Agente IA para agendar citas en WhatsApp: guia LATAM 2026

# Instalar el SDK de Meta para Node.js
npm install whatsapp-business-sdk @anthropic-ai/sdk googleapis pg

# Variables de entorno necesarias
WHATSAPP_PHONE_NUMBER_ID=tu_phone_number_id
WHATSAPP_TOKEN=tu_access_token
WHATSAPP_VERIFY_TOKEN=tu_webhook_verify_token
ANTHROPIC_API_KEY=tu_api_key
GOOGLE_SERVICE_ACCOUNT_JSON=ruta_al_json

import Anthropic from #43a047">"@anthropic-ai/sdk";
import { google } from #43a047">"googleapis";

const client = new Anthropic();

const TOOLS = [
  {
    name: #43a047">"check_availability",
    description: #43a047">"Consulta los horarios disponibles en el calendario para una fecha especifica. Devuelve lista de slots libres en formato HH:MM.",
    input_schema: {
      type: #43a047">"object",
      properties: {
        date: { type: #43a047">"string", description: "Fecha en formato YYYY-MM-DD" },
        duration_minutes: { type: #43a047">"number", description: "Duracion en minutos (default 30)" }
      },
      required: [#43a047">"date"]
    }
  },
  {
    name: #43a047">"create_appointment",
    description: #43a047">"Crea una cita confirmada en el calendario. Usar solo cuando el cliente haya confirmado explicitamente.",
    input_schema: {
      type: #43a047">"object",
      properties: {
        date: { type: #43a047">"string", description: "Fecha YYYY-MM-DD" },
        time: { type: #43a047">"string", description: "Hora HH:MM (24h)" },
        client_name: { type: #43a047">"string" },
        client_phone: { type: #43a047">"string" },
        service: { type: #43a047">"string", description: "Tipo de servicio o motivo" }
      },
      required: [#43a047">"date", "time", "client_name", "client_phone"]
    }
  }
];

const SYSTEM_PROMPT = #43a047">`Eres el asistente de agenda de [Nombre del Negocio]. 
Tu funcion es agendar citas por WhatsApp de forma rapida y amigable.
Horario: lunes a sabado, 9am a 7pm.
Reglas:
- Habla en espanol neutro, se conciso (maximo 3 oraciones por respuesta)
- Siempre confirma la cita verbalmente antes de crearla: "Confirmo tu cita para el [dia] a las [hora], correcto?"
- Solo crea el evento cuando el cliente confirme con "si", "perfecto", "dale" o equivalente
- Si el usuario pide un horario ocupado, ofrece las 3 alternativas mas proximas`;

async function runAgent(userMessage: string, history: any[]) {
  const messages = [...history, { role: #43a047">"user", content: userMessage }];
  
  const response = await client.messages.create({
    model: #43a047">"claude-sonnet-4-5",
    max_tokens: 512,
    system: SYSTEM_PROMPT,
    tools: TOOLS,
    messages
  });

  if (response.stop_reason === #43a047">"tool_use") {
    const toolResults = await processToolCalls(response.content);
    return runAgent(#43a047">"", [
      ...messages,
      { role: #43a047">"assistant", content: response.content },
      { role: #43a047">"user", content: toolResults }
    ]);
  }

  const text = response.content.find(b => b.type === #43a047">"text")?.text ?? "";
  return { text, updatedHistory: [...messages, { role: #43a047">"assistant", content: text }] };
}

import express from #43a047">"express";
import Redis from #43a047">"ioredis";

const app = express();
app.use(express.json());

const redis = new Redis(process.env.REDIS_URL);

// Verificacion del webhook (requerida por Meta)
app.get(#43a047">"/webhook", (req, res) => {
  if (req.query[#43a047">"hub.verify_token"] === process.env.WHATSAPP_VERIFY_TOKEN) {
    res.send(req.query[#43a047">"hub.challenge"]);
  } else {
    res.sendStatus(403);
  }
});

app.post(#43a047">"/webhook", async (req, res) => {
  res.sendStatus(200); // Responder inmediatamente a Meta (timeout en 20s)

  const message = req.body.entry?.[0]?.changes?.[0]?.value?.messages?.[0];
  if (!message || message.type !== #43a047">"text") return;

  const from = message.from;
  const text = message.text.body;

  // Historial con TTL de 24h (ventana de conversacion de WhatsApp)
  const rawHistory = await redis.get(#43a047">`chat:${from}`);
  const history = rawHistory ? JSON.parse(rawHistory) : [];

  const { text: reply, updatedHistory } = await runAgent(text, history);

  await redis.set(#43a047">`chat:${from}`, JSON.stringify(updatedHistory), "EX", 86400);
  await sendWhatsAppMessage(from, reply);
});

app.listen(3000);

async function checkAvailability(date: string, durationMinutes = 30): Promise<string[]> {
  const startOfDay = new Date(#43a047">`${date}T09:00:00-04:00`);
  const endOfDay   = new Date(#43a047">`${date}T19:00:00-04:00`);

  const { data } = await calendar.freebusy.query({
    requestBody: {
      timeMin: startOfDay.toISOString(),
      timeMax: endOfDay.toISOString(),
      items: [{ id: #43a047">"primary" }]
    }
  });

  const busy = data.calendars?.primary?.busy ?? [];
  return generateFreeSlots(startOfDay, endOfDay, busy, durationMinutes).slice(0, 5);
}

async function createAppointment(data: AppointmentData): Promise<string> {
  const { data: event } = await calendar.events.insert({
    calendarId: #43a047">"primary",
    requestBody: {
      summary: #43a047">`Cita - ${data.client_name}`,
      description: #43a047">`Servicio: ${data.service || "No especificado"}\nWA: ${data.client_phone}`,
      start: { dateTime: #43a047">`${data.date}T${data.time}:00-04:00` },
      end:   { dateTime: addMinutes(#43a047">`${data.date}T${data.time}:00-04:00`, durationMinutes) },
      reminders: {
        useDefault: false,
        overrides: [{ method: #43a047">"popup", minutes: 30 }]
      }
    }
  });
  return event.id!;
}