JavaScript / Node SDK

@fobo-tools/datamaker reads a .dmf, validates, sealed-box encrypts, and posts. Node ≥ 18.20 (uses global fetch + Web Crypto). Ships TypeScript types.

Install

npm install @fobo-tools/datamaker

Submit

import fs from 'node:fs';
import * as dm from '@fobo-tools/datamaker';

const dmf  = fs.readFileSync('contact.dmf');
const form = await dm.readForm(dmf); // verifies signature + form hash

const result = await dm.submit({
  form,
  values: { email: 'ada@example.com', full_name: 'Ada' },
});
// → { submissionId, editToken, formId }

Or pass the bundle straight in: await dm.submit({ dmf, values }).

Building the values object

values is keyed by each field’s name (its storage key — not the label). Inspect the form to see the names + kinds you need to fill:

for (const f of form.fields) {
  console.log(f.key, '·', f.kind, f.required ? '(required)' : '');
}
// email · email (required)
// full_name · text
// age · number
// subscribed · boolean
// plan · choice
// interests · multi-choice
// signup_date · date
// budget · money

Then map your data to those names, using the value type each kind expects:

const values = {
  email:       'ada@example.com',  // email        → string
  full_name:   'Ada Lovelace',     // text         → string
  age:          37,                // number        → number  (37, not "37")
  subscribed:   true,              // boolean       → boolean
  plan:        'pro',              // choice        → string (one of the choice values)
  interests:   ['news', 'beta'],   // multi-choice  → string[]
  signup_date: '2026-05-29',       // date          → "YYYY-MM-DD"
  budget:       1999.99,           // money         → number
};

await dm.submit({ form, values });

For image / attachment fields, upload the bytes first and pass the returned ref as the value — see Files & attachments.

The full value type for every kind is in the field kinds reference.

The SDK is forgiving — but be intentional

By default submit coerces ("37" → 37, "yes" → true, a single choice → ["x"] for multi-choice) and validates: it throws a ValidationError (with .issues) for a missing required field, an unknown key (typo protection), a value for a read-only kind, or a choice that isn’t in the list. Pass validate: false to skip, or allowUnknown: true to ignore extra keys.

try {
  await dm.submit({ form, values });
} catch (err) {
  if (err.code === 'VALIDATION_FAILED') {
    for (const i of err.issues) console.error(`${i.field}: ${i.message}`);
  } else throw err;
}

API

• readForm(dmfBytes, { verify = true }) → Promise of a form descriptor (formId, name, schemaVersion, submitPolicy, envelopeVersion, recipientUserId, recipientPublicKey, signer, fields, verified). Throws DmfError on tampering.
• submit({ form | dmf, values, ...opts }) → { submissionId, editToken, formId }. Options: apiBaseUrl, submitterId (default null), validate (default true), allowUnknown, verify, fetch.
• buildSubmission(form, values, opts) → seal without sending ({ submissionId, envelope, payload, values }).
• postSubmission(envelope, opts) → post a pre-built envelope.
• validateValues(fields, input, opts) → { values, issues }.

Validation throws ValidationError (with .issues) for missing required fields, unknown keys, read-only kinds, and bad choices. SubmissionError carries a non-2xx .status.

CLI

datamaker inspect contact.dmf
datamaker submit contact.dmf --field email=ada@example.com --field full_name=Ada
datamaker submit contact.dmf --data-file answers.json --dry-run

Browser

A bundled build (dist/datamaker.browser.js, global DataMaker) powers the web embed:

• createSubmitHandler(config) — adapts the lightweight JS renderer’s onSubmit to a sealed POST.
• mountWasm(config, opts?) — frames the high-fidelity Wasm renderer (pixel-parity with the desktop designer) into #form-root; returns an unmount fn. DEFAULT_WASM_HOST is the default bundle host.

Both read config.theme: 'auto' (default) follows the visitor’s prefers-color-scheme and re-themes live; 'light' / 'dark' force one. Other common config: recipientPublicKey (required), apiBaseUrl, applyFormStyle. Full list in web embed.