# n8n Workflow: Automate WhatsApp Booking System with GPT-4 Assistant, Cal.com, and SMS Reminders

This n8n workflow creates a sophisticated, automated WhatsApp booking system. It leverages an AI assistant (GPT-4 via LangChain) to manage booking requests, integrates with Cal.com for scheduling, and sends SMS reminders for appointments.

## What it does

This workflow automates the following steps:

1.  **Receives WhatsApp Messages**: Listens for incoming messages via a webhook, acting as the entry point for booking requests.
2.  **Processes with AI Assistant**: Routes the incoming message to an AI Agent (powered by OpenAI's GPT-4) which uses a "Simple Memory" to maintain context and an "HTTP Request Tool" to interact with external services (like Cal.com).
3.  **Handles AI Responses**:
    *   **If AI requests an external HTTP Action**: The workflow executes the HTTP request (e.g., to Cal.com to create a booking) and then feeds the result back to the AI Agent for further processing or confirmation.
    *   **If AI provides a direct response**: The workflow sends the AI's response back to the user via the initial webhook.
4.  **Schedules SMS Reminders**: (Implied, as a Google Sheets node and an SMS77 node are present, suggesting a separate or integrated flow for reminders based on booking data). The Google Sheets node likely stores booking details, which the SMS77 node would then use to send reminders.

## Prerequisites/Requirements

To use this workflow, you will need:

*   **n8n Instance**: A running n8n instance.
*   **WhatsApp Integration**: A WhatsApp Business API or a similar service that can send messages to a webhook (e.g., Twilio, MessageBird, or a custom integration).
*   **OpenAI API Key**: For the AI Agent (GPT-4) to function.
*   **Cal.com Account & API Key**: For scheduling appointments. The "HTTP Request Tool" will likely interact with the Cal.com API.
*   **Google Sheets Account**: To store booking data (e.g., appointment details, customer information).
*   **SMS77 Account & API Key**: For sending SMS reminders.

## Setup/Usage

1.  **Import the Workflow**:
    *   Download the provided JSON file.
    *   In your n8n instance, click "New" in the workflows section.
    *   Click the "Import from JSON" button and paste the workflow JSON or upload the file.
2.  **Configure Credentials**:
    *   **Webhook Trigger**: Configure your WhatsApp integration to send messages to the webhook URL provided by the "Webhook" trigger node.
    *   **OpenAI Chat Model**: Add your OpenAI API Key credential.
    *   **HTTP Request Tool**: Configure the HTTP Request Tool with your Cal.com API endpoint and authentication details.
    *   **Google Sheets**: Set up your Google Sheets credential and specify the spreadsheet and sheet where booking data will be stored.
    *   **seven (SMS77)**: Add your SMS77 API Key credential.
3.  **Customize AI Agent**:
    *   Review the "AI Agent" node's configuration. You might need to adjust its instructions or "tools" to fit your specific booking scenarios and Cal.com API interactions.
    *   The "Simple Memory" node will handle conversational context for the AI.
4.  **Activate the Workflow**: Once all credentials and configurations are set, activate the workflow.

This setup will allow your WhatsApp users to interact with an AI assistant to book appointments, with the system automatically handling scheduling and reminders.