Quickstart

Prefer the CLI? Install @launchmystore/cli and skip steps 1–4: lms auth login then lms app create scaffolds a working app, registers it with your developer account, writes credentials, and starts a Cloudflare tunnel via lms app dev. See CLI Setup for the fast path.

Prerequisites

Node.js 18+

Required for development

Developer Account

Step 1: Create a Developer Account

Go to app.launchmystore.io/developer
Sign up or log in with your LaunchMyStore account
Navigate to Apps in the developer dashboard

Step 2: Create Your App

Click Create App

In the developer dashboard, click the Create App button.

Configure App Details

Fill in your app information:

App name: A descriptive name for your app
App handle: URL-safe identifier (e.g., my-awesome-app)
App URL: Where your app is hosted (e.g., https://my-app.com)
Redirect URLs: OAuth callback URLs

Select Scopes

Choose the permissions your app needs:

read_products, write_products
read_orders, write_orders
read_customers

Save Credentials

After creation, you’ll receive:

Client ID: Public identifier for your app
Client Secret: Keep this secure, never expose publicly

Step 3: Set Up Your Project

Create a new project with your preferred framework:

mkdir my-lms-app && cd my-lms-app
npm init -y
npm install express @launchmystore/app-bridge

npx create-react-app my-lms-app
cd my-lms-app
npm install @launchmystore/app-bridge @launchmystore/app-bridge-react

Step 4: Implement the `/auth` install handoff

Your app receives its first access token through the managed install handoff: when a merchant installs your app, LaunchMyStore redirects their browser to {appUrl}/auth?shop=…&storeId=…&code=…&state=…&host=…&timestamp=…&hmac=…. Verify the HMAC, exchange the code, and land the merchant back in their admin. (Do not redirect merchants to /apps/oauth/authorize — it is a merchant-authenticated JSON API used by the LaunchMyStore admin, not a browser flow.)

server.js

const express = require('express');
const crypto = require('crypto');
const app = express();

const CLIENT_ID = process.env.LMS_CLIENT_ID;
const CLIENT_SECRET = process.env.LMS_CLIENT_SECRET;

// Install handoff — LaunchMyStore redirects the merchant here on install
app.get('/auth', async (req, res) => {
  const params = req.query;

  // 1. Verify the HMAC (raw query string minus the hmac= field)
  const qs = req.url.split('?')[1]
    .split('&')
    .filter((p) => !p.startsWith('hmac='))
    .join('&');
  const expected = crypto
    .createHmac('sha256', CLIENT_SECRET)
    .update(qs)
    .digest('hex');
  const a = Buffer.from(String(params.hmac));
  const b = Buffer.from(expected);
  if (a.length !== b.length || !crypto.timingSafeEqual(a, b)) {
    return res.status(401).send('Invalid HMAC');
  }

  // 2. Exchange the pre-authorized code for tokens
  const response = await fetch('https://api.launchmystore.io/apps/oauth/token', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      client_id: CLIENT_ID,
      client_secret: CLIENT_SECRET,
      code: params.code,
      grant_type: 'authorization_code',
      state: params.state          // echo the handoff state verbatim
    })
  });

  // Token payload is wrapped in the platform envelope — read `data`
  const { data } = await response.json();

  // 3. Store tokens keyed by the immutable storeId (not the shop host)
  await saveTokens(params.storeId, data.access_token, data.refresh_token);

  // 4. Land the merchant back in their admin
  res.redirect(Buffer.from(params.host, 'base64').toString('utf8'));
});

app.listen(3000);

Step 5: Make API Calls

Use your access token to call the API:

const accessToken = await getAccessToken(storeId);

const response = await fetch('https://api.launchmystore.io/api/v1/products.json', {
  headers: {
    'Authorization': `Bearer ${accessToken}`,
    'Content-Type': 'application/json'
  }
});

const products = await response.json();

Step 6: Add App Bridge (Embedded Apps)

If your app is embedded in the LaunchMyStore admin:

import { createApp } from '@launchmystore/app-bridge';

const app = createApp({
  apiKey: 'your-client-id',
  host: new URLSearchParams(location.search).get('host')
});

// Show a toast notification — dispatch(actionName, payload)
app.dispatch('TOAST_SHOW', { message: 'Hello from my app!', duration: 3000 });

Next Steps

Build Extensions

Add UI to storefronts, checkout, and admin

Create Functions

Custom logic for shipping, payments, and more

App Bridge

Communicate with the host application

API Reference

Full REST API documentation

Get Started

Guides

Extensions

Functions

App Bridge

Billing

AI & MCP

Prerequisites

Node.js 18+

Developer Account

Step 1: Create a Developer Account

Step 2: Create Your App

Step 3: Set Up Your Project

Step 4: Implement the `/auth` install handoff

Step 5: Make API Calls

Step 6: Add App Bridge (Embedded Apps)

Next Steps

Build Extensions

Create Functions

App Bridge

API Reference

​Prerequisites

Node.js 18+

Developer Account

​Step 1: Create a Developer Account

​Step 2: Create Your App

​Step 3: Set Up Your Project

​Step 4: Implement the /auth install handoff

​Step 5: Make API Calls

​Step 6: Add App Bridge (Embedded Apps)

​Next Steps

Build Extensions

Create Functions

App Bridge

API Reference

Prerequisites

Step 1: Create a Developer Account

Step 2: Create Your App

Step 3: Set Up Your Project

Step 4: Implement the `/auth` install handoff

Step 5: Make API Calls

Step 6: Add App Bridge (Embedded Apps)

Next Steps