# API for Querying Client Status

{% hint style="info" %}
This feature is currently only available to NaaS partners, enabling efficient querying of the status of multiple clients in bulk.
{% endhint %}

### Prerequisite

Please make sure you obtain `x-ak` & `x-sk` issued by Aethir. 

### Query Client Online Status

#### **Description**

This interface is used to query whether the client is online.

#### **URL**

<https://app.aethir.com/console-api/v2/client/onLineState>

#### **Method**

POST

#### Rate Limit

Each `x-ak` can make a request every 5 seconds.&#x20;

#### **Request Headers**

<table><thead><tr><th width="136">Header</th><th width="101">Type</th><th width="119">Mandatory</th></tr></thead><tbody><tr><td>x-ak</td><td>string</td><td>Yes</td></tr><tr><td>x-op-token</td><td>string</td><td>Yes</td></tr></tbody></table>

{% hint style="info" %}
**x-ak** is a verification code issued to qualified partner Node Operators.
{% endhint %}

{% hint style="info" %}
**x-op-token** is consists of three parts

<pre><code><strong>x-op-token = header.payload.signature
</strong></code></pre>

* **Header**

  A compact JSON string encoded with base64, representing the header.

  ```json
  {
    "alg": "HS256",  // Encryption algorithm, fixed as HS256
    "typ": "CHK_OP"  // Token type, fixed as CHK_OP
  }
  ```
* **Payload**

  A compact JSON string encoded with base64, representing the payload.

  ```json
  {
    "ak": "",       // Issued to nodeOperator's AK
    "exp": 1,       // Token expiration timestamp in ms, configured by the user
    "ip": "",       // Client IP
    "nonce": 1      // Random number generated by the user
  }
  ```
* **Signature**

  <pre class="language-json"><code class="lang-json"><strong>signature = base64UrlEncode(HmacSHA256.sign(base64UrlEncode(header) + "." + base64UrlEncode(payload), sk))
  </strong></code></pre>

  where `sk`is a verification code issued to qualified partner Node Operators.
  {% endhint %}

#### **Request Body**

The request body is an array of `clientId`, supporting a maximum of 100 IDs.

```json
[
  "clientId1",
  "clientId2",
  ...
]
```

#### **Response**

Possible responses and their corresponding meanings are:

* `HttpStatus 200`: Query successful; the query result is parsed in the `HttpResponseBody`.
* `HttpStatus 400`: The `x-op-token` format is incorrect or [rate limit](#rate-limit) exceeded.
* `HttpStatus 401`: The client needs to regenerate the `x-op-token` and retry the query.

#### **Response Body**

```json
[
  {
    "clientId": "clientId1",
    "onLineState": 1
  }
]
```

| Field       | Type   | Description           |
| ----------- | ------ | --------------------- |
| clientId    | string | Client ID             |
| onLineState | int    | 1: Online, 0: Offline |