Use caseYour customers book appointments on WhatsApp, and your calendar fills up.

Step by step, for real.

1. 1

   The agent’s two actions

   Claude Code sets them with set_agent_action: “Appointment request”, which notes the reason and the city, and “Slot choice”, which notes the slot picked. The agent triggers them on its own, as the conversation goes.

2. 2

   The request arrives, signed

   Your route, declared with create_webhook_endpoint, receives agent.action (unchecked by default, you tick it on purpose) and checks its signature: a request without a signature is refused.

3. 3

   Three free slots

   Your app reads your calendar near the city given and answers the customer with POST /v1/messages/whatsapp: they just wrote, the 24-hour window is open, no template is needed.

4. 4

   The slot booked

   The customer picks one; the agent triggers “Slot choice”, and your app books once per request, then confirms on WhatsApp.

What you type in Claude Code

With the plugin installed, one sentence is enough: Claude Code sets up the agent, writes the route and your calendar link, and tests.

when a customer asks for an appointment on whatsapp, the AI agent gets the reason and city, my app (route /api/webhooks/messagingme) offers 3 free slots from the calendar (lib/calendar.ts), and when they pick one we book it and confirm on whatsapp

The route, as Claude Code writes it

import { verifyWebhook, WebhookVerificationError } from '@messagingme/sdk';
import { messagingme } from '../../../../lib/messagingme';
import { book, offerSlots } from '../../../../lib/calendar';

// Subscribed to agent.action: the AI agent’s two actions, Appointment request (fields reason and city) and Slot
// choice (field slot). The type is unchecked by default on a webhook address.
export async function POST(req: Request) {
  // The RAW body: the signature covers its bytes.
  const body = await req.text();
  let event;
  try {
    event = await verifyWebhook({ secret: process.env.MESSAGINGME_WEBHOOK_SECRET!, headers: req.headers, body });
  } catch (e) {
    if (e instanceof WebhookVerificationError) return new Response(null, { status: 401 });
    throw e;
  }
  if (event.type !== 'agent.action' || !event.data.contact) return new Response(null, { status: 204 });
  const { action, fields, contact } = event.data;
  let text: string | null = null;
  if (action.name === 'Appointment request') text = await offerSlots(String(fields.city ?? ''), 3);
  if (action.name === 'Slot choice' && fields.slot !== undefined) text = await book(event.id, String(fields.slot));
  if (text) await messagingme.POST('/v1/messages/whatsapp', { body: { contactId: contact.id, text } });
  // Answer fast (under 10 s): a slow job runs after, otherwise the webhook is retried.
  return new Response(null, { status: 204 });
}

app/api/webhooks/messagingme/route.ts · all the code in the guide