Open-source alternatives to Websocket Sharp

libhv is a high-performance C/C++ network library and event-driven I/O framework used to build TCP, UDP, SSL, HTTP, WebSocket, and MQTT clients and servers. It provides a non-blocking event loop for managing network sockets, timers, and system signals across multiple threads. The project is distinguished by its integrated support for specialized network roles, including a full HTTP web server with RESTful routing and middleware, an MQTT messaging client for IoT communication, and the ability to implement SOCKS5 and HTTP proxies. It also features a reliable UDP implementation to ensure ordered

This is a header-only C++ library that provides implementations for HTTP clients, HTTP servers, and a WebSocket framework. It allows for the creation of network services and the consumption of remote APIs without requiring a separate compilation step or external binary linking. The project features backend-agnostic TLS integration for secure HTTPS and WSS communication and employs a thread-pool model to process concurrent requests. It distinguishes itself with a full-duplex WebSocket state-machine and a middleware-based request pipeline that supports regular-expression path routing. The libr

SocketRocket is an Objective-C WebSocket client library designed to establish bidirectional real-time communication channels between an application and a server. It provides a networking layer for real-time data streaming, utilizing a heartbeat monitor to maintain the stability of active network streams. The library is built to operate across restricted networks by routing traffic through HTTP proxies. It secures data transmission using TLS encryption and SSL certificate pinning to prevent unauthorized interception of network traffic. Its underlying capabilities include low-level TCP socket

wscat is a command-line WebSocket client and server tool that provides an interactive terminal interface for connecting to WebSocket endpoints, sending and receiving text messages in real time, and managing WebSocket control frames through typed slash commands. It supports basic HTTP authentication by injecting credentials into the initial WebSocket handshake request, and can route connections through an HTTP proxy using the CONNECT tunneling method. The tool includes a built-in WebSocket server mode that listens on a specified port, accepts incoming client connections, and relays messages be

websockets is a Python library for building WebSocket servers and clients using coroutines and the asyncio framework. It provides a complete toolkit for creating production-ready WebSocket applications, including a coroutine-based framework for handling connections, messages, and lifecycle events, as well as a client library for opening persistent bidirectional connections to remote endpoints. The library manages the full lifecycle of WebSocket connections, including handshake, message exchange, and graceful closure, with support for path-based routing to organize server logic across multiple

Starscream is a Swift WebSocket client library that provides a concrete implementation of the WebSocket protocol for iOS and macOS applications. It functions as an event-driven wrapper for establishing and managing bidirectional connections to send and receive text and binary frames over TCP. The library includes a secure WebSocket client capable of encrypting traffic and validating server identities. It manages the full connection lifecycle, from the initial handshake and header exchange to session termination with custom close codes. The project covers a broad range of networking capabilit

This is a header-only C++ library and asynchronous network framework used to implement WebSocket clients and servers. It provides a full implementation of the WebSocket protocol, including handshakes, subprotocol negotiation, and frame parsing. The framework is distinguished by a policy-based transport layer and template-driven protocol negotiation, allowing the underlying network implementation to be swapped between raw buffers, streams, or custom policies. It supports per-message deflate compression to reduce data transmission volume and integrates Transport Layer Security for encrypted bid

This project is a Node.js WebSocket library that provides a high-performance client and server implementation for the WebSocket protocol. It functions as a transport layer for real-time bidirectional communication, supporting both UTF-8 strings and binary data transport through the use of TCP socket wrappers. The library enables the creation of WebSocket servers that manage full-duplex connections and broadcast messages to multiple clients, as well as WebSocket clients that establish persistent links to remote servers. It handles the protocol upgrade process via TCP-based handshake negotiatio

AndroidAsync is a non-blocking networking library for Android that provides asynchronous sockets, HTTP clients, and servers based on Java NIO. It serves as a toolkit for managing raw TCP socket connections and bidirectional data streams using an asynchronous input and output architecture. The library includes a dedicated WebSocket framework for establishing persistent full-duplex communication channels between Android clients and servers. It also enables the hosting of a lightweight asynchronous HTTP server directly on an Android device to handle incoming network traffic. Its broader capabil

