Prop types

Props are declared when you call sheet.object() or sheet.props(). Import constructors from @unseenco/backstage:

import {types} from '@unseenco/backstage'

Shorthand vs explicit

sheet.object('key', {x: 0}) // number inferred

sheet.object('key', {
  x: types.number(0, {range: [0, 10], label: 'X'}),
})

range guides the Studio UI; it is not a runtime clamp unless you enforce it in onValuesChange.

Number precision

Studio number inputs round and format using a resolved precision (decimal places):

• Project default — pass numberPrecision to getProject() (default 3).
• Per prop — types.number(default, {precision: 2}) overrides the project default for that prop.

const project = getProject('My Project', {numberPrecision: 2})

sheet.object('Fine', {
  // Uses project default (2 here)
  coarse: types.number(0),
  // Overrides to 4 decimals in Studio
  exact: types.number(0, {precision: 4}),
})

See Projects for where project config lives.

Common types

Type	Purpose
types.number(default, opts?)	Sliders, scrubbing, keyframed floats
types.compound({ ... })	Grouped props (e.g. rotation.x/y/z)
types.boolean(default, opts?)	Toggles
types.string(default, opts?)	Text; optional custom interpolate
types.stringLiteral(default, labels)	Enum / radio / switch UI
types.rgba(default?)	Colors
types.image(default?, opts?)	Image assets (see Assets)

String literals and switches

types.stringLiteral('a', {a: 'Option A', b: 'Option B'})

Pass object-level options {as: 'switch', label: 'Mode'} as the third argument to sheet.object() when needed.

Sequencing

Props start static. Right-click in the Details Panel → Sequence to add tracks. Compound props can be sequenced as a group (Sequence all).

Playground

Run yarn playground and open the shared/dom demo for many prop types in one scene.

API

Full prop-type surface: backstage-core API (search for types).