Anyone opening this link gets the same experience loaded automatically. QR-code display + GitHub Gist sync are coming in a follow-up.

OBS must be running on this machine with Tools → WebSocket Server Settings → Enable WebSocket server, and the address must be 127.0.0.1 on that panel's Server Port. A LAN address can't work: this page is https, so the browser upgrades a plaintext ws:// to wss:// (which OBS can't answer) or blocks it outright — loopback is the only exemption. Build the scene once in OBS — Display Capture of the screen this app is fullscreened on is the most faithful (it catches native dropdowns and OS menus that window capture can miss); Window Capture of the installed PWA window works when you want the app without the rest of the desktop. For audio, add OBS's per-app audio source (Windows: Application Audio Capture; macOS 13+: the macOS Screen Capture source's app audio) pointed at this app, or route the rig through a virtual device. With restart auto on, both of those get their Restart Capture pressed for you just before recording starts — the fix for a source that came back from a sleep or a Space switch black and/or silent.

Recording only ever sends StartRecord / StopRecord (plus the scene switch above) — nothing that reconfigures OBS runs at showtime. match ⚠ is the one exception and it is a setup-time button on purpose: changing the canvas over the WebSocket rebuilds OBS's entire video pipeline and can take OBS down with it. Prefer OBS → Settings → Video.