A/B experiments

getExperiment buckets the bound user into an A/B experiment and returns the variant assignment plus its parameters.

Reading an experiment

import ai.shipeasy.Client;
import ai.shipeasy.ExperimentResult;
import java.util.Map;

Client c = new Client(Map.of("user_id", "u_123"));

// The second argument is the default params used when the user is NOT enrolled.
ExperimentResult r = c.getExperiment("checkout_button", Map.of("color", "blue"));

The ExperimentResult shape

ExperimentResult exposes three public fields — read them directly, there are no getter methods:

public final class ExperimentResult {
    public final boolean inExperiment; // is the user enrolled?
    public final String  group;        // assigned variant (e.g. "control" / "treatment")
    public final Object  params;       // variant params (Map), or the defaults if not enrolled
}

if (r.inExperiment) {
    @SuppressWarnings("unchecked")
    Map<String, Object> params = (Map<String, Object>) r.params;
    String color = (String) params.get("color");
    // render the assigned variant
}

A user who is not enrolled returns r.inExperiment == false, r.group == "control", and r.params set to the defaultParams you passed.

Tracking conversions with track(...)

Conversion events are recorded with track, right on the bound Client — the same handle you already have for getExperiment. The unit id is derived from the bound attributes (user_id, else anonymous_id), so there is no user argument. Fire your success event — {{SUCCESS_EVENT}} — after the user converts:

Client c = new Client(Map.of("user_id", "u_123"));

ExperimentResult r = c.getExperiment("checkout_button", Map.of("color", "blue"));
// ... render the variant ...

c.track("{{SUCCESS_EVENT}}", Map.of("amount", 49));  // no-props overload: c.track("{{SUCCESS_EVENT}}")

track is fire-and-forget (POSTed to /collect off the calling thread) and is a no-op in test / snapshot mode. The analysis pipeline joins these events to experiment exposures to compute lift and significance. See Metrics for the full track contract.

Exposure logging

The server is stateless and never auto-logs exposure. When you actually present the treatment, call c.logExposure("checkout_button") on the bound Client — it re-evaluates with the bound attributes (so targeting gates and bucketBy resolve correctly) and emits exactly one exposure for an enrolled user:

c.logExposure("checkout_button");

See Advanced → Manual exposure logging.