Phone and tablet

The app on your computer shows the same interface on your phone or tablet: the chats, the changes, the approvals and benchmark progress, live. The model keeps running on your computer's GPU. There are two ways to connect the devices, and you can turn on both: a free direct connection (WebRTC), or Tailscale, a private network between your own devices.

Two ways to connect

• Direct (WebRTC). Free, nothing to install on the computer, no account. The phone and the computer connect straight to each other, encrypted and authenticated with keys exchanged when you pair them. It needs the Android app. It cannot work when both networks block direct connections (for example a phone on a mobile network that shares addresses, and a strict router); there is no relay in between.
• Tailscale. Works through any network, also from iPhone and iPad, with Tailscale installed on both devices (see its own terms below). No server of ours is involved.

Direct (WebRTC)

Set up

1. On the computer: Settings, Phone & tablet, switch on Allow phones and tablets to connect directly, then Pair a phone. A QR code and a typed code appear. Leave Local Quench running while you use the phone; the computer must not sleep.
2. Install the Android app (LocalForge.apk; the Tailscale section below shows how to get it from your computer). Open it, choose Direct (WebRTC), tap Scan the QR code and point the camera at the code. Or scan it with the phone's camera app, which opens Local Quench, or type the code.
3. The phone pairs and connects. Next time, open the app and tap the computer's name.

The pairing code works once and expires after ten minutes. The phone then shows a 6-digit code and Local Quench asks you on the computer to compare it and click Pair (or Reject, which burns the code), so someone who saw the QR code cannot pair without you. Every paired phone is listed in Settings, Phone & tablet, with the time it last connected; Remove disconnects it at once and it cannot connect again unless you pair it anew.

How it works, and what we can see

• The computer and each phone have their own key pair. The code you scan carries the computer's public key and a random pairing secret; the phone's private key never leaves the phone.
• To start a connection the two exchange short messages through a small server of ours (a mailbox that keeps them for a few minutes). The messages are encrypted with the pairing secret, so the server only sees opaque blobs, how big they are and when they arrive. There are no accounts and nothing is logged by the mailbox. Your hosting provider's web server may still keep ordinary access logs.
• Each side signs the fingerprint of its encrypted connection with its key and checks the other's signature against the key from pairing. The server therefore cannot place itself in the middle, and a phone that is not paired is refused.
• The two find each other's addresses with public STUN servers (by default Google's and Cloudflare's; you can change the list in Settings). A STUN server learns your public IP address and that you asked, nothing else. The chats and files travel directly between the devices, never through us.

When it does not connect

• "No direct connection was possible". Both networks block direct paths. Use Tailscale for this phone instead.
• "The computer did not answer". Local Quench is not running or the computer sleeps, Direct (WebRTC) is off, or the phone was removed. The computer looks for new connections every few seconds, so a first connection can take about ten seconds. Also check that the clock on both devices is right (within two minutes).
• The code has a typing mistake. The typed code has a check value; compare it with the one on the computer, or scan the QR code instead.
• It worked, then stopped. The phone went to sleep or changed network. The app reconnects by itself; if not, close and open it.

Tailscale

1. Tailscale on both devices

1. Install Tailscale on the computer: tailscale.com/download. On Linux, curl -fsSL https://tailscale.com/install.sh | sh, then sudo tailscale up.
2. Install Tailscale on the phone or tablet (Google Play or the App Store).
3. Sign in to the same account on both. The Tailscale app on the phone should list your computer as connected.

2. Turn on phone access in Local Quench

On the computer: Settings, Phone & tablet, switch on the Tailscale option. The page shows your computer's Tailscale address, a pairing code and two QR codes. Leave Local Quench running while you use the phone; the computer must not sleep.

3a. Android

1. Scan the first QR code ("Get the app") with the phone's camera. It downloads LocalForge.apk from your own computer. Android warns about apps that do not come from Google Play: allow installing from your browser once, and if Play Protect says the app is from an unknown developer, tap More details, then Install anyway.
2. Open the file to install it. Android asks once to allow installing from your browser.
3. Scan the second QR code ("Pair"), or open the app and enter the address and code by hand.

The app updates itself from your computer: when the desktop app gets a newer phone app, the phone offers it on the next start. Updating the phone never updates the computer, and the other way round.

3b. iPhone and iPad

There is no App Store app yet; Safari works the same way.

1. On the computer, in Phone & tablet, click "Copy the link". It carries the address and the code.
2. Send it to the iPhone or iPad (AirDrop, a message to yourself) and open it in Safari.
3. Tap Share, then Add to Home Screen. From then on Local Quench opens from its icon on the Home Screen.

When it does not connect

• The page does not load. Check that the Tailscale app on the phone is on and shows the computer as connected, and that Local Quench is running on the computer. Open the address shown in Phone & tablet directly.
• "Pairing code needed" or "not paired". The code changed (someone clicked New code), or the device is not in your tailnet. Scan the pair QR code again.
• Works on Wi-Fi at home but not on mobile data. The phone is reaching the computer over the local network, not Tailscale. Turn Tailscale on in the phone.
• The computer went to sleep. Nothing answers then. Change the power settings, or keep the computer awake while you work remotely.
• A firewall on the computer. Allow incoming connections on the port shown in Phone & tablet (Advanced) on the Tailscale interface.

Security

Only devices in your Tailscale network can reach Local Quench, and Tailscale encrypts the traffic between them. By default your own Tailscale devices need no code; if other accounts share your tailnet, turn that off in Phone & tablet so each device needs the pairing code. The code is the key to your computer: "New code" disconnects every paired device. Access over plain Wi-Fi without Tailscale is off by default, because that traffic is not encrypted.

About Tailscale

Tailscale is a separate product of Tailscale Inc. You install it yourself and use it under Tailscale's own terms; Local Quench does not include, provide or resell it. Tailscale's free Personal plan is meant for personal, non-commercial use: a company that uses phone access for work needs its own paid Tailscale plan.

Tailscale is a trademark of Tailscale Inc. Local Quench is an independent product and is not affiliated with, endorsed by or sponsored by Tailscale Inc.