Segments Reference

Core Concepts

Segment

A subset of identities defined by rules that match identity traits. Each segment:

• Belongs to a single environment
• Contains one or more rules
• Can override feature states
• Can be project-wide or feature-specific

Segment Rule

A condition that determines segment membership based on identity traits:

• Evaluated in order (top to bottom)
• Can use multiple operators
• Supports various data types
• Can be combined with AND/OR logic

Data Types

Trait Types

Type	Description	Example Value
String	Text values	"user@example.com"
Boolean	True/false values	true
Integer	Whole numbers	42
Float	Decimal numbers	3.14

Type Coercion Rules

From Type	To Type	Coercion Rules
String → Boolean	"true", "True", "1" → true
String → Integer	Parsed as base-10
String → Float	Parsed as decimal

Operators

Comparison Operators

Operator	Description	Example	Data Types
=	Exact match	age = 21	All
!=	Not equal	country != US	All
>	Greater than	logins > 10	Number
>=	Greater than/equal	spent >= 100	Number
<	Less than	age < 18	Number
<=	Less than/equal	version <= 2.1	Number

String Operators

Operator	Description	Example
Contains	Substring match	email Contains @company.com
Does not contain	No substring match	plan Does not contain free
Matches regex	Regex pattern match	email Matches .*@gmail\.com
In	List membership	country In US,UK,CA

Special Operators

Operator	Description	Example
% Split	Percentage bucket	% Split = 25
Is set	Trait exists	premium_until Is set
Is not set	Trait doesn't exist	trial_ended Is not set
SemVer	Version comparison	version SemVer >= 2.1.0
Modulo	Division remainder	`user_id % 2

SDK Version Requirements

SDK	Modulo	In
Python	2.3.0	3.3.0
Java	5.1.0	7.1.0
.NET	4.2.0	5.0.0
Node.js	2.4.0	2.5.0
Ruby	3.1.0	3.2.0
PHP	3.1.0	4.1.0
Go	2.2.0	3.1.0
Rust	0.2.0	1.3.0
Elixir	1.1.0	2.0.0

System Limits

Resource	Limit
Segments per project	100
Segment overrides per environment	100
Rules per segment override	100
Segment rule value size	1000 bytes

Evaluation Precedence

1. Identity Override
2. Segment Override (first matching)
3. Environment Default

Performance Characteristics

Local Evaluation

• Sub-millisecond evaluation time
• No network requests
• Rules evaluated in-memory
• Linear scaling with rule count

Remote Evaluation

• Network latency dependent
• Cached segment results
• Server-side evaluation
• Constant time regardless of rule count