# 1. Pre-fetch Links in Background (Zero-Delay)

Secretly pre-fetch verification links with zero delay before the user clicks login.

---

**ReOTP** is designed to deliver a "Zero-Type Auth" experience. Simply request the verification links and we will magically capture the user's phone number directly from their message!

### Request Body Parameters:
- `apiKey` (string - Required): Your project's API Key.
- `phoneNumber` (string - Optional): The user's phone number. If omitted, we will automatically capture it from the sender.
- `method` (string - Required): Must be `"WHATSAPP"` or `"TELEGRAM"`.
- `returnUrl` (string - Optional): Redirect URL for Telegram bot completion.

### Response Body Parameters:
- `requestId` (string): Unique identifier for the verification session.
- **UI Best Practices:** We highly recommend displaying a countdown timer in your UI to guide the user to complete the verification before it times out.

Send a <code>POST</code> request to the endpoint shown in the code panel to initialize the session.

## Code Examples

### cURL (WhatsApp)

```javascript
curl -X POST https://[your-domain.com]/api/verify/init \
  -H "Content-Type: application/json" \
  -d '{
    "apiKey": "YOUR_API_KEY",
    "method": "WHATSAPP"
  }'
```

### cURL (Telegram)

```javascript
curl -X POST https://[your-domain.com]/api/verify/init \
  -H "Content-Type: application/json" \
  -d '{
    "apiKey": "YOUR_API_KEY",
    "method": "TELEGRAM",
    "returnUrl": "https://your-app.com/success"
  }'
```

### JavaScript

```javascript
const initVerification = async () => {
  const res = await fetch("https://[your-domain.com]/api/verify/init", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      apiKey: "YOUR_API_KEY",
      method: "WHATSAPP", // Or "TELEGRAM"
      returnUrl: "https://your-app.com/success" // Optional for Telegram
    })
  });
  
  const data = await res.json();
  if (data.requestId) {
    console.log("Success! Session ID:", data.requestId);
    // Redirect or open the link
    const destinationLink = data.waLink || data.tgLink;
    window.open(destinationLink, "_blank");
  }
};
```

### Node.js

```javascript
const axios = require('axios');

axios.post('https://[your-domain.com]/api/verify/init', {
  apiKey: 'YOUR_API_KEY',
  method: 'WHATSAPP', // or 'TELEGRAM'
  returnUrl: 'https://your-app.com/success'
})
.then(response => {
  console.log('Session ID:', response.data.requestId);
  console.log('Verification Link:', response.data.waLink || response.data.tgLink);
})
.catch(error => {
  console.error('Error starting verification:', error);
});
```

### Python

```javascript
import requests

payload = {
    "apiKey": "YOUR_API_KEY",
    "method": "WHATSAPP", # or "TELEGRAM"
    "returnUrl": "https://your-app.com/success"
}

response = requests.post(
    "https://[your-domain.com]/api/verify/init",
    json=payload
)

data = response.json()
print("Session ID:", data.get("requestId"))
print("Link:", data.get("waLink") or data.get("tgLink"))
```


## Interactive Demo

Demo type: init
Title: Interactive Verification Demo

See the live demo at: https://reotp.com/hi/docs/api-init