Element positions

Every page's box, and every element with an id on each page it is drawn on, from the engine's own placement.

curl https://api.reflowpdf.com/v1/layout \
  -H "Authorization: Bearer $REFLOWPDF_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"html": "<h2 id=\"terms\">Terms</h2>…<table id=\"items\">…</table>"}'

const { pages, elements } = await reflow.layout.create({ html })
const terms = elements.find(e => e.id === 'terms')   // { id, page, x, y, width, height }

layout = client.layout.create(html=html)
terms = next(e for e in layout.elements if e.id == "terms")

{
  "object": "layout",
  "unit": "pt",
  "document_pages": 2,
  "pages": [
    {
      "number": 1,
      "width": 595.28,
      "height": 841.89
    },
    {
      "number": 2,
      "width": 595.28,
      "height": 841.89
    }
  ],
  "elements": [
    {
      "id": "terms",
      "page": 1,
      "x": 56.69,
      "y": 412.3,
      "width": 481.89,
      "height": 21.6
    },
    {
      "id": "items",
      "page": 1,
      "x": 56.69,
      "y": 452.1,
      "width": 481.89,
      "height": 332.1
    },
    {
      "id": "items",
      "page": 2,
      "x": 56.69,
      "y": 56.69,
      "width": 481.89,
      "height": 120.4
    }
  ],
  "missing_variables": [],
  "skipped_resources": []
}

Rectangles in points (1/72 inch) from each page's top-left corner.
An element across pages is on each: the table above starts on page 1 and ends on page 2.
Only elements with an id are reported: name what you want to find.

Build a table of contents with page numbers, place a signature field or a stamp where a block ended, check that a summary fits on its first page before you send it. A template's: POST /v1/templates/{id}/layout. Counted as the document's pages.