NodeCG is a broadcast graphics framework and application. It is primarily aimed at Twitch broadcasters using Open Broadcaster Software, but is usable in any environment that can render HTML, including CasparCG. NodeCG is based on the overlay system developed for the Tip of the Hats 2014 charity event.

Looking for a list of NodeCG bundles and resources? Check out awesome-nodecg.

Have questions about NodeCG, or just want to say 'hi'? Join our Gitter chatroom!

NOTICE: NodeCG v0.8 and above require Node.js >= 6 and Chrome >= 49. This means that as of right now, NodeCG graphics will not work in OBS1, XSplit, or CasparCG. The only platforms that can currently display NodeCG graphics are OBS Studio (with v1.21 of its Browser Source plugin) and vMix.

Who should use NodeCG?

NodeCG is a programming framework. As such, it's most useful to developers capable of creating their own graphics using HTML, CSS, and JavaScript. NodeCG is still in beta and the ecosystem of bundles is quite small. Those expecting to download NodeCG and use off-the-shelf bundles to get a complete stream overlay without writing any code may be disappointed.

Installation

Install node.js (version 6 or greater) & npm (version 2 or greater).
Then, run the following commands from a terminal (command prompt):

npm install -g bower
git clone https://github.com/nodecg/nodecg.git
cd nodecg
npm install --production
bower install
node index.js

To run NodeCG in production, pm2 is recommended.

Installing bundles

NodeCG's individual graphics packages are called bundles. They can be installed either from the command-line (via nodecg-cli), or by simply placing the folder into the ./bundles directory.

The easiest way to install bundles is via the command-line using nodecg-cli. To install a bundle from Github, enter the owner and repository name:

nodecg install lange/lange-notify

... to install a bundle from Bitbucket, enter the owner and repository name prefixed with bitbucket:

nodecg install bitbucket:username/repo-name

... to install a bundle from any other git provider, enter the git URL:

nodecg install https://github.com/GamesDoneQuick/agdq16-layouts.git

Bundles are just directories inside the ./bundles folder. They can always be added and removed by simply moving them into or out of that folder. Avoid installing or uninstalling bundles while NodeCG is running.

Usage

Install a bundle to the bundles folder
Start NodeCG
Open the dashboard (http://localhost:9090)
Open a graphic from the "Graphics" menu, accessible by clicking the top-left menu button on the dashboard
You can configure NodeCG by creating and editing cfg/nodecg.json.

Configuration

./cfg/nodecg.json is an optional file that you can create to configure NodeCG. See the NodeCG Configuration tutorial for more information on configuring NodeCG.

Bundles

Each NodeCG graphic is called a bundle. A bundle has one or more of the following:

Graphics: Visual elements to render and broadcast
Dashboard Panels: Controls used to manipulate and manage the bundle
Extension: Server-side code

A bundle can have multiple graphics and dashboard panels, and an extension can be split up into multiple files.

If you wish to quickly start a new bundle from a template, try generator-nodecg.

Graphics

Graphics are, as the name implies, the actual graphics intended for broadcast. They are standard HTML webpages, and there are no restrictions on their content. When serving a graphic, NodeCG injects an instance of the API into the global scope.

Dashboard Panels

Dashboard panels are the interface used to control and manage a bundle. They too are standard HTML webpages. Each panel is served as an iframe on the dashboard. This is done to ensure full code and style encapsulation. Because dashboard panels are iframes, they cannot render any content outside of their bounding box. For example, it is not possible to have a tooltip in a panel that extends beyond the bounding box of the panel itself.

When serving panels, NodeCG injects an instance of the API into the global scope, as well as a few default styles.

It is strongly recommended to use Polymer elements to build panels, though it is not required. Google's official Polymer elements, specifically their Paper elements, are a great place to start. The official NodeCGElements organization also has a selection of Polymer elements that are integrated with NodeCG's API.

Extensions

Extensions are server-side code. They are standard Node.js JavaScript files. An extension must export a function that accepts a single argument. That argument will be an instance of the NodeCG API:

// bundles/my-bundle/extension.js
module.exports = function(nodecg) {
    nodecg.listenFor('foo', function() {
        console.log('bar');
    });
};

NodeCG automatically attempts to load the following files as extensions:

your-bundle/extension.js
your-bundle/extension/index.js

Bundles may have one of, but not both of the above files. If your extension is simple enough to fit in one file, use the former approach. If your extension is broken up into multiple files, you may want to use the latter structure and keep all those files in a single extension folder. If using an extension folder, NodeCG will only load your-bundle/extension/index.js. It is up to you to load any other files that your extension needs via require.

package.json manifest

Every bundle must have a package.json. In addition to the required fields like name and version outlined in that link, NodeCG bundles must also have a nodecg object in their package.json with some additional properties that tell NodeCG about the bundle and how to load it.

See the manifest tutorial for more information on creating a valid package.json for a bundle.

Contributing

Fork it ( http://github.com/nodecg/nodecg/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request

Before creating your pull request:

Ensure your code matches our existing style using our provided EditorConfig options
Ensure the existing tests pass, or are updated appropriately, with npm test
For new features, you should add new tests

Check which branch you should PR to. NodeCG is still in an unstable state, so we follow these semver guidelines:

Bug fixes and new features go to the next 'patch' branch (0.current.x)
Breaking changes go to the next 'minor' branch (0.next.0)

Running tests locally

Install selenium-standalone (npm install --global selenium-standalone), then run the installer (selenium-standalone install)
Open one terminal and start Selenium: selenium-standalone start
Open a second terminal, navigate to the NodeCG root and run npm test

License

NodeCG is provided under the MIT license, which is available to read in the LICENSE file.

Contributors

Special Thanks

Atmo, original dashboard concept and code
Alex "Lange" Van Camp, designer & developer of toth-overlay

LA1TV / nodecg