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View, visually edit and simulate JSON-based forms.


This library exports a form viewer, editor and playground.

Display a form

Renders a form based on a form schema and existing data:

import { Form } from '@bpmn-io/form-js';

const form = new Form({
  container: document.querySelector('#form')

await form.importSchema(schema, data);

form.on('submit', (event) => {
  console.log(, event.errors);

See viewer documentation for further details.

Create and edit a form

Create a new form or edit an exsting one:

import { FormEditor } from '@bpmn-io/form-js';

const formEditor = new FormEditor({
  container: document.querySelector('#form-editor')

await formEditor.importSchema(schema);

See editor documentation for further details.

Create and simulate a form with input and output data

Create and simulate a form with input and output data:

import { FormPlayground } from '@bpmn-io/form-js';

const formPlayground = new FormPlayground({
  container: document.querySelector('#form-playground'),

See playground documentation for further details.

Retrieve schema variables from a form

Use the getSchemaVariables util to retrieve the variables defined in a form schema. This is useful to gather what data is consumed and produced by a form.

import { getSchemaVariables } from '@bpmn-io/form-js';

const variables = getSchemaVariables(schema);

console.log('Schema variables', variables);

It is also possible to distinct between input and output variables:

import { getSchemaVariables } from '@bpmn-io/form-js';

const outputVariables = getSchemaVariables(schema, { inputs: false});
const inputVariables = getSchemaVariables(schema, { outputs: false});


Build and run

Build the project in a Posix environment. On Windows, that is Git Bash or WSL.

Note we currently support development environments with Node.js version 16 (and npm version 8). We encourage you to use a Node.js version manager (e.g., nvm or n) to set up the needed versions.

Prepare the project by installing all dependencies:

npm install

Then, depending on your use-case you may run any of the following commands:

# build the library and run all tests
npm run all

# spin up a single local form-js instance
npm start

# spin up a specific instance

## viewer
npm run start:viewer

## editor
npm run start:editor

## playground
npm run start:playground

To run the visual regression tests, read the docs here


Use under the terms of the license.