Agente de IA para WhatsApp com NestJS e Zavu

Combine a arquitetura modular do NestJS com o AI Gateway da Zavu para oferecer suporte inteligente em WhatsApp.

Setup

bash
npx nest new whatsapp-agent
cd whatsapp-agent
npm install @zavudev/sdk @nestjs/config

ConfigModule

src/app.module.ts:

typescript
import { Module } from '@nestjs/common'
import { ConfigModule } from '@nestjs/config'
import { WebhookModule } from './webhook/webhook.module'

@Module({
  imports: [ConfigModule.forRoot({ isGlobal: true }), WebhookModule]
})
export class AppModule {}

Service

src/webhook/zavu.service.ts:

typescript
import { Injectable } from '@nestjs/common'
import Zavudev from '@zavudev/sdk'
import { ConfigService } from '@nestjs/config'

@Injectable()
export class ZavuService {
  private client: Zavu

  constructor(private config: ConfigService) {
    this.client = new Zavu({ apiKey: this.config.get('ZAVUDEV_API_KEY') })
  }

  async reply(messageId: string, contactId: string) {
    return this.client.senders.agent.reply({
      senderId: this.config.get('ZAVU_SENDER_ID'),
      messageId,
      contactId
    })
  }
}

Controller

src/webhook/webhook.controller.ts:

typescript
import { Controller, Post, Req, Res, Headers, HttpException } from '@nestjs/common'
import * as crypto from 'crypto'
import { ZavuService } from './zavu.service'

@Controller('webhooks')
export class WebhookController {
  constructor(private readonly zavu: ZavuService) {}

  @Post('whatsapp')
  async handle(@Req() req, @Res() res, @Headers('x-zavu-signature') signature: string) {
    const secret = process.env.ZAVU_WEBHOOK_SECRET
    const digest = crypto.createHmac('sha256', secret).update(req.rawBody).digest('hex')
    if (!crypto.timingSafeEqual(Buffer.from(digest), Buffer.from(signature || ''))) {
      throw new HttpException('invalid signature', 401)
    }

    const event = req.body
    if (event.type === 'message.received') {
      await this.zavu.reply(event.data.message.id, event.data.contact.id)
    }

    res.json({ status: 'ok' })
  }
}

Ative rawBody em main.ts:

typescript
app.use(json({ verify: (req: any, res, buf) => (req.rawBody = buf) }))

Criando o agente

typescript
await zavu.senders.agent.create({
  senderId: process.env.ZAVU_SENDER_ID,
  name: 'Nest Support',
  provider: 'zavu',
  model: 'gemini-pro',
  systemPrompt: 'Responda clientes SaaS em PT-BR',
  contextWindowMessages: 10,
  enabled: true
})

Knowledge bases e ferramentas

client.senders.agent.knowledge_bases.attach para anexar docs
client.senders.agent.tools.create para expor APIs internas (ex.: verificar pedido)

Observabilidade

Use interceptors Nest para logar cada execucao do agente e envie metricas ao Prometheus ou OpenTelemetry.

Deploy

Dockerize (Node 20) e suba em Kubernetes/ECS
Configure secrets via AWS SSM/Azure Key Vault
Configure auto scaling baseado em QPS do webhook

Pronto! Agora voce tem um modulo NestJS que responde automaticamente no WhatsApp. Para ver integrações com CRM/ERP funcionando ao vivo, agende uma demo.