C++ Requests: Curl for People

Announcements

• Like you probably have noticed, cpr moved to a new home from https://github.com/whoshuu/cpr to https://github.com/libcpr/cpr. Read more here.
• This project is being maintained by Fabian Sauter and Kilian Traub.
• For quick help, and discussion libcpr also offer a gitter chat.

TLDR

C++ Requests is a simple wrapper around libcurl inspired by the excellent Python Requests project.

Despite its name, libcurl's easy interface is anything but, and making mistakes, misusing it is a common source of error and frustration. Using the more expressive language facilities of C++17 (or C++11 in case you use cpr < 1.10.0), this library captures the essence of making network calls into a few concise idioms.

Here's a quick GET request:

#include <cpr/cpr.h>

int main(int argc, char** argv) {
    cpr::Response r = cpr::Get(cpr::Url{"https://api.github.com/repos/whoshuu/cpr/contributors"},
                      cpr::Authentication{"user", "pass", cpr::AuthMode::BASIC},
                      cpr::Parameters{{"anon", "true"}, {"key", "value"}});
    r.status_code;                  // 200
    r.header["content-type"];       // application/json; charset=utf-8
    r.text;                         // JSON text string
    return 0;
}

And here's less functional, more complicated code, without cpr.

Documentation

You can find the latest documentation here. It's a work in progress, but it should give you a better idea of how to use the library than the tests currently do.

Features

C++ Requests currently supports:

• Custom headers
• Url encoded parameters
• Url encoded POST values
• Multipart form POST upload
• File POST upload
• Basic authentication
• Bearer authentication
• Digest authentication
• NTLM authentication
• Connection and request timeout specification
• Timeout for low speed connection
• Asynchronous requests
• 🍪 support!
• Proxy support
• Callback interfaces
• PUT methods
• DELETE methods
• HEAD methods
• OPTIONS methods
• PATCH methods
• Thread Safe access to libCurl
• OpenSSL and WinSSL support for HTTPS requests

Planned

For a quick overview about the planed features, have a look at the next Milestones.

Usage

CMake

fetch_content:

If you already have a CMake project you need to integrate C++ Requests with, the primary way is to use fetch_content. Add the following to your CMakeLists.txt.

include(FetchContent)
FetchContent_Declare(cpr GIT_REPOSITORY https://github.com/libcpr/cpr.git
                         GIT_TAG 871ed52d350214a034f6ef8a3b8f51c5ce1bd400) # The commit hash for 1.9.0. Replace with the latest from: https://github.com/libcpr/cpr/releases
FetchContent_MakeAvailable(cpr)

This will produce the target cpr::cpr which you can link against the typical way:

target_link_libraries(your_target_name PRIVATE cpr::cpr)

That should do it! There's no need to handle libcurl yourself. All dependencies are taken care of for you.
All of this can be found in an example here.

find_package():

If you prefer not to use fetch_content, you can download, build, and install the library and then use CMake find_package() function to integrate it into a project.

Note: this feature is feasible only if CPR_USE_SYSTEM_CURL is set. (see #645)

$ git clone https://github.com/libcpr/cpr.git
$ cd cpr && mkdir build && cd build
$ cmake .. -DCPR_USE_SYSTEM_CURL=ON
$ cmake --build .
$ sudo cmake --install .

In your CMakeLists.txt:

find_package(cpr REQUIRED)
add_executable(your_target_name your_target_name.cpp)
target_link_libraries(