Rheo documentation
Core concepts

Experiment

Channel-scoped A/B test comparing published flow variants with statistical readouts.

Purpose

An experiment splits traffic on a single channel across two or more published flow variants. Rheo assigns each end user to one arm and keeps that assignment stable across sessions, so results are comparable over time.

Experiments require Grow+ and count toward your workspace limit on concurrent experiments (draft, running, and pending-decision slots combined).

Status lifecycle

StatusMeaning
DraftConfiguring variants and weights; not serving traffic
RunningActively assigning users until the scheduled end time
Pending decisionEnd time reached; traffic continues with frozen weights until you promote a winner or extend
StoppedExperiment ended; the channel may fall back to a direct flow assignment

When an experiment runs, the channel's assignment type is experiment instead of direct.

Experiment detail page showing variant arms, traffic weights, status badge, and completion stats comparison

Statistical design

While configuring a draft, you can set baseline completion, minimum detectable effect (MDE), significance level, and statistical power so the sample size planner estimates how many starters you need per arm. After the run, the dashboard compares arms to the control (first variant) with confidence intervals, lift, and diagnostics for uneven traffic split.

Operator workflow

  1. Create an experiment on a channel with variant weights.
  2. Start the run—the SDK assigns variants as users resolve.
  3. Monitor stats on the experiment detail page and per-flow analytics.
  4. At end: promote a winner to a direct channel assignment or extend the run.