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socket.io

4.8.4 · 25 Sep 2026MIT16.6M / weekRepositoryHomepagenpmAtom feed

Your version

4.5.0

23 Apr 2022Where it was published

4.8.4 is the newest release of 4.x.

In short

1 fixed2 internal

Security

1 advisory affects 4.5.0; 4.6.2 fixes them

Release note

The section about socket.io of a note shared by several packages.

Bug Fixes

  • typings: ensure compatibility with TypeScript 3.x

Features

Catch-all listeners for outgoing packets

This is similar to onAny(), but for outgoing packets.

Syntax:

socket.onAnyOutgoing((event, ...args) => {
  console.log(event);
});

Added in 531104d.

Broadcast and expect multiple acknowledgements

Syntax:

io.timeout(1000).emit("some-event", (err, responses) => {
  // ...
});

Added in 8b20457.

maxHttpBufferSize value negotiation

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.