Add ramp-up¶

Ramp-up is how Konditional does gradual rollout. The rule still returns a typed value, but eligibility is now gated by a deterministic bucket derived from the namespace, the feature, and a stable ID.

Add a stable ID to the context¶

Ramp-up is most useful when the context carries a stable identity. Add the StableIdContext mix-in to the context you use for rollout decisions.

import io.amichne.konditional.context.Context
import io.amichne.konditional.core.id.StableId

data class RolloutContext(
    override val stableId: StableId,
) : Context, Context.StableIdContext

Add a ramp-up rule¶

Define a boolean feature and add rampUp { ... } inside the rule.

import io.amichne.konditional.core.Namespace
import io.amichne.konditional.core.dsl.enable

object RolloutFlags : Namespace("rollout") {
    val checkoutUpsell by boolean<RolloutContext>(default = false) {
        enable {
            rampUp { 25 }
        }
    }
}

This rule means matching users are eligible for the feature only when their deterministic bucket falls inside the first 25 percent of the rollout.

Inspect the result with explain(...)¶

evaluate(...) gives you the value. explain(...) gives you the same decision plus the bucket metadata that led to it.

import io.amichne.konditional.api.explain
import io.amichne.konditional.core.id.StableId

val context = RolloutContext(stableId = StableId.of("same-user"))

val first = RolloutFlags.checkoutUpsell.explain(context)
val second = RolloutFlags.checkoutUpsell.explain(context)

check(first.value == second.value)
check(first.decision == second.decision)

The result stays stable for the same feature, same salt, and same stable ID.

Next steps¶

The next page adds the JSON boundary on top of the same namespace model.

• Load JSON safely