targeting, you can specify a randomly selected fraction of your users whom a feature will be enabled or a different value will be served.

Enable feature

1. Log in to access the *Dashboard*
2. Go to Feature Flags & Settings
3. Select TARGET % OF USERS after clicking the actions icon.

Anatomy of the percentage-based targeting

Percentage based targeting consists of % value and the Served value pairs.

% value

Any number between 0 and 100 that represents a randomly allocated fraction of your users.

Served value

The exact value that will be served to the users that fall into that fraction. Depending on the kind of your setting this could be:

Setting Kind	Setting Type	Description
On/Off Toggle	Boolean	true/false, usually the state of a feature flag
Text	String	any string, max. 65535 characters
Whole Number	Integer	any whole number within the range of Int32
Decimal Number	Double	any decimal number within the range of double

Stickiness & Consistency

The percentage-based targeting is sticky by design and consistent across all SDKs.

Percentage-based targeting is based on the identifier of the User Object passed to the SDK's getValue() methods. The SDKs are hashing the concatenated value of the User Object's identifier and the requested Feature Flag's Key. Then they assign a 0-99 number to the User for a specific Feature Flag. This number is used to evaluate a particular Feature Flag's value based on it's configured rules.
This number is fix and consistent for each User across all SDKs. The SDKs check if the assigned number is greater or less than the percentage set on the ConfigCat Dashboard.

caution

As not only the User's identifier is hashed but the User's identifier concatenated with the evaluated Feature Flag's key, we can ensure that you won't test on the same userbase for all of your Feature Flags.

info

As the evaluation happens in the SDKs, your User's sensitive information will never leave your system. The data flow is unidirectional (only from ConfigCat CDN servers to your SDKs), and ConfigCat doesn't receive or store any of the User Object's attributes passed to the SDKs.

Example

Let's say you have two users and two different Feature Flags with percentage-based targeting.

	isTwitterSharingEnabled	isFacebookSharingEnabled
Jane	hash('Jane' + 'isTwitterSharingEnabled') mod 100 -> The assigned number is 8	hash('Jane' + 'isFacebookSharingEnabled') mod 100 -> The assigned number is 64
Joe	hash('Joe' + 'isTwitterSharingEnabled') mod 100 -> The assigned number is 32	hash('Joe' + 'isFacebookSharingEnabled') mod 100 -> The assigned number is 12

1. Let's start with both Feature Flags set to 0% ON / 100% OFF.

	isTwitterSharingEnabled 0% ON / 100% OFF	isFacebookSharingEnabled 0% ON / 100% OFF
Jane	8 >= 0 -> OFF	64 >= 0 -> OFF
Joe	32 >= 0 -> OFF	12 >= 0 -> OFF

2. Let's set both Feature Flags to 10% ON / 90% OFF.

	isTwitterSharingEnabled 10% ON / 90% OFF	isFacebookSharingEnabled 10% ON / 90% OFF
Jane	8 < 10 -> ON	64 >= 10 -> OFF
Joe	32 >= 10 -> OFF	12 >= 10 -> OFF

caution

Although both Feature Flags are set to 10% ON / 90% OFF, Jane is only evaluated to ON for the isTwitterSharingEnabled Feature Flag.

3. The Twitter Sharing Feature seems alright, so let's increase the isTwitterSharingEnabled to 40% ON / 60% OFF.

	isTwitterSharingEnabled 40% ON / 60% OFF	isFacebookSharingEnabled 10% ON / 90% OFF
Jane	8 < 40 -> ON	64 >= 10 -> OFF
Joe	32 < 40 -> ON	12 >= 10 -> OFF

4. Something seems strange with the Twitter Sharing Feature, so let's rollback to the safe 10% ON / 90% OFF.

	isTwitterSharingEnabled 10% ON / 90% OFF	isFacebookSharingEnabled 10% ON / 90% OFF
Jane	8 < 10 -> ON	64 >= 10 -> OFF
Joe	32 >= 10 -> OFF	12 >= 10 -> OFF

As percentage-based targeting is sticky, the same user base is evaluated to ON like in the 2. step.

5. If everything seems alright, we can safely increase both Feature Flags to 100% ON / 0% OFF.

	isTwitterSharingEnabled 100% ON / 0% OFF	isFacebookSharingEnabled 100% ON / 0% OFF
Jane	8 < 100 -> ON	64 < 100 -> ON
Joe	32 < 100 -> ON	12 < 100 -> ON

Multiple options

On/Off Toggle

When the Setting Kind is On/Off Toggle, the number of options must be 2. One for the On and one for the Off state.

Text and Number

When the Setting Kind is Text, Whole Number, or Decimal Number the maximum number options depend on your subscription plan. You can add/remove options by clicking the Actions icon.

The sum of all % values must be equal to 100.

All other cases

This value will be served as a fallback if none of the above rules apply or a User Object was not passed to the ConfigCat SDK correctly within your application.