Oatpp Backend Framework

• When want to build a RESTful API Backend Web App, nowdays there are a hot framework in Github that named Oatpp. and the offical website

Setup the environment

install Oatpp environment

Optional 1: complied oatpp

git clone https://github.com/oatpp/oatpp.git
cd oatpp/
mkdir build && cd build
cmake .. -DCMAKE_TOOLCHAIN_FILE=../vcpkg/scripts/buildsystems/vcpkg.cmake
sudo make && sudo make install

Optional 2: install oatapp by VCPG, which is a package management way supported by Microsoft

git clone https://github.com/microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg install oatpp

Build the Backend App

mkdir my_oatapp_api

build the dir as the following

my_oatpp_api/
├── CMakeLists.txt
├── src/
│   ├── AppComponent.hpp
│   ├── Controller.hpp
│   ├── main.cpp
│   └── dto/
│       ├── MessageDto.hpp

Resource

• App.cpp

#include "AppComponent.hpp"
#include "Controller.hpp"
#include "oatpp/core/macro/component.hpp"
#include "oatpp/network/Server.hpp"

int main() {
    oatpp::base::Environment::init();

    AppComponent components;

    OATPP_COMPONENT(std::shared_ptr<oatpp::network::ServerConnectionProvider>, connectionProvider);
    OATPP_COMPONENT(std::shared_ptr<oatpp::network::ConnectionHandler>, connectionHandler);
    OATPP_COMPONENT(std::shared_ptr<oatpp::web::server::HttpRouter>, router);
    OATPP_COMPONENT(std::shared_ptr<oatpp::data::mapping::ObjectMapper>, objectMapper);

    auto helloController = std::make_shared<HelloController>(objectMapper);

    router->addController(helloController);

    oatpp::network::Server server(connectionProvider, connectionHandler);

    OATPP_LOGI("Oatpp", "Server running on port 8000...");
    server.run();

    oatpp::base::Environment::destroy();
    return 0;
}

• AppComponent.hpp

#pragma once
#include "oatpp/network/tcp/server/ConnectionProvider.hpp"
#include "oatpp/web/server/HttpConnectionHandler.hpp"
#include "oatpp/web/server/HttpRouter.hpp"
#include "oatpp/core/macro/component.hpp"
#include "oatpp/core/data/mapping/ObjectMapper.hpp"
#include "oatpp/parser/json/mapping/ObjectMapper.hpp"

class AppComponent {
public:

  OATPP_CREATE_COMPONENT(std::shared_ptr<oatpp::network::ServerConnectionProvider>, serverConnectionProvider)([] {
      oatpp::network::Address address("0.0.0.0", 8000, oatpp::network::Address::IP_4);
      return oatpp::network::tcp::server::ConnectionProvider::createShared(address);
  }());

  OATPP_CREATE_COMPONENT(std::shared_ptr<oatpp::web::server::HttpRouter>, httpRouter)([] {
      return oatpp::web::server::HttpRouter::createShared();
  }());

  OATPP_CREATE_COMPONENT(std::shared_ptr<oatpp::network::ConnectionHandler>, serverConnectionHandler)([] {
      OATPP_COMPONENT(std::shared_ptr<oatpp::web::server::HttpRouter>, router);
      return oatpp::web::server::HttpConnectionHandler::createShared(router);
  }());

  OATPP_CREATE_COMPONENT(std::shared_ptr<oatpp::data::mapping::ObjectMapper>, apiObjectMapper)([] {
      return oatpp::parser::json::mapping::ObjectMapper::createShared();
  }());
};

Controller.hpp

#pragma once
#include "oatpp/web/server/api/ApiController.hpp"
#include "oatpp/core/macro/codegen.hpp"

#include "oatpp/core/macro/codegen.hpp"
#include "dto/MessageDto.hpp"

#include OATPP_CODEGEN_BEGIN(ApiController)

class HelloController : public oatpp::web::server::api::ApiController {
public:
    HelloController(const std::shared_ptr<oatpp::data::mapping::ObjectMapper>& objectMapper)
        : oatpp::web::server::api::ApiController(objectMapper) {}

    ENDPOINT("GET", "/hello", hello) {
        return createResponse(Status::CODE_200, "Hello, Oat++!");
    }

    ENDPOINT("GET", "/echo/{msg}", echo, PATH(String, msg)) {
        return createResponse(Status::CODE_200, "You said: " + msg);
    }

    ENDPOINT("GET", "/json", getJson) {
        auto dto = MessageDto::createShared();
        dto->message = "Hello, Oat++ JSON!";
        return createDtoResponse(Status::CODE_200, dto);
    }
};

#include OATPP_CODEGEN_END(ApiController)

• MessageDto.hpp

#include "oatpp/core/macro/codegen.hpp"
#include "oatpp/core/macro/codegen.hpp"

#include OATPP_CODEGEN_BEGIN(DTO)

class MessageDto : public oatpp::DTO {
    DTO_INIT(MessageDto, DTO)

    DTO_FIELD(String, message);
};

#include OATPP_CODEGEN_END(DTO)

CMAKE

• CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(my_oatpp_api VERSION 1.0 LANGUAGES CXX)

# using C++ 17
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

# setup vcpkg toolchain
# set(CMAKE_TOOLCHAIN_FILE "../vcpkg/scripts/buildsystems/vcpkg.cmake")

# find oatpp package (vcpkg will supports the config file)
find_package(oatpp 1.3.0 REQUIRED)

file(GLOB DTO_HEADERS "src/dto/*.hpp")

# points the source file
set(SRC
    src/App.cpp
    src/AppComponent.hpp
    src/Controller.hpp
    ${DTO_HEADERS}
)

# create the bin file
add_executable(${PROJECT_NAME} ${SRC})

# link to the `oatpp` package
target_link_libraries(${PROJECT_NAME} PRIVATE oatpp::oatpp oatpp::oatpp-test)

# Generate Oatpp API controller
# if using codegen endpoint define，you can open the next lines
# oatpp_generate_api_controller_api(${PROJECT_NAME})

Build the Project

• Build

mkdir build && cd build
cmake ..
make

• Run the bin file

./my_oatpp_api

• Terminal

(myenv) dipeng-xu@Unknown-Mac build % ./my_oatpp_api 
 I |2025-10-08 21:27:07 1759930027513565| Oatpp:Server running on port 8000...