Open-source alternatives to Websocket

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

The C++ REST SDK is a library for asynchronous HTTP and RESTful communication in native C++ applications. It provides a non-blocking network client for sending requests and receiving responses, a JSON parser for serializing and deserializing data, and a WebSocket client library for real-time, full-duplex communication. The project includes a dedicated OAuth2 authentication client to manage access tokens and authorization flows for secure communication with protected cloud resources. It utilizes a task-based asynchronous model to coordinate background operations and keep application interfaces

Salvo is a comprehensive Rust web framework for building asynchronous HTTP servers and web applications. It features a hierarchical web router that uses a tree-based structure to map requests to handlers and an asynchronous middleware pipeline based on the onion model for request and response pre- and post-processing. The framework is distinguished by its native support for modern network protocols, including a QUIC-based HTTP/3 implementation alongside HTTP/1 and HTTP/2. It includes an integrated OpenAPI documentation generator that extracts schemas directly from handler signatures to produc

This Go library provides low-level components for implementing high-performance WebSocket connections. It focuses on minimal memory allocations and efficient data throughput via a dedicated frame processor, an HTTP connection upgrader, and a compression layer. The project distinguishes itself through the use of zero-allocation buffer reuse to reduce garbage collection pressure. It operates directly on raw network bytes for frame parsing and manages the lifecycle of connections through state-based tracking. The library covers core network protocol capabilities including the transformation of

Kore is an event-driven web and WebSocket server framework designed for building high-performance web services and APIs in C or Python. It functions as a secure, concurrent application framework that utilizes non-blocking I/O and isolated worker processes to handle high-concurrency traffic. The project is distinguished by a security-first architecture that features OS-level process sandboxing, privilege separation, and the isolation of private encryption keys into dedicated processes. It enables zero-downtime deployments through dynamic module hot-reloading and provides automated TLS certific

This project is a cross-platform implementation of the WebRTC standard, providing a comprehensive library for building real-time audio, video, and data communication applications. It functions as a peer-to-peer networking framework and media processing engine, enabling direct, low-latency connections between devices without relying on central servers. By strictly adhering to official protocol specifications, the library ensures interoperability with browsers and other native communication software across mobile, desktop, and server environments. The engine distinguishes itself through a modul

Pipecat is a framework and software development kit for building real-time multimodal AI agents and speech-to-speech systems. It utilizes a frame-based data pipeline to route audio, video, and text through a modular sequence of processors, enabling the orchestration of low-latency conversational AI. The project is distinguished by its ability to coordinate complex multimodal services, including speech-to-text, language models, and text-to-speech, within a single pipeline. It features semantic voice activity detection for natural turn-taking, state-machine conversation flows for dialogue manag

NanoHTTPD is a lightweight, embeddable HTTP server for Java applications. It allows developers to integrate web server capabilities directly into a Java project to handle incoming requests without requiring a standalone installation. The project provides specialized implementations for an HTTPS web server, a WebSocket server for bidirectional real-time communication, and a static file web server. These capabilities enable secure network traffic through SSL certificates and the delivery of local files with automatic MIME type detection. The server includes systems for request routing and hand

Fasthttp is a high-performance networking framework for Go, designed to maximize throughput and minimize memory overhead in demanding web applications. It functions as a specialized HTTP server and client library that prioritizes efficient resource management, allowing developers to build scalable services capable of handling massive concurrent traffic with minimal garbage collection pressure. The library distinguishes itself through a focus on zero-allocation processing and low-level optimization. It achieves this by recycling temporary request and response objects through managed pools and

This project is a comprehensive sample library and implementation guide for ASP.NET Core. It provides a collection of practical examples and projects that demonstrate how to build web applications, RESTful APIs, and high-performance services. The repository focuses on a variety of architectural patterns, including the development of Minimal APIs, contract-first gRPC services, and real-time communication using WebSockets and Server-Sent Events. It includes detailed implementations for user identity and security, such as token-based authentication and CSRF protection. The codebase covers a bro

NATS Server is a high-performance, lightweight messaging system designed for cloud-native applications, edge computing, and distributed microservices. It functions as a distributed publish-subscribe broker that routes messages using hierarchical, dot-separated subject strings, enabling decoupled communication between services without requiring centralized broker lookups. The system supports core messaging patterns including asynchronous publish-subscribe, request-reply, and load-balanced queue processing. The platform distinguishes itself through a decentralized architecture that eliminates t

