Overview

Last Updated At: 2025-10-16 11:16:30

Description

COS uses XML APIs, which are lightweight, connectionless, and stateless. By calling XML APIs, you can send requests and receive responses directly over HTTP/HTTPS to interact with the COS backend.

Before consulting other API documents, please read the signature authentication in detail first.

Basic Info

This section introduces the main concepts and terms that are essential for using COS more effectively.

Name Description
AppID User-dimensional unique resource identifier of a developer when accessing COS services, which is used to identify resources.
SecretID SecretID is the project identity identification ID owned by the developer, used for identity authentication.
SecretKey SecretKey is the project identity key owned by the developer.
Bucket A bucket is a container used to store data in COS, which is the first-level directory stored under Appid by the user, and each object is stored in a bucket.
Object An object is a specific file stored in COS and is the basic entity of storage.
Region Region information in the domain name, enumerated values: reg1 (Region1)

Getting Started

To use COS APIs, perform the following steps:

  1. Obtain the AppID, SecretID, and SecretKey.
  2. Write a signature authentication algorithm program (or use any server-side SDK).
  3. Calculate the signature and call the APIs to perform operations.