---
path: /studio/hathor/world-version-branching
surface: studio
domain: hathor
auth: signed-in + studio entitlement
source: apps/oshun/web/src/app/studio/hathor/world-version-branching/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)'
---

# Studio Hathor · World Version Branching

## Purpose

Admin lane console for the real `@hathor/pre-production` multi-version timeline
branch-diff engine. Describe a set of timeline versions (each a clip set plus
duration / metadata-parity / approval-readiness metrics), pick a baseline and a
candidate branch, and read back which clips were added, removed, and kept, plus
the rounded metric deltas (added = candidate \ baseline, removed = baseline \
candidate, shared = candidate ∩ baseline). Admin-scoped and fail-closed.

## Entry points

- **Quick-action link from `/studio/hathor/pre-production-project-management`**
  (this page links out to pre-production-project-management)
- **Direct URL / bookmark** — yes; `alternates.canonical` set
- **Studio overview** — see
  [`../../studio-overview.md`](../../studio-overview.md)

## Layout regions

`page.tsx` renders inside `<ShellLayout active="studio">`:

- **Workspace** `<section data-hathor-world-version-branching-workspace>`:
  - `<h1>` (WorkspaceHeading) "Hathor World Version Branching Workspace"
  - Summary `<p data-hathor-world-version-branching-summary>`
  - The compare form lane: `data-hathor-wvb-compare-form`
- **Route Map panel** (`data-hathor-world-version-branching-route-map`): `<h2>`
  "Route Map" + 5 entries from `STUDIO_HATHOR_WORLD_VERSION_BRANCHING_ROUTE_MAP`
- **Quick-action lane**: two `Link.quickAction` anchors — Pre-Production Project
  Management, Back to Studio workspace index

## States

- [ ] **Loading** — `<p data-hathor-wvb-loading>`
- [ ] **Unauthorized** — `data-hathor-wvb-unauthorized` on 401/403 (admin Hathor
      scope required); fail-closed
- [ ] **Error** — `data-hathor-wvb-error` on non-OK GET / malformed catalog
- [ ] **Ready (form)** — `data-hathor-wvb-compare-form` once the catalog loads
- [ ] **Result** — `data-hathor-wvb-result` after a 200 compare;
      `data-hathor-wvb-parse-error` (bad version lines) and
      `data-hathor-wvb-compare-error` (non-200)

## Interactions

### Workspace body (compare form lane)

- [ ] **Versions** — `<textarea data-hathor-wvb-versions>` (aria-label "timeline
      versions"), one per line:
      `versionId | clip,clip | durationSec | parityPct | approvalPct`
- [ ] **Baseline** — `<select data-hathor-wvb-baseline>`
- [ ] **Candidate** — `<select data-hathor-wvb-candidate>`
- [ ] **Diff branches** —
      `<button data-hathor-wvb-compare-submit type="submit">` → POST
      `/v1/admin/hathor/world-version-branching/compare`
- [ ] **Result** — `data-hathor-wvb-result-branches`, `data-hathor-wvb-added`,
      `data-hathor-wvb-removed`, `data-hathor-wvb-shared`, and the deltas
      `data-hathor-wvb-duration-delta`, `data-hathor-wvb-parity-delta`,
      `data-hathor-wvb-approval-delta`

### Route Map panel

- [ ] **5 route entries** — verify match with
      `STUDIO_HATHOR_WORLD_VERSION_BRANCHING_ROUTE_MAP`

### Quick-action lane

- [ ] **"Open Hathor Pre-Production Project Management workspace"** (→
      `/studio/hathor/pre-production-project-management`)
- [ ] **"Back to Studio workspace index"** (→ `/studio`)

## Data & contracts

- **Reads**: GET `/v1/admin/hathor/world-version-branching` on mount
- **Writes**: POST `/v1/admin/hathor/world-version-branching/compare`
- **Realtime**: none
- **Caching**: client `fetch` on mount, `cache: 'no-store'`; `buildBffAuthHeaders`
- **Auth/role check**: admin-scoped fail-closed (401/403); behind the signed-in
  + studio proxy gate

## Cross-references

- Parent: [`../../studio-overview.md`](../../studio-overview.md)
- Shell:
  [`../../../shell/04-auth-session.md`](../../../shell/04-auth-session.md)
- Sibling routes:
  [`./studio-hathor-pre-production-project-management.md`](./studio-hathor-pre-production-project-management.md),
  [`./studio-hathor-entity-version-management.md`](./studio-hathor-entity-version-management.md)
- Component sources:
  - `apps/oshun/web/src/components/studio/StudioHathorWorldVersionBranchingWorkspace.tsx`
  - `apps/oshun/web/src/components/studio/StudioHathorWorldVersionBranchingRouteMap.ts`

## Open questions / known gaps

- [ ] Hathor is `unconfirmed-v1` per `WALKTHROUGH/matrix/routes.csv`. Confirm
      whether the dedicated `/studio/hathor/*` admin lane consoles ship in V1.
- [ ] The engine computes a two-branch set diff only; confirm whether N-way merge
      or conflict resolution is planned given the route's `merges/` sub-route.
- [ ] Route Map advertises `branches/`, `merges/`, `releases/`, and
      `governance/` sub-routes with no `page.tsx` yet.