A framework for building create web apps – powered by Gleam and React!

Package Version Hex Docs

import gleam/int
import lustre
import lustre/element.{ button, div, p, text }
import lustre/event.{ dispatch, on_click }

pub fn main () {
    let app = lustre.application(0, update, render)
    lustre.start(app, "#app")

type Action {

fn update (state, action) {
    case action {
        Incr -> state + 1
        Decr -> state - 1

fn render (state) {
    div([], [
        button([ on_click(dispatch(Decr)) ], [ text("-") ]),
        p([], [ text(int.to_string(state)) ]),
        button([ on_click(dispatch(Incr)) ], [ text("+") ])

❗️ This package relies on Gleam’s JavaScript FFI and will not work if your are targeting Erlang.


If available on Hex, this package can be added to your Gleam project:

gleam add lustre

and its documentation can be found at You will also need to install react and react-dom from npm:

npm i react react-dom


First, make sure you have both Gleam and Node.js installed, then:

npm i
npm start

This sets up chokidar to watch our gleam source code and runs the compiler whenever we make a change. It also starts a server that will serve the examples located in test/examples/.


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