# Common Parameters
<a name="CommonParameters"></a>

This section lists the request parameters that all actions use. Any action-specific parameters are listed in the topic for the action.

 **Action**   
The action to be performed.  
Default: None  
Type: string  
 Required: Yes 

 **AuthParams**   
The parameters that are required to authenticate a Conditional request. Contains:  
+ AWSAccessKeyID
+ SignatureVersion
+ Timestamp
+ Signature
Default: None  
 Required: Conditional 

 **AWSAccessKeyId**   
The access key ID that corresponds to the secret access key that you used to sign the request.  
Default: None  
Type: string  
 Required: Yes 

 **Expires**   
The date and time when the request signature expires, expressed in the format YYYY-MM-DDThh:mm:ssZ, as specified in the ISO 8601 standard.  
Condition: Requests must include either *Timestamp* or *Expires*, but not both.  
Default: None  
Type: string  
 Required: Conditional 

 **SecurityToken**   
The temporary security token that was obtained through a call to AWS Security Token Service. For a list of services that support AWS Security Token Service, go to [Using Temporary Security Credentials to Access AWS](http://docs.aws.amazon.com/IAM/latest/UsingSTS/UsingTokens.html) in **Using Temporary Security Credentials**.  
Default: None  
Type: string  
 Required: No 

 **Signature**   
The digital signature that you created for the request. For information about generating a signature, go to the service's developer documentation.  
Default: None  
Type: string  
 Required: Yes 

 **SignatureMethod**   
The hash algorithm that you used to create the request signature.  
Default: None  
Type: string  
 Valid Values: `HmacSHA256 | HmacSHA1`   
 Required: Yes 

 **SignatureVersion**   
The signature version you use to sign the request. Set this to the value that is recommended for your service.  
Default: None  
Type: string  
 Required: Yes 

 **Timestamp**   
The date and time when the request was signed, expressed in the format YYYY-MM-DDThh:mm:ssZ, as specified in the ISO 8601 standard.  
Condition: Requests must include either *Timestamp* or *Expires*, but not both.  
Default: None  
Type: string  
 Required: Conditional 

 **Version**   
The API version that the request is written for, expressed in the format YYYY-MM-DD.  
Default: None  
Type: string  
 Required: Yes