Set up.
Play together.

Windows

Share your PC's screen with friends so they can play your games with their own controllers, or join a friend's shared screen. Friends use CouchRelay on Windows or the CouchRelay Decky plugin on a handheld.

Getting started

1. Unzip the folder anywhere and run couchrelay-app.exe. Keep the folder together: the app needs the files next to it. If Windows says "Windows protected your PC", select "More info", then "Run anyway" (the app is not signed with a paid certificate yet).
2. Up-to-date graphics drivers are recommended. Sharing uses the graphics card's video encoder.

Share this PC (host)

1. Open "Share this PC" and select "Start hosting".
2. The first time, CouchRelay installs a virtual controller driver so friends' controllers work in your games. It asks first, and Windows asks for administrator permission.
3. If Windows Firewall asks about couchrelay-stream, allow it.
4. Give your friend one of the addresses shown on screen (see below) and the PIN.
5. When your friend has typed the PIN, CouchRelay asks whether to allow their device: select "Allow". (To skip this question, turn on "Allow new devices without asking".)

Which address to give:

• Local network: for a friend on the same home network as you.
• Internet (public IP): for a friend somewhere else, over the internet.
• VPN / shared network: if you both use a VPN that connects your devices (only shown then).

For friends over the internet, UDP port 47910 must reach this PC. Turn on "Open ports with UPnP" to let CouchRelay ask your router, or forward the port on the router by hand ("Router ports" shows the details). If the router doesn't open it, sharing still works at home and over a VPN, and the app tells you. Some internet connections (behind "carrier-grade NAT") can't accept incoming connections at all; a VPN works there. CouchRelay uses that one port for everything, encrypted.

Join a friend (guest)

1. Open "Join", type the address your friend gave you, then the PIN (only the first time).
2. Their screen opens in a window. Your controller, keyboard and mouse work in their games.

In the stream window:

• Move the pointer to the top-right corner of the picture for the "End stream" button.
• Ctrl+Alt+Shift+Q ends the stream, Ctrl+Alt+Shift+X switches full screen on and off. Every other key goes to your friend's PC.

Settings apply when a stream starts. "Optimize automatically" (the default) adapts the quality to your connection. "Favor" chooses what it keeps first: frame rate (as smooth as your screen allows, the default) or quality (at most 60 fps, for a sharper picture).

Updates

When a new version is out, a banner at the top of the app offers it: "Update now" downloads it, checks that it is genuine, and restarts the app with it (not while you share or stream).

Removing CouchRelay

In the app: Settings, About, "Remove CouchRelay from this PC". This removes the controller driver it installed (with its certificate), your pairings and your settings. Then close the app and delete the folder.

Handheld (Decky plugin)

Join a friend's shared screen from Gaming Mode on a handheld (SteamOS, Bazzite, CachyOS Handheld) and play with your own controls, or share the handheld's screen with friends. Friends use the CouchRelay app on Windows or this plugin.

Join a friend

1. Open the Quick Access menu (… button) → CouchRelay.
2. Pick a recent host, or type the address your friend gave you.
3. The first time, enter the PIN shown on their screen.
4. Select Join. The stream opens like a game. To end it, open the Quick Access menu → CouchRelay → End stream (or quit it from the Steam menu).

Join settings apply when a stream starts. Optimize automatically (the default) adapts the quality to your connection; Favor chooses what it keeps first: frame rate (as smooth as your screen allows, the default) or quality (at most 60 fps, for a sharper picture).

Share this handheld

1. Select Share this handheld.
2. Give your friend one of the addresses it shows (see below) and the PIN.
3. When they have typed it, a notification asks you to allow their device: press ···, open CouchRelay and select Allow (or turn on Allow new devices without asking).

Which address to give:

• LAN: for a friend on the same home network as you.
• Public (internet): for a friend somewhere else, over the internet.
• VPN / Shared network: if you both use a VPN that connects your devices (only shown then).

For friends over the internet, UDP port 47910 must reach the handheld: turn on Open ports with UPnP before sharing, or forward the port on your router by hand. If the router doesn't open it, sharing still works at home and over a VPN, and the panel tells you. Some internet connections (behind "carrier-grade NAT") can't accept incoming connections at all; a VPN works there.

Stay awake while sharing keeps the handheld from sleeping until you stop sharing, so friends can join later; with it on, Keep the screen dark and Keep the speakers quiet dim the screen and mute the speakers after a minute without using the handheld's controls (friends still see and hear the game).

What the plugin does on your handheld

• Settings and pairings live in ~/.local/share/CouchRelay. Joining adds a non-Steam shortcut called "CouchRelay", so Gaming Mode shows the stream and Steam Input maps your controls.
• The plugin runs with administrator rights for a few jobs a stream needs, all undone when the stream or sharing ends: Wi-Fi power saving is turned off and Wi-Fi stays on its current access point while a stream runs, the handheld is kept awake, and with the sharing options on, the screen brightness and volume are lowered.
• While sharing, friends' controllers become virtual controllers on the handheld.
• It connects only to the friends you share with or join. Once a day it also checks CouchRelay's website for a new version (a small file; nothing about you is sent), and offers it in the panel under Updates, where the check can be turned off. Installing an update restarts Decky.
• While sharing, it shows your public IP: it asks your router, or if the router doesn't say, ipify (once per start), which sees your connection's IP and nothing else.

Removing

In the panel: Remove → Remove from this handheld removes the settings, pairings and the shortcut. Then uninstall the plugin in Decky's settings.