NexNet

Real-time bidirectional networking for .NET. Source-generated hubs and proxies with zero reflection, multiple transports, and full AOT compatibility.

Documentation | API Reference

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Packages

Name	NuGet	Description
NexNet		Core library for server and client communication.
NexNet.Generator		Source generator for hubs and proxies.
NexNet.Quic		QUIC transport support.
NexNet.Asp		ASP.NET Core integration for WebSocket and HttpSocket transports.

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Why NexNet

NexNet is a networking framework for .NET that handles bidirectional communication between servers and clients. A Roslyn source generator emits all hub and proxy code at compile time — there is no reflection, no runtime code generation, and the result is fully NativeAOT compatible.

Interfaces define the contract between server and client. The generator produces strongly-typed proxies, invocation dispatchers, and serialization code. At runtime, connecting and invoking methods is straightforward: start a server, connect a client, and call methods through the proxy. NexNet handles reconnection, multiplexing, and transport abstraction.

Beyond RPC, NexNet provides synchronized collections that keep data in sync across server and clients, duplex pipes for raw byte streaming, typed channels for structured data streaming, and a declarative authorization system — all source-generated with the same zero-reflection approach.

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Comparison

Capability	NexNet	SignalR	gRPC
Source generated (no reflection)	Yes	No	Yes (protobuf)
Bidirectional RPC	Yes	Yes (hub methods)	Yes (streams)
Transport options	6 (UDS, TCP, TLS, QUIC, WS, HttpSocket)	3 (WS, SSE, Long Polling)	1 (HTTP/2)
Synchronized collections	Yes	No	No
Duplex byte streaming	Yes (pipes + channels)	Yes (streams)	Yes (streams)
Auto reconnection	Yes	Yes	No
Built-in rate limiting	Yes	No	No
NativeAOT compatible	Yes	No	Partial
Session groups	Yes	Yes	No
Interface versioning	Yes (hash-locked)	No	Yes (protobuf)
ASP.NET integration	Yes	Native	Native

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Features

• Source-generated hubs and proxies — all invocation code emitted at compile time; no reflection
• Bidirectional method invocation — server-to-client and client-to-server calls with void, ValueTask, and ValueTask<T> returns
• Synchronized collections — INexusList with server-to-client, bidirectional, and relay modes
• Duplex pipes — bidirectional byte streaming with built-in congestion control
• Typed channels — INexusDuplexChannel<T> and INexusDuplexUnmanagedChannel<T> with IAsyncEnumerable support
• Session management — per-session hub instances, named groups for targeted broadcasting, automatic reconnection
• Authentication — token-based connection authentication with IIdentity
• Authorization — declarative [NexusAuthorize<TPermission>] with caching and compile-time diagnostics
• Interface versioning — version hierarchy with HashLock validation and runtime enforcement
• Six transports — UDS, TCP, TLS, QUIC, WebSocket, HttpSocket
• ASP.NET Core integration — middleware with DI, authentication, and reverse proxy support
• Rate limiting — per-IP limits, sliding windows, and automatic banning
• Benchmarks — ~27,000 invocations/sec with minimal allocations

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Quick Start

// Shared interfaces
public interface IClientNexus
{
    ValueTask<string> GetUserName();
}
public interface IServerNexus
{
    ValueTask<int> GetStatus(int userId);
}

// Client nexus
[Nexus<IClientNexus, IServerNexus>(NexusType = NexusType.Client)]
partial class ClientNexus
{
    public ValueTask<string> GetUserName()
        => new("Bill");
}

// Server nexus
[Nexus<IServerNexus, IClientNexus>(NexusType = NexusType.Server)]
partial class ServerNexus
{
    public ValueTask<int> GetStatus(int userId)
        => new(1);
}

// Usage
var server = ServerNexus.CreateServer(serverConfig, () => new ServerNexus());
var client = ClientNexus.CreateClient(clientConfig, new ClientNexus());

await server.StartAsync();
await client.ConnectAsync();
var status = await client.Proxy.GetStatus(42);

The generator emits all hub and proxy classes at compile time. See Getting Started for the full walkthrough.

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Benchmarks

BenchmarkDotNet v0.15.8, Windows 11 (10.0.26100.7462/24H2/2024Update/HudsonValley)
Intel Core i7-10700 CPU 2.90GHz, 1 CPU, 16 logical and 8 physical cores
.NET SDK 9.0.305
  [Host]     : .NET 9.0.9 (9.0.9, 9.0.925.41916), X64 RyuJIT x86-64-v3
  Job-FJSVHN : .NET 9.0.9 (9.0.9, 9.0.925.41916), X64 RyuJIT x86-64-v3

Platform=X64  Runtime=.NET 9.0

Method	Mean	Error	StdDev	Op/s	Allocated
InvocationNoArgument	36.7 us	0.33 us	0.31 us	27,241.7	595 B
InvocationUnmanagedArgument	37.4 us	0.52 us	0.48 us	26,769.8	649 B
InvocationUnmanagedMultipleArguments	37.3 us	0.28 us	0.25 us	26,800.8	700 B
InvocationNoArgumentWithResult	36.9 us	0.35 us	0.32 us	27,095.2	633 B
InvocationWithDuplexPipe_Upload	51.8 us	0.60 us	0.51 us	19,295.4	14,951 B

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Transport Selection Guide

Scenario	Recommended Transport	Reason
Same machine IPC	Unix Domain Sockets	Highest performance, no network overhead
Local network	TCP	Simple, reliable, fast
Internet/WAN	TLS over TCP	Secure, widely supported
Mobile/unstable networks	QUIC	Connection migration, better congestion control
Web applications	WebSockets	Browser compatibility, firewall-friendly
Reverse proxy setups	HttpSockets	Lower overhead than WebSockets

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Dependencies

• MemoryPack for message serialization.
• Internally packages Marc Gravell's Pipelines.Sockets.Unofficial with additional performance modifications for pipeline socket transports.
• QUIC transport requires libmsquic on Linux. Windows Support

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Samples

Sample	Description
NexNetDemo	Console app demonstrating invocations, channels, duplex pipes, collections, and API versioning
NexNetSample.Asp	ASP.NET Core server and client with HttpSocket transport, bearer auth, duplex pipes, and collections