C++ WebSocket Library

What is WebSocket and why do you need a C++ library?

WebSocket is a communication protocol that provides a full-duplex channel over a single TCP connection. Unlike HTTP, it allows the server and client to exchange data in real time without constant requests. For C++, there are several libraries that simplify integrating WebSocket into applications. One of the most popular is Boost.Beast (part of the Boost C++ Libraries). It provides both low-level and high-level APIs for working with WebSocket and HTTP.

How to install Boost.Beast?

Boost.Beast is a header-only library (up to version 1.75) or part of Boost that requires compilation. Installation:

# Ubuntu / Debiansudo apt install libboost-all-dev

# macOS (Homebrew)brew install boost

# Windows (vcpkg)vcpkg install boost-beast

For header-only mode, simply copy the header files into your project.

Main features of the library

• WebSocket client and server — support for both client and server connections.
• Asynchronous operation — integration with Boost.Asio for non-blocking I/O.
• SSL/TLS support — secure connections via Boost.Asio SSL.
• Framing and control frames — automatic handling of ping/pong, close.
• HTTP upgrade — built-in support for the HTTP to WebSocket handshake.

Code example: a simple WebSocket server in C++

#include <boost/beast/core.hpp>#include <boost/beast/websocket.hpp>#include <boost/asio/ip/tcp.hpp>#include <iostream>#include <string>

namespace beast = boost::beast;namespace http = beast::http;namespace websocket = beast::websocket;namespace net = boost::asio;using tcp = net::ip::tcp;

int main() {    try {        net::io_context ioc{1};        tcp::acceptor acceptor{ioc, {tcp::v4(), 8080}};        tcp::socket socket{ioc};        acceptor.accept(socket);

        websocket::stream<tcp::socket> ws{std::move(socket)};        ws.accept();

        for(;;) {            beast::flat_buffer buffer;            ws.read(buffer);            std::string message = beast::buffers_to_string(buffer.data());            std::cout << "Received: " << message << std::endl;            ws.write(beast::buffer("Echo: " + message));        }    } catch(std::exception const& e) {        std::cerr << "Error: " << e.what() << std::endl;        return 1;    }    return 0;}

The example creates a server on port 8080, accepts a single connection, reads messages, and sends them back with the prefix "Echo: ".

When to use a WebSocket C++ library?

The library is suitable for projects where performance and low latency are critical: chats, online games, financial trading systems, real-time monitoring, IoT devices. If you need a reliable, cross-platform tool with an active community, Boost.Beast is the best choice for C++.