Rules and Segmentation

Prefab provides powerful rules that can you can compose to target exactly the users you're interested in.

Segments are reusable sets of rules that you can use across multiple feature flags.

tip

Rules are evaluated in order. You can drag and drop rules to rearrange them. The first matching rule determines which variant is served.

When a rule matches, you can either:

• Return a specific variant (e.g. true, false, or yellow)
• Return a variant based on a percentage (e.g. true 10% of the time and false 90% of the time)

Note that the variant determined by percentage rollouts is "sticky" to the provided lookup key and won't change unless the lookup key changes or the percentage values change.

Available Rules

Name	Function	Example usage
Always True	Always matches	An Always True rule that serves true means a feature is always enabled.   Always True serving false 50% of the time and true 50% of the time works like a coin flip.
Lookup Key In	Use Lookup Key In to target specific users.   Matches when the lookup key for the user/visitor is in specified comma-separated list	Lookup Key In with Criteria Values of user-1234,user-5678 will match when the lookup key is user-1234 or user-5678 but not for other lookup keys.
Lookup Key Not In	Use Lookup Key Not In to exclude specific users.   Matches when the lookup key for the user/visitor is not in specified comma-separated list	Lookup Key Not In with Criteria Values of user-1234,user-5678 will match any lookup key except user-1234 or user-5678.
In Segment	Segments are reusable sets of rules. In Segment matches if any of the segment's rules match.	If you've built a segment for "beta users", you can choose "beta users" for your Criteria Values and the "beta users" ruleset will determine which variant is shown.
Not In Segment	Segments are reusable sets of rules. Not In Segment matches if none of the segment's rules match.	If you've built a segment for "freebie users", you can choose "freebie users" for your Criteria Values and Not In Segment will match non-freebie users.
Property Is One Of	Use Property Is One Of to target users with specific attributes.	If you set Criteria Property to subscription and Criteria Values to pro,advanced then it will match users with a pro or advanced subscription.
Property Is Not One Of	Use Property Is Not One Of to target users who do not match a specific attribute.	If you set Criteria Property to subscription and Criteria Values to pro,advanced then it will match users who have neither a pro nor an advanced subscription.
Property Ends With One Of	Use Property Ends With One Of to target users with an attribute that ends with a value.	If you set Criteria Property to email and Criteria Values to @example.com then it will match users who have an email ending with @example.com
Property Does Not End With One Of	Use Property Does Not End With One Of to target users with an attribute that does not end with a value.	If you set Criteria Property to email and Criteria Values to @gmail.com,@yahoo.com then it will match users who have an email that does not end with @gmail.com or @yahoo.com.