PartyKit is a serverless WebSocket backend platform for building real-time multiplayer applications. It provides a globally distributed edge computing runtime that runs stateful server code close to users, with automatic scaling and hibernation for idle rooms. The platform handles WebSocket connections, HTTP requests, and durable storage without requiring infrastructure management, and includes a client and server SDK with hooks, storage, and Yjs integration for building collaborative features. The platform distinguishes itself through per-room isolation using Durable Objects, where each uniq

Websocat is a specialized set of command-line tools for WebSocket communication, acting as a client, server, and stream processor. It provides a terminal-based interface for connecting to WebSocket servers, hosting secure WebSocket servers, and bridging data between WebSockets and other network transports. The project distinguishes itself by functioning as a bidirectional network relay, allowing the routing of data between WebSocket streams, TCP sockets, UNIX sockets, and standard system input and output. It includes specialized implementations for SOCKS5 and HTTP proxying, as well as a strea

SignalR is a .NET real-time web framework designed to push content from a server to connected browser and non-browser clients. It provides a server-to-client push framework and a remote procedure call system that enables bidirectional communication over persistent connections. The library utilizes WebSockets to establish full-duplex connections and includes a transport-layer abstraction to manage different network protocols. It employs client-side connection negotiation to determine the best available communication protocol during the initial handshake. The system manages persistent connecti

This project is a library for establishing bidirectional, real-time communication channels between clients and servers using the WebSocket protocol. It provides a foundational toolkit for managing persistent network connections and processing data frames in accordance with the RFC 6455 standard. The library distinguishes itself through its focus on low-level control and network efficiency. It utilizes an asynchronous, event-driven architecture to manage multiple concurrent connections without requiring dedicated threads for each session. Developers can fine-tune data transmission through manu

Elysia is a high-performance TypeScript web framework designed for building type-safe backend services. It provides a modular, plugin-based architecture that allows developers to compose server logic, middleware, and validation schemas into scalable application instances. By leveraging native web standards, the framework ensures portability across diverse JavaScript runtimes, including Node.js, Deno, and various edge computing environments. The framework distinguishes itself through its focus on end-to-end type safety, automatically synchronizing request and response definitions between the s

smtp4dev is a suite of tools featuring a mock SMTP server that intercepts outgoing email traffic and stores messages for inspection instead of delivering them to recipients. It includes a web-based viewer for inspecting email metadata, raw source code, and MIME structures, alongside a responsive email previewer that simulates how HTML emails appear across different viewport sizes and device layouts. The project provides a traffic analyzer to log protocol interactions and session data for debugging delivery failures. It also operates as a TLS SMTP server, supporting encrypted connections via T

Typhoeus is a Ruby wrapper for libcurl that functions as a session-based HTTP client. It provides an interface for making both synchronous and asynchronous network requests. The project acts as a parallel request manager, using a managed queue to execute multiple network requests concurrently. It further distinguishes itself as a mocking tool for stubbing requests with predefined responses and as a caching layer that stores responses to avoid redundant network calls. The library covers a broad range of capabilities including session cookie management, response body streaming for large files,

websockets is a Python library that provides both client and server implementations for the WebSocket protocol, enabling real-time, bidirectional communication between applications. At its core, it offers the fundamental primitives for establishing persistent connections, managing their lifecycles, and exchanging text or binary messages asynchronously using coroutines. The library distinguishes itself through comprehensive support for various messaging patterns, including broadcast messaging to all connected clients, targeted messaging to specific clients, and shared application state synchro

Crow is a minimalist C++ micro web framework designed for building fast web servers and REST APIs. It provides a lightweight toolkit for web development in C++, offering core routing and request handling capabilities. The framework includes a built-in JSON parser for converting strings into structured data and an HTML template engine for generating dynamic web pages on the server. It also functions as a WebSocket server library to enable bidirectional, real-time communication between servers and web clients. Additional capabilities include a middleware-based request pipeline for executing sh

