---
path: /studio/isis/model-comparison
surface: studio
domain: isis
auth:
  signed-in + studio entitlement (AAA-gated — `model-comparison` is in
  `AAA_ONLY_STUDIO_ROUTES`)
source: apps/oshun/web/src/app/studio/isis/model-comparison/page.tsx
status: walked
last_walked:
  '2026-05-29 automated runtime walk (Playwright headless) — render, /v1 data
  (2xx), console/page-errors, expected content, screenshot verified; live
  screen-reader, touch, offline, and telemetry-delivery checks pending a manual
  AT pass. Evidence: WALKTHROUGH/results/runtime-sweep-2026-05-29.md; body
  re-derived 2026-06-03 from current source (lane-console architecture)'
---

# Isis Model Comparison

## Purpose

Admin lane console for §24.10 A/B output comparison. It loads the output gallery,
lets an operator select two or more outputs of the same kind, and builds a
2-up / 4-up / n-up compare grid with per-pair diff metrics (pixel / frame /
audio / waveform / mesh delta). Cross-kind comparisons (e.g. image vs. audio)
are rejected.

## Entry points

- Sibling quick-action card from `/studio/isis/model-merging`
- Studio index (`/studio`)
- Direct URL / bookmark

## Layout regions

`page.tsx` mounts `ShellLayout active="studio"` and three panels (no breadcrumb
panel).

- **Workspace panel** (`data-isis-model-comparison-workspace`):
  - `<h1>` "Isis Model Comparison Workspace" (`WorkspaceHeading`)
  - Summary paragraph (`data-isis-model-comparison-summary`)
  - Layout + build controls (`data-compare-layout` select,
    `data-compare-build` button, `data-compare-result` /
    `data-compare-status`)
  - Output list (`data-compare-records`, `<h2>`) of selectable
    `data-compare-record` rows
- **Route map panel** (`data-isis-model-comparison-route-map`): `<h2>` "Route
  Map" enumerating `STUDIO_ISIS_MODEL_COMPARISON_ROUTE_MAP`
- **Quick-actions panel**: `quickAction` links to `/studio/isis/model-merging`
  and "Back to Studio workspace index" → `/studio`

## States

- [ ] **Loading** — `data-compare-loading` "Loading outputs…"
- [ ] **Unauthorized** — `data-compare-unauthorized` (admin-scope fail-closed on
      401/403)
- [ ] **Error** — `data-compare-error` on non-OK / malformed response
- [ ] **Ready** — layout/build controls + selectable output list render
- [ ] **Result** — `data-compare-result` with `data-compare-status` (`ok` /
      `error`); build disabled until ≥2 selected

## Interactions

### Build a compare grid

- [ ] **Layout** — `data-compare-layout` select (`2-up` / `4-up` / `n-up`);
      persisted via workspace persistence
- [ ] **Output selection** — `data-compare-record={outputId}` selectable rows
      (≥2 of the same kind required)
- [ ] **Build compare grid** — `data-compare-build` button; POSTs to
      `/v1/admin/isis/model-comparison/grid`

### Route map

- [ ] **Route-map articles** — non-interactive path + purpose entries

### Quick-actions

- [ ] **Open Isis Model Merging workspace** → `/studio/isis/model-merging`
- [ ] **Back to Studio workspace index** → `/studio`

## Data & contracts

- **Reads**: `GET /v1/admin/isis/output-gallery` (`GALLERY_ENDPOINT`) on mount —
  comparable outputs
- **Writes**: `POST /v1/admin/isis/model-comparison/grid` (`COMPARE_ENDPOINT`)
  — build a diff grid
- **Realtime**: None
- **Caching**: client `fetch` on mount, `cache: 'no-store'`,
  `buildBffAuthHeaders()`; layout preference persisted locally
- **Auth**: admin-scoped fail-closed (401/403 → unauthorized state); AAA-gated
  studio route behind the signed-in + studio proxy gate
- **Component sources**:
  - `apps/oshun/web/src/components/studio/StudioIsisModelComparisonWorkspace.tsx`
  - `apps/oshun/web/src/components/studio/StudioIsisModelComparisonRouteMap.ts`

## Cross-references

- Studio overview: [`../../studio-overview.md`](../../studio-overview.md)
- Sibling routes:
  - [`studio-isis-model-merging.md`](./studio-isis-model-merging.md)
  - [`studio-isis-output-registry.md`](./studio-isis-output-registry.md)
  - [`studio-isis-model-quality-assessment.md`](./studio-isis-model-quality-assessment.md)

## Open questions / known gaps

- [ ] Diff metrics are computed server-side over the output gallery — confirm
      how large galleries paginate into the selectable list
- [ ] Cross-kind selection is rejected on build; the UI does not pre-disable
      mismatched picks