Two-PC setup (CroStream Companion)

Game on one PC and stream from another. Set the gaming PC to companion mode, pair it with your streaming PC, and choose what runs where. Beta.

If you game on one PC and stream from another, some things need to happen on the gaming PC: Steam sees your games there, Discord runs there, and you press hotkeys there. CroStream Companion handles that. It is the same CroStream program, set to companion mode on the gaming PC. The main app stays on your streaming PC with OBS.

Note: Beta

CroStream Companion is a beta. Windows is the target. The app also builds for macOS and Linux, but the companion is tested on Windows.

What moves to the gaming PC

Feature	What it does on the gaming PC
Steam	Reads game state, launches games, takes screenshots.
Discord	Sets your activity and status.
Global hotkeys	Notices keys you press while gaming.
Screen flash	Shows on the gaming PC’s monitor.
Sounds	Play on the gaming PC’s speakers.

You choose each one separately in Settings → Companion on the streaming PC: This PC or Gaming PC. Once paired, they default to the gaming PC.

Your triggers and macros don’t change. The same Game started trigger, hotkey and screen flash steps work wherever the feature runs.

Requirements

The Supporter subscription on the streaming PC. Subscribe to Haliebug13 on Twitch. A free Prime sub counts. Without it, pairing is refused and everything keeps running on the streaming PC.
Both PCs on the same local network, including Tailscale’s 100.64 range.
Firewall access. The streaming PC listens on TCP port 62700 and announces itself on UDP port 62701 while you pair. Allow CroStream through Windows Firewall when it asks.

Pair the two PCs

Install CroStream on the gaming PC.
On the gaming PC, open Settings → Companion and choose Use this PC as a companion at the bottom of the panel. The app switches to the companion screen.
On the streaming PC, open Settings → Companion and choose Pair a gaming PC. It shows a 6-digit code, valid for 5 minutes, and its address.
On the gaming PC, choose Find streaming PC, or type the address (the default port is 62700). Enter the code.
On the streaming PC, choose which features run on the gaming PC.

The connection is encrypted (TLS), and the gaming PC remembers the streaming PC’s identity. The code is only for pairing. It is a password-authenticated exchange, so no one on the network can learn it or test guesses offline.

Run the gaming PC headless

The gaming PC can also run companion mode without a window:

crostream serve -mode companion

Open its browser UI to pair.

Switch back

On the companion screen, choose Switch back to the full app.

How you know it works

On the streaming PC, features running on the gaming PC show a Gaming PC badge. Gaming PC offline means the connection is down.
On the gaming PC, the companion screen shows Connected to and the name of the streaming PC.

If something goes wrong

Problem	What to do
Find streaming PC finds nothing.	Type the streaming PC’s address and port `62700` instead.
It still can’t connect.	Allow CroStream through the firewall on the streaming PC. Check that both PCs are on the same network.
The code doesn’t work.	It lasts 5 minutes. Start pairing again on the streaming PC.
It worked, then stopped after a restart.	The streaming PC’s IP address may have changed. Pair again.
Gaming PC offline.	Is CroStream running on the gaming PC?
Pairing is refused.	The streaming PC needs the Supporter subscription.

Limits

One gaming PC per streaming PC.
Local network only. There is no pairing over the internet.
Flash images and sounds come from the streaming PC’s media library. Sound files must be on the streaming PC.
VTube Studio already works across PCs by itself: connect it to the other PC’s address. It isn’t part of the companion. See VTube Studio.
Moments still needs CroStream on the OBS PC.

Steam and Discord
Hotkeys and Screen flash