Pipeline

Snapshots follow a four-stage pipeline:

1. Mark elements in the live DOM.
2. Serialize the HTML.
3. Clean with a mode-specific cleaner.
4. Assign counters.

Modes

Mode	Use	Includes
action	Before click/input/select/scroll	Interactive elements with counters
extraction	Before extract	Data-bearing elements with counters
clickable	Identify clickable targets	Only clickable elements
scrollable	Identify scrollable regions	Only scrollable containers
full	Complete page structure	All elements

await opensteer.snapshot({ mode: 'action' })
await opensteer.snapshot({ mode: 'extraction' })

Counter semantics

Counter values (c) follow these rules:

• Assigned fresh on every snapshot() call.
• Snapshot HTML and live DOM share the same c values.
• Action lookup: strict unique match. No match returns not found; multiple matches return ambiguous.
• Extraction lookup: tolerant. No match returns null; multiple matches fail as ambiguous.
• Boundary wrappers (os-iframe-root, os-shadow-root) may be unnumbered.
• Inaccessible iframes and closed shadow roots are not counter-addressable.

Best practices

• Re-snapshot before counter-based actions after page navigation or significant DOM changes.
• Use action mode before interactions, extraction mode before data extraction.
• The full mode returns the largest payload. Use it only when you need complete page structure.