A better command-line interface for Tailscale Taildrop

[Contextualist]

Taildrop

Tailscale is a software-defined networking tool that put your devices on a virtual LAN. It forms encrypted connections among your devices, and maps them as virtual network devices. Building upon that, Taildrop is the file transfer service offered by Tailscale, allowing you to send files across Tailscale devices.

acp

acp is my personal project, aiming to provide the simplest experience for sending files on terminal among your devices. The interface is designed to micmic cp as much as possible: forget about typing alias, IP address, path, or one-time code or passphrase:

# sender
acp path/to/files

# receiver, to $(pwd)
acp
# or receive to/as specified target
acp -d path/to/target

To ensure any two devices can make P2P connections, I implemented NAT traversal by hand. My hobbist implementation ends up covering lots of scenarios, but NAT traversal is a complex problem, so my code doesn't work in some cases.

acp, with Tailscale as backend

Until one day I tried Tailscale, and I was quite impressed by their NAT traversal implementation. I started using their Taildrop, too, but its CLI version gave me lots of usage frictions (e.g. need root on Linux, no file access on macOS sandbox, no directory transfer support).

So why not having acp's UX + Tailscale's backend? That was the story behind acp v0.3.0

Now we have a "better Taildrop":

• Directory transfer support
• Sender does not need to enter the device name of the receiver
• Save to arbitrary path on macOS and Windows, not just the Downloads folder

And a "better acp":

• Higher success rate for NAT traversal
• Make use of Tailscale's distributive relay nodes, ensuring connectivity in all scenarios

For current user of acp ...

If you are reading this and yell "don't try to sell me tailscale", no worries: Tailscale integration will not be enabled by default if you update acp from an older version.

Try it out

Install or update to v0.3.0

For new users, if you have Tailscale running before installing acp, Tailscale support is automatically enabled. Or you can manually set one of the followings in your acp config file:

• strategy:["tailscale","tcp-punch"] to prefer Tailscale connection, or
• strategy:["tcp-punch","tailscale"] to use Tailscale as backup connection option

Make terminal personal file transfers as simple as cp