Rails 8 adds Solid Cable for built-in WebSocket pub/sub support

Rails 8 introduces Solid Cable, a new built-in pub/sub backend for Action Cable that removes the need for Redis when building real-time features. Solid Cable works alongside other database-backed infrastructure like Solid Cache and Solid Queue to reduce external dependencies.

For years, Rails applications relied on Redis to power WebSocket broadcasting. While Redis works well, it adds operational overhead for smaller apps and teams. Solid Cable simplifies this by using your database as the message bus, allowing developers to run real-time Rails apps without external infrastructure.

This continues a broader Rails 8 theme: reducing dependency on external services while keeping applications scalable.

What is Solid Cable?

Solid Cable is a database-backed Action Cable adapter designed to replace Redis for WebSocket pub/sub messaging.

Instead of publishing messages through Redis channels, Solid Cable stores messages in database tables and distributes them to connected clients.

This means a standard Rails deployment can support real-time features using only:

• Rails
• a relational database
• Action Cable

No Redis required.

Why Solid Cable?

Traditional Action Cable setups required running Redis alongside Rails.

That setup works well for large-scale deployments, but it introduces extra infrastructure for smaller applications.

Solid Cable offers several benefits:

• Removes the Redis dependency
• Simplifies deployment environments
• Uses transactional database guarantees
• Works well for moderate real-time workloads

For many SaaS applications, this makes real-time features significantly easier to operate.

How to enable Solid Cable

To use Solid Cable, configure the Action Cable adapter:

1# config/cable.yml
2
3production:
4  adapter: solid_cable

Once enabled, Rails automatically handles pub/sub messaging through the database.

Broadcasting example

Broadcasting still works exactly like a traditional Action Cable setup:

1ActionCable.server.broadcast(
2  "messages",
3  { body: "Hello from Rails 8" }
4)

Connected clients subscribed to the messages stream will immediately receive the payload over WebSockets.

Summary

Solid Cable makes real-time Rails applications easier to deploy by removing Redis from the default Action Cable stack. By using the database as a pub/sub backend, Rails 8 simplifies infrastructure while still supporting powerful WebSocket-driven features.