### 4. **Kiwi.com API**:
- **Kiwi.com** offers an API for flight booking and searches.
- You can integrate this with Twilio to power a flight search service via WhatsApp.

### 5. **Custom Bot on WhatsApp Business API**:
- You can use WhatsApp Business API along with your own bot or a third-party flight search API.
- Create a conversational experience for users, where they ask for flights and receive real-time results.

WhatsApp itself does not offer a direct API for flight search, but you can integrate a flight search service with WhatsApp through the following approaches:

### 1. **Twilio API for WhatsApp**:
- **Twilio** provides an API to send and receive WhatsApp messages.
- You can integrate a flight search service (such as Skyscanner, Amadeus, or Kiwi.com) with Twilio to allow users to request flight information via WhatsApp.
- Example flow:
- A user sends a message like "Find flights from New York to London."
- Your backend fetches flight data from an API (Skyscanner, etc.) and replies to the user through Twilio's WhatsApp API.

### 2. **Amadeus API**:
- **Amadeus** provides a comprehensive flight search API, which you can use to search flights, get flight offers, and more.
- You can integrate Amadeus with Twilio to respond to WhatsApp messages with flight search results.

### 3. **Skyscanner Flight Search API**:
- **Skyscanner** offers a flight search API that allows you to search flights and get price comparisons.
- Once integrated with your backend, you can use a service like Twilio to allow users to interact through WhatsApp for real-time flight searches.