RL Overlay Hub - Creator Documentation¶
RL Overlay Hub is a desktop application that reads live data from Rocket League and broadcasts it to HTML-based overlays. Overlays are web pages that run inside OBS as Browser Sources. The hub serves them over a local HTTP server and pushes game events through a WebSocket connection.
This documentation covers how to build, install, and test your own overlay.
What an overlay is¶
An overlay is a folder containing at minimum two files:
manifest.json- metadata that tells the hub about your overlay (id, name, author)index.html- the page that OBS loads and displays on stream
You can include any additional files you need: CSS, JavaScript, images, fonts. All files in the folder are served as static assets relative to your index.html.
How data reaches your overlay¶
The hub runs a FastAPI server on http://127.0.0.1:49100 by default. When your index.html loads, it includes a script tag for /overlay-api.js. That script opens a WebSocket to the hub and exposes a global object called window.RLOverlay. You use RLOverlay.on() to subscribe to game events.
Events include goal scored, match started, score updates, player stat changes, and more. The full list is in JavaScript API.
Pages in this documentation¶
- Quick Start - create and install your first overlay in minutes
- Manifest Reference - all fields in
manifest.json - JavaScript API -
RLOverlaymethods and every event with its data shape - State Reference - the match, player, and session objects in detail
- Testing and Preview - test your overlay without Rocket League running
- Adding to OBS - configure a Browser Source
- Event Snippets - quick copy-paste patterns for simple events
- Examples - annotated walkthroughs of the built-in overlays