# Integration Options
## Overview
Client Gateway offers a user interface for managing topics and channels, as well as for sending and receiving data; however, these functions can also be performed using REST APIs. Additionally, two-way interactive communication between senders and receivers can also be achieved using the WebSocket APIs.
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## User Guide
### Pre-requisites
* Authorization to Client Gateway
### HTTP API
Navigate to Client Gateway Swagger to see the available REST API collection
Integration APIs
Client Gateway Swagger
#### Sending Requests and Consuming Data (example)
{% hint style="info" %}
This example uses `axios` library to demonstrate requests.
{% endhint %}
```typescript
import axios from 'axios';
axios.get('https://{the-client-gw-api-here}/api/v2/identity', {
headers: {
'Content-Type': 'application/json',
'x-api-key': '{the-api-key-here}'
}
})
.then(response => {
console.log(response.data);
})
.catch(error => {
console.error('Error fetching data:', error);
});
```
### WebSocket API
Unlike REST APIs, which require separate requests for each interaction, WebSockets allow continuous, two-way communication — ideal for real-time messaging. Navigate to Web Socket API for DDHub Gateway Web Socket API 1.0.0
Integration APIs
WebSocket API documentation
#### Connecting
Please ensure to use `Sec-WebSocket-Protocol` : `ddhub-protocol` in the header
```javascript
// Connect websocket
const socket = new WebSocket('wss:{ddhub-wss-url}', ['ddhub-protocol']);
socket.onopen = () => {
console.log('Connected with subprotocol:', socket.protocol);
};
```
#### Sending a WS Message (example)
```javascript
// send message
socket.send(JSON.stringify({
"fqcn": "test.pub.chnl",
"topicName": "test_topic",
"topicVersion": "1.0.1",
"topicOwner": "ddhub.test",
"transactionId": "45d5a89f-7c2c-48b0-ae9a-54f4128e818",
"payload": "{ data: 70 }"
}));
```
#### Consuming a WS Message
```javascript
// set up a listener for incoming messages
socket.onmessage = function (event) {
const data = JSON.parse(event.data);
console.log('Received:', data);
};
```
