> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oppiwallet.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Generate JWT Token

> Learn how to create and sign JWT tokens for API authentication

### JWT Requirements

Your JWT must meet the following specifications:

* **Algorithm**: HS256 (HMAC SHA-256)
* **Signature**: Created using SHA-256 hash
* **Expiration**: Short-lived token (60 seconds)

### Creating the Signature

Before generating the JWT, you need to create a signature:

```javascript theme={null}
const crypto = require('crypto');

// Example values
const currency = 'BTC';
const amount = '0.001';
const orderId = '12345';

// Create signature string
const signatureData = `${currency}#${amount}#${orderId}`;

// Generate signature hash
const signature = crypto
  .createHash("sha256")
  .update(JSON.stringify(signatureData))
  .digest("hex");
```

### JWT Payload Structure

Your JWT payload must include:

```javascript theme={null}
const payload = {
  "url": "/path/to/endpoint",  // API endpoint path
  "iat": Date.now(),          // Issued at time (milliseconds)
  "exp": Date.now() + 60000,  // Expiration time (current time + 60 seconds)
  "key": "YOUR_AUTH_KEY",     // Your Auth Key
  "signature": signature      // The signature created above
};
```

**Important Notes:**

* All datetime values must be in GMT format
* The expiration time (`exp`) must be set to current time + 60 seconds (in milliseconds)

### Generating the JWT

Use your Enc Key to sign the JWT:

```javascript theme={null}
const jwt = require('jsonwebtoken');

// Create the signed token
const token = jwt.sign(
  payload,
  'YOUR_ENC_KEY',   // Your Enc Key
  { algorithm: 'HS256' }
);

// The token can now be used in your API request
```

### Using the JWT in Requests

Include the JWT in your API requests:

```javascript theme={null}
const headers = {
  'Authorization': `Bearer ${token}`,
  'x-auth-key': 'YOUR_AUTH_KEY',
  'Content-Type': 'application/json'
};

// Make your API request with these headers
```

### Troubleshooting

If you encounter authentication errors:

* Verify your Auth Key and Enc Key are correct and active
* Check that your system clock is synchronized (JWT validation is time-sensitive)
* Ensure all required payload fields are present and correctly formatted
* Verify that your signature is being generated correctly