This topic describes how to make API requests over HTTP. This topic is intended for users who initiate HTTP or HTTPS GET requests based on URLs to call API operations.

If you are using SDKs, OpenAPI Explorer, or Alibaba Cloud CLI, skip this topic.

The request URL consists of different parameters and has a fixed syntax. The URL contains common request parameters, your signature, and operation-specific parameters. Sample request URLs are provided for each API operation. These URLs are not encoded, which makes them easy to read. Before you make a request, you must encode the request URL. After the request is verified based on your signature, the results are returned to you. Response parameters are displayed if the call succeeds, and an error message is displayed if the call fails. You can troubleshoot issues based on the common error codes and API operation-specific error codes.

Note We recommend that you use an SDK to call operations and manage resources, which eliminates the need for manual authentication.