UIAutomator hierarchy

A selector-shaped projection of Compose semantics: just enough metadata per node to formulate a UIAutomator-style By.text(...) / By.contentDescription(...) selector that uniquely targets it.

At a glance


Kind	`uia/hierarchy`
Schema version	1
Modules	`:data-uiautomator-core` (published) · `:data-uiautomator-hierarchy-android` (published) · `:data-uiautomator-connector`
Render mode	default
Cost	low
Token usage	Inline JSON, not yet benchmarked (scales with selector node count). See token usage.
Transport	inline
Platforms	Android

What it answers

For each actionable node, what selector inputs are available — text, contentDescription, testTag, role?
Which uia.* actions does it support — uia.click, uia.scrollForward, uia.inputText, …?
What is the node’s bounds in source-bitmap pixels (same shape as AccessibilityNode’s boundsInScreen)?
Does the node have testTag ancestors that a hasParent({testTag: …}) / hasAncestor selector chain could resolve?

The default filter keeps only nodes that expose at least one of the supported actions, dropping ~80% of layout-wrapper / pure-text nodes while still emitting everything an agent’s click / scroll / type could plausibly target. Snapshots can be taken against the merged semantics tree (the on-device UIAutomator default — Button { Text("Submit") } collapses into one node) or the unmerged tree.

What it does NOT answer

It is not a full SemanticsNode dump — for that, use compose/semantics.
It does not execute a selector — it gives you what is targetable; running a uia.click is the daemon’s renderNow path, not a data product fetch.
It does not include modifier or constraint detail; pair with layout/inspector when you need positioning context.

Use cases

Generate a UIAutomator-like end-to-end test plan for a screen without touching an emulator.
Confirm every actionable node has at least one stable selector input — fail review if a button has neither text, contentDescription, nor testTag.
Train an agent’s “which selector should I use” heuristic on the same shape it will see at runtime.

Payload shape

UiAutomatorHierarchyNode, Selector in :data-uiautomator-core.

// uia/hierarchy
{
  "merged": true,
  "nodes": [
    { "text": "Submit", "contentDescription": null,
      "testTag": "submit-button",
      "testTagAncestors": ["checkout-screen"],
      "role": "Button",
      "actions": ["uia.click"],
      "boundsInScreen": "48,200,144,232" }
  ]
}

Enabling

Producer runs once the UIAutomator extension is publicly enabled. Hierarchy snapshot is emitted by UiAutomatorHierarchyExtractor in :data-uiautomator-hierarchy-android (Android-only).

Companion products

Layout inspector — compose/semantics for the full SemanticsNode shape and layout/inspector for positioning.
Focus — compose/focus for the focused-node subset that a directional traversal would target.
Accessibility — a11y/hierarchy for the assistive-technology view of the same tree.