# Authenticate Request

{% hint style="info" %}
**Note:** Add apiKey, signature and payload in every request header.
{% endhint %}

### Sample header to add API key, Signature and Payload

```javascript
const headers = {
      'apikey': apiKey,
      'payload': payload,
      'signature': signature,
    };
```

### Generate Payload and Signature

```javascript
const CryptoJS = require('crypto-js');

async function generatePayloadAndSignature(secret, body) {
  const timestamp = Date.now().toString();
  const obj = {
    body,
    timestamp
  };
  const payload = CryptoJS.enc.Base64.stringify(CryptoJS.enc.Utf8.parse(JSON.stringify(obj)));
  const signature = CryptoJS.enc.Hex.stringify(CryptoJS.HmacSHA512(payload, secret));
  return { payload, signature };
}
```

### Postman Pre request Script

```javascript
const apiKey = "" 
const secret = "" 
let body;
if(pm.request.body.urlencoded){
    body = pm.request.body.urlencoded.reduce((data, param) => {
    data[param.key] = param.value;
    return data;
    }, {});   
}
else if(pm.request.body.formdata){
    body = pm.request.body.formdata.reduce((data, param) => {
    data[param.key] = param.value;
    return data;
    }, {});
}
else{
    body = {}
}
const timestamp = Date.now().toString()
const obj = {
    body,
    timestamp
}

let payload = CryptoJS.enc.Base64.stringify(CryptoJS.enc.Utf8.parse(JSON.stringify(obj)));
let signature = CryptoJS.enc.Hex.stringify(CryptoJS.HmacSHA512(payload, secret));

pm.request.headers.add({ 
    key: "apiKey", 
    value: apiKey 
}); 

pm.request.headers.add({ 
    key: "payload", 
    value: payload 
}); 
 
pm.request.headers.add({ 
    key: "signature", 
    value: signature 
}); 
```

#### AUTHENTICATION ERROR CODE

| Error Codes | Error Message                 |
| ----------- | ----------------------------- |
| 429         | Too many requests!            |
| 500         | Internal server error.        |
| 401         | Invalid Signature             |
| 401         | Missing necessary header data |
| 401         | Invalid api key               |
| 401         | Missing timestamp in payload  |
| 401         | Missing body in payload       |
| 401         | Timestamp expired             |
| 401         | Ahead of time                 |
| 401         | Body and Payload mismatch     |