Socket.IO

Open-source WebSocket library

FreeRealtime, comments & collabsocket.io

What it is

Node.js library wrapping WebSockets with automatic reconnection, HTTP long-polling fallback, rooms, namespaces and message acknowledgements; version 4.x is current. Scaling past a single process requires an adapter such as Redis to broadcast between nodes. Client libraries exist for browsers, React Native, Python, Java and Swift.

Why it earns a slot

Zero vendor bill and total control over the protocol. If you already run a Node server, adding live comments or a presence counter is one dependency and about twenty lines, not a new SaaS contract with a per-message meter.

Know before you commit

You own the operations: sticky sessions behind the load balancer, a Redis adapter once you exceed one node, and reconnect storms after every deploy. Most serverless hosts — Vercel and Netlify functions among them — cannot hold the long-lived connections it needs.

Getting started

npm i socket.io socket.io-client

Field notes

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Pricing snapshot

Free and MIT licensed, with no hosted service and no vendor bill — you pay only for the server you run it on. The Redis and cluster adapters used for multi-node scaling are also free

Snapshots move fast — verify at checkout, and post a field note if it changed.

Drop into your Lovable chat

Evaluate Socket.IO (https://socket.io) for this project, then use it only if it fits what we are already building.
Context: Open-source WebSocket library. Node.js library wrapping WebSockets with automatic reconnection, HTTP long-polling fallback, rooms, namespaces and message acknowledgements; version 4.x is current. Scaling past a single process requires an adapter such as Redis to broadcast between nodes. Client libraries exist for browsers, React Native, Python, Java and Swift.
Reviewer notes (general, not written for this codebase): Zero vendor bill and total control over the protocol. If you already run a Node server, adding live comments or a presence counter is one dependency and about twenty lines, not a new SaaS contract with a per-message meter.
Watch out for: You own the operations: sticky sessions behind the load balancer, a Redis adapter once you exceed one node, and reconnect storms after every deploy. Most serverless hosts — Vercel and Netlify functions among them — cannot hold the long-lived connections it needs.
Pricing: Free and MIT licensed, with no hosted service and no vendor bill — you pay only for the server you run it on. The Redis and cluster adapters used for multi-node scaling are also free
Setup: npm i socket.io socket.io-client
Rules: treat the notes above as background only. Do not assume a theme, style, layout or feature that is not already in this project — inspect the existing code first and ask me before changing visual direction.

/api/public/tools/socket-io

Neighbourhood

How Socket.IO sits against the rest of the atlas — swaps, companions and the tools builders actually save alongside it.

Instead of thisGiscus PartyKit Yjs Ably Agora Chatwoot Circle Crisp Cusdis Daily.co

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Free: 6M messages/mo, 200 concurrent connections, 200 channels, 500 msg/sec. Standard $29/mo plus usage (10k connections, 10k channels); Pro $399/mo plus usage (50k). Usage: $2.50 per million messages, $1.00 per million connection-minutes, $0.25/GiB transfer

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Agora

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Free monthly: 10,000 combined RTC minutes, 1M signaling messages, 500 chat users, 300 conversational AI minutes. RTC $0.59 per 1,000 minutes; recording $0.99 per 1,000; speech-to-text $16.99 per 1,000; real-time translation $8.99 per 1,000 per language. Analytics add-on from $449/mo

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Chatwoot

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Open-source support inbox + chat

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Self-host free under the MIT licence. Cloud Hacker $0 (2 agents, 500 conversations/mo, live chat only, 30-day retention); Startups $19/agent/mo annual; Business $39/agent/mo; Enterprise $99/agent/mo. Extra Captain AI credits $20 per 1,000

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Circle

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Hosted community and courses

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Professional $89/mo (3 admin seats, 2% transaction fee, 200 GB); Business $199/mo (5 seats, 1% fee, 500 GB); Circle Plus custom (unlimited seats, 0.5% fee, 1 TB). Unlimited members on every plan. 14-day trial, no permanent free plan

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