docs/schema.md

Schema

Payload — one observation, four tar members

The tars are uncompressed, members of one observation are consecutive, and the key is everything before the first . in a member name. Keys contain no dots.

<key>.png             screenshot, PNG, never re-encoded
<key>.leaf.json       list of visible elements
<key>.screentag.txt   serialized markup
<key>.record.json     sanitized metadata

<key> is <shard>__<stem>, e.g. shard-0106__scene-002ad3e5b23cbfd9-step00. It is shard-qualified because a few scenes were captured in two shards, so a stem alone is not unique; (shard, stem) is.

leaf.json — an element

{
  "type": "Button",                 // release class, 55 in the schema
  "role": "push button",            // AT-SPI role it came from
  "name": "Save",
  "visible_text": "Save",           // text a reader can actually see
  "visible_text_status": "visible",
  "rect":  {"x": 312, "y": 88, "w": 64, "h": 28},   // amodal: the whole element
  "visible_fragments": [                             // modal: pixels it occupies
    {"x": 312, "y": 88, "w": 40, "h": 28}
  ],
  "is_occluded": true,
  "occlusion_state": "partially_occluded",
  "app_name": "homebank",
  "reading_order_index": 41,
  "_window_stack_index": 2,
  "uid": "80b06ebf5db974e2"         // stable within an episode; action targets use it
}

rect is amodal and visible_fragments is modal. A box drawn from rect alone claims pixels another window is covering. Train grounding on the fragments; use rect when the question is where the whole element is.

screentag.txt

One flat string per screenshot: <Tag><loc_N>×4 [state] [text]</Tag>, nested to mirror the element tree. Coordinates are on a 0–500 grid, normalized to the viewport (record["screentag_grid"]).

record.json

Scene metadata for the observation. Carries observation_key, scene_id, episode_id, step_index, split, group, width, height, apps, theme, scene, n_elements, n_windows, window_stack, occlusion, flags, provenance, and — on any observation that an action led to — action_into_this_state and effect_of_that_action.

group is ep for a frame of a click episode and st for a standalone scene.

Indexes

file	one row per	notable columns
index/scenes.parquet	scene	split, split_source, apps, theme, resolution
index/observations/<split>.parquet	observation	tar_path, *_member, occluded_ratio, n_elements, n_windows, the flags
index/transitions/<split>.parquet	transition	before_key, after_key, action fields, effect, exclusion_reasons
index/instructions/<split>.parquet	transition with an instruction	primary_instruction, instruction_variants, referring_expression
index/episodes/<split>.parquet	episode	observation_keys, transition_ids, episode_status
index/shard_members.parquet	tar member	byte_offset, byte_size, sha256
checksums/shard_stats.parquet	tar	bytes, sha256, observations

split_source is extended for the 12,515 scenes that are published but not state-train-eligible, and v3 for all others.

Transitions

An action is stored on the step it produced:

observation[k-1]  --  steps[k].action  -->  observation[k]

Step 0 has no action. Reading it the other way pairs every action with the screen it was not taken on, and nothing downstream would notice.

Coordinates: action_point_px is authoritative. action_point_norm_1000 and action_point_screentag_500 are derived from it and agree to within one grid cell; action_target_bbox_px is [x0, y0, x1, y1].

effect counts what changed between the endpoints — changed, magnitude, appeared, disappeared, moved, text_changed, state_changed, newly_occluded, revealed, semantic_changes, persisted.

exclusion_reasons is empty when transition_train_eligible is true and otherwise names every rule the transition failed.

Instructions

index/instructions/<split>.parquet has one row per transition with an instruction, joined to the corpus by transition_id, before_key and after_key:

column	content
transition_id, split, before_key, after_key, target_uid	the transition and its target element
action_type, action_point_px, action_target_bbox_px	the recorded click, as in index/transitions
primary_style, primary_instruction	the main instruction: standard where it exists, else detailed_contextual
instruction_variants	every phrasing, as style and text
referring_expression	how the target is identified on the before screen

Instructions are coordinate-free: they name a goal, never a position.

demo/preview.parquet

A stratified sample of observations, one row per observation with the image inline, for browsing without the shards. It is stratified over split, theme, resolution, element density, occlusion band, static against episode, changed against no-op, and common against rare application.

Its images are downscaled to 1024 px on the long edge; data/ is canonical. ScreenTag is on a 0–500 grid normalized to the viewport, so it still describes the resized image, and width/height remain the original pixel dimensions.

demo/transitions/<split>.tar — the transitions_preview subset

A browsing sample of recorded clicks for the Dataset Viewer, 100 per split, one per episode, varied over target application, element role, appearance preset and resolution. The key is the transition_id; each sample has six members:

<transition_id>.instruction.txt   primary instruction for the click
<transition_id>.before.png        the before observation's PNG, byte-identical
<transition_id>.target.png        crop of the before screen around the target, outlined
<transition_id>.after.png         the after observation's PNG, byte-identical
<transition_id>.action.txt        e.g. click (1521, 688) on table column header "Compressed" in xarchiver
<transition_id>.transition.json   ids, instruction variants, action, target, effect, scene

before.png and after.png hash to the sha256 of their members in index/shard_members.parquet. target.png is the only derived image: a crop of the before screen around the target, with the target box and click point drawn on it.