Documentation

Overview

Castalong has three pieces:

• The dashboard (this site) — where you sign up, create rooms, and get your links.
• The OBS plugin — turns each guest into a native OBS source you can switch, plus a control-panel dock and a graphics overlay.
• The guest page — a link you share; guests open it and their camera / screen / game goes into your show over WebRTC.

A room is one show. Guests join a room by its link; you control that room from OBS or the web.

Quick start

1. Create an account.
2. On the dashboard, click Create room and name your show.
3. Copy the room's guest link and send it to your guests.
4. Set up OBS once (next section) using the room's plugin key, room id and links.
5. Open the control panel, hit Connect, and punch a guest live.

Rooms & links

Each room on your dashboard gives you four things:

Your plugin key (shown at the top of the dashboard, starts with ck_) authenticates OBS and the control panel. Room ids carry a random suffix so links can't be guessed.

Set up OBS

Do this once per machine. You'll add a guest source, the control dock, and the graphics overlay.

1 · Add a guest source

1. In Sources, click + → Castalong Guest.
2. Fill in the properties from your dashboard:

2 · Add the control panel as a dock

1. Docks menu → Custom Browser Docks…
2. Name it Castalong Control, paste your room's control panel link, click Apply.
3. Drag the new dock wherever you like.

3 · Add the graphics overlay

1. Sources → + → Browser.
2. URL = your room's graphics link, size 1920 × 1080.
3. Right-click the source → Transform → Fit to screen.

Switch guests & placements

In the control panel (dock or browser): enter the room and hit Connect. Each guest's camera and screen show up as their own tile, each with a live connection dot (🟢 good / 🟠 ok / 🔴 poor) and the bitrate it's using — so you can see at a glance who's about to have trouble.

• Placements — every Castalong source you add is a placement, named by its Bus (e.g. one source fullscreen, another facecam). The panel discovers them automatically and shows a button per placement on each guest tile.
• Route — click a placement button to drop that guest into that spot; click it again to clear it. Any guest can go to any placement, and an empty placement is transparent (your scene shows through, not a black box).
• Take — Cut (instant) or Fade with a duration in ms.
• Talkback — the 🎙 button sends your mic into the room so your guests can hear you.
• Clear all — take every placement to nothing.

To run a big fullscreen source and a small facecam corner, add two Castalong sources, name their buses, and place them in your scene where you want — then route any guest into either.

Add a Castalong Audio source to hear every guest at once on your stream — it mixes all guests' audio into one track, so a conversation stays audible no matter who's on the program video.

On-screen titles

Open Graphics & titles at the bottom of the control panel.

• Template — Lower third, Center card, or Ticker.
• Line 1 / Line 2, an accent colour, and a position — edits apply live.
• Auto names (on by default) — when you punch a guest, their name appears in your chosen style automatically.
• Timer — start / stop / reset a clock on screen.

Joining a show (guests)

No account needed. Open the link the host sent you:

1. Type your name (it can appear on screen) and click Join.
2. Allow camera and microphone when asked.
3. Use the buttons to toggle Camera / Mic, Flip camera (on phones), or Share screen — pick a window, a whole screen, or a game.

The host switches you into the show; you don't need to do anything else.

Guests who use OBS

A guest who also runs OBS can send their own OBS content straight to the streamer — no browser tab needed.

1. Install the Castalong plugin (the same one the streamer uses).
2. Add a Castalong Publisher source. Set the room (or paste a Config URL from your host) and your name.
3. Pick the OBS source to send from the Source to send dropdown — a camera, a game capture, a scene. Its audio is sent too. (Blank = a test pattern.)

It shows up on the streamer's panel as a normal guest input — video and audio — that they can place. To send several sources at once, add a Publisher per source; each arrives as its own input.

Bandwidth & requirements

Everything runs over WebRTC, which adapts to the connection — Castalong publishes several quality layers and automatically drops the top one when no one needs it, so these are planning figures, not hard floors.

Comfortable minimums: guests want ~3–5 Mbps up; the streamer wants ~5 Mbps down per guest shown. Wired or strong Wi-Fi is best for guests on camera.

You'll need

• Streamer: OBS 30+ on Windows with the Castalong plugin; a modern browser for the dashboard.
• Guests: any recent Chrome / Edge / Safari / Firefox, a camera and mic. Screen/game share works on desktop browsers. No install, no account.
• Headphones for everyone on a call — stops the host's talkback echoing back through open speakers.

Security

• Your plugin key controls all your rooms — keep it secret. You can't see other streamers' rooms and they can't see yours.
• Room links are unguessable (random suffix). Share them only with your guests.
• Guests can publish their camera / screen / mic but cannot control the switcher.
• Everything runs over HTTPS / encrypted WebRTC.

Troubleshooting

A guest's camera won't start

Another app or tab is using it (often OBS's own Video Capture, or a second join tab). Close it, then click Camera on. The guest stays connected on mic-only meanwhile.

Control panel says "denied"

The link is missing your key. Use the control panel link from your dashboard, which includes it.

Titles don't show in OBS

Make sure you added the graphics browser source and ran Fit to screen. Names appear when you punch a guest from the control panel.

Guest source is black

That guest hasn't turned on their camera or shared a screen yet, or the source's Track doesn't match what they're sending (e.g. Track = Screen but they only have a camera).