Racelink terms — Documentation

The overlay and where it is shown

Overlay: A small web page Racelink shows over the game: a standings table, a speedometer, a map. Your project is one overlay.
Layout: A set of overlays with their places and sizes on screen. A player may have several, say one for races and one for practice, and switch between them.
Instance: One copy of an overlay in a layout. A player may add the same overlay more than once; each copy has its own settings and size.
Edit mode: While the player moves and resizes the overlays of a layout. The overlay knows and may show hints.
OBS link: The address of an overlay for a browser source in OBS: the stream sees the same overlay with the same data.
Preview: A short showing of the overlay on demo data: in “Add overlay”, and as an animation on its Workshop page.

Telemetry: The game’s data: speed, pedals, laps, where the cars are, the weather and everything else Racelink gives overlays.
Topic: A group of related values that arrive together: car holds pedals, speed and gear; timing lap times; drivers every car of the session. Every topic is listed in the field reference.
Field: One value inside a topic, such as the speed speedKph in car.
Path: The address of a field: the topic and the field joined by a dot, car.speedKph. [] marks a list: drivers[].lastLapSeconds is the last lap of each car.
Common field, game field: A common field means the same in every game that gives it (throttle, lap times). A field of one game lives under ext.<game>, such as iRating under ext.iracing.
null: “No value”: the game does not give it, or it has not arrived yet.
Demo data: A made-up race Racelink or the SDK plays instead of a game, so you can build without one running.
Session recording: A file with the data of a real race that Racelink can play to overlays instead of the game (Testing on recorded sessions).

Overlay API: The service inside Racelink that gives overlays their data and settings. It works only on the player’s computer.
SDK: The npm package @racelink/overlay: connects to the Overlay API, keeps the latest data, and brings types and build commands. Your code talks to Racelink through it.
Manifest: racelink.overlay.json at the project’s root: the overlay’s name, version, games, size, settings and permissions.
Settings: What the player changes in the overlay’s panel: colours, units, what to show. You describe them in the manifest.
Action: A setting of type binding: the player binds a key or a wheel button to it, and the overlay responds to the press.
Permission: Access beyond the usual (music, Steam messages, the internet) that the overlay asks for and the player grants or not.
Dev server: What npm run dev starts: your overlay’s page on your computer, refreshed on every save. Racelink finds it by itself.
Package: The finished overlay, the dist/ folder after npm run build. This is what goes to the Workshop and to players.
Studio: Racelink’s tab for authors: projects, checks, API data, previews and publishing. Turn it on in Settings, For developers, or from the title bar’s right-click menu.
Workshop: The Steam Workshop, where players find and install overlays and you publish them.