Agente de IA para WhatsApp com Fastify e Zavu

Fastify oferece alta performance e tipagem nativa. Veja como criar webhooks de WhatsApp e integrar agentes da Zavu em minutos.

Setup

bash
npm init -y
pnpm add fastify fastify-plugin @fastify/formbody @zavudev/sdk dotenv

src/env.ts carrega as variaveis ZAVUDEV_API_KEY, ZAVU_WEBHOOK_SECRET, ZAVU_SENDER_ID.

Servidor Fastify

typescript
import Fastify from 'fastify'
import crypto from 'crypto'
import Zavudev from '@zavudev/sdk'
import { config } from './env'

const app = Fastify({ logger: true })
const zavu = new Zavu({ apiKey: config.ZAVUDEV_API_KEY })

function verifySignature(payload: Buffer, signature?: string) {
  if (!signature) return false
  const digest = crypto
    .createHmac('sha256', config.ZAVU_WEBHOOK_SECRET)
    .update(payload)
    .digest('hex')
  return crypto.timingSafeEqual(Buffer.from(digest), Buffer.from(signature))
}

app.addHook('preValidation', (req, reply, done) => {
  req.rawBody = Buffer.from('')
  req.raw.on('data', (chunk) => (req.rawBody = Buffer.concat([req.rawBody, chunk])))
  req.raw.on('end', () => done())
})

app.post('/webhooks/whatsapp', async (request, reply) => {
  if (!verifySignature(request.rawBody, request.headers['x-zavu-signature'])) {
    return reply.code(401).send({ error: 'invalid signature' })
  }

  const event = request.body as any
  if (event.type === 'message.received') {
    await zavu.senders.agent.reply({
      senderId: config.ZAVU_SENDER_ID,
      contactId: event.data.contact.id,
      messageId: event.data.message.id
    })
  }

  return reply.send({ status: 'ok' })
})

app.listen({ port: 3000 })

Criando o agente

typescript
await zavu.senders.agent.create({
  senderId: config.ZAVU_SENDER_ID,
  name: 'Fastify Support',
  provider: 'zavu',
  model: 'mistral-large',
  systemPrompt: 'Atenda clientes B2B de forma concisa e tecnica.',
  contextWindowMessages: 12,
  includeContactMetadata: true,
  enabled: true
})

Extensoes recomendadas

fastify-rate-limit para proteger o webhook
fastify-helmet para cabecalhos de seguranca
pino (ja incluso) para logs estruturados

Recursos do AI Gateway

Conhecimento (PDFs, URLs)
Ferramentas HTTP/GraphQL
Fallback multicanal
Analytics com latencia e CSAT

Deploy e observabilidade

Hospede no Fly.io/Render (Node 20)

Configure health checks e log drains

Use bunx convex dev --once se tiver workflows relacionados conforme doc interna

Se quiser ver pipelines prontos de agente + CRM, agende uma demo.