Used For

• +**Your chat app loses messages when users hit subway tunnels** → AnyCable recovers missed messages automatically when they reconnect
• +**Rails Action Cable crashes above 1,000 connections during live events** → Handles 5,000+ concurrent users without breaking a sweat
• +**Your notification system drops messages during mobile network handoffs** → Reliable delivery even when phones switch towers or go offline briefly
• +Streams AI responses in real-time - handles the chunked data flow that breaks regular WebSockets
• +Tracks who's online without constantly polling - shows presence status that actually updates

Best For

• >Your Rails app chokes at 500 concurrent chat users during events
• >Messages disappear when people switch between WiFi and mobile data
• >Action Cable is your bottleneck and you need something that just works

Not For

• -Teams with under 1,000 concurrent connections — stick with Action Cable, it's simpler
• -Developers afraid of running extra services — this adds a Go server, Redis, and gRPC to your stack
• -Anyone wanting plug-and-play — you'll spend 2-3 hours setting up the moving parts

Pairs With

• *Rails (drop-in replacement for Action Cable that actually scales)
• *Redis (stores messages during disconnections so nothing gets lost)
• *Docker (because you're now deploying a Go binary alongside your Rails app)
• *Hotwire (gets faster with AnyCable's Pro compression for HTML updates)
• *PostgreSQL (your main app database while AnyCable handles the real-time layer)
• *Vercel (for serverless functions that need WebSocket auth tokens)

The Catch

• !You're now running 4 services instead of 1 (Go server + gRPC + Redis + your app) which makes debugging more fun
• !The free version works great but Pro pricing isn't listed anywhere — prepare for 'contact sales'
• !Your Rails devs will need to learn gRPC basics or you'll be the only one who can fix it

Bottom Line

Handles 10x more chat connections than Rails without losing messages when users go underground.