> ## Documentation Index
> Fetch the complete documentation index at: https://panopticon-cli.com/llms.txt
> Use this file to discover all available pages before exploring further.

# UAT Batch Trains

> Always one tested batch of every ready feature, ready to merge in one click

# UAT Batch Trains

When agents land merge-ready features faster than you can review and merge them
one at a time, the bottleneck becomes the last-mile UAT. **UAT batch trains** fix
that: Overdeck keeps **one assembled, testable batch of every ready feature**
available at all times, so you can exercise the combined result and then land
exactly what you tested — in a single click.

<Note>
  Batch trains run only while a **Flywheel** run is active and the merge-train flag
  (`flywheel.merge_train_enabled`) is on. They are inert otherwise.
</Note>

## What you see

On the Flywheel page, the **UAT batches** card shows, newest first:

* A **ready batch** — a `uat/<codename>` branch bundling every ready feature,
  with the conflicts between them already resolved. It offers **Open UAT
  frontend** (a live dashboard serving that exact branch), a per-feature **What
  to UAT** checklist, and **Merge batch (N) to main**.
* A batch **assembling** in the background when a new feature becomes ready — the
  current batch stays fully testable until the new one is ready and supersedes it.
* **Held-out** features, with the reason, when a conflict couldn't be resolved
  automatically. Nothing blocks the batch; the held-out feature is retried in a
  later generation.

## How it works

1. **Assemble.** A 60-second reconciler builds a generation — a throwaway
   `uat/<label>-<codename>-<MMDD>` branch off `main` — merging each ready feature
   in order. When two features conflict, a timeboxed assembly agent resolves the
   conflict *inside the batch*; if it can't, that feature is held out (never the
   whole batch).
2. **Accumulate.** New ready features trigger a new, larger generation in the
   background. Generations accumulate — you can test and promote an earlier,
   smaller batch if the newest isn't what you want.
3. **Test.** Click **Open UAT frontend** to exercise the combined branch on a
   real running stack. The checklist pulls each feature's acceptance criteria,
   plus an explicit "verify the touchpoint" item wherever a conflict was resolved.
4. **Promote.** **Merge batch (N) to main** lands exactly the tree you tested —
   conflict resolutions included — in one merge. Each feature then closes out
   through the normal post-merge flow.

Merging a single feature on its own is still available as an escape hatch; doing
so simply restales the live batches and a fresh one reassembles automatically.

## Live UAT stacks

Each generation can serve a live dashboard at
`uat-<codename>.overdeck.localhost`, spun on demand from the batch's worktree.
Overdeck runs **at most two UAT stacks at once** (Docker's network pool is
limited) and tears down the oldest when you start a third; promoting or
invalidating a batch always tears its stack down.

## Honest controls

Every action names its exact effect and confirms before anything happens —
"Merge batch (3) to main" lists the three issues and states that it lands the
tree you tested. There is no opaque "Ship batch" button: a batch builds itself,
and nothing reaches `main` until you say so.

<Card title="Engineering reference" icon="book" href="https://github.com/eltmon/overdeck/blob/main/docs/UAT-BATCH-TRAINS.md">
  The full model, modules, reconciler, API, and promotion semantics live in
  `docs/UAT-BATCH-TRAINS.md`.
</Card>