Easy-to-use and Fast C++ HTTP Web Server built on Boost.Beast

Features

• Static and Dynamic Routes
• Multi-threaded
• Support for GET, POST and HEAD requests
• Static files

Defining routes

Static and dynamic routes can be defined using the get and post functions. Routes are resolved in the following order: static routes, static files, dynamic routes. Static files are served from the public directory in the current working directory, and the server handles MIME types for common file types.

Static routes

Routes can be defined by returning a std::string. By default, the context type is text/html and the status is 200 OK.

get("/", [] {
    return "Hello World!";
});

The request (const http::request<http::string_body>&) and the response (http::response<http::string_body>&) can be accessed as parameters in the lambda function.

get("/json", [](Request req, Response res) {
    res.set(http::field::content_type, "application/json");
    return R"({"Hello": "World"})";
});

Routes can also be defined by returning a http::response to handle responses without body or with non-string bodies.

get("/redirect", [](Request req) {
    http::response<http::string_body> res{http::status::moved_permanently, req.version()};
    res.set(http::field::location, "/");
    return res;
});

Dynamic routes

Dynamic routes allow you to define routes using regular expressions (boost::regex). Dynamic routes are resolved in the same order as they are defined.

get(boost::regex(".*"), [](Request req, Response res) {
    res.result(http::status::not_found);
    return "<h1>404 Not Found!</h1>";
});

The matched values can be accessed by adding Match (const boost::smatch&) as the last parameter.

get(boost::regex{"/user/(\\d+)"}, [](Match match) {
    return "User ID: " + match[1];
});

Example

A complete example server can be found in example-server.

#include "webServer/webServer.h"

int main(const int argc, char* argv[]) {
    get("/", [] {
        return "<h1>Hello World!</h1>";
    });
    
    get("/json", [](Request req, Response res) {
        res.set(http::field::content_type, "application/json");
        return R"({"Hello": "World"})";
    });
    
    get("/redirect", [](Request req) {
        http::response<http::string_body> res{http::status::moved_permanently, req.version()};
        res.set(http::field::location, "/");
        return res;
    });
    
    get(boost::regex(".*"), [](Request req, Response res) {
        res.result(http::status::not_found);
        return "<h1>404 Not Found!</h1>";
    });
    
    startServer(argc, argv);
    return 0;
}

Requirements

• C++ 20 or later
• Boost 1.83 or later