Working with S3 and Cloud Storage in C++: aws-sdk-cpp Library

aws-sdk-cpp Library: Integrating S3 and Cloud Storage in C++

Modern C++ applications increasingly require interaction with cloud storage. Whether for backup, media file storage, or data exchange between services — S3-compatible storage (Amazon S3, MinIO, Yandex Object Storage, DigitalOcean Spaces) has become the de facto standard. The official aws-sdk-cpp library from Amazon provides a powerful and flexible toolkit for working with S3 directly from C++ code.

In this article, we will cover how to set up aws-sdk-cpp, configure authentication, perform basic operations with objects and buckets, and explore features for working with compatible storage.

What is aws-sdk-cpp?

aws-sdk-cpp is the official SDK from Amazon Web Services for the C++ language. It includes modules for all major AWS services, including S3, DynamoDB, Lambda, EC2, and others. The S3 module is used for working with cloud storage and supports:

• Creating, deleting, and listing buckets.
• Uploading, downloading, copying, and deleting objects.
• Working with multipart upload for large files.
• Managing metadata and ACLs (Access Control Lists).
• Support for streaming data and asynchronous operations.

Installation and Setup

The easiest way to install the SDK is via the vcpkg package manager:

vcpkg install aws-sdk-cpp[s3]

For manual building from source, you will need CMake and a compiler with C++14 or newer support. After installation, include the library in CMakeLists.txt:

find_package(aws-sdk-cpp REQUIRED COMPONENTS s3 s3-crt)target_link_libraries(your_project PRIVATE AWS::aws-cpp-sdk-s3 AWS::aws-cpp-sdk-s3-crt)

Note: s3-crt is an alternative implementation based on Common Runtime, which provides better performance for streaming operations.

Configuring the S3 Client

Before starting, you need to create an Aws::S3::S3Client object. To access compatible storage (e.g., MinIO or Yandex Object Storage), you must specify a custom endpoint:

#include <aws/core/Aws.h>#include <aws/s3/S3Client.h>#include <aws/s3/model/ListObjectsV2Request.h>

Aws::SDKOptions options;Aws::InitAPI(options);{    Aws::Client::ClientConfiguration config;    config.endpointOverride = "https://storage.yandexcloud.net"; // for Yandex Object Storage    config.region = "ru-central1";    config.scheme = Aws::Http::Scheme::HTTPS;

    // For local MinIO: config.endpointOverride = "http://localhost:9000";    // config.region = "us-east-1"; // MinIO uses this region by default

    Aws::Auth::AWSCredentials credentials("YOUR_ACCESS_KEY", "YOUR_SECRET_KEY");    Aws::S3::S3Client s3_client(credentials, config);

    // Work with the client here}Aws::ShutdownAPI(options);

Example: Uploading a File to S3

Let's look at a basic operation — uploading a local file to a bucket:

#include <aws/s3/model/PutObjectRequest.h>#include <fstream>

bool UploadFile(const Aws::S3::S3Client& client,                const std::string& bucket_name,                const std::string& object_key,                const std::string& file_path){    Aws::S3::Model::PutObjectRequest request;    request.SetBucket(bucket_name);    request.SetKey(object_key);

    std::shared_ptr<Aws::IOStream> input_data =        Aws::MakeShared<Aws::FStream>("UploadFile",                                       file_path.c_str(),                                       std::ios_base::in | std::ios_base::binary);

    if (!input_data->good())\