Read real books in a new language — tap any word to understand.

The format

Simple enough to read by hand

A .tbook is a ZIP with a manifest and one JSON file per chapter. Here's the shape of the data.

• tappable source words
• per-language translations
• word-level alignment spans
• inline emphasis (italic / bold)
• per-paragraph roles

words marks the character range of every tappable token. tr maps each language to its translation. align ties spans of the translation back to source words — that is exactly what lights up when you tap.

The optional spans and paragraphStyles add inline emphasis and paragraph roles. Readers ignore fields they do not recognize and clamp out-of-range offsets, so the format can grow without breaking older apps.

{
  "src": "Stan went to the living room.",
  "words": [[0,4],[5,9],[10,12],[13,16],[17,23],[24,28]],
  "tr": {
    "ru": {
      "text": "Стэн прошёл в гостиную.",
      "align": [
        { "t": [0,4],   "w": [0] },
        { "t": [5,11],  "w": [1] },
        { "t": [12,13], "w": [2] },
        { "t": [14,22], "w": [4,5] }
      ]
    }
  },
  "spans": [ { "s": 17, "e": 28, "k": "i" } ]
}