If you're running StimulusReflex or other CableReady-powered libraries (such as Optimism or Futurism), CableReady is already installed and you can move on to Hello World. 🎉

Client and Server Packages

CableReady has both client (npm package) and server (Ruby gem) components which need to be installed. It is vitally important that you make sure that your server and client versions match exactly.

There can be issues with conflicting versions introduced when we're testing a pre-release build, since yarn will typically install the most recent package available, while Rubygems will install the last official release. 🤯

bundle add cable_ready
yarn add cable_ready

You can manually tweak and/or lock the versions you want to install by modifying Gemfile and package.json respectively, then re-running bundle install && yarn install.

stream_from Helper

CableReady v5 introduces the stream_from helper, which allows Rails developers to broadcast operations to DOM targets without having to do any manual Channel setup.

You should only need to run this once:

rails g cable_ready:stream_from

If there's any issue, you need to make sure that your index.js or application.js includes the following:

import consumer from '../channels/consumer'
import CableReady from 'cable_ready'
CableReady.initialize({ consumer })

CableReady Initializer

CableReady supports an optional Rails initializer which, among other things, allows you to declare custom operations. We provide a generator to create a handy blank initializer which has all of the options listed as comments:

rails g cable_ready:initializer

Upgrading, package versions and sanity

When upgrading CableReady, it's very important that you make sure your gem version and npm package versions match.

Since mismatched versions are the first step on the path to hell, by default CableReady won't allow the server to start if your versions are mismatched in the development environment.

If you have special needs, you can override this setting in your initializer. :warn will emit the same text-based warning but not prevent the server process from starting. :ignore will silence all mismatched version warnings, if you really just DGAF. ¯\_(ツ)_/¯

CableReady can also let you know when new, stable versions are released during the application start-up process. This opt-in behaviour is :ignore by default, but you can set it to :warn or even :exit so that you're never left behind.

CableReady.configure do |config|
config.on_failed_sanity_checks = :warn
config.on_new_version_available = :warn

Upgrading to v5.0.0

  • git repos are now living in the stimulusreflex organization on GitHub

  • make sure that you update cable_ready to 5.0.0 in both your Gemfile and package.json

  • create an initializer with rails g cable_ready:initializer if needed

  • install stream_from support with rails g cable_ready:stream_from

  • install the @cable_ready/audio_operations npm package if required

  • convert your custom operations to use the new CableReady.operations object


CableReady depends on the ActionCable framework (installed by default as part of Ruby on Rails) to handle sending data to the client over websockets. You must have ActionCable installed on both the client and server... and it will be unless you've disabled it.

You can check your package.json to verify that @rails/actioncable is installed. If you have trouble with ActionCable, consider verifying that it's installed correctly.


If you are preparing to deploy your site into production, you are advised to consider using AnyCable or AnyCable Pro, which boasts lower memory consumption, Apollo GraphQL compatibility and support for a binary transport protocol.


Redis for everything: caching, sessions, jobs and yes, ActionCable. Redis is a dependency for StimulusReflex; the installation task sets up Redis for ActionCable's subscription adapter in the development environment.

While Redis in development is not mandatory for standalone CableReady use, we do recommend it:

gem "redis", ">= 4.0", :require => ["redis", "redis/connection/hiredis"]
gem "hiredis"
adapter: redis
url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
channel_prefix: your_application_development

Rails 5.2

The CableReady documentation assumes that you are running Rails 6.x. It is possible to use CableReady with Rails 5.2, but you must make some adjustments to your configuration.

  1. Replace actioncable with @rails/actioncable in package.json

    • yarn remove actioncable

    • yarn add @rails/actioncable

  2. Replace any instance of import Actioncable from "actioncable" with import { createConsumer } from "@rails/actioncable"

    • This imports the createConsumer function directly

    • Previously, you might call createConsumer() on the Actioncable import: Actioncable.createConsumer()

    • Now, you can reference createConsumer() directly

Polyfills for IE11

If you need to provide support for older browsers, you can yarn add @cable_ready/polyfills and include them before your Stimulus controllers (if any) and CableReady channels:

// other stuff
import '@cable_ready/polyfills'
import 'channels'
import 'controllers'