API

A signal derived from the signals fn reads: computed on first read, and again only once one of them changed.

Auto-tracks signals read synchronously and retracks on subsequent updates.

Called while a component sets up: the value the nearest component above it provides for key, or the key's fallback, as a signal its JSX follows.

A value descendants inherit, as a CSS property is inherited.

Registers fn to run when the component's instance is disposed, without running it on mount.

Runs after a successful native mount; cleaned up and re-run on accepted refresh.

Called while a component sets up: its descendants inherit value for key.

Loads data for a component once it has mounted, with its progress, result and error as signals and refresh() to load it again.

A signal.

A store over initial, which it wraps rather than copies: every path is a signal.

Makes a Task running work on demand with an abort signal, under a replace or drop policy.

Runs fn when a signal, or what source reads, changes; with immediate, once at the start too.

Use db for structured offline records that need filtering, sorting and reactive counts. Queries return read-only signals that update after table writes.

Use fileSystem for documents, cached downloads and media files in the app sandbox. Use storage or db for structured app state.

Use secureStore for tokens or other small string secrets. Use storage or db for general app data; use persisted with secure enabled for a reactive secret.

Choose storage by how the data is used: persisted signals for preferences, typed database tables for collections, string storage for explicit key/value access, and secureStore for secrets.

A signal whose value survives the app's restarts.

Resolves at the response's head; see docs/web-apis.md for what it doesn't do.

Names are case-insensitive and iterate lowercased, sorted.

WHATWG URL without internationalized domain names; see docs/web-apis.md.

The URLSearchParams constructor Kuito's runtime provides, taking a query string, pairs, a record or another instance.

A WebSocket connection, for messages a server pushes to the app as they happen.

Open external websites or apps, and receive URLs that launched or returned to your app. Use typed routes for navigation between your own screens.

Show an offline hint or defer a large download using the platform network state. Always handle the actual request result as well.

Makes a signal and cancels whatever it was given to, a fetch or a task, with an optional reason.

Cancels a fetch or other work it is given to; AbortSignal.timeout() makes one that fires after a delay.

Cancels an id from setInterval or setTimeout, which share ids; undefined is ignored.

Cancels an id from setTimeout or setInterval, which share ids; undefined is ignored.

Every entry reaches the LogBox and the kuito dev terminal; see docs/logbox.md.

The platform's CSPRNG, with getRandomValues and randomUUID; no SubtleCrypto.

now() is milliseconds since the app's JS runtime started, on a monotonic clock.

Runs callback in the microtask queue, before the next task.

Shares ids with setTimeout: clearTimeout and clearInterval cancel either.

Runs callback with args after delay milliseconds and returns an id clearTimeout cancels.

Deep copy with cycles; functions and symbols throw a DataCloneError.

UTF-8 only; invalid bytes decode as U+FFFD.

Turns strings into UTF-8 bytes, for hashing, uploading or writing them.

source, kept between min and max.

Keep moving at velocity, slowing down until it stops or meets the clamp.

Start after ms.

Cubic-bezier curves, the same data the CSS compiler emits for transition.

Enters from transparent, leaves to transparent.

source mapped from input to output, piece by piece: numbers, or hex colors channel by channel.

Stops by percentage, as CSS @keyframes: values for one prop make an animation, objects of props make an effect.

Create an instance-local motion value during component initialization.

Effects at once: parallel(a, b) is a.and(b).

Run animation again and again, forever by default.

Create, during component initialization, the motion values a Scroll or a List moves as it scrolls; give it to one view's motion prop.

One after another.

Create, during component initialization, the motion values a Sheet moves; give it to one Sheet's motion prop.

Moves by distance (24 by default) in its direction: slide.up(12) enters rising 12 into place and leaves rising 12 away.

With a spring; it keeps the velocity of what it interrupts.

Effects at once, each each ms after the one before.

Along a curve: 300ms ease-in-out by default; a number is the duration.

Grows from scale (0.85 by default) as it enters, shrinks to it as it leaves.

A quick swipe in a direction.

A press held for after milliseconds.

Each in turn: a gesture waits for the ones before it to fail, so orElse(tap({ count: 2 }), tap()) is a double tap, or else a tap.

A drag; axis keeps it to one direction.

Two fingers apart or together: scale.

The first to activate wins; the others fail.

Two fingers turning: rotation, in degrees.

One tap, or count in a row.

All may be active at once: pinch and rotate a photo together.

Raw touches: where the first finger is (x, y) from the moment it lands.

Closes the top presented screen, or pops the current stack.

Shows to (docs/navigation.md#moving-between-routes).

Shows to as a new screen, and resolves with what it passes to its dismiss, or undefined when the user closes it.

Every route by name: routes.show({ id: 42 }).

Use the clipboard for user-requested copy and paste actions, such as copying a code or inserting a shared URL.

