SimpleS3

A simple, cross-platform desktop client for browsing and managing files on S3-compatible storage. Built with Tauri v2 and Rust.

Features

• Open Source and unencombered -- Fully Open Source and unencumbered
• Dual-pane file browser — local filesystem on the left, S3 on the right
• Multiple S3 endpoints — connect to AWS S3, MinIO, Backblaze B2, Cloudflare R2, or any S3-compatible service; switch between them instantly
• Secure credentials — access keys are stored in your OS keychain (macOS Keychain, Windows Credential Manager, Linux Secret Service)
• Transfer queue — upload and download files with pause, resume, and cancel support
• Multipart transfers — large files (>100 MB) are transferred in parts automatically
• Dark mode — follows your system theme or can be set manually
• Keyboard shortcuts — F5 to refresh, Delete to delete, Ctrl+U to upload, Ctrl+D to download
• Offline detection — active transfers are paused automatically when network connectivity drops and resumed when it returns

Install

Nix / NixOS

Run directly without installing:

nix run github:owner/simples3

Or add it to your NixOS / Home Manager configuration:

# flake.nix
{
  inputs.simples3.url = "github:owner/simples3";

  # ... then in your outputs:
}

# configuration.nix (NixOS) or home.nix (Home Manager)
{ inputs, system, ... }:
{
  environment.systemPackages = [          # NixOS
    inputs.simples3.packages.${system}.default
  ];

  # — or —

  home.packages = [                       # Home Manager
    inputs.simples3.packages.${system}.default
  ];
}

A .desktop entry and icons are included, so SimpleS3 will appear in your application menu.

Pre-built Binaries

Download the latest release for your platform from the Releases page:

Platform	Format
Linux	.deb, .AppImage
Windows	.msi, .exe (NSIS)
macOS	.dmg

macOS Installation Note

On macOS, you may need to remove the quarantine attribute after installing the application:

xattr -c /Applications/SimpleS3.app

This is required because the app is not currently signed with an Apple Developer certificate. After running this command, you should be able to launch SimpleS3 normally.

Development Setup

Using devenv (NixOS / Nix)

The recommended way to set up the development environment is with devenv. This handles all system dependencies automatically.

# Enter the dev shell (installs Rust, Bun, Tauri CLI, GTK, WebKitGTK, etc.)
devenv shell

# Install frontend dependencies
bun install

# Start the app in development mode
dev
# — or equivalently —
bun run tauri dev

devenv also provides these helper scripts:

Command	Description
dev	Install deps and launch the app
build	Production build
test	Run Rust and frontend tests
lint	Run clippy and eslint
format	Auto-format Rust and TypeScript
check	Format check + lint + test
clean	Remove build artifacts

Using the Nix flake

If you have Nix with flakes enabled but not devenv, you can use the flake directly:

nix develop              # enter dev shell with all dependencies
bun install
bun run tauri dev

Manual Setup

If you are not using Nix, install the following prerequisites:

1. Rust 1.75+ — https://rustup.rs/
2. Bun — https://bun.sh/
3. Linux system libraries (Linux only):

   sudo apt-get install -y \
     libgtk-3-dev libwebkit2gtk-4.1-dev libappindicator3-dev \
     librsvg2-dev patchelf libsoup-3.0-dev \
     libjavascriptcoregtk-4.1-dev libssl-dev

Then:

bun install
bun run tauri dev

Building for Production

bun run tauri build

Build artifacts are written to src-tauri/target/release/bundle/.

Project Structure

simples3/
├── src/                    # Frontend (React + TypeScript)
│   ├── components/         # UI components
│   ├── contexts/           # React contexts (clipboard)
│   ├── hooks/              # React hooks (theme, network)
│   ├── styles/             # CSS / Tailwind
│   ├── types/              # TypeScript type definitions
│   ├── App.tsx             # Main application component
│   └── main.tsx            # Entry point
├── src-tauri/              # Backend (Rust + Tauri)
│   ├── src/
│   │   ├── commands/       # Tauri IPC commands
│   │   ├── models/         # Data models
│   │   ├── services/       # S3, config, transfer logic
│   │   └── lib.rs          # Library root
│   ├── Cargo.toml          # Rust dependencies
│   └── tauri.conf.json     # Tauri configuration
├── flake.nix               # Nix flake (package + dev shell)
├── devenv.nix              # Nix dev environment (devenv)
└── README.md

Testing

# Rust tests
cd src-tauri && cargo test

# Frontend tests
bun test

# Linting
cd src-tauri && cargo clippy
bun run lint

Local S3 Testing with MinIO

MinIO provides an S3-compatible server you can run locally:

mkdir -p ~/minio-data
minio server ~/minio-data --console-address ":9001"

Default credentials: minioadmin / minioadmin. Add a new endpoint in SimpleS3 pointing to http://localhost:9000.

Contributing

Contributions are welcome! Please open an issue or pull request.

1. Fork the repository
2. Create a feature branch (git checkout -b my-feature)
3. Commit your changes
4. Push to your fork and open a pull request

License

SimpleS3 is licensed under the GNU General Public License v3.0.