BDUI documentation

← Module overview · Architecture · State · Widgets · Actions · Themes · Observers · Streaming · Compatibility · Extensions · OTA widgets · Examples

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BDUI renders a Compose Multiplatform widget tree from JSON. Place BduiView anywhere in the host UI. The backend chooses from a client-owned vocabulary of widgets and actions; it cannot execute arbitrary native code or instantiate unregistered capabilities.

Read the pages in this order when integrating BDUI:

Quick reference

Need	Read
Embed a JSON, stream, or both	Architecture — embedding a view
Open a full-screen BDUI destination	Architecture — full-screen hosts and Actions — `openScreen`
Read root, local, ancestor, or named state	State — reference paths
Make any widget clickable	Widgets — common rules and architecture — widget document
Know every widget parameter and default	Widget reference
Know every action field and failure mode	Action reference
Patch state and tree in one RFC 6902 list	Actions — `patch` and state — patch paths
Run actions in order or concurrently	Actions — `sync` and `async`
Safely run backend JavaScript	Actions — `jsUpdateState` and HTTP `jsMap`
Handle one action error or all view errors	Actions — errors and error observers
Stream incremental tree/state changes	Streaming
Keep personal data off AppSana	Streaming — sensitive data
Support older installed clients	Compatibility
Register app-specific capabilities	Extensions
Ship composite widgets over the air from the admin panel	Over-the-air widgets

Core JSON shape

{
  "id": "root",
  "type": "Column",
  "state": {
    "title": "Offer",
    "form": { "email": "", "agreed": false }
  },
  "modifier": [{ "name": "fillMaxWidth" }],
  "params": {
    "horizontalAlignment": "Start"
  },
  "observers": [],
  "children": [
    {
      "type": "Text",
      "params": { "text": "$root.title" }
    }
  ]
}

Only containers have children. modifier and onClick live on the widget envelope, not in params. Any widget with onClick is clickable. Params are either literals or explicit paths; there is no bind object and no implicit state lookup.

Platform targets

Android
iOS
Desktop JVM
Web JS / Wasm

The document, store, action runtime, paths, observers, Ktor HTTP/SSE, and extension contracts live in commonMain. Platform source sets provide JavaScript engines and host effects such as navigation, dialogs, clipboard, sharing, and URL handling.