Shopping Flow

Build a small shop: pick a product and a quantity from numbered menus, confirm, enter the address in a reusable sub-flow, or go back and start over.

Level: Intermediate · Tags: WhatsApp, Telegram, Flows

Features shown: .choose() menus · then sub-flows · goto · c.state · .timeout() and timeoutMessage · bot.lint()

Prerequisites

Node.js 22.12 or newer and a folder with "type": "module" (see Getting started). Then install:

npm install @botmesh/core @botmesh/baileys

The complete bot

// bot.js
import { Bot, defineBot, flow, isMainModule, slashCommandsPlugin } from '@botmesh/core'
import { BaileysProvider } from '@botmesh/baileys'

const PRODUCTS = {
  phone: { label: '📱 Phone ($599)', price: 599 },
  shirt: { label: '👕 Shirt ($25)', price: 25 },
  lamp: { label: '🏠 Lamp ($35)', price: 35 },
}

const createBot = defineBot((provider) => {
  const bot = new Bot({
    provider,
    // Sent when a wait of the flow times out
    conversation: { timeoutMessage: '⏰ Your cart expired. Send "shop" to start again.' },
  })
  bot.plug(slashCommandsPlugin)

  // A reusable sub-flow: runs inline from the checkout and comes back
  const address = flow([]).ask('🏠 Street and number?', 'street').ask('🏙️ City?', 'city')

  bot.use(
    flow('shop')
      .timeout('2m')
      .choose('🛒 *What do you want to buy?*', {
        phone: PRODUCTS.phone.label,
        shirt: PRODUCTS.shirt.label,
        lamp: PRODUCTS.lamp.label,
      }, 'product')
      .choose('How many?', { one: '1 unit', two: '2 units', three: '3 units' }, 'qty')
      .say((_ctx, c) => {
        const qty = { one: 1, two: 2, three: 3 }[c.state.qty]
        const product = PRODUCTS[c.state.product]
        c.state.total = qty * product.price
        return `🧾 ${qty} × ${product.label} = $${c.state.total}`
      })
      .choose('Confirm your order?', {
        yes: { label: 'Yes ✅', then: address },
        change: { label: '⬅️ Pick another product', goto: 'shop' },
      })
      .say((_ctx, c) => `📦 Order placed: $${c.state.total}, shipping to ${c.state.street}, ${c.state.city}.`),
  )

  bot.onMessage((ctx) => ctx.reply('Send "shop" to start shopping.'))

  return bot
})

export default createBot

// `node bot.js` connects to WhatsApp; `npx botmesh dev bot.js` skips this block
if (isMainModule(import.meta)) {
  const bot = await createBot(new BaileysProvider({ session: 'shop-bot' }))
  bot.on('ready', () => console.log('✅ Connected. Send "shop" from another phone.'))
  await bot.start()
}

Sample transcript

Captured with npx botmesh dev bot.js:

user › shop
bot › 🛒 *What do you want to buy?*

      1) 📱 Phone ($599)
      2) 👕 Shirt ($25)
      3) 🏠 Lamp ($35)
user › 1
bot › How many?

      1) 1 unit
      2) 2 units
      3) 3 units
user › 2
bot › 🧾 2 × 📱 Phone ($599) = $1198
bot › Confirm your order?

      1) Yes ✅
      2) ⬅️ Pick another product
user › 2
bot › 🛒 *What do you want to buy?*

      1) 📱 Phone ($599)
      2) 👕 Shirt ($25)
      3) 🏠 Lamp ($35)
user › 2
bot › How many?

      1) 1 unit
      2) 2 units
      3) 3 units
user › 3
bot › 🧾 3 × 👕 Shirt ($25) = $75
bot › Confirm your order?

      1) Yes ✅
      2) ⬅️ Pick another product
user › 1
bot › 🏠 Street and number?
user › 742 Evergreen Terrace
bot › 🏙️ City?
user › Springfield
bot › 📦 Order placed: $75, shipping to 742 Evergreen Terrace, Springfield.

How it works

• .choose(prompt, options, key) sends a numbered menu, accepts the number, the key or the label, and stores the chosen key in c.state[key]. Without a key it goes to c.state.choice.
• then: address runs the address flow inline when “Yes” is picked; it shares c.state, so the last .say() reads street and city. flow([]) has no trigger: it only runs from here.
• goto: 'shop' leaves the current flow and starts the named one (here, the same shop from the top). bot.lint() reports a goto to a flow that is not registered as an error (goto-target-missing).
• A function .say() can compute and store values (c.state.total) for later steps.
• .timeout('2m') applies to every wait of the flow; when it fires the bot sends conversation.timeoutMessage. A then sub-flow uses its own .timeout() (or the bot-wide default).

Run it on WhatsApp or Telegram

node bot.js prints a QR: scan it in WhatsApp → Linked devices. For Telegram, install @botmesh/telegram and swap the provider as shown in Or connect Telegram; the factory does not change.

Next steps

• Support with timeout: bot.conversation() with full control
• Menu bot: native buttons where the channel has them
• Inspect & lint flows: check flows before running them