v4.0.0

[4.0.0] - 2026-01-28

Architecture Refactor

• Reworked the internal architecture to improve modularity, maintainability, and long-term extensibility
• Clearer separation of responsibilities between core components
• Reduced coupling between modules, making future enhancements safer and easier

Performance Enhancements

• Improved execution efficiency in key processing paths
• Reduced unnecessary allocations and redundant operations
• Optimized data access and internal workflows for better runtime performance

v3.0.8

[3.0.8] - 2023-03-04

Added

• Expose namepsace as a readonly property #304

Changed

• Update NuGet dependencies
• Cancel reconnecting when calling Disconnect or Dispose #307
• Improve proformance

v3.0.6

[3.0.6] - 2022-03-17

Added

• auth handshake for socket.io server v3
• support auto upgrade transport protocol

Changed

• Fixed OnDisconnect not fired for 'io server disconnect' event #269

v3.0.5

[3.0.5] - 2022-01-12

Changed

• Fixed an error when pinInterval and pingTimeout are strings #243
• Clean up event handler when the connection is disconnected
• Fixed IOClientDisconnect #254

v3.0.4

Changed

• Fix the problem of out of order when sending json, it will cause the server to received an Error: Invalid Payload.

v3.0.3

Added

• Regression support for socket.io server v2, for socket.io server v2 users, please explicitly set EIO = 3.
• Added Transport option, default is Websocket
• EIO option

Removed

• AutoUpgrade option

v3.0.2

Added

• ExtraHeaders

Changed

• fix WebSocketException on manual reconnection after manual disconnection
• fix that the query cannot be changed after the connection is successful

v3.0.1

Added

• Support for Xamarin is more friendly

Changed

• Fix 'Attemps' count wrong when reconnecting

v3.0.0

SocketIOClient v3.0.0 supports http polling and websocket, socket.io server v2.x is no longer supported. If a large number of users use this version, please feedback.

Added

• http polling
• SocketIOClient.ClientWebSocketProvider
• If you want to use http polling and do not want the library to upgrade the transport, please set Options.AutoUpgrade = false.

Removed

• EIO option
• SocketIOClient.Socket
• socket.io server v2.x is no longer supported.

v2.3.1

Changed

• fix: first OnReconnectAttempt will not triggered when reconnecting
• fix: incorrect disconnect reason