Use haptics to confirm selection, communicate success or failure, or reinforce a physical-feeling interaction.

Offer a short list of actions in a system action sheet. Use it for choosing what to do with an item; use ContextMenu when the actions should be attached to a long-press target.

Show a system alert for a decision that interrupts the current task. Use prompt for a short text response; use a screen or Sheet for a larger form.

Shows an alert with a text field (docs/alert.md) and resolves with the button the user picked and what they typed, or null when they dismissed it.

Open the platform share sheet for text, URLs or a file. Use it when the user chooses where content should go.

Use a native audio player for music, podcasts or sound clips, and a recorder for voice notes. Playback and recording expose reactive state and native motion clocks.

Loads font files at run time, for families the app does not bundle through kuito.config.ts.

Works with the images an Image shows, ahead of showing them.

Use the system media picker when the user should select a photo or video. Use capture for the system camera UI; use Camera for an embedded preview you control.

Makes a CameraRef while a component sets up: a Camera ref whose ready and error signals follow the view's events.

Creates a VideoRef while a component sets up: a Video ref with playback state signals and time/duration motion values.

Creates a WebViewRef while a component sets up: a WebView ref with url, title, loading and history signals.

Ask the operating system to run occasional work while your app is not in front. Use it for opportunistic sync or maintenance, not an exact timer.

Request a position for nearby results, follow movement on an active screen, or register background updates for a feature that needs them.

Use local notifications for reminders and iOS remote push for server-originated updates. A notification can open a specific screen through its URL.

Check access before a feature needs it, explain why it helps, and handle denial without trapping the user. Use the shared permissions API for camera, microphone, photos, location and notifications.

Refresh data when the app becomes active, pause foreground work in the background, and release expendable caches on memory warnings.

Read the system color scheme and font scale. Use these signals when JavaScript behavior must follow appearance; use CSS media queries for most visual styling.

Set app-scoped screen brightness for a reader, scanner or presentation, then restore the system setting when that mode ends.

Use device metadata for support diagnostics and platform-specific presentation. These fields describe the device and operating system; they are not a stable user identity.

Follows the software keyboard, for layouts and animations that react to it, and dismisses it.

Controls the native launch screen: keep it up while the app loads, hide it, or pick the look of the next launch.

Read the current window size, insets, orientation and width class. Use these signals for behavior that depends on available space.

Prevent automatic display sleep for an active reader, navigation session or presentation.

Adapts the app to assistive technology: whether a screen reader runs or the user prefers reduced motion, and speaking or moving focus for them.

Use localization for the user’s language order, calendars and clock preferences. Use message catalogs for UI strings and Intl for numbers and dates.

An event an app makes and dispatches through a view's element, with a payload of its own, for signalling between components without props.

'ios' or 'android', fixed when the app is compiled: each platform gets its own bundle, and a branch on platform for the other one is dropped from it (docs/styles.md#platforms

Makes a stable ElementRef to a native view while a component sets up; current holds the handle.

Compiler-only StyleX-inspired declarations: each named style becomes a class name, its variants picked by data attributes in the class list, `class={[sheet.card, { size: 'large' }]

A native module: name is what Swift and Kotlin implement as <name>Spec.

Declares an event the platform sends while JavaScript listens: levelChanged: event<{ level: number }>().

Declares a module function and the thread it runs on: fn.sync<() => number>().

Declares platform state an app reads as a signal: level: live<number>().

Declares the view a module contributes, rendered in JSX: view: view<SliderProps>({ events: ['change'] }).

The UIBackgroundModes values ios.backgroundModes accepts, from audio and location to push-to-talk.

Checks value is Info.plist data; fail reports the key at fault.

The config file exported, for environment: what it declares is untrusted until here.

The shells' own behavior: a setting left at its default writes nothing.

Moves the test's clock on by ms: timers fire and animations step, a frame at a time.

Node's strict assertions, typed for a Kuito test file, for checking what the app shows and did.

Picks a moment in the DatePicker view is, or an option or item by its label in a Select, SegmentedControl or ContextMenu, as a user does.

Runs interaction once the app has settled, settles what it started, and returns what it cost the main thread in counts (docs/testing.md#cost-budgets): `(await costOf(() => press(

Groups related tests under one name, as Node's test runner does.

Taps view, or the Pressable, Button or Toggle it is in.

Renders tree (<App />) as the screen's only root, with the platform options describe, and resolves once the app has settled: its requests answered, its timers due now run and

Replays a recording a device saved on the headless host, for a golden test that the layout still matches the device's.

Queries over what the last render shows.

Scrolls the Scroll or list view is in to offset, in points.

Declares one test, as Node's test runner does, run by kuito test on the headless host.

A view of the headless tree, as a query finds it.

Types text into the TextField view is.

Queries over the views inside view.