View a markdown version of this page

Using the API for Amazon EC2 - Amazon Elastic Compute Cloud
Required knowledgeAvailable APIs for Amazon EC2Common query parameters
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Using the API for Amazon EC2

Important

As of October 14, 2022, HTTP responses from the Amazon EC2 APIs no longer include a reason-phrase element. As recommended by RFC7230, you should ensure that your applications do not make use of the reason-phrase content. Ensure that your applications use the 3-digit status-code element included in the HTTP response instead.

We provide the Query API for Amazon EC2, as well as software development kits (SDK) for Amazon that enable you to access Amazon EC2 from your preferred programming language. For more information, see the Amazon EC2 Developer Guide.

Contents

Required knowledge

If you plan to access Amazon EC2 through an API, you should be familiar with the following:

  • XML

  • Web services

  • HTTP requests

  • One or more programming languages, such as Java, PHP, Perl, Python, Ruby, C#, or C++.

Available APIs for Amazon EC2

The Amazon EC2 Query API provides HTTP or HTTPS requests that use the HTTP verb GET or POST and a Query parameter named Action.

Amazon provides libraries, sample code, tutorials, and other resources for software developers who prefer to build applications using language-specific APIs instead of submitting a request over HTTP or HTTPS. These libraries provide basic functions that automatically take care of tasks such as cryptographically signing your requests, retrying requests, and handling error responses, so that it is easier for you to get started.

For more information, see Create Amazon EC2 resources using an Amazon SDK in the Amazon EC2 Developer Guide.

Common query parameters

Most Amazon EC2 API actions support the parameters described in the following tables. The common parameters vary depending on whether you're using Signature Version 2 or Signature Version 4 to sign your requests. For more information, see Signing Amazon API requests in the IAM User Guide.

Parameters for Signature Version 4

Name Description Required

Action

The action to perform.

Example: RunInstances

 Yes

Version

The API version to use.

 Yes

X-Amz-Algorithm

The hash algorithm you use to create the request signature.

Example: AWS4-HMAC-SHA256

Yes

X-Amz-Credential

The credential scope for the request, in the format access-key-ID/YYYYMMDD/region/service/aws4_request

Example: AKIDEXAMPLE/20140707/us-east-1/ec2/aws4_request

Yes

X-Amz-Date

The date and time at which the request is signed, in the format YYYYMMDDThhmmssZ. The date must match the date that's included in the credential scope for the X-Amz-Credential parameter, or the date used in an Authorization header (see the note below the table).

Example: 20140707T150456Z

 Yes
X-Amz-SignedHeaders

The headers you are including as part of the request. At a minimum, you must include the host header. If you include an x-amz-date header in your request, you must include it in the list of signed headers.

Example: content-type;host;user-agent

 Yes

X-Amz-Signature

A signature derived from your secret access key.

Example: ced6826de92d2bdeed8f846f0bf508e8559example

 Yes

X-Amz-Security-Token

The temporary security token obtained through a call to Amazon Security Token Service.

Example: AQoEXAMPLEH4aoAH0gNCAPyJxz4BlCFFxWNE1OPTgk5TthT+FvwqnKwRcOIfrRh3c/L

 No

DryRun

Checks whether you have the required permissions for the action, without actually making the request. If you have the required permissions, the request returns DryRunOperation; otherwise, it returns UnauthorizedOperation.

 No

The X-Amz-Algorithm, X-Amz-Credential, X-Amz-SignedHeaders, and X-Amz-Signature parameters can either be specified as separate parameters in the query string, or their values can be included in a single Authorization header. For more information, see Signing Amazon API requests in the IAM User Guide.

Parameters for Signature Version 2

Name Description Required

Action

The action to perform.

Example: RunInstances

 Yes

Version

The API version to use.

 Yes

AWSAccessKeyId

The access key ID for the request sender. This identifies the account which will be charged for usage of the service. The account that's associated with the access key ID must be signed up for Amazon EC2, or the request isn't accepted.

Example: AKIAIOSFODNN7EXAMPLE

Yes

Expires

The date and time at which the signature included in the request expires, in the format YYYY-MM-DDThh:mm:ssZ. For more information, see ISO 8601.

Example: 2006-07-07T15:04:56Z

 Conditional. Requests must include either Timestamp or Expires, but cannot contain both.

Timestamp

The date and time at which the request is signed, in the format YYYY-MM-DDThh:mm:ssZ. For more information, see ISO 8601.

Example: 2006-07-07T15:04:56Z

 Conditional. Requests must include either Timestamp or Expires, but cannot contain both.

Signature

The request signature.

Example: Qnpl4Qk/7tINHzfXCiT7VEXAMPLE

 Yes

SignatureMethod

The hash algorithm you use to create the request signature. Valid values: HmacSHA256 | HmacSHA1.

Example: HmacSHA256

Yes

SignatureVersion

The signature version you use to sign the request. Set this value to 2.

Example: 2

Yes

DryRun

Checks whether you have the required permissions for the action, without actually making the request. If you have the required permissions, the request returns DryRunOperation; otherwise, it returns UnauthorizedOperation.

 No

SecurityToken

The temporary security token obtained through a call to Amazon Security Token Service.

Example: AQoEXAMPLEH4aoAH0gNCAPyJxz4BlCFFxWNE1OPTgk5TthT+FvwqnKwRcOIfrRh3c/L

 No

Parameter values must be URL-encoded. This is true for any Query parameter passed to Amazon EC2 and is typically necessary in the Signature parameter. Some clients do this automatically, but this is not the norm.