---
path: /studio/typography
surface: studio
domain: design
auth: signed-in + studio entitlement
source: apps/oshun/web/src/app/studio/typography/page.tsx
status: walked + e2e-covered
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);
  2026-07-02 studio-design-lane-consoles Playwright pass covers live BFF
  catalog/generate, auth/schema gates, error states, quick actions, and mobile
  no-overflow.'
---

# Studio · Typography

## Purpose

Generate a modular type scale with the real generator: the Type Scale Lane
computes `font size = base × ratio^step` and snaps each line height up to the
baseline grid for vertical rhythm. It is a live admin console wired to
`/v1/admin/studio/type-scale`, not an in-page simulation.

## Entry points

- **Direct URL / bookmark** — `/studio/typography` (signed-in + studio
  entitlement; admin scope required to generate)
- **Sibling Studio routes** — reached via the quick-action panel on
  color-system, spacing-layout, design-language, and other design/governance
  pages

## Layout regions

`page.tsx` mounts `<ShellLayout active="studio">` and renders
`<StudioTypographyWorkspace />` followed by a single `panel` of quick-action
links.

- **Shell**: `ShellLayout` chrome with the Studio tab active
- **Workspace heading**: `WorkspaceHeading` renders the page `<h1>` "Studio
  Typography", followed by the `data-typography-summary` paragraph
- **Type Scale Lane**: an `<h2>` `data-ts-lane-heading` ("Type Scale Lane")
  section with the load states and, when ready, the generate form and result
  table
- **Quick-actions panel**: 17 sibling `quickAction` `Link`s — Color System,
  Spacing/Layout, Component Primitives, Complex Interactions, Search/Discovery,
  Cross-Domain Entity Model, Workspace Context Switching, Multi-Project
  Operations, Authentication Architecture, Session and Device Management, RBAC
  and Permission Policy UX, Enterprise Tenant Isolation, Audit and Compliance
  Surfaces, Notification Center, Activity and Change Feeds, "Back to Design
  Language workspace", and "Back to Studio IA workspace" (`/studio`). No
  self-link and no Route Map panel.

## States

- [x] **Loading** — `data-ts-loading` ("Loading type-scale generator…")
- [x] **Unauthorized** — `data-ts-unauthorized` ("Access restricted.") on
      401/403
- [x] **Error** — `data-ts-error` ("Could not load the type-scale generator.")
- [x] **Ready / form** — `data-ts-enums` ("N common ratios") plus the
      `data-ts-form` generate form
- [x] **Result** — `data-ts-result` headline (`data-ts-headline` with
      `data-ts-range`) and the `data-ts-scale` table of `data-ts-step-row` rows
      (`data-ts-font`, `data-ts-line-height`)
- [x] **Generate error** — `data-ts-generate-error` for invalid JSON or a
      non-200 response

## Interactions

- [x] **Scale (JSON)** — `textarea` `data-ts-payload`,
      `aria-label="type scale     json"`, seeded with
      `{ baseSizePx, ratio, steps[], lineHeightMultiplier,     baselineGridPx }`
- [x] **Generate scale** — `button` `data-ts-submit` (`type="submit"`); POSTs
      the parsed JSON to `/v1/admin/studio/type-scale/generate`, setting
      `data-ts-result` on a 200 with a valid `result`, or
      `data-ts-generate-error` otherwise
- [x] **Quick-action links** — each `quickAction` `Link` navigates to its
      sibling Studio route (see Layout regions for the 17 targets)

## E2E coverage

**Coverage depth**: deep.

- `studio-design-lane-consoles.spec.ts` drives `/studio/typography` through the
  live catalog, malformed-JSON client guard, real BFF 400 validation detail,
  successful modular-scale generation, exact quick-action href list, loading /
  unauthorized / malformed-catalog fail-closed states, mobile no-overflow, and
  direct BFF 401 / 403 / 400 gates.

## Data & contracts

- **Reads**: `GET /v1/admin/studio/type-scale` on mount — returns the catalog
  (`commonRatios{}`)
- **Writes**: `POST /v1/admin/studio/type-scale/generate` — returns
  `{ result: { scale[], summary{ stepCount, minFontSizePx, maxFontSizePx } } }`
- **Realtime**: none
- **Caching**: client `fetch` with `cache: 'no-store'`; `buildBffAuthHeaders()`
  attaches the bearer token
- **Auth/role check**: admin-scoped fail-closed — `admin:*` or `admin:studio`,
  401/403 under the studio workspace gate

## Cross-references

- Parent: [`../studio-overview.md`](../studio-overview.md)
- Sibling: [`studio-color-system.md`](./studio-color-system.md),
  [`studio-spacing-layout.md`](./studio-spacing-layout.md),
  [`studio-component-primitives.md`](./studio-component-primitives.md),
  [`studio-complex-interactions.md`](./studio-complex-interactions.md),
  [`studio-design-language.md`](./studio-design-language.md)
- Component source:
  `apps/oshun/web/src/components/studio/StudioTypographyWorkspace.tsx`
- BFF store: `apps/oshun/bff/src/studio/` type-scale generator behind
  `/v1/admin/studio/type-scale`

## Known downstream boundaries

- Current source intentionally uses the flat quick-action panel and no Route Map
  panel; the 2026-07-02 browser spec asserts the exact target list.
- The generator snaps to the caller-provided `baselineGridPx`; feeding the scale
  into a future live theming pipeline is outside this route's current contract.