Common parameters, including common request parameters and common response parameters, are the API request parameters that are required in all API requests for a service.
Common request parameters
Common request parameters must be included in all API requests.
| Parameter | Type | Required | Description |
|---|---|---|---|
| Format | String | No | The format in which to return the response. Valid values: JSON and XML. Default value: JSON. |
| Version | String | Yes | The version number of the API. The value is in the YYYY-MM-DD format. Set the value to 2019-03-15. |
| AccessKeyId | String | Yes | The AccessKey ID provided to you by Alibaba Cloud. |
| Signature | String | Yes | The signature string of the request. For more information about how signatures are calculated, see Request signatures. |
| SignatureMethod | String | Yes | The encryption method of the signature string. Set the value to HMAC-SHA1. |
| Timestamp | String | Yes | The timestamp of the request. Specify the time in the ISO 8601 standard in the yyyy-MM-ddTHH:mmZ format. The time must be in UTC. For example, 2013-08-15T12:00:00Z indicates 20:00:00 on August 15, 2013, UTC+8. |
| SignatureVersion | String | Yes | The version of the signature encryption algorithm. Set the value to 1.0. |
| SignatureNonce | String | Yes | A unique and random number that is used to prevent replay attacks. You must use different numbers for different requests. |