bonji — Siddhaṁ Converter

English ｜ 繁體中文 ｜ 日本語

A single-page WebApp that converts ASCII / IAST romanization into Siddhaṁ (悉曇梵字) script, its Latin transliteration, and Unicode code points — entirely in the browser.

The Siddhaṁ engine is the mandel59/bonji-input engine, vendored (copied in, unmodified, MIT) and used only through a thin anti-corruption layer, SiddhamConverter.

Part of the nodeapp WebApp family — shared conventions and workflow live at https://github.com/scottgfhong310/nodeapp-webapp-family (DESIGN_GUIDELINES.md, WORKFLOW.md).

Features

• Two-column layout: input on the left, output on the right (stacks on narrow screens).
• An optional title field plus the input text (both copyable); live conversion as you type — five copyable outputs: Siddhaṁ script · Latin transliteration · ASCII notation (e.g. ṁ/ṃ → ;m) · Unicode code points · an HTML snippet (<span class="siddham" data-latin="{latin}">{siddham}</span>, one per line — for typesetting scriptural texts).
• Options: input method (ISO 15919 / Kyoto-Harvard), transliteration (ISO 15919 / IAST), ignore spaces & hyphens.
• Bundled Noto Sans Siddham webfont (SIL OFL) so the script renders without a system font.
• Trilingual UI (zh-Hant / en / ja, default zh-Hant); light / dark theme.
• Per-field copy buttons (title input + each output); example chips.
• JSON export — save the current result to the server as bonji-yyyyMMddHHmmss.json under /download/bonji/ (captures title, options, input and the three outputs); the download button exports first and then downloads that JSON; a dehaze side panel lists exports newest-first and a delete_sweep button clears the folder.
• Round-trip a saved export — click an entry in the panel to load its title / options / input back into the page (the loaded file's sourceFile is shown below the options); tweak and export again to get a new file that records the file it came from in sourceFile.
• Reference pages (side-tools, open in a new tab): a table_chart character chart (chart.html, engine-derived: notation → Siddhaṁ / Latin) and a menu_book font catalog (catalog.html, from BonjiInput.xlsx — one column per category: vowel / consonant / variant / symbol / bindu / ligature / upper- & lower-ligature, each glyph rendered in its source font: Unicode Siddham · Mojikyo · Siddham). Click any cell to copy its notation.
• Input assist (keyboard side-tool): a glyph palette docked on the right (toggle), fed by the same catalog.json — browse by category or search by notation, then click a glyph to insert its ASCII notation at the cursor (re-converts live). Opening it hides the side-tools and pins the palette to the right edge — it overlays the page rather than reflowing it (the input area stays put). A ⋮ button on the panel brings the side-tools back, and × closes it. A footer row inserts space / newline / dash (- = word-group separator). For transcribing / collating from source texts: recognize the shape, click, done. The two catalog fonts load lazily on first open.

The conversion engine runs entirely in the browser. JSON export / listing use the Node backend below, so those two features need the server (the converter itself does not).

Notation (a few examples)

type	get		type	get
;m	ṁ		aa	ā
.h	ḥ		ii	ī
~m	m̐		uu	ū

e.g. siddha;m → 𑖭𑖰𑖟𑖿𑖠𑖽 (siddhaṁ), na ma.h → 𑖡𑖦𑖾 (na maḥ).

Run

npm install && npm start          # → http://localhost:3000/apps/bonji/
npm test                          # verify the vendored engine (5 cases + code points)

PORT env var overrides the default 3000.

API

All responses use the family { ok } envelope.

Method	Path	Description
POST	/api/bonji/export	Save { title, options, input, output, sourceFile } as bonji-yyyyMMddHHmmss.json in public/download/bonji/ (sourceFile = the export this was loaded/derived from, or null). Returns { ok, filename, path }.
GET	/api/bonji/downloads	List the JSON files in public/download/bonji/, sorted descending. Returns { ok, files: [{ name, size, mtime }] }.
POST	/api/bonji/clear	Delete all JSON files in public/download/bonji/ (target hard-wired server-side). Returns { ok, removed }.

Exported files are served statically at /download/bonji/<file>.

JSON shapes

Two JSON structures appear in this project.

