simples3

A Go library for manipulating objects in S3 buckets using REST API calls signed with AWS Signature Version 4. Used in production at Zerodha.

Scope

I looked into whether simples3 should add support for AWS S3 Files. I decided not to put that into the core library. S3 Files is a separate AWS service with its own control plane and operational model, and it would pull simples3 away from its main job: being a small S3 object client. I wrote up the reasoning here: AWS S3 Files and simples3.

Why simples3?

The official AWS Go SDK is massive. If all you need is basic S3 operations, pulling in a much larger dependency tree feels excessive. simples3 provides a minimal alternative with zero dependencies beyond the Go standard library.

Features

• Simple, intuitive API following Go idioms
• Complete S3 operations: Upload, Download, Delete, List, Details
• Multipart upload with parallel uploads and progress tracking
• Bucket management: Create, Delete, List
• AWS Signature Version 4 signing
• Custom endpoint support (MinIO, DigitalOcean Spaces, etc.)
• Presigned URL generation for secure browser uploads/downloads
• Object versioning and server-side encryption (SSE-S3, SSE-KMS)
• IAM credential support for EC2 instances
• Iterator-based ListAll for memory-efficient large bucket iteration

Quick Start

s3 := simples3.New("us-east-1", "access-key", "secret-key")

// Upload
resp, err := s3.FileUpload(simples3.UploadInput{
    Bucket:      "my-bucket",
    ObjectKey:   "path/to/file.txt",
    ContentType: "text/plain",
    Body:        file,
})

// Download
data, err := s3.FileDownload(simples3.DownloadInput{
    Bucket:    "my-bucket",
    ObjectKey: "path/to/file.txt",
})

// Presigned URL
url := s3.GeneratePresignedURL(simples3.PresignedInput{
    Bucket:        "my-bucket",
    ObjectKey:     "path/to/file.txt",
    Method:        "GET",
    ExpirySeconds: 3600,
})

Install

go get github.com/rhnvrm/simples3