AI router: intents to flows, chit-chat to the AI

A phone-company bot where the model only classifies free text: payments and order tracking run as deterministic flows, and the rest is answered by the AI.

Level: Advanced · Tags: AI, Flows, Intent routing, WhatsApp, Telegram

Features shown: ctx.tools.ai.generate() · replyInChat() with chat history · flows with validation and menus · starting a flow from code (bot.trigger) · catch-all handler · cost and latency settings

Prerequisites

• Node.js 22.12 or newer.
• An Anthropic API key in the ANTHROPIC_API_KEY environment variable (or another model provider, see below).

npm install @botmesh/core @botmesh/ai @anthropic-ai/sdk @botmesh/baileys

The bot

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

const INTENTS = ['payment', 'order', 'chat']
const CLASSIFIER = [
  'Classify the message a customer sent to Nimbus Mobile, a phone company, with one label:',
  'payment (wants to pay a bill or asks how to pay),',
  'order (asks where an order, a phone or a SIM card delivery is),',
  'chat (anything else). Reply with the label only.',
].join(' ')

// One small, bounded model call. The label is checked in code: the model only picks.
async function classify(ctx) {
  const { text } = await ctx.tools.ai.generate({
    system: CLASSIFIER,
    messages: [{ role: 'user', content: ctx.body }],
    maxTokens: 100,
    effort: 'low',
  })
  const label = text.trim().toLowerCase().replace(/[^a-z]/g, '')
  return INTENTS.includes(label) ? label : 'chat'
}

// Stand-in for your order system.
const trackOrder = (id) => `📦 Order ${id.toUpperCase()} left our warehouse and arrives tomorrow.`

const createBot = defineBot((provider) => {
  const bot = new Bot({ provider })

  bot.plug(slashCommandsPlugin, {
    greeting: '📱 Hi! I am the Nimbus Mobile assistant. I can take a payment, track an order or answer questions.',
  })

  // Deterministic flows. Typing their name ("payment", "order") starts them without any AI call.
  bot.use(
    flow('payment')
      .say('💳 *Pay your bill*')
      .ask('What is your account number? (6 digits)', 'account', {
        validate: (body) => (/^\d{6}$/.test(body.trim()) ? true : '❌ The account number has 6 digits, try again'),
      })
      .choose('How do you want to pay?', { card: 'Card', transfer: 'Bank transfer' }, 'method')
      .say((_ctx, c) => `✅ We sent a ${c.state.method === 'card' ? 'card payment' : 'bank transfer'} link for account ${c.state.account}.`),
  )
  bot.use(
    flow('order')
      .ask('What is your order number? (like N-1234)', 'id', {
        validate: (body) => (/^n-\d{4}$/i.test(body.trim()) ? true : '❌ That does not look like N-1234, try again'),
      })
      .say((_ctx, c) => trackOrder(c.state.id.trim())),
  )

  bot.plug(aiPlugin({
    provider: 'anthropic',
    apiKey: process.env.ANTHROPIC_API_KEY,
    model: 'claude-haiku-5-5',
    persona: 'You are the assistant of Nimbus Mobile, a phone company. Answer briefly and only about Nimbus Mobile.',
    autoReply: false, // the router below decides who answers
  }))

  // Free text: classify, then hand off to a flow or let the AI answer.
  bot.onMessage(async (ctx) => {
    // Photos, audio or locations without text: nothing to classify, so no model call.
    if (!ctx.body.trim()) return ctx.reply('✍️ I can only read text for now. Type "payment", "order" or your question.')
    try {
      const intent = await classify(ctx)
      if (intent === 'chat') {
        await ctx.reply(await ctx.tools.ai.replyInChat(chatKeyOf(ctx), ctx.body))
        return
      }
      await bot.trigger(intent, { chatId: ctx.from, userId: ctx.sender, isGroup: ctx.isGroup })
    } catch (err) {
      // No key, timeout, rate limit or outage: log it and never leave the customer in silence.
      bot.logger.warn({ err }, 'AI router failed')
      await ctx.reply('😕 I cannot answer that right now. Type "payment" or "order", or try again in a moment.')
    }
  })

  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: 'router-bot' }))
  bot.on('ready', () => console.log('✅ Connected'))
  await bot.start()
}

How it works

• The model classifies, your code decides. classify() asks for one label with ctx.tools.ai.generate(), a call without chat history or persona. The answer is cleaned and checked against INTENTS; anything unexpected falls back to chat, so a confused model can never start a flow you did not list.
• Money stays deterministic. The payment flow validates the account number, offers a fixed menu and builds the confirmation in code. The model never sees the account number or decides the amount.
• bot.trigger() starts the flow. It is safe to await from a handler of the same chat: it runs in that message’s turn. The flow then owns the next messages, exactly as if the user had typed its name.
• Chit-chat keeps a history. replyInChat(chatKeyOf(ctx), text) reads and stores the chat’s AI history and uses the plugin’s persona. With autoReply: false the plugin does not add its own catch-all.
• Never silent. A model error (no key, timeout, rate limit, outage) is logged and the customer gets a fixed answer that points to the flows, which still work without the AI. Messages with no text (a photo, a voice note, a location) get a fixed answer too, without a model call.
• Cost. Keywords (“payment”, “order”) and slash commands skip the classifier. The classifier call is short (maxTokens: 100, effort: 'low'); maxTokens includes the thinking tokens of reasoning models, so do not set it too low.

Try it

npx botmesh dev bot.js --env-file .env   # .env has the line ANTHROPIC_API_KEY=sk-ant-...

A run of the code above in the terminal simulator. The model (the classifier labels and the chit-chat answer) is scripted by the test that runs this page (packages/ai/tests/docs-examples-ai.test.ts); the flows are the real ones.

user › hi, I'd like to pay my bill please
bot › 💳 *Pay your bill*
bot › What is your account number? (6 digits)
user › 12345
bot › ❌ The account number has 6 digits, try again
user › 123456
bot › How do you want to pay?

      1) Card
      2) Bank transfer
user › 1
bot › ✅ We sent a card payment link for account 123456.
user › where is my new SIM card?
bot › What is your order number? (like N-1234)
user › N-2041
bot › 📦 Order N-2041 left our warehouse and arrives tomorrow.
user › thanks, you are great!
bot › Happy to help! 😊 Anything else about your Nimbus plan?

Other model providers

Switch to OpenAI, Gemini or a local Ollama model

Change the aiPlugin options; effort is ignored by providers other than Anthropic.

OpenAI (npm install openai, key in OPENAI_API_KEY):

aiPlugin({ provider: 'openai', apiKey: process.env.OPENAI_API_KEY, model: 'gpt-5-mini', autoReply: false })

Gemini (npm install @google/genai, key in GEMINI_API_KEY):

aiPlugin({ provider: 'gemini', apiKey: process.env.GEMINI_API_KEY, model: 'gemini-3.8-flash', autoReply: false })

Ollama on your machine (no package, no key; run ollama pull llama3.1 first):

aiPlugin({ provider: 'ollama', model: 'llama3.1', autoReply: false })

Run it on WhatsApp or Telegram

node bot.js prints a QR code: scan it with WhatsApp (Linked devices). For Telegram, install @botmesh/telegram and start the factory with new TelegramProvider({ token: process.env.TELEGRAM_TOKEN ?? '' }).

Next steps

• Conversation flows: every step of the flow DSL
• AI with human escalation: let the model pass the chat to a person
• Examples overview