Full Documentation  |   Discord

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Zero-Config WebSockets.

No accounts, no API keys, nothing to deploy. Just connect and start sending.

~466 bytes • free forever

After building realtime apps for years, I wanted something absolutely frictionless for prototyping. Spinning up socket servers or authenticating to services like Pusher/Ably involves overhead every time... so I built a service for myself (and everyone else). Then I designed this super-tiny WebSocket client that made even that side really easy to work with.

Welcome to itty-sockets!

Features

• Zero Config/Cost - No accounts, no API keys, no server. Pick a channel name and you're live.
• Private - No logging, no tracking, no storage. Messages are relayed and forgotten.
• Flexible - Send any JSON-serializable data/shape.
• Access Control - Reserve a namespace to control who can join or send on your channels.
• Use Anywhere - No vendor lock. This client works with any WebSocket server. Want to host your own? No problem.
• Tiny Client - Only 466 bytes gzipped.

Chat Example

import { connect } from 'itty-sockets' // ~466 bytes

// connect to a room
const bob = connect('my-secret-chat-room', { as: 'Bob' })

bob
  .send('hey Alice!')
  .send([1, 2, 3])
  .send({ foo: 'bar' })

meanwhile, elsewhere...

// connect to the same room as above, and listen for messages
const alice = connect('my-secret-chat-room', { as: 'Alice' })
  .on('message', ({ message, alias }) =>
    console.log(`${alias}: ${message}`)
  )

// → "Bob: hey Alice!"
// → "Bob: [1, 2, 3]"
// → "Bob: { foo: 'bar' }"

Installation

npm install itty-sockets

Or just paste the following snippet (loses TypeScript support):

let connect=(e,s={})=>{let a,t,n=[],p={},o=()=>(a||(a=new WebSocket((/^wss?:/.test(e)?e:"wss://itty.ws/c/"+e)+"?"+new URLSearchParams(s)),a.onmessage=(e,s=JSON.parse(e.data),a=s?.message,t={...null==a?.[0]&&a,...s})=>[t.type,s.type?0:"message","*"].map(e=>p[e]?.map(e=>e(t))),a.onopen=()=>(n.splice(0).map(e=>a.send(e)),p.open?.map(e=>e(t)),t&&a?.close()),a.onclose=()=>(t=a=null,p.close?.map(e=>e(t)))),l),l={open:o,send:(e,s)=>(e=(s?`�${s}�`:"")+JSON.stringify(e),1&a?.readyState?a.send(e):n.push(e),o()),on:(e,s)=>((p[e?.[0]?e:"*"]??=[]).push(e?.[0]?s:a=>e?.(a)&&s(a)),o()),remove:(e,s)=>(p[e]=p[e]?.filter(e=>e!=s),l),close:()=>(1&a?.readyState?a.close():t=1,l),push:(e,s)=>(t=1,l.send(e,s))};return l};

API at a Glance

Method	Description
connect(channel, options?)	Connect to a channel (or raw wss:// URL)
.on(type, listener)	Listen for events ('message', 'join', 'leave', 'open', 'close', 'error', custom types, or '*')
.on(filterFn, listener)	Listen with a custom filter function
.send(message, uid?)	Send a message (optionally to a specific user)
.push(message, uid?)	Send a message and disconnect afterwards
.open()	(Re)connect — safe to call anytime, listeners are preserved
.close()	Disconnect
.remove(type, listener)	Remove a listener

See the full documentation.