S3 Nexus

S3 Nexus is a lightweight, fast, and fully open-source cross-platform S3 browser. Built with Tauri v2, Rust, and React 19 to deliver the best cloud storage management experience on Windows, macOS, and Linux.

Features

• Lightweight: < 100MB RAM thanks to Rust and Tauri engine
• Cross-Platform: Runs natively on Windows, macOS (Intel & Apple Silicon), and Linux
• Wide Compatibility: Supports AWS S3, MinIO, Cloudflare R2, DigitalOcean Spaces, and other S3-compatible providers
• Security: Credentials encrypted locally with AES-256-GCM. No data leaves your computer except to the target S3 endpoint
• Multipart Upload: Upload files up to 5GB+ with parallel chunk transfers and auto-retry
• Transfer Manager: Queue up to 10 concurrent transfers with pause/resume, progress tracking, and bandwidth throttling
• File Preview: Preview images, text, and markdown files without downloading
• Folder Sync: One-way or bidirectional sync between local folders and S3 prefixes
• Dark/Light Mode: System-aware theming with manual toggle

Tech Stack

Layer	Technology
Desktop Framework	Tauri v2
Backend	Rust
Frontend	React 19, Tailwind CSS v4
State Management	Zustand
Storage SDK	aws-sdk-rust
Database	SQLite (via rusqlite)
Encryption	ring (AES-256-GCM)
Icons	Lucide React

Getting Started

Prerequisites

1. Rust (stable) — Install

2. Node.js (LTS v20+) — Install

3. Tauri v2 system dependencies for your OS:

   Windows:

   • Microsoft Visual Studio C++ Build Tools
   • WebView2 (pre-installed on Windows 10/11)

   macOS:

   xcode-select --install

   Linux (Debian/Ubuntu):

   sudo apt update
   sudo apt install libwebkit2gtk-4.1-dev build-essential curl wget file libxdo-dev libssl-dev libayatana-appindicator3-dev librsvg2-dev

   See the full Tauri Prerequisites Guide for other distributions.

Installation

# Clone the repository
git clone https://github.com/idbara/s3nexus.git
cd s3nexus

# Install frontend dependencies
npm install

# Run in development mode (starts both Vite dev server and Rust backend)
npm run tauri dev

On the first run, Rust will compile all dependencies (~2-5 minutes). Subsequent runs start in seconds.

Development Commands

Command	Description
npm run tauri dev	Start the app in development mode with hot-reload
npm run tauri build	Build production installers (.msi, .dmg, .AppImage)
npm run build	Build frontend only (TypeScript check + Vite bundle)
npm run dev	Start Vite dev server only (no Rust backend)
npx tsc --noEmit	Type-check the frontend without building
cd src-tauri && cargo check	Type-check the Rust backend
cd src-tauri && cargo clippy	Run Rust linter
cd src-tauri && cargo fmt	Format Rust code
cd src-tauri && cargo test	Run Rust tests

Dev Server

• Frontend dev server runs on http://localhost:1420
• HMR (Hot Module Reload) on port 1421
• Tauri connects to the Vite dev server and opens the native window
• Changes to src/ trigger instant hot-reload
• Changes to src-tauri/src/ trigger Rust recompilation (~5-10s)

