Show HN: SX – Transfer files from within SSH sessions without reconnecting

6 hours ago 2

SX (SSH eXchange) is a modern, cross-platform file transfer system that enables seamless file transfers between remote SSH sessions and local machines without requiring separate connections or re-authentication.

🚀 Blazing Fast - Native .NET performance with progress bars
🔒 Secure - Uses SSH reverse tunnels for encrypted transfers
🌐 Cross-Platform - Works on Windows, Linux, and macOS
📊 Beautiful UI - Rich console output with progress indicators and file tables
🎯 Simple - Just three commands: sxd (download), sxu (upload), sxls (list)
⚡ Tab Completion - Smart shell completion for remote file paths
📁 Directory Browsing - Explore remote directories with file sizes and dates
🎨 No Dependencies - Self-contained executables

# List files on remote server with beautiful table $ sxls ┌──────┬─────────────────┬──────────┬──────────────┐ │ Type │ Name │ Size │ Modified │ ├──────┼─────────────────┼──────────┼──────────────┤ │ DIR │ projects │ - │ 2h ago │ │ FILE │ presentation.pdf│ 2.4 MB │ yesterday │ │ FILE │ data.csv │ 156.7 KB │ 3d ago │ └──────┴─────────────────┴──────────┴──────────────┘ # Download with tab completion and progress $ sxd presentation.pdf 📥 Downloading: presentation.pdf (2.4 MB) ████████████████████████████████████████ 100% | 2.4 MB/s | 00:00:01 # Upload local files $ sxu myfile.txt 📤 Uploading: myfile.txt (45.2 KB) ████████████████████████████████████████ 100% | 1.2 MB/s | 00:00:01 ✅ Upload completed successfully!

SX requires .NET 9.0 or later. If you don't have it installed:

Ubuntu/Debian:

# Ubuntu 24.10 sudo apt update && sudo apt install dotnet-sdk-9.0 # Ubuntu 24.04, 22.04, 20.04 (requires backports PPA) sudo add-apt-repository ppa:dotnet/backports sudo apt update && sudo apt install dotnet-sdk-9.0

Other Linux/macOS/Windows:
See Microsoft's .NET 9 installation guide

Verify installation:

dotnet --version # Should show 9.x.x

Option A: Via .NET Tool

# Install globally via .NET tool dotnet tool install -g SX.Client dotnet tool install -g SX.Server

Option B: Via Snap (Coming Soon!)

# Snap packages are currently under review # Will be available as: sx-client and sx-server

Option C: Build from Source

git clone https://github.com/Memphizzz/sx cd sx dotnet pack SX.Client --configuration Release --output ./packages dotnet tool install --global --add-source ./packages SX.Client

2. Setup Convenient Commands

The setup scripts are included with the client package:

For Bash/Zsh:

# From the package source ~/.dotnet/tools/.store/sx.client/1.x.x/sx.client/1.x.x/scripts/setup-sx-commands.sh # Or download from GitHub if you prefer curl -sL https://raw.githubusercontent.com/Memphizzz/SX/main/setup-sx-commands.sh | bash

For Fish Shell:

# From the package source ~/.dotnet/tools/.store/sx.client/1.x.x/sx.client/1.x.x/scripts/setup-sx-fish.fish # Or download from GitHub curl -sL https://raw.githubusercontent.com/Memphizzz/SX/main/setup-sx-fish.fish | fish

Or manually create aliases:

# Add to your shell config (.bashrc, .zshrc, etc.) alias sxd='~/.dotnet/tools/sx sxd' alias sxu='~/.dotnet/tools/sx sxu' alias sxls='~/.dotnet/tools/sx sxls'

# Start SX server to serve files from a directory dotnet run --project SX.Server -- --dir ~/Downloads

# Connect to remote server with reverse tunnel ssh -R 53690:localhost:53690 user@remote-server

# List files with beautiful table (generates completion cache) sxls # Enable tab completion (first time only, after running sxls) source ~/.sx/sx_completion.bash # or .fish for fish shell # Download files (with tab completion!) sxd <TAB> # Shows available files sxd largefile.zip # Upload files (shell handles local completion) sxu mylocal.txt

Command Description Example

sxls [path]	List files and directories	sxls, sxls projects/
sxd <remote> [local]	Download file from server	sxd file.pdf, sxd data.csv backup.csv
sxu <local>	Upload file to server	sxu document.pdf

SX includes intelligent shell completion that updates automatically:

