UP is a simple file transfer tool that acts as a drop-in replacement for scp and sftp. It sends data over HTTPS for much faster uploads without any extra setup. Up uses your existing SSH keys and reads ~/.ssh/config so you can keep working with the host aliases you already have.

Why UP?

• Transfers are noticeably quicker than traditional scp or sftp.
• No setup: use the same SSH keys and host aliases you already have.
• Small single binary for sending and receiving.
• Uses TLS 1.3 with HTTP/2 by default and supports HTTP/3 with --http3/-h3.

	Protocol	Performance Considerations
scp	SSH (TCP)	Typically uses a single TCP connection, limited by TCP window size and RTT. Can incur higher per-byte overhead from SSH protocol framing and encryption for raw data.
sftp	SSH (TCP)	Similar to scp in TCP limitations, though the SFTP protocol itself can be slightly more efficient for block-based transfers. Still subject to SSH overhead.
https	TLS over HTTP (TCP/QUIC)	Benefits from modern TCP stack optimizations. HTTP/2 and HTTP/3 (QUIC) allow for efficient multiplexing and reduced latency. Optimized for large data streams.

Installation

You can bootstrap up with a single command. This script will detect your OS (linux/darwin) and CPU (amd64/arm64), download the correct binary and install it to /usr/local/bin/up.

curl -sL https://src.w2k.sh/up/install.sh | sh

Quick Start

Pre-built binaries for common operating systems are available in the releases. Choose the download that matches your OS and architecture or build the latest development version yourself:

go build -o up .

Start the server (listens on port 7966) and then upload a file:

./up receive

./up send very_big.tar.xz localhost:7966

Uploaded files are stored under the server's files/ directory. Up will prompt to trust the server's certificate on first use and will remember it afterwards. The server forces HTTP/2 with TLS 1.3 by default. Pass --http3 or -h3 on both the server and client to switch to HTTP/3 over QUIC. When HTTP/3 mode is enabled, Up will not work behind reverse proxies like nginx.

Reverse Proxy Setup (http2)

Here is an example nginx configuration that proxies HTTPS traffic to an Up server running locally. Replace the certificate paths with your own.

server {
    listen 443 ssl;
    server_name up.example.com;

    ssl_certificate /etc/ssl/certs/example.pem;
    ssl_certificate_key /etc/ssl/private/example.key;

    location / {
        proxy_pass https://127.0.0.1:7966;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_ssl_verify off;
    }
}

License

This project is licensed under the GNU General Public License v3.0 License. See LICENSE for details.