Export profiles

Prerequisites: Getting Started.

An export profile configures presentation — page size, fonts, margins, indentation, page numbers — for a specific output. It never changes MDI syntax or meaning; the same source with two different profiles produces two different-looking PDFs of the same document. The package is @illusions-lab/mdi-export-profile; resolveExportProfile validates every field and throws a descriptive Error rather than silently accepting malformed layout data (see below).

The schema

{
  "layout": { "system": "word" },
  "metadata": {
    "title": "The Last Station",
    "author": "A Writer",
    "publisher": "Example Press",
    "identifier": "isbn:9780000000000"
  },
  "typesetting": {
    "writingMode": "horizontal",
    "fontFamily": "Noto Serif JP",
    "textIndentEm": 1,
    "fullwidthSpaceIndent": false
  },
  "pagination": {
    "pageSize": "A4",
    "landscape": false,
    "charactersPerLine": 40,
    "linesPerPage": 34,
    "margins": { "top": 25.4, "bottom": 25.4, "left": 25.4, "right": 25.4 },
    "pageNumbers": { "enabled": true, "format": "simple", "position": "bottom-center" }
  },
  "epub": { "chapterSplitLevel": "h1", "coverPath": "cover.png" },
  "text": { "fullwidthSpaceIndent": true, "indentCount": 1 }
}

resolveExportProfile({}) is available for internal/default resolution, but every configured CLI or @illusions-lab/mdi export must state layout.system. Choose one contract: "japanese-publisher" for a strict, mirrored Japanese book grid, or "word" for flowing Word-style pages. They are intentionally not mixed.

Field	Type	Default	Validation
`layout.system`	`"japanese-publisher" \| "word"`	publisher for internal resolution; required at configured-export boundaries	Selects the complete layout contract.
`layout.marginMode` / `bindingSide` / `gutter`	`"single"\|"mirror"` / `"left"\|"right"` / mm	publisher: mirror, direction-dependent binding, 0 mm	`word` has no gutter and defaults to single margins.
`metadata.title`/`author`/`publisher`/`identifier`/`language`/`date`	`string`	—	Must be a string if present.
`typesetting.writingMode`	`"horizontal" \| "vertical"`	`"horizontal"`	Must be exactly one of the two.
`typesetting.fontFamily`	`string`	Mincho fallback stack	Must be a non-empty string; whitespace-only falls back to default.
`typesetting.textIndentEm`	`number`	`1`	`0`–`4`.
`typesetting.fullwidthSpaceIndent`	`boolean`	`false`	—
`pagination.pageSize`	one of `PAGE_SIZES`	publisher: `"Shirokuban"`; word: `"A4"`	Must be a key of the exported `PAGE_DIMENSIONS` map.
`pagination.landscape`	`boolean`	`false`	—
`pagination.charactersPerLine` / `linesPerPage`	`number`	publisher horizontal: `27`×`26`; vertical: `40`×`30`; word: informational	`10`–`400`.
`pagination.gridMode`	`"strict" \| "typographic"`	publisher: strict; word: typographic	`word` rejects strict; strict rejects explicit line spacing.
`pagination.margins.{top,bottom,left,right}`	`number` (mm)	publisher: 16.5/18/18/15.5; word: `25.4` each	Must leave printable width and height.
`pagination.pageNumbers.enabled`	`boolean`	`true`	—
`pagination.pageNumbers.format`	`"simple" \| "dash" \| "fraction"`	`"simple"`	Must be one of the three.
`pagination.pageNumbers.position`	one of the six `*-{left,center,right}` combinations	`"bottom-center"`	Must be one of the six.
`epub.chapterSplitLevel`	`"h1" \| "h2" \| "h3" \| "none"`	`"h1"`	Must be one of the four.
`epub.coverPath`	`string` (path, resolved relative to the `--config` file)	—	Must be `.jpg`/`.jpeg`/`.png` when used by the CLI.
`text.fullwidthSpaceIndent`	`boolean`	`false`	—
`text.indentCount`	`number`	`1`	`1`–`4`.

Any value outside these constraints — an unsupported pageSize, a charactersPerLine of 5, a writingMode of "rtl" — throws a specific Error naming the offending field, both from resolveExportProfile() directly and from parseExportProfileJson() (used by the CLI’s --config), rather than clamping or ignoring it silently.

Using it

mdi build novel.mdi --to pdf --config novel.export.json -o novel.pdf
mdi build novel.mdi --to docx --config novel.export.json
mdi build novel.mdi --to epub --config novel.export.json
mdi build novel.mdi --to txt-ruby --config novel.export.json

import { parseExportProfileJson, resolveExportProfile } from "@illusions-lab/mdi-export-profile";

const profile = parseExportProfileJson(await readFile("novel.export.json", "utf8"));
const resolved = resolveExportProfile(profile); // every field filled in, fully validated

resolvePrintProfile(profile, sourceWritingMode) is the PDF/print convenience wrapper: a document’s front matter supplies the writing-mode default, while an explicit profile wins. It does not silently switch paper orientation.

Format support today

Setting	PDF	TXT / `txt-ruby`	EPUB / DOCX
Page geometry, fonts, page numbers	Yes	—	DOCX: Yes; EPUB uses typography but is reflowable
Metadata / writing mode	Yes	—	EPUB / DOCX: Yes
Full-width-space indent	Yes	Yes (1–4 spaces via `text.indentCount`)	EPUB / DOCX: Yes
Cover image, chapter split level	—	—	EPUB: Yes

The adapters package Rust-owned parsed IR; layout policy remains outside the MDI parser. EPUB cannot promise fixed physical pages because it is reflowable.

Next steps

Bindings: CLI — --config in context.
Rust Core API status — exactly which renderer functions exist and what they currently accept.