Build widgets for PlayerVox OverCrow

A PlayerVox OverCrow widget is a small package that the overlay draws over your game: a clock, a frame-rate counter, a checklist, a chat. You describe its view in markup, style it with a small subset of CSS, and write its logic in TypeScript against @overcrow/sdk. The overcrow-widget command-line tool checks, tests and packages it; the signed catalog brings it to users.

Every built-in widget of PlayerVox OverCrow is written this way, with the same public SDK, package format and sandbox as yours. Their sources are the reference widgets.

What a widget is made of

The view and the logic meet like this: the view reads state.count and calls the handlers the logic exports.

<box class="counter">
  <text class="value">{state.count}</text>
  <box class="actions">
    <button class="step" label={t("decrement")} on:activate={decrement}>
      <icon name="minus"/>
    </button>
    <button class="step" label={t("increment")} on:activate={increment}>
      <icon name="plus"/>
    </button>
  </box>
</box>

const state = initState({ count: 0 });

export function increment(): void {
  state.count += 1;
}

How a widget runs

• The logic runs in its own small JavaScript VM, in its own sandboxed process. It has no DOM, no file system, no network and no access to other widgets; it reaches PlayerVox OverCrow only through the SDK.
• After each event, timer tick or service answer, the VM evaluates the view again and sends PlayerVox OverCrow only what changed. OverCrow lays out and paints the widget itself: no web engine is involved.
• Everything that reaches the outside (network, storage, clipboard, game data) is a service of PlayerVox OverCrow, which checks the widget's declared and consented permissions at each call. See services and permissions.

These pages call PlayerVox OverCrow the host when they describe what it does for a widget: the host draws the view, answers the services and keeps the user's data.

Where to start

1. Follow the creator guide: from overcrow-widget init to a submitted widget, in twelve short steps.
2. Read the reference widgets: the built-ins, with their tests.
3. Go deeper, one topic per page: the manifest, the view, the style, the logic, services and permissions, forms.
4. Use the tools: the CLI, tests and the development channel that runs your widget in PlayerVox OverCrow while you write it.
5. Look up an element, a style property, a service or an SDK function in the reference.
6. Before you publish, read the package and security.
7. Publish in the creator space: getting started, then publish a widget.

Widgets run on Windows and Linux alike: the same package, the same SDK and the same rendering.