SiddhamConverter.convert(input) → result — the in-browser conversion result (returned by the library; also drives the UI):

{
  "input":      "siddhaṃ",           // the input text, echoed back
  "ascii":      "siddha;m",          // canonical ASCII notation (IAST/ISO 15919 → ASCII, e.g. ṁ/ṃ → ;m; newlines kept)
  "siddham":    "𑖭𑖰𑖟𑖿𑖠𑖽",          // Siddhaṁ script
  "latin":      "siddhaṃ",           // Latin transliteration (IAST by default; ISO 15919 optional)
  "codepoints": "U+115AD U+115B0 U+1159F U+115BF U+115A0 U+115BD"
  //            code points of `siddham`, space-separated (one line per input line)
}

bonji-yyyyMMddHHmmss.json — an exported record (written by POST /api/bonji/export; the filename timestamp is server-generated). It nests the three outputs under output and adds metadata:

{
  "app":        "bonji",
  "exportedAt": "2026-06-13T01:25:59.123Z", // ISO 8601, UTC
  "sourceFile": "bonji-20260613092011.json",// the export this was loaded/derived from, or null
  "title":      "心經種子字",                 // optional, user-entered
  "options": {
    "inputMethod":            "ISO15919",   // "ISO15919" | "KH"
    "transliteration":        "IAST",       // "ISO15919" | "IAST"
    "ignoreSpacesAndHyphens": true
  },
  "input":  "siddha;m",                     // normalized ASCII notation (IAST/ISO 15919 → ASCII, e.g. ṁ/ṃ → ;m)
  "output": {
    "siddham":    "𑖭𑖰𑖟𑖿𑖠𑖽",
    "latin":      "siddhaṃ",
    "codepoints": "U+115AD U+115B0 U+1159F U+115BF U+115A0 U+115BD"
  }
}

The export stores input as the normalized ASCII notation (e.g. a typed siddhaṃ is saved as siddha;m), so the file is portable and re-typeable. output holds the three outputs siddham / latin / codepoints; app, exportedAt, sourceFile, title and options are export metadata. (The library's convert() instead echoes the raw input and exposes the ASCII separately as ascii.)

Structure

bonji/
├─ app.js                          # Express: static + /api/bonji + ( / → 302 /apps/bonji/ ) + PORT||3000
├─ routes/bonji.js                 # POST /export, GET /downloads ({ ok } envelope)
├─ package.json · .gitignore · LICENSE
├─ test/verify-siddham.mjs         # engine verification (npm test)
└─ public/
   ├─ download/bonji/.gitkeep      # exported JSON lands here (contents gitignored)
   └─ apps/bonji/
      ├─ index.html · bonji.css · bonji.js     # converter page: structure / styles / glue (ESM module)
      ├─ chart.html · chart.css · chart.js     # character chart (engine-derived)
      ├─ catalog.html · catalog.css · catalog.js   # font catalog (from BonjiInput.xlsx)
      ├─ siddham-converter.js                  # anti-corruption layer (the ONLY Siddhaṁ interface)
      ├─ config.json                           # backend toggle { backend: true|false }
      ├─ data/{catalog.json, BonjiInput.xlsx}  # catalog data (catalog.json generated from the xlsx)
      ├─ vendor/bonji-input/{siddham.js, LICENSE, SOURCE.md}   # vendored engine (MIT, unmodified)
      ├─ fonts/{NotoSansSiddham-Regular.woff2 + OFL.txt, Mojikm13.TTF, Siddham.ttf}   # Siddhaṁ / Mojikyo / Siddham (catalog fonts ~7.5 MB)
      ├─ i18n.js · locales/{zh-Hant,en,ja}.js
      └─ side-tool.css · materialize-dark.css

Using the core (SiddhamConverter)

siddham-converter.js is the only module the app imports for conversion; it never reaches into the vendored engine directly. It is a zero-dependency ES module:

import { SiddhamConverter } from "./siddham-converter.js";

const converter = new SiddhamConverter();           // defaults: ISO15919 input, IAST transliteration, ignore spaces
const { input, ascii, siddham, latin, codepoints } = converter.convert("siddhaṃ");
// input:      "siddhaṃ"    (the text passed in, echoed back)
// ascii:      "siddha;m"   (canonical ASCII notation; IAST/ISO 15919 → ASCII, e.g. ṁ/ṃ → ;m; newlines kept)
// siddham:    "𑖭𑖰𑖟𑖿𑖠𑖽"
// latin:      "siddhaṃ"    (IAST default; ṃ — ISO15919 would be ṁ)
// codepoints: "U+115AD U+115B0 U+1159F U+115BF U+115A0 U+115BD"

converter.setOptions({ transliteration: "ISO15919" });  // → latin uses ṁ instead of ṃ

Updating the vendored engine

See public/apps/bonji/vendor/bonji-input/SOURCE.md for the pinned upstream commit. To soft-sync, diff upstream against the pinned commit, apply only engine-relevant fixes into vendor/bonji-input/, re-run npm test, and update SOURCE.md. Because the app only depends on SiddhamConverter, upstream internal changes at most require touching that wrapper.

License

MIT © 2026 Scott G.F. Hong. Bundles the bonji-input Siddhaṁ engine (MIT, © 2021 Ryusei Yamaguchi) and Noto Sans Siddham (SIL OFL 1.1). See LICENSE, the vendored LICENSE/SOURCE.md, and fonts/OFL.txt.