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Rule DSL Reference

This page documents the core rule-building DSL available in konditional-core.

Rule basics​

object AppFeatures : Namespace("app") {
    val darkMode by boolean<Context>(default = false) {
        rule(true) { platforms(Platform.IOS) }
        rule(true) { locales(AppLocale.UNITED_STATES) }
    }
}

Boolean sugar​

val darkMode by boolean<Context>(default = false) {
    enable { ios() }
    disable { android() }
}

Targeting primitives​

Inside a rule block (RuleScope):

  • locales(...) targets locale ids
  • platforms(...) targets platform ids
  • versions { min(...); max(...) } targets version ranges
  • axis(...) targets custom axes
  • extension { ... } custom predicate
  • rampUp { ... } percentage rollout
  • allowlist(...) stable IDs that bypass ramp-up
  • note("...") attaches a human-readable note
  • always() / matchAll() mark a catch-all rule explicitly

Example​

val checkout by string<Context>(default = "v1") {
    rule("v2") {
        platforms(Platform.IOS)
        versions { min(3, 0, 0) }
        rampUp { 25.0 }
        note("iOS v2 rollout")
    }
}

Custom predicates​

extension { ... } receives the Context type for the feature.

data class EnterpriseContext(
    override val locale: AppLocale,
    override val platform: Platform,
    override val appVersion: Version,
    override val stableId: StableId,
    val subscriptionTier: Tier,
) : Context

val enterpriseOnly by boolean<EnterpriseContext>(default = false) {
    rule(true) { extension { subscriptionTier == Tier.ENTERPRISE } }
}

  • Guarantee: Custom predicates participate in specificity ordering.

  • Mechanism: Predicate implementations report their own specificity() which is added to the rule total.

  • Boundary: Konditional does not validate predicate correctness or determinism.

Ramp-up allowlists​

allowlist(...) bypasses the ramp-up check after the rule matches by criteria.

  • Boundary: It does not override rule criteria, isActive, or the namespace kill-switch.

Next steps​