Run sxls - Updates completion cache with current server files
Press TAB - Get smart completions:
- sxd <TAB> - Complete with downloadable files
- sxls <TAB> - Complete with directories

Setup completion (one-time):

# Bash echo "source ~/.sx/sx_completion.bash" >> ~/.bashrc # Fish echo "source ~/.sx/sx_completion.fish" >> ~/.config/fish/config.fish

dotnet run --project SX.Server -- [options] Options: -p, --port <port> Port to listen on (default: 53690) -d, --dir <path> Directory to serve (default: ~/Downloads) --max-size <size> Maximum file size (default: 10GB) --no-overwrite Don't overwrite existing files -h, --help Show help

# Custom server port and directory dotnet run --project SX.Server -- --port 9999 --dir /data/shared # With size limits dotnet run --project SX.Server -- --max-size 1GB --no-overwrite # Client using custom port export SX_PORT=9999 sxd file.txt # Client connects to port 9999

┌─────────────────┐ SSH Tunnel ┌─────────────────┐ │ Remote Server │◄─────────────────┤ Local Machine │ │ │ │ │ │ sxd/sxu/sxls │ Port 53690 │ SX.Server │ │ (SX.Client) │ │ │ └─────────────────┘ └─────────────────┘

SX.Core - Core library with protocol, file handling, and utilities
SX.Server - Server executable (local machine)
SX.Client - Client commands (remote machine via SSH)
Protocol - JSON-based communication over TCP

dotnet build dotnet build --configuration Release

# Start server dotnet run --project SX.Server -- --dir ./test-files # Test client (in another terminal) dotnet run --project SX.Client -- sxls dotnet run --project SX.Client -- sxd testfile.txt

Check if SX server is running locally
Verify SSH tunnel: ssh -R 53690:localhost:53690 user@server
Check firewall settings
Try different port if conflicts occur

# Use different port dotnet run --project SX.Server -- --port 9999 export SX_PORT=9999 ssh -R 9999:localhost:9999 user@server

# Regenerate completion rm -rf ~/.sx/ sxls # Regenerates completion files # Re-source completion source ~/.sx/sx_completion.bash

If you prefer manual setup:

Create wrapper scripts:

mkdir -p ~/.local/bin # Download command echo '#!/bin/bash exec ~/.dotnet/tools/sx sxd "$@"' > ~/.local/bin/sxd chmod +x ~/.local/bin/sxd # Upload command echo '#!/bin/bash exec ~/.dotnet/tools/sx sxu "$@"' > ~/.local/bin/sxu chmod +x ~/.local/bin/sxu # List command echo '#!/bin/bash exec ~/.dotnet/tools/sx sxls "$@"' > ~/.local/bin/sxls chmod +x ~/.local/bin/sxls # Add to PATH export PATH="$HOME/.local/bin:$PATH"

Fish shell functions:

mkdir -p ~/.config/fish/functions echo 'function sxd --description "SX Download - Get file from server" ~/.dotnet/tools/sx sxd $argv end' > ~/.config/fish/functions/sxd.fish echo 'function sxu --description "SX Upload - Send file to server" ~/.dotnet/tools/sx sxu $argv end' > ~/.config/fish/functions/sxu.fish echo 'function sxls --description "SX List - List files on server" ~/.dotnet/tools/sx sxls $argv end' > ~/.config/fish/functions/sxls.fish

# Remove tool dotnet tool uninstall -g SX.Client # Remove wrapper scripts rm -f ~/.local/bin/sxd ~/.local/bin/sxu ~/.local/bin/sxls # Remove completion rm -rf ~/.sx/ # Remove shell config additions (manual cleanup)

.NET 9.0 or later
SSH 2.0 or later (for reverse port forwarding support)

🚧 Known Issues & Planned Features

Upload disconnection detection: Server detects client disconnections during upload with ~1 second delay

🔄 v1.0.3: Multiple simultaneous client support with request queuing
🔄 Future: Resume interrupted transfers
🔄 Future: Directory synchronization

Fork the repository
Create a feature branch
Make your changes
Add tests if applicable
Submit a pull request

This project is licensed under the MIT License - see the LICENSE file for details.

Built with .NET 9
UI powered by Spectre.Console
JSON handling via Newtonsoft.Json
Development assistance by Claude (Anthropic)

Made with ❤️ for seamless SSH file transfers

This software is provided "as is" for development and productivity purposes. While designed with security in mind through SSH tunnels, users are responsible for: