This topic describes the request parameters and response parameters that each operation uses.

Common request parameters

Table 1. Common request parameters
Parameter Type Required Description
Format String No The format in which data is returned. Valid values:

JSON and XML. The default value is XML.

Version String Yes The version number of the API, in the format of YYYY-MM-DD. For example,


AccessKeyId String Yes The AccessKey ID provided to you by Alibaba Cloud.
Signature String Yes The signature string in the API request.
SignatureMethod String Yes The encryption method of the signature string. Valid value:


Timestamp String Yes The timestamp of the request. This parameter specifies the UTC time in the ISO 8601 standard, formatted in YYYY-MM-DDThh:mm:ssZ.

for example, 2013-01-10T12:00:00Z.

SignatureVersion String Yes The version of the signature encryption algorithm. Valid value:


SignatureNonce String Yes A unique and random number used to prevent replay attacks.

You must use different numbers for multiple requests.

ResourceOwnerAccount String No The account that owns the resource to be accessed through this API request.
http(s)://[Endpoint]/? Action=GetInstance

Common response parameters

All Alibaba Cloud API responses use a unified format, either the JSON format or XML format. You can specify the response format when you make the request. The default response format is XML. Every response includes a unique RequestId regardless of whether the call is successful.
  • API responses contain a HTTP status code. A 2xx status code indicates a successful call.
  • A 4xx or 5xx status code indicates a failed call.
The following are sample responses:
  • XML format
    <? xml version="1.0" encoding="utf-8"? > 
        <Response data>
            [DO NOT TRANSLATE]
            [DO NOT TRANSLATE]
        </Response data>
  • JSON format
        /*Response data*/