Webpack error with Inputs

Back in March, I was able to use webpack with a JS embedded notebook that imported from ‘@observablehq/inputs’ but I think inputs got updated at some point and now I get this error:

RuntimeError: Inputs is not defined

I’ve created a toy notebook to test. It’s just these two cells:

viewof replay = Button("Test")

import {Button} from @observablehq/inputs

And this is how I import the code in my project:

import { Runtime, Inspector } from '@observablehq/runtime';
import define from '@nachocab/testing-embed';

new Runtime().module(define, Inspector.into('#myDiv'));

I have a pretty standard webpack config:

const path = require('path');

const javascript = {
  test: /\.js$/,
  exclude: /node_modules/,
  use: {
    loader: 'babel-loader',
    options: {
      presets: [
            useBuiltIns: 'entry',
            corejs: '3.9',
      cacheDirectory: true,

const config = {
  mode: 'production',
  entry: {
    app: './public/index.js',
  output: {
    path: path.resolve(__dirname, 'public', 'dist'),
    filename: '[name].bundle.js',

  module: {
    rules: [

module.exports = config;

What could be the problem?

Inputs was recently added to the standard library, so you probably need to update the version of the Observable Runtime that you are using locally. (The Runtime includes a copy of the Standard Library.)

Also, since Inputs is now part of the standard library, you don’t need the import in your test notebook, and you can say simply:

viewof replay = Inputs.button("Test")

You’ll need Version 3.5.0 or higher of the standard library.

1 Like

Ah, so simple.

Thanks a lot, Mike. You saved me!