---
title: Configuration
audience: developers
summary: The URL the tablet opens, the brand it wears, the language it speaks, and the flags for testing.
description: "Configure the World of Regions livestream tablet: backend address, white-label branding, language, transport selection, preview mode and debugging."
order: 3
updated: "2026-09-14"
---

Two things configure a tablet, and it is worth keeping them apart. **The session** carries
everything that should follow the customer — the brand, the language, what they are allowed to
touch — and your desktop application sets it. **The URL** carries what belongs to the device or to
whoever is testing it.

## Where the tablet points

The tablet talks to one backend, and by default it is ours:

```text
https://livestream.world-of-regions.com/api
```

That address is absolute on purpose, whatever host serves the app. On a white-label domain a
same-origin `/api` would fall through to the single-page fallback and answer with the app's own
`index.html` — at status 200, so the failure arrives as a JSON parse error rather than as a 404.

Two overrides, in order of precedence:

| Override | Where | Use it for |
|---|---|---|
| `?api=<url>` | the URL | Pointing one device at another backend without rebuilding. |
| `VITE_LS_API` | build environment | A deployment that always talks to somewhere else. |

Cross-origin is expected and supported: the backend echoes the caller's `Origin` and exposes
`X-Livestream-Device`, which is the one response header the transport has to read back.

## Branding

The palette arrives with the session, so the tablet is already wearing the agency's colours by the
time the customer looks at it. You send a small set of values and the rest is derived:

| Value | What it sets |
|---|---|
| `brand` | The accent. A deeper text shade and a tint are derived from it, each mixed against the background so the result stays readable rather than blue-on-blue. |
| `background` | The page **and every card surface**. A saturated colour here flattens the whole interface into one field — it is the setting most worth testing before a shop sees it. |
| `text` | The ink. Left out, it is chosen automatically against the background. |
| `nav` | The bar. |
| `stars` | The rating colour. |

Everything else — muted inks, hairlines, the input surface, elevation — is mixed from those against
the background, so a partner supplies five values rather than fifty.

**One colour is deliberately not themeable:** the text over photography stays white in every
palette. It sits on somebody's holiday photograph, not on your background, and following the theme
there is how it becomes unreadable.

Before a session exists there is nothing to theme from, which matters for the pairing screen. Pass
the brand in the URL and it applies immediately:

```text
?brand=%231f6fb2&name=Your%20Agency&logo=https://example.com/logo.svg
```

## Language

The **operator** decides, not the device. `config.language` on the session is applied when the
session lands and remembered for the next boot, so a tablet keeps its language between customers.

That is deliberate: the device's own OS language is not evidence. An English Android tablet in a
Polish agency still serves Polish customers.

Polish is the source language here — copy is authored in Polish and translated outward, which
inverts the convention on the rest of World of Regions. A language that has not been published yet
falls back to Polish rather than to key names.

## Flags for testing

None of these are meant for a live tablet, and two of them will damage a live session if you use
them on one.

| Flag | Does |
|---|---|
| `?transport=poll` | Forces the polling path, ignoring the socket. |
| `?transport=ws` | Pins the socket and never falls back — for debugging the transport itself, where an automatic fallback hides what you came to see. |
| `?preview=1` | Local-only mirror mode, for embedding the tablet in a desktop panel. It claims nothing and polls nothing; the desktop pushes state in directly. |
| `?previewOrigin=<origin>` | Restricts a preview to accept pushes from one origin only. |
| `?debug=1` | Loads an on-screen console, so a tablet in a shop can be asked for one. |

> **Never open a live session with `?preview=1` missing on an embedded mirror.** A preview that
> reaches the network registers as a second tablet, takes the session's only device slot, and keeps
> resetting the idle window — so a session whose real tablet has been put down never times out.