What's Changed

• Added a netstandard2.0 target so full .NET Framework applications can consume Websocket.Client again.
• Kept the existing .NET 6/7/8/9/10 paths on the current Memory<byte>/ReadOnlyMemory<byte> WebSocket APIs, with compatibility fallbacks isolated to netstandard2.0.
• Modernized the .NET Framework sample to SDK-style net472 with PackageReference dependencies and current Websocket.Client API usage.
• Added Windows CI coverage for the .NET Framework sample and net472 benchmark build.
• Added .NET Framework client receive benchmark coverage and documented the measured results.

Compatibility

• NuGet package version: 5.5.0.
• Adds support for full .NET Framework consumers through the netstandard2.0 package asset.
• No breaking API changes for existing .NET Core / modern .NET targets.

Highlights

• Published Websocket.Client 5.4.0 to NuGet.
• Added .NET 9 and .NET 10 targets while keeping the existing supported target frameworks for backward compatibility.
• Added a BenchmarkDotNet project and documented benchmark results in benchmarks/README.md.
• Updated the main README with a high-level performance overview for the library.

Performance

• Optimized receive processing to reduce allocations with pooled buffers and lower-copy message construction.
• Reduced queued send request overhead by replacing internal request wrapper allocations with a value-type envelope.
• Added send framing, receive buffering, text encoding, response message, observable property, and logging benchmarks to make future performance changes measurable.
• Current queued send benchmark improved from 31.54 ns / 24 B to 29.65 ns / 0 B per operation.

Compatibility and Reliability

• Added ReadOnlySequence<byte> send support and tests for binary-as-text send overload behavior.
• Added support for reusing an external RecyclableMemoryStreamManager.
• Fixed reconnect logic and increased the default connect timeout to 5 seconds.
• Conditionalized dependencies for cleaner target-framework-specific package output.

Notes

• No intentional public contract breaks.
• CI now builds with the .NET 10 SDK and the release pipeline passed for this version.

Features

• Usage of RecyclableMemoryStream for processing incoming messages. Thanks @Odonno !
• The new methods available
  • SendAsText(byte[] | ArraySegment<byte>) - send binary message as Text type. Use it to avoid double serialization.

Breaking changes

• removed LibLog in favor of Microsoft.Extensions.Logging. You need to provide ILogger instance in the constructor parameter.
• library no longer targeting netstandard2.0 and net5

Features

• nullable reference types enabled, you should now get a better info on what can be null

Breaking changes

• timeout properties changed from milliseconds (int) to TimeSpan
• DisconnectionHappened, ReconnectionHappened streams now return complex info object instead of enum
• changed return type from Task to void in Send() methods (sending is done through the queue)

Features

• ability to disable last chance reconnection (when no message comes from server for predefined time) - ReconnectTimeout = null
• streaming fake messages - to mimic server response - StreamFakeMessage(...)
• fail fast for starting, stopping and manual reconnection - throws an exception when the initial connection fails - StartOrFail(), ReconnectOrFail(), StopOrFail()
• more info in DisconnectionHappened stream - close status, exception that caused disconnection, etc.
• runtime reconnection canceling from DisconnectionHappened stream - it will stop ongoing reconnection - disconnectionInfo.CancelReconnection = true
• normal closure - automatically Close client when server sends Close message, could be disabled by DisconnectionHappened stream - disconnectionInfo.CancelClosing= true
• performance optimizations
  • sending is done through Channels
  • listening now allocates less memory and handles differently single chunk vs multi chunks

Breaking changes

• return type of MessageReceived observable was changed from string to ResponseMessage

Features

• support for binary messages
  • a new method Send() and SendInstant() with parameter byte[]
  • MessageReceived observable now streams text or binary data (there is type property to distinguish between them)
• a new MessageEncoding property to change encoding of sent/received text messages (default is UTF8)

Breaking changes

• dependency to Serilog was removed, switched to logging abstraction (LibLog)

Features

• a new Name property to distinguish between websocket clients in the logs