Project Structure

s3nexus/
├── src/                            # React frontend
│   ├── App.tsx                     # Root layout
│   ├── App.css                     # Tailwind + custom styles
│   ├── main.tsx                    # Entry point
│   ├── types/index.ts              # TypeScript interfaces (mirrors Rust structs)
│   ├── lib/
│   │   ├── tauri.ts                # Typed IPC wrappers (api.*)
│   │   └── utils.ts                # Formatting utilities
│   ├── stores/                     # Zustand state management
│   │   ├── profileStore.ts         # Profile CRUD + active profile
│   │   ├── explorerStore.ts        # Buckets, objects, navigation
│   │   ├── transferStore.ts        # Transfer queue + progress
│   │   ├── themeStore.ts           # Dark/light/system theme
│   │   ├── toastStore.ts           # Toast notifications
│   │   └── modalStore.ts           # Modal state management
│   └── components/
│       ├── layout/                 # Sidebar, Toolbar, Breadcrumb
│       ├── profiles/               # Profile form and list
│       ├── explorer/               # File table, context menu, modals
│       ├── transfers/              # Transfer panel with progress bars
│       ├── presigned/              # Presigned URL generator
│       ├── acl/                    # ACL permission editor
│       ├── policies/               # Bucket policy JSON editor
│       ├── preview/                # File preview (text/image/markdown)
│       ├── versioning/             # Version history viewer
│       ├── sync/                   # Folder sync UI
│       ├── monitor/                # Folder monitoring UI
│       ├── settings/               # App settings page
│       └── ui/                     # Reusable UI primitives
│
├── src-tauri/                      # Rust backend
│   ├── src/
│   │   ├── lib.rs                  # Tauri setup + command registration
│   │   ├── main.rs                 # Entry point
│   │   ├── state.rs                # AppState (DB + TransferManager)
│   │   ├── error.rs                # AppError enum
│   │   ├── commands/               # Tauri IPC command handlers
│   │   │   ├── profiles.rs         # Profile CRUD + credential helpers
│   │   │   ├── buckets.rs          # Bucket listing
│   │   │   ├── objects.rs          # File operations
│   │   │   ├── transfers.rs        # Transfer queue management
│   │   │   ├── presigned.rs        # Presigned URL generation
│   │   │   ├── acl.rs              # ACL operations
│   │   │   ├── policies.rs         # Bucket policy operations
│   │   │   ├── preview.rs          # File preview
│   │   │   ├── versioning.rs       # Version history
│   │   │   ├── sync_cmd.rs         # Sync commands
│   │   │   ├── monitor_cmd.rs      # Monitor commands
│   │   │   └── settings.rs         # App settings
│   │   ├── crypto/                 # AES-256-GCM encryption
│   │   ├── db/                     # SQLite database layer
│   │   ├── s3/                     # AWS S3 SDK wrappers
│   │   ├── transfer/               # Transfer engine
│   │   │   ├── manager.rs          # Queue coordinator (10 concurrent)
│   │   │   ├── multipart.rs        # Multipart upload engine
│   │   │   ├── download.rs         # Streaming download
│   │   │   ├── events.rs           # Progress event emitter
│   │   │   └── throttle.rs         # Bandwidth rate limiter
│   │   ├── sync/                   # Sync engine (diff + execute)
│   │   └── monitor/                # Filesystem watcher
│   ├── Cargo.toml                  # Rust dependencies
│   ├── tauri.conf.json             # Tauri build configuration
│   └── icons/                      # App icons
│
├── package.json                    # Node dependencies + scripts
├── tsconfig.json                   # TypeScript configuration
├── vite.config.ts                  # Vite build configuration
├── index.html                      # HTML entry point
├── CLAUDE.md                       # AI assistant guidance
└── docs/
    └── Product Requirements Document.md

Architecture

S3 Nexus uses Tauri's two-process model:

┌─────────────────────────────────────────────┐
│              Tauri Shell                     │
│  ┌──────────────────┐  ┌─────────────────┐  │
│  │   Rust Backend    │  │  Webview (React) │  │
│  │                   │  │                  │  │
│  │  • S3 SDK calls   │◄─┤  invoke("cmd")   │  │
│  │  • SQLite DB      │──►  • File Explorer │  │
│  │  • Encryption     │  │  • Transfer UI   │  │
│  │  • Transfer Mgr   │  │  • Settings      │  │
│  │  • File Watcher   │  │  • Dark/Light    │  │
│  └──────────────────┘  └─────────────────┘  │
└─────────────────────────────────────────────┘

IPC Communication

Frontend calls Rust commands via invoke():

// Frontend (TypeScript)
import { api } from "./lib/tauri";
const buckets = await api.listBuckets(profileId);

// Backend (Rust)
#[tauri::command]
pub async fn list_buckets(state: State<'_, AppState>, profile_id: String) -> Result<Vec<BucketInfo>, AppError> {
    // ...
}

Data Flow

1. Credentials: User input → AES-256-GCM encrypt → SQLite → decrypt on use → build S3 client
2. Transfers: Frontend triggers upload → TransferManager queues → Tokio spawns task → progress events emitted back to UI
3. File listing: Frontend requests → Rust calls S3 ListObjectsV2 → returns parsed results

Build for Production

# Build installers for your current platform
npm run tauri build

Output locations:

• Windows: src-tauri/target/release/bundle/msi/ and nsis/
• macOS: src-tauri/target/release/bundle/dmg/
• Linux: src-tauri/target/release/bundle/appimage/ and deb/

Contributing

We welcome contributions of any kind! Please read the Contribution Guidelines before submitting.

License

This project is licensed under the MIT License.