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

Quarkus is a Kubernetes-native Java framework designed for building high-performance, memory-efficient applications. It utilizes ahead-of-time native compilation to transform Java code into standalone, optimized binaries that eliminate the need for a virtual machine, enabling rapid startup and reduced memory consumption. By performing code augmentation during the build phase, it shifts heavy processing tasks away from runtime, ensuring that applications are optimized for cloud-native environments. The framework distinguishes itself through a unified approach to reactive and imperative program

Baileys is a TypeScript API client library used to interact with the WhatsApp Web API via WebSockets without requiring a browser. It functions as a real-time communication tool that handles bidirectional data exchange and event-based socket connections. The project includes a dedicated toolkit for managing WhatsApp Business profiles and product catalogs, alongside a session manager that authenticates accounts using QR codes or pairing codes and persists session state to disk. Its capabilities cover a wide range of messaging functions, including multi-type message transmission, chat history s

Socket.IO Client is a real-time WebSocket client library that establishes persistent bidirectional connections to a server, with automatic fallback to HTTP long-polling when WebSocket connections are unavailable. It provides an event-based bidirectional messaging framework where clients and servers exchange named events with serializable data, supporting acknowledgements and timeouts for reliable communication. The client distinguishes itself through automatic reconnection with exponential backoff, maintaining connection reliability by monitoring health and reconnecting with increasing delays

Socket.io is a real-time communication engine that enables bidirectional, event-based data exchange between clients and servers. It provides a robust transport-agnostic protocol layer that automatically manages connection lifecycles, including heartbeat signals, automatic reconnection, and seamless fallback between WebSockets and HTTP long-polling. By maintaining persistent links, it ensures reliable messaging across diverse network environments. The project distinguishes itself through a scalable, distributed architecture that supports multi-node synchronization and room-based message routin

This project is a memory-safe implementation of the QUIC transport protocol and HTTP/3, designed for high-throughput and efficient network communication. It provides a comprehensive toolkit for building secure, low-latency network applications by managing the full lifecycle of transport connections, including protocol negotiation, stream data exchange, and connection state management. The library distinguishes itself through a focus on performance and protocol integrity. It utilizes a formal state machine to enforce strict adherence to transport rules and employs zero-copy buffer management t

This project provides a comprehensive implementation of the AT Protocol, serving as a framework for building decentralized social networking applications. It enables the creation of distributed data repositories where users maintain cryptographic ownership of their identity and content, allowing for portable accounts that can be migrated between independent servers without central authority intervention. The platform distinguishes itself by decoupling content hosting from discovery through modular algorithmic curation. Users can select third-party services to filter and organize their feeds,

This project is a high-performance implementation of the QUIC transport protocol, providing a library for establishing multiplexed, low-latency network connections over UDP. It serves as a foundational networking stack for building modern web servers and clients, with native support for HTTP/3 and WebTransport standards. The library distinguishes itself through advanced connection management, including the ability to maintain stable sessions across changing network paths or IP addresses using connection identifiers. It optimizes data throughput by employing packet batching to reduce kernel ov

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

Highly scalable realtime pub/sub and RPC framework

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

Model Context Protocol is a standardized framework for connecting large language models to external data sources and executable tools. It enables the creation of a universal interface where servers expose tools, resources, and prompts that can be discovered and utilized by various AI clients. The protocol utilizes a JSON-RPC message system that is transport-agnostic, supporting both standard input/output for local processes and HTTP with server-sent events for remote connections. It emphasizes security and control by delegating model sampling to the client to keep API keys secure from servers

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

wstunnel is a tool that tunnels arbitrary TCP traffic through WebSocket connections, enabling communication across restrictive firewalls and proxies. It operates as both a client and server, encapsulating TCP data within WebSocket binary frames and multiplexing multiple connections over a single WebSocket link. The tool supports mutual TLS authentication, requiring clients to present signed certificates for verification before establishing a tunnel, and provides shared secret access control and tunnel forwarding restrictions for additional security. The project distinguishes itself by offerin

Ratchet is a PHP library for building asynchronous WebSocket servers that handle persistent, bidirectional communication between clients and the server. It provides a complete server-side WebSocket implementation, including protocol handshake negotiation, message framing over TCP, and an event-loop-based concurrency model that manages thousands of simultaneous connections without blocking. The library implements a connection registry pattern for tracking all active WebSocket sessions, enabling the server to broadcast or unicast messages to any connected client on demand. It relies on non-bloc