vaayu 0.2.0

A modern, secure, parallel, and resumable SSH file transfer CLI (scp/rsync replacement).

Modern • Secure • Parallel • Resumable

Vaayu is the next-generation SSH file transfer tool that moves your data like air - fast, light, and omnipresent.

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✨ Why Vaayu?

Vaayu (Sanskrit: वायु) means "air"—the element that flows everywhere with speed and grace. Just as air adapts to any environment while maintaining its essential properties, Vaayu delivers files across networks with uncompromising reliability and performance.

🚀 Core Capabilities

Feature	Description
🔒 Secure by Design	Modern SSH ciphers (ChaCha20-Poly1305, AES-256-GCM) with optional strict host key verification
⚡ Lightning Fast	Parallel transfers with intelligent concurrency auto-tuning
🔄 Bulletproof Resume	Atomic writes with .part files and intelligent offset recovery
🛡️ Data Integrity	SHA-256 verification with robust remote fallback chains
🎯 Smart Operations	Recursive directory sync, wildcard matching, and real-time progress
👁️ Live Monitoring	Watch mode for continuous synchronization
🌐 Universal	Windows, macOS, Linux (Python 3.9+)

📡 Transfer Modes

• 📤 Send — Local → Remote with recursive directory support
• 📥 Get — Remote → Local with wildcard expansion
• 🔄 Relay — Remote → Remote without local download

🏗️ Architecture

Built on enterprise-grade foundations:

• AsyncIO + AsyncSSH — High-performance asynchronous I/O
• Rich Progress — Beautiful terminal UI with real-time metrics
• Watchdog — Filesystem monitoring for live sync
• zstd — Optional compression pipeline (future enhancement)

🚀 Quick Start

Installation

Windows (PowerShell)

python -m venv .venv
.\.venv\Scripts\Activate.ps1
pip install -e .

macOS/Linux (Bash)

python3 -m venv .venv
source .venv/bin/activate
pip install -e .

Verify Installation

vaayu --help

📚 Command Reference

Global Options

Short	Long	Description
-h	--help	Show help message
-p	--port	SSH port (default: 22)
-u	--username	SSH username
-P	--password	SSH password
-i	--identity	Path to private key
-j	--parallel	Parallel transfer jobs
-r	--retries	Max retries per file (default: 5)
-b	--backoff	Initial backoff seconds (default: 0.5)
-c	--compress	Enable compression
-z	--zstd-level	Compression level (default: 3)
-k	--verify-host-key	Strict host key verification
-n	--no-verify	Skip hash verification

Commands

Command	Description
send	Transfer files from local to remote
get	Transfer files from remote to local
relay	Transfer files between two remote hosts

💼 Usage Examples

📤 Send Operations

Basic File Upload

vaayu -u alice -i ~/.ssh/id_ed25519 send [e-mail] /remote/backup file.txt

Recursive Directory Upload

vaayu -u alice -i ~/.ssh/id_ed25519 send [e-mail] /remote/backup /local/project/

Wildcard Upload with High Parallelism

vaayu -u alice -i ~/.ssh/id_ed25519 -j 16 send [e-mail] /remote/logs *.log

Password Authentication

vaayu -u alice -P mypassword send [e-mail] /remote/backup document.pdf

Custom Port and Strict Host Key Verification

vaayu -u alice -p 2222 -k -i ~/.ssh/id_ed25519 send [e-mail] /backup file.txt

Multiple Files and Directories

vaayu -u alice -i ~/.ssh/id_ed25519 send [e-mail] /backup file1.txt dir1/ *.csv

Live Watch Mode

vaayu -u alice -i ~/.ssh/id_ed25519 send [e-mail] /remote/www /local/website/ -W

📥 Get Operations

Basic File Download

vaayu -u bob -i ~/.ssh/id_ed25519 get [e-mail] /local/downloads /remote/file.txt

Wildcard Download

vaayu -u bob -i ~/.ssh/id_ed25519 get [e-mail] /local/logs /var/log/*.log

Recursive Directory Download

vaayu -u bob -i ~/.ssh/id_ed25519 get [e-mail] /local/backup /remote/project/

Multiple Remote Paths

vaayu -u bob -i ~/.ssh/id_ed25519 get [e-mail] /local/data /remote/file1.txt /remote/dir/ /remote/*.csv

High Concurrency Download

vaayu -u bob -i ~/.ssh/id_ed25519 -j 32 get [e-mail] /local/download /remote/bigdata/

🔄 Relay Operations

Direct Remote-to-Remote Transfer

vaayu -u admin -i ~/.ssh/id_ed25519 relay [e-mail] [e-mail] /data/file.txt /backup/file.txt

Multiple File Relay

vaayu -u admin -i ~/.ssh/id_ed25519 relay [e-mail] [e-mail] /data/file1.txt /data/file2.txt /backup/file1.txt /backup/file2.txt

Cross-Server Directory Sync

vaayu -u admin -i ~/.ssh/id_ed25519 relay [e-mail] [e-mail] /var/www/ /backups/www/

⚙️ Advanced Usage

Resume Interrupted Transfer

vaayu -u alice -i ~/.ssh/id_ed25519 send [e-mail] /remote/backup largefile.zip

Skip Verification for Trusted Networks

vaayu -u alice -i ~/.ssh/id_ed25519 -n send [e-mail] /remote/backup *.txt

Custom Retry Strategy

vaayu -u alice -i ~/.ssh/id_ed25519 -r 10 -b 1.0 send [e-mail] /backup file.txt

Compression Enabled

vaayu -u alice -i ~/.ssh/id_ed25519 -c -z 6 send [e-mail] /backup archive.tar

🔧 Performance Tuning

Parallelism Guidelines

File Count	Recommended -j	Use Case
1-10	2-4	Large files
10-100	4-8	Mixed workload
100-1000	8-16	Many small files
1000+	16-32	Massive parallel I/O

Network Optimization

vaayu -u user -j 8 -r 3 -b 0.2 send user@host /dest /large/dataset/

🛡️ Security Features

Authentication Methods

• SSH Key Authentication (Recommended)
• Password Authentication
• SSH Agent Support

Encryption Standards

• [e-mail] (Primary)
• [e-mail] (Fallback)

Data Integrity

• SHA-256 Verification (Default)
• Atomic Writes (.part → rename)
• Multiple Remote Hash Sources

🏥 Error Handling & Recovery

Automatic Recovery Features

• Resume from Interruption — Continues from last byte
• Exponential Backoff — Smart retry timing
• Hash Verification — Detects corruption
• Atomic Operations — No partial writes

Common Issues & Solutions

Issue	Solution
Connection timeout	Increase -r retries and -b backoff
Permission denied	Check SSH key permissions and remote path access
Hash mismatch	Network corruption; transfer will auto-retry
Host key verification failed	Use -k flag with proper known_hosts

🧪 Testing & Validation

Run Test Suite

pytest -q

Feature Validation Commands

Resume Testing

vaayu -u user send user@host /dest largefile.bin

Verification Testing

vaayu -u user send user@host /dest testfile.txt
sha256sum testfile.txt
ssh user@host "sha256sum /dest/testfile.txt"

Performance Testing

time vaayu -u user -j 16 send user@host /dest /large/dataset/

📊 Project Structure

vaayu/
├── cli.py           # Command-line interface
├── ssh_client.py    # AsyncSSH wrapper
├── transfer.py      # Core transfer logic
├── verify.py        # Hash verification
├── utils.py         # Utilities and helpers
├── watch.py         # Filesystem monitoring
├── compress.py      # Compression (future)
└── cloud.py         # Cloud protocols (future)

🗺️ Roadmap

Upcoming Features

• 🗜️ In-stream zstd compression
• 🔍 Enhanced remote hash detection
• 📄 Configuration file support
• 🌩️ Cloud provider integration
• 📈 Advanced performance metrics
• 🔐 Certificate-based authentication

🤝 Contributing

We welcome contributions! Please check out our development setup:

python -m venv .venv
source .venv/bin/activate  # or .venv\Scripts\Activate.ps1 on Windows
pip install -e .[dev]
pytest

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📄 License

Released under the MIT License. See LICENSE for details.

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Built with ❤️ for the SSH community

Vaayu — Where files flow like air

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📝 Note: This README was generated with AI assistance because the developer was too lazy to write comprehensive documentation (but smart enough to make AI do it properly). 😴✨