STBY

STBY (short for Standby) is a professional cue light system for live theatre and events. It replaces expensive dedicated hardware with software that runs on devices your venue already owns — Mac laptops, iPads, iPhones, and Android phones.

A cue light system is how a Stage Manager or DSM communicates with performers waiting offstage: a STANDBY signal means "get ready", and a GO signal means "go now". STBY handles all of this over your venue's Wi-Fi network.

STBY has three types of users. Understanding which role each person plays is the key to getting set up quickly.

This is the fastest path from zero to firing your first cue light. Every device needs to be on the same Wi-Fi network.

The server app runs on your Mac and is the brain of the whole system. Everything else — iPads, phones, QLab — talks to it.

Click the ⚙ Settings tab on the left to configure the system before starting the server.

Each channel is one cue position — a place offstage where a performer or technician is waiting. You can have as many channels as you need.

Channels are named in the Settings tab. The name you give a channel is what performers see when they open their Listener screen and choose their position.

Every channel is always in one of four states, shown clearly on each card in the Master view:

Groups let you fire multiple channels simultaneously with a single button press. A DSM running a complex musical with overlapping cues can set up Group A for the DSM wing, Group B for the director's cue positions, and fire them independently.

You can have up to three groups: ★ Group A (yellow), ● Group B (cyan), and ■ Group C (purple). Enable the groups you need in Settings before starting the server.

The Group Control toolbar sits above the channel cards in both the server app and the Master browser view. It gives you STBY, GO, and Clear buttons for each active group.

Each channel card has a group badge at the bottom (★ A, ● B, ■ C). Tap it to assign the channel to that group — it highlights in the group colour. A channel can only be in one group at a time; assigning it to a new group removes it from the old one automatically.

First tap — if any channels in the group are active (STANDBY or GO), it clears them back to Idle but keeps them in the group. "GO Reset."

Second tap — if all channels are already Idle, it removes them from the group. "Ungroup."

This means you can safely hit Clear mid-show without losing your group setup.

STBY can receive OSC messages from QLab or any OSC-capable system, letting you fire cue lights automatically as part of your cue stack.

OSC messages are received on UDP port 9001 by default (changeable in Settings). The OSC addresses and port are always shown in the footer of the server app window.

Channel numbers follow the order in the channel list — ch1 is the first channel, ch2 the second, and so on.

Any device with a modern web browser can connect to STBY — iPad, iPhone, Android phone, laptop. All devices must be on the same Wi-Fi network as the Mac running the server.

The Master view is where the DSM or cue caller operates. It shows all channel cards and group controls. Access it in the STBY server app directly, or in a browser after entering the PIN.

This is what the performer or offstage technician sees. The entire screen is their cue light — big, bright, and impossible to miss in a dark wing. It's the default view when any device opens the STBY URL.

The Monitor view is a read-only status board showing all channels at a glance. No controls — just a clear picture of who is in what state. Perfect for a second screen at the prompt desk, or for a QLab operator who needs situational awareness without firing cues.

Click the Monitor button in the STBY server app — it opens in your default browser automatically. Or navigate directly to: http://[server-ip]:3000?page=monitor

The STBY mobile app (iOS & Android) includes automatic server discovery — it scans your local network and finds the STBY server without you needing to type an IP address.

If automatic discovery finds a server, tap it to connect. If discovery doesn't work on your venue's network, use the manual IP entry at the bottom of the screen — type the address shown in the STBY server app.

The app remembers the last server it connected to, so from the second night of a run you can connect with a single tap.

After connecting, the app asks which role you're taking — Listener (no PIN, goes straight to the fullscreen display) or Master (requires the PIN). The app remembers your choice between sessions.

Here's exactly what happens, step by step, when a DSM calls a cue:

The PIN protects the Master view. Only people who know the PIN can control cue lights. Listeners do not need the PIN — they go straight to their screen.

Set the PIN in the ⚙ Settings tab of the server app. The PIN is automatically sent to any Master device that connects — you don't configure it on each device separately.

Check all devices are on the same Wi-Fi network. The Mac and every connecting device must be on the same network — same SSID, not split between 2.4GHz and 5GHz.

Check the full URL. Type the address including http:// and the :3000 port — e.g. http://192.168.1.50:3000. Leaving either out will fail.

Check the Mac's firewall. Go to System Settings → Network → Firewall. If it's on, either disable it or add STBY to the allowed apps list.

Check the card header colour. Grey means no listener is connected on that channel — check the performer's device and position selection.

Reload the page. Pull down to refresh in the browser. STBY reconnects automatically within a few seconds.

Check the server log. The log shows every connection event. Look for the listener connecting and cue messages being received.

Check the IP and port. QLab needs to send to your Mac's IP (shown in the STBY app) on port 9001, UDP not TCP.

Check the OSC address format. Must match exactly — /stby/ch1/standby — lowercase, correct channel number.

Check the OSC port in STBY. The port is shown in the footer of the server window. It defaults to 9001 but can be changed in Settings.

The browser version can't prevent auto-lock. On iPhone/iPad go to Settings → Display & Brightness → Auto-Lock and set it to Never for the show. The STBY mobile app handles this automatically.

Right-click (or Control-click) the STBY app and choose Open from the menu. Click Open in the dialog. You only need to do this once.