> For the complete documentation index, see [llms.txt](https://docs.console.zenlayer.com/api-reference/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.console.zenlayer.com/api-reference/compute/vm/virtual-machine-instance/modifyinstancetype.md).

# ModifyInstanceType

## 1. API Description

This API (ModifyInstanceType) is used to modify the specifications of a virtual machine instance.

{% hint style="info" %} <mark style="color:blue;">**Note**</mark>

* <mark style="color:blue;">You can only perform this operation on instances whose status is</mark> <mark style="color:blue;">`RUNNING`</mark> <mark style="color:blue;">or</mark><mark style="color:blue;">`STOPPED`</mark><mark style="color:blue;">.</mark>
* <mark style="color:blue;">If the</mark> <mark style="color:blue;">`internetChargeType`</mark> <mark style="color:blue;">of your instance is</mark> <mark style="color:blue;">`PREPAID:`</mark>
  * <mark style="color:blue;">Upgrade (target > current) operation will generate an order to be paid and deduct the amount required for this instance purchase. The request takes effect immediately.</mark>
  * <mark style="color:blue;">Downgrade (target < current) operation will generate an order for the next billing cycle and will take effect by then.</mark>
* <mark style="color:blue;">If the</mark> <mark style="color:blue;">`internetChargeType`</mark> <mark style="color:blue;">of your instance is</mark> <mark style="color:blue;">`POSTPAID`</mark><mark style="color:blue;">:</mark>
  * <mark style="color:blue;">The change takes immediate effect.</mark>
* <mark style="color:blue;">This API is an async API. Use</mark> <mark style="color:blue;">`DescribeInstanceTypeStatus`</mark> <mark style="color:blue;">to query specifications of an instance.</mark>
* <mark style="color:blue;">Rules of specification change:</mark>
  * <mark style="color:blue;">Changes between models with same series are allowed. For example, change the model of</mark> <mark style="color:blue;">`c.1c2g`</mark> <mark style="color:blue;">to</mark> <mark style="color:blue;">`c.2c4g`</mark><mark style="color:blue;">.</mark>
  * <mark style="color:blue;">Some changes between models with different series are allowed. For example, changes between</mark> <mark style="color:blue;">`c`</mark><mark style="color:blue;">,</mark> <mark style="color:blue;">`g`</mark> <mark style="color:blue;">and</mark> <mark style="color:blue;">`m`</mark> <mark style="color:blue;">series.</mark>
  * <mark style="color:blue;">Some changes between models with different series are not allowed. For example, changes between</mark> <mark style="color:blue;">`s`</mark> <mark style="color:blue;">and</mark> <mark style="color:blue;">`h`</mark> <mark style="color:blue;">series.</mark>
    {% endhint %}

## 2. Input Parameters

The following request parameter list only provides API request parameters.

| Parameter Name | Required | Type   | Description                                                                                                                                                    |
| -------------- | -------- | ------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| instanceId     | Yes      | String | <p>ID of the instance to be modified.</p><p>To obtain the instance ID, you can call DescribeInstances and look for instanceId in the response.</p>             |
| instanceTypeId | Yes      | String | <p>ID of the target model to change.</p><p>To obtain the model ID, you can call DescribeZoneInstanceConfigInfos and look for instanceType in the response.</p> |

## 3. Output Parameters

| Parameter Name | Type   | Description                                                                                                           |
| -------------- | ------ | --------------------------------------------------------------------------------------------------------------------- |
| requestId      | String | <p>The unique request ID, which is returned for each request.</p><p>RequestId is required for locating a problem.</p> |
| orderNumber    | String | Number of order.                                                                                                      |

## 4. Code Example

{% tabs %}
{% tab title="Example" %}
**Modify the model of an instance.**

```javascript
POST /api/v2/vm HTTP/1.1
Host: console.zenlayer.com
Content-Type: application/json
X-ZC-Action: ModifyInstanceType
<Common Request Params>

Request：
{
  "instanceId": "instanceId",
  "instanceTypeId": "c.2c4g"
}

Response：
{
  "requestId": "T05992D0C-7E8B-4047-B0C0-780F2CD549D3",
  "response": {  
    "requestId": "T05992D0C-7E8B-4047-B0C0-780F2CD549D3",
    "orderNumber": "xxxx"
  }
}
```

{% endtab %}
{% endtabs %}

## 5. Developer Resources

Zenlayer Cloud API 2.0 integrates [SDKs](/api-reference/api-introduction/toolkit/api-sdk.md)，to make it easier for you to call APIs. More programming languages will be supported.

## 6. Error Codes

The following only lists the error codes related to the API business logic. For other error codes, see [Common Error Codes](/api-reference/api-introduction/instruction/commonerrorcode.md).

| HTTP Status Code | Error Code                                       | Description                                                              |
| ---------------- | ------------------------------------------------ | ------------------------------------------------------------------------ |
| 404              | INVALID\_INSTANCE\_NOT\_FOUND                    | Instance does not exist.                                                 |
| 400              | INVALID\_INSTANCE\_TYPE\_NOT\_CHANGED            | Instance model does not changed.                                         |
| 400              | OPERATION\_FAILED\_INSTANCE\_TYPE\_UNSUPPORTED   | Unsupported model for the current instance.                              |
| 403              | OPERATION\_DENIED\_INSTANCE\_EXIST\_PLAN         | A scheduling change exists.                                              |
| 403              | OPERATION\_DENIED\_INSTANCE\_PLAN\_PROCESSING    | A processing change exists.                                              |
| 400              | UNSUPPORTED\_OPERATION\_INSTANCE\_STATUS         | Only operations on instances in RUNNING or STOPPED status are supported. |
| 400              | UNSUPPORTED\_OPERATION\_ZONE\_NOT\_SUPPORT       | Operations not supported in current zone.                                |
| 400              | UNSUPPORTED\_OPERATION\_INSTANCE\_BEING\_RECYCLE | Operations on instances in recycle bin are not supported.                |
| 404              | INVALID\_PRODUCT\_NOT\_FOUND                     | Model does not exist.                                                    |