Drogon for C++: Complete Guide with Examples

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Welcome to the world of high-performance web development in C++ with the Drogon framework. If you are accustomed to the asynchronous capabilities of Node.js, the convenience of Flask or Django, but performance at the level of native code is critical for you, Drogon is what you need. In this article, we will thoroughly examine how to install Drogon, write your first application, use its key methods, and avoid common mistakes.

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1. What It Is and Why You Need It

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Drogon is a high-performance, cross-platform web framework for the C++ language. Unlike many other solutions, it is built on an asynchronous input/output (IO) model using its own event loop. This allows it to handle thousands of concurrent connections without creating a separate thread for each one, dramatically reducing memory overhead and context switching costs.

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Why use Drogon? First, it's speed. Thanks to compiled C++ and non-blocking IO, Drogon can process requests with microsecond latency, making it an ideal choice for high-load REST APIs, microservices, and real-time applications. Second, it offers rich functionality "out of the box": an ORM for working with databases, WebSocket support, JSON, SSL/TLS, middleware, a template engine (ctemplate), and a built-in HTTP client.

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The framework is actively developed, has clear documentation, and a friendly community. If you need to create a backend that will run at the limit of hardware capabilities, and you don't want to sacrifice code expressiveness, Drogon will become your reliable tool.

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2. Installation

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Drogon is not installed via a package manager like pip or npm. It needs to be built from source. However, the process is highly automated using CMake and vcpkg.

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Method 1: Installation via vcpkg (recommended)

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# Clone vcpkg if you haven't already\ngit clone https://github.com/Microsoft/vcpkg.git\ncd vcpkg\n./bootstrap-vcpkg.sh  # or bootstrap-vcpkg.bat on Windows\n\n# Install Drogon\n./vcpkg install drogon\n

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Method 2: Manual build from source

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# Install dependencies (Ubuntu/Debian)\nsudo apt-get install git cmake build-essential libssl-dev libjsoncpp-dev libboost-all-dev libsqlite3-dev libmariadb-dev libpq-dev\n\n# Clone the repository\ngit clone https://github.com/drogonframework/drogon.git\ncd drogon\n\n# Create a build directory\nmkdir build && cd build\n\n# Configure and build\ncmake ..\nmake -j$(nproc)\n\n# Install to the system\nsudo make install\n

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After installation, you can include Drogon in your CMake projects:

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find_package(Drogon REQUIRED)\ntarget_link_libraries(my_app PRIVATE Drogon::Drogon)\n

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3. Quick Start — Minimal Working Example

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Let's write a simple HTTP server that responds with "Hello, World!" to any GET request.

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// main.cpp\n#include <drogon/drogon.h>\n\nint main() {\n    // Create an application instance\n    drogon::app().registerHandler("/", [](const drogon::HttpRequestPtr& req,\n                                          std::function<void (const drogon::HttpResponsePtr&)> &&callback) {\n        // Create a response\n        auto resp = drogon::HttpResponse::newHttpResponse();\n        resp->setBody("Hello, World!");\n        callback(resp);\n    });\n\n    // Start the server on port 8080\n    drogon::app().addListener("0.0.0.0", 8080).run();\n    return 0;\n}\n

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Build and run:

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g++ -std=c++17 -o hello main.cpp -ldrogon -ljsoncpp -lssl -lcrypto -lpthread\n./hello\n

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Now open your browser and go to http://