Core Concepts

This page defines the minimum vocabulary you need to read and write Konditional features.

Terms

• Namespace: A registry that owns a set of features.
• Feature: A typed configuration value with rules and a default.
• Context: Runtime inputs used for evaluation (locale, platform, appVersion, stableId).
• Rule: Criteria -> value mapping. All criteria must match for the rule to apply.
• Specificity: A numeric measure of how constrained a rule is. Higher specificity wins.
• Bucketing: Deterministic assignment of a stableId to a ramp-up bucket.

Compile-time vs runtime

Aspect	Guarantee Level	Mechanism
Property access	Compile-time	Property delegation on Namespace
Return types	Compile-time	Generic type propagation (Feature<T, C, M>)
Rule values	Compile-time	Typed DSL builders (boolean, string, enum, custom)
Non-null returns	Compile-time	Required defaults
Rule matching	Runtime	Deterministic evaluation over Context
Business logic correctness	Not guaranteed	Human responsibility

Typed values in practice

enum class Theme { LIGHT, DARK }

object AppFeatures : Namespace("app") {
  val darkMode by boolean<Context>(default = false)
  val theme by enum<Theme, Context>(default = Theme.LIGHT)
  val retries by integer<Context>(default = 3)
}

val theme: Theme = AppFeatures.theme.evaluate(ctx)

Type-safety guarantee

• Guarantee: Feature access and return types are compile-time safe for statically-defined features.

• Mechanism: Feature properties are declared with explicit type parameters and enforced by the Kotlin type system.

• Boundary: Dynamically-generated features are outside this guarantee.