This is a Python WebSocket client library designed to establish full-duplex, persistent network connections for real-time exchange of text and binary data. It functions as an asynchronous network client and a TCP socket wrapper, managing the complete lifecycle of a connection from the initial handshake to graceful closure. The implementation includes a secure WebSocket client that handles SSL/TLS encryption, certificate verification, and secure handshake protocols. It further distinguishes itself by supporting advanced connectivity options, including proxy routing via HTTP or SOCKS proxies an

Robyn is a high-performance asynchronous web framework and server for Python that utilizes a Rust-powered runtime to execute code. It functions as an asynchronous Python web server designed to handle many concurrent requests efficiently through a multithreaded execution model. The project includes specialized capabilities for AI agent request routing, managing communication between agents and external tools. It also serves as a WebSocket communication server, maintaining persistent bidirectional channels for real-time data exchange. The framework covers a broad range of web infrastructure, i

This project is a PHP library designed for establishing persistent, bidirectional communication channels using the WebSocket protocol. It functions as both a client and a server implementation, providing the necessary tools to initiate connections with remote endpoints or host custom messaging services. The library manages the full lifecycle of network connections, including the initial HTTP handshake negotiation required to upgrade standard web traffic to a persistent stream. It utilizes low-level stream resources to handle data flow and incorporates automated heartbeat signals to monitor co

Drogon is a high-performance C++ HTTP web framework and asynchronous web server designed for building web applications and REST APIs. It utilizes an event-driven, non-blocking architecture to handle concurrent HTTP and WebSocket connections, and it implements a model-view-controller structure to separate business logic from presentation. The framework includes an integrated C++ object-relational mapping system and database client for performing asynchronous operations with relational databases and Redis key-value stores. It supports real-time, full-duplex communication via WebSockets and prov

Handy is a C++11 network server framework and event-driven networking engine designed for building high-performance concurrent TCP and UDP servers. It functions as an asynchronous I/O library and an HTTP server implementation that separates asynchronous network I/O from synchronous business logic to simplify server development. The framework distinguishes itself by utilizing platform-specific event notifications to manage millions of simultaneous network connections and providing an SSL/TLS network wrapper for encrypted asynchronous data transmission. It implements a half-sync/half-async proc

node-http-proxy is a Node.js HTTP proxy library used for forwarding requests to target servers. It functions as reverse proxy middleware capable of mapping incoming routes to target destinations and transforming request and response data streams. The library includes a WebSocket proxy gateway that upgrades standard HTTP connections into bidirectional streams between clients and backend servers. It also provides a response transformer for modifying bodies, location headers, and cookie domains. The project covers traffic routing management via rule-based translation tables and secure connectio

Melody is a WebSocket server framework designed to upgrade HTTP connections into bidirectional streams. It functions as a session manager and binary streaming library that facilitates real-time data exchange between a server and multiple remote clients. The project features a broadcast engine that optimizes multi-client transmissions through wire-representation caching. It includes a dedicated session management system for attaching custom state to persistent network connections and an upgrade handler that validates handshake headers. The framework covers broad capability areas including eve

netty-socketio is a Java implementation of a Socket.IO server designed for real-time bidirectional communication between clients and servers. It functions as a real-time event engine and WebSocket communication server, utilizing the Netty network framework to manage high-performance socket connections. The project enables distributed socket server scaling by acting as a distributed message broker. It synchronizes client states and broadcasts messages across multiple server nodes through the use of an external data store. The system manages traffic via namespace-based connection routing and r

uWebSockets.js is a high-performance tool for building WebSocket and HTTP servers within Node.js. It focuses on high-throughput web servers and real-time data streaming, enabling the creation of network applications that handle a large number of concurrent connections with low memory and CPU overhead. The project distinguishes itself through a native C++ implementation that integrates directly with the Node.js event loop. It utilizes native-layer route matching and a shared memory architecture to minimize allocation overhead and avoid data duplication during message transmission. The impleme