- 4.7.2 (Aug 2023)
- 4.7.1 (Jun 2023)
- 4.7.0 (Jun 2023)
- 4.6.2 (May 2023)
- 4.6.1 (Feb 2023)
- 4.6.0 (Feb 2023)
- 4.5.4 (Nov 2022)
- 4.5.3 (Oct 2022)
- 4.5.2 (Sep 2022)
- 2.5.0 (Jun 2022) (from the 2.x branch)
- 4.5.1 (May 2022)
- 4.5.0 (Apr 2022)
- 4.4.1 (Jan 2022)
- 4.4.0 (Nov 2021)
- 4.3.2 (Nov 2021)
- 4.3.1 (Oct 2021)
- 4.3.0 (Oct 2021)
- 4.2.0 (Aug 2021)
- 4.1.3 (Jul 2021)
- 4.1.2 (May 2021)
- 4.1.1 (May 2021)
- 4.1.0 (May 2021)
- 4.0.2 (May 2021)
- 4.0.1 (Mar 2021)
- 4.0.0 (Mar 2021)
- 3.1.2 (Feb 2021)
- 3.1.1 (Feb 2021)
- 3.1.0 (Jan 2021)
- 2.4.1 (Jan 2021) (from the 2.x branch)
- 3.0.5 (Jan 2021)
- 2.4.0 (Jan 2021) (from the 2.x branch)
- 2.3.0 (Sep 2019)
4.7.5 (2024-03-14)
- close the adapters when the server is closed (bf64870)
- remove duplicate pipeline when serving bundle (e426f3e)
engine.io@~6.5.2
(no change)ws@~8.11.0
(no change)
4.7.4 (2024-01-12)
engine.io@~6.5.2
(no change)ws@~8.11.0
(no change)
4.7.3 (2024-01-03)
- return the first response when broadcasting to a single socket (#4878) (df8e70f)
- typings: allow to bind to a non-secure Http2Server (#4853) (8c9ebc3)
engine.io@~6.5.2
(no change)ws@~8.11.0
(no change)
4.7.2 (2023-08-02)
- clean up child namespace when client is rejected in middleware (#4773) (0731c0d)
- webtransport: properly handle WebTransport-only connections (3468a19)
- webtransport: add proper framing (a306db0)
engine.io@~6.5.2
(diff)ws@~8.11.0
(no change)
4.7.1 (2023-06-28)
The client bundle contains a few fixes regarding the WebTransport support.
engine.io@~6.5.0
(no change)ws@~8.11.0
(no change)
4.7.0 (2023-06-22)
The Socket.IO server can now use WebTransport as the underlying transport.
WebTransport is a web API that uses the HTTP/3 protocol as a bidirectional transport. It's intended for two-way communications between a web client and an HTTP/3 server.
References:
- https://w3c.github.io/webtransport/
- https://developer.mozilla.org/en-US/docs/Web/API/WebTransport
- https://developer.chrome.com/articles/webtransport/
Until WebTransport support lands in Node.js, you can use the @fails-components/webtransport
package:
import { readFileSync } from "fs";
import { createServer } from "https";
import { Server } from "socket.io";
import { Http3Server } from "@fails-components/webtransport";
// WARNING: the total length of the validity period MUST NOT exceed two weeks (https://w3c.github.io/webtransport/#custom-certificate-requirements)
const cert = readFileSync("/path/to/my/cert.pem");
const key = readFileSync("/path/to/my/key.pem");
const httpsServer = createServer({
key,
cert
});
httpsServer.listen(3000);
const io = new Server(httpsServer, {
transports: ["polling", "websocket", "webtransport"] // WebTransport is not enabled by default
});
const h3Server = new Http3Server({
port: 3000,
host: "0.0.0.0",
secret: "changeit",
cert,
privKey: key,
});
(async () => {
const stream = await h3Server.sessionStream("/socket.io/");
const sessionReader = stream.getReader();
while (true) {
const { done, value } = await sessionReader.read();
if (done) {
break;
}
io.engine.onWebTransportSession(value);
}
})();
h3Server.startServer();
Added in 123b68c.
The bundles will now have the right Access-Control-Allow-xxx
headers.
Added in 63f181c.
engine.io@~6.5.0
(diff)ws@~8.11.0
(no change)
4.6.2 (2023-05-31)
engine.io@~6.4.2
(diff)ws@~8.11.0
(no change)
4.6.1 (2023-02-20)
- properly handle manually created dynamic namespaces (0d0a7a2)
- types: fix nodenext module resolution compatibility (#4625) (d0b22c6)
engine.io@~6.4.1
(diff)ws@~8.11.0
(no change)
4.6.0 (2023-02-07)
- add timeout method to remote socket (#4558) (0c0eb00)
- typings: properly type emits with timeout (f3ada7d)
This commit adds some syntactic sugar around acknowledgements:
emitWithAck()
try {
const responses = await io.timeout(1000).emitWithAck("some-event");
console.log(responses); // one response per client
} catch (e) {
// some clients did not acknowledge the event in the given delay
}
io.on("connection", async (socket) => {
// without timeout
const response = await socket.emitWithAck("hello", "world");
// with a specific timeout
try {
const response = await socket.timeout(1000).emitWithAck("hello", "world");
} catch (err) {
// the client did not acknowledge the event in the given delay
}
});
serverSideEmitWithAck()
try {
const responses = await io.timeout(1000).serverSideEmitWithAck("some-event");
console.log(responses); // one response per server (except itself)
} catch (e) {
// some servers did not acknowledge the event in the given delay
}
Added in 184f3cf.
This feature allows a client to reconnect after a temporary disconnection and restore its state:
- id
- rooms
- data
- missed packets
Usage:
import { Server } from "socket.io";
const io = new Server({
connectionStateRecovery: {
// default values
maxDisconnectionDuration: 2 * 60 * 1000,
skipMiddlewares: true,
},
});
io.on("connection", (socket) => {
console.log(socket.recovered); // whether the state was recovered or not
});
Here's how it works:
- the server sends a session ID during the handshake (which is different from the current
id
attribute, which is public and can be freely shared) - the server also includes an offset in each packet (added at the end of the data array, for backward compatibility)
- upon temporary disconnection, the server stores the client state for a given delay (implemented at the adapter level)
- upon reconnection, the client sends both the session ID and the last offset it has processed, and the server tries to restore the state
The in-memory adapter already supports this feature, and we will soon update the Postgres and MongoDB adapters. We will also create a new adapter based on Redis Streams, which will support this feature.
Added in 54d5ee0.
This feature implements middlewares at the Engine.IO level, because Socket.IO middlewares are meant for namespace authorization and are not executed during a classic HTTP request/response cycle.
Syntax:
io.engine.use((req, res, next) => {
// do something
next();
});
// with express-session
import session from "express-session";
io.engine.use(session({
secret: "keyboard cat",
resave: false,
saveUninitialized: true,
cookie: { secure: true }
}));
// with helmet
import helmet from "helmet";
io.engine.use(helmet());
A workaround was possible by using the allowRequest option and the "headers" event, but this feels way cleaner and works with upgrade requests too.
Added in 24786e7.
The disconnect
event will now contain additional details about the disconnection reason.
io.on("connection", (socket) => {
socket.on("disconnect", (reason, description) => {
console.log(description);
});
});
Added in 8aa9499.
This commit adds a new option, "cleanupEmptyChildNamespaces". With this option enabled (disabled by default), when a socket disconnects from a dynamic namespace and if there are no other sockets connected to it then the namespace will be cleaned up and its adapter will be closed.
import { createServer } from "node:http";
import { Server } from "socket.io";
const httpServer = createServer();
const io = new Server(httpServer, {
cleanupEmptyChildNamespaces: true
});
Added in 5d9220b.
The trailing slash which was added by default can now be disabled:
import { createServer } from "node:http";
import { Server } from "socket.io";
const httpServer = createServer();
const io = new Server(httpServer, {
addTrailingSlash: false
});
In the example above, the clients can omit the trailing slash and use /socket.io
instead of /socket.io/
.
Added in d0fd474.
- precompute the WebSocket frames when broadcasting (da2b542)
engine.io@~6.4.0
(https://github.com/socketio/engine.io/compare/6.2.1...6.4.0)ws@~8.11.0
(https://github.com/websockets/ws/compare/8.2.3...8.11.0)
4.5.4 (2022-11-22)
This release contains a bump of:
engine.io
in order to fix CVE-2022-41940socket.io-parser
in order to fix CVE-2022-2421.
engine.io@~6.2.1
(diff)ws@~8.2.3
(no change)
4.5.3 (2022-10-15)
- typings: accept an HTTP2 server in the constructor (d3d0a2d)
- typings: apply types to "io.timeout(...).emit()" calls (e357daf)
engine.io@~6.2.0
(no change)ws@~8.2.3
(no change)
4.5.2 (2022-09-02)
- prevent the socket from joining a room after disconnection (18f3fda)
- uws: prevent the server from crashing after upgrade (ba497ee)
engine.io@~6.2.0
(no change)ws@~8.2.3
(no change)
2.5.0 (2022-06-26)
The default value of the maxHttpBufferSize
option has been decreased from 100 MB to 1 MB, in order to prevent attacks by denial of service.
Security advisory: GHSA-j4f2-536g-r55m
- fix race condition in dynamic namespaces (05e1278)
- ignore packet received after disconnection (22d4bdf)
- only set 'connected' to true after middleware execution (226cc16)
- prevent the socket from joining a room after disconnection (f223178)
engine.io@~3.6.0
(https://github.com/socketio/engine.io/compare/3.5.0...3.6.0)ws@~7.4.2
(no change)
4.5.1 (2022-05-17)
- forward the local flag to the adapter when using fetchSockets() (30430f0)
- typings: add HTTPS server to accepted types (#4351) (9b43c91)
engine.io@~6.2.0
(no change)ws@~8.2.3
(no change)
4.5.0 (2022-04-23)
This is similar to onAny()
, but for outgoing packets.
Syntax:
socket.onAnyOutgoing((event, ...args) => {
console.log(event);
});
Added in 531104d.
Syntax:
io.timeout(1000).emit("some-event", (err, responses) => {
// ...
});
Added in 8b20457.
A "maxPayload" field is now included in the Engine.IO handshake, so that clients in HTTP long-polling can decide how many packets they have to send to stay under the maxHttpBufferSize
value.
This is a backward compatible change which should not mandate a new major revision of the protocol (we stay in v4), as we only add a field in the JSON-encoded handshake data:
0{"sid":"lv_VI97HAXpY6yYWAAAC","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":5000,"maxPayload":1000000}
Added in 088dcb4.
engine.io@~6.2.0
(https://github.com/socketio/engine.io/compare/6.1.0...6.2.0)ws@~8.2.3
(no change)
4.4.1 (2022-01-06)
- types: make
RemoteSocket.data
type safe (#4234) (770ee59) - types: pass
SocketData
type to custom namespaces (#4233) (f2b8de7)
4.4.0 (2021-11-18)
- only set 'connected' to true after middleware execution (02b0f73)
- add an implementation based on uWebSockets.js (c0d8c5a)
- add timeout feature (f0ed42f)
- add type information to
socket.data
(#4159) (fe8730c)
4.3.2 (2021-11-08)
4.3.1 (2021-10-16)
4.3.0 (2021-10-14)
- typings: add name field to cookie option (#4099) (033c5d3)
- send volatile packets with binary attachments (dc81fcf)
- serve ESM bundle (60edecb)
4.2.0 (2021-08-30)
- typings: allow async listener in typed events (ccfd8ca)
4.1.3 (2021-07-10)
4.1.2 (2021-05-17)
- typings: ensure compatibility with TypeScript 3.x (0cb6ac9)
- ensure compatibility with previous versions of the adapter (a2cf248)
4.1.1 (2021-05-11)
- typings: properly type server-side events (b84ed1e)
- typings: properly type the adapter attribute (891b187)
4.1.0 (2021-05-11)
- add support for inter-server communication (93cce05)
- notify upon namespace creation (499c892)
- add a "connection_error" event (7096e98, from
engine.io
) - add the "initial_headers" and "headers" events (2527543, from
engine.io
)
- add support for the "wsPreEncoded" writing option (dc381b7)
4.0.2 (2021-05-06)
4.0.1 (2021-03-31)
- typings: add fallback to untyped event listener (#3834) (a11152f)
- typings: update return type from emit (#3843) (1a72ae4)
4.0.0 (2021-03-10)
- make io.to(...) immutable (ac9e8ca)
- add some utility methods (b25495c)
- add support for typed events (#3822) (0107510)
- allow to exclude specific rooms when broadcasting (#3789) (7de2e87)
- allow to pass an array to io.to(...) (085d1de)
3.1.2 (2021-02-26)
- ignore packets received after disconnection (494c64e)
3.1.1 (2021-02-03)
- properly parse the CONNECT packet in v2 compatibility mode (6f4bd7f)
- typings: add return types and general-case overload signatures (#3776) (9e8f288)
- typings: update the types of "query", "auth" and "headers" (4f2e9a7)
3.1.0 (2021-01-15)
- confirm a weak but matching ETag (#3485) (161091d)
- esm: export the Namespace and Socket class (#3699) (233650c)
- add support for Socket.IO v2 clients (9925746)
- add room events (155fa63)
- allow integers as event names (1c220dd)
2.4.1 (2021-01-07)
- fix(security): do not allow all origins by default (a169050)
3.0.5 (2021-01-05)
- properly clear timeout on connection failure (170b739)
- restore the socket middleware functionality (bf54327)
2.4.0 (2021-01-04)
- security: do not allow all origins by default (f78a575)
- properly overwrite the query sent in the handshake (d33a619)
3.0.4 (2020-12-07)
3.0.3 (2020-11-19)
3.0.2 (2020-11-17)
- merge Engine.IO options (43705d7)
3.0.1 (2020-11-09)
- export ServerOptions and Namespace types (#3684) (f62f180)
- typings: update the signature of the emit method (50671d9)
3.0.0 (2020-11-05)
- close clients with no namespace (91cd255)
- emit an Error object upon middleware error (54bf4a4)
- serve msgpack bundle (aa7574f)
- add support for catch-all listeners (5c73733)
- make Socket#join() and Socket#leave() synchronous (129c641)
- remove prod dependency to socket.io-client (7603da7)
- move binary detection back to the parser (669592d)
- add ES6 module export (8b6b100)
- do not reuse the Engine.IO id (2875d2c)
- remove Server#set() method (029f478)
- remove Socket#rooms object (1507b41)
- remove the 'origins' option (a8c0600)
- remove the implicit connection to the default namespace (3289f7e)
- throw upon reserved event names (4bd5b23)
-
the Socket#use() method is removed (see 5c73733)
-
Socket#join() and Socket#leave() do not accept a callback argument anymore.
Before:
socket.join("room1", () => {
io.to("room1").emit("hello");
});
After:
socket.join("room1");
io.to("room1").emit("hello");
// or await socket.join("room1"); for custom adapters
- the "connected" map is renamed to "sockets"
- the Socket#binary() method is removed, as this use case is now covered by the ability to provide your own parser.
- the 'origins' option is removed
Before:
new Server(3000, {
origins: ["https://example.com"]
});
The 'origins' option was used in the allowRequest method, in order to determine whether the request should pass or not. And the Engine.IO server would implicitly add the necessary Access-Control-Allow-xxx headers.
After:
new Server(3000, {
cors: {
origin: "https://example.com",
methods: ["GET", "POST"],
allowedHeaders: ["content-type"]
}
});
The already existing 'allowRequest' option can be used for validation:
new Server(3000, {
allowRequest: (req, callback) => {
callback(null, req.headers.referer.startsWith("https://example.com"));
}
});
-
Socket#rooms is now a Set instead of an object
-
Namespace#connected is now a Map instead of an object
-
there is no more implicit connection to the default namespace:
// client-side
const socket = io("/admin");
// server-side
io.on("connection", socket => {
// not triggered anymore
})
io.use((socket, next) => {
// not triggered anymore
});
io.of("/admin").use((socket, next) => {
// triggered
});
- the Server#set() method was removed
This method was kept for backward-compatibility with pre-1.0 versions.
3.0.0-rc4 (2020-10-30)
3.0.0-rc3 (2020-10-26)
- add support for catch-all listeners (5c73733)
- make Socket#join() and Socket#leave() synchronous (129c641)
- remove prod dependency to socket.io-client (7603da7)
-
the Socket#use() method is removed (see 5c73733)
-
Socket#join() and Socket#leave() do not accept a callback argument anymore.
Before:
socket.join("room1", () => {
io.to("room1").emit("hello");
});
After:
socket.join("room1");
io.to("room1").emit("hello");
// or await socket.join("room1"); for custom adapters
3.0.0-rc2 (2020-10-15)
- close clients with no namespace (91cd255)
- remove duplicate _sockets map (8a5db7f)
- move binary detection back to the parser (669592d)
- the "connected" map is renamed to "sockets"
- the Socket#binary() method is removed, as this use case is now covered by the ability to provide your own parser.
3.0.0-rc1 (2020-10-13)
- add ES6 module export (8b6b100)
- do not reuse the Engine.IO id (2875d2c)
- remove Server#set() method (029f478)
- remove Socket#rooms object (1507b41)
- remove the 'origins' option (a8c0600)
- remove the implicit connection to the default namespace (3289f7e)
- throw upon reserved event names (4bd5b23)
- the 'origins' option is removed
Before:
new Server(3000, {
origins: ["https://example.com"]
});
The 'origins' option was used in the allowRequest method, in order to determine whether the request should pass or not. And the Engine.IO server would implicitly add the necessary Access-Control-Allow-xxx headers.
After:
new Server(3000, {
cors: {
origin: "https://example.com",
methods: ["GET", "POST"],
allowedHeaders: ["content-type"]
}
});
The already existing 'allowRequest' option can be used for validation:
new Server(3000, {
allowRequest: (req, callback) => {
callback(null, req.headers.referer.startsWith("https://example.com"));
}
});
-
Socket#rooms is now a Set instead of an object
-
Namespace#connected is now a Map instead of an object
-
there is no more implicit connection to the default namespace:
// client-side
const socket = io("/admin");
// server-side
io.on("connection", socket => {
// not triggered anymore
})
io.use((socket, next) => {
// not triggered anymore
});
io.of("/admin").use((socket, next) => {
// triggered
});
- the Server#set() method was removed
This method was kept for backward-compatibility with pre-1.0 versions.
2.3.0 (2019-09-20)
This release mainly contains a bump of the engine.io
and ws
packages, but no additional features.
2.2.0 (2018-11-29)
2.1.1 (2018-05-17)
socket.local.to('room101').emit(/* */);
2.1.0 (2018-03-29)
// by default, the object is recursively scanned to check whether it contains some binary data
// in the following example, the check is skipped in order to improve performance
socket.binary(false).emit('plain-object', object);
// it also works at the namespace level
io.binary(false).emit('plain-object', object);
io.of(/^\/dynamic-\d+$/).on('connect', (socket) => {
// socket.nsp.name = '/dynamic-101'
});
// client-side
const client = require('socket.io-client')('/dynamic-101');
- properly emit 'connect' when using a custom namespace (#3197) (f4fc517)
- include the protocol in the origins check (#3198) (1f1d64b)
Important note ⚠️ from Engine.IO 3.2.0 release
There are two non-breaking changes that are somehow quite important:
ws
was reverted as the default wsEngine (socketio/engine.io#550), as there was several blocking issues withuws
. You can still useuws
by runningnpm install uws --save
in your project and using thewsEngine
option:
var engine = require('engine.io');
var server = engine.listen(3000, {
wsEngine: 'uws'
});
pingTimeout
now defaults to 5 seconds (instead of 60 seconds): socketio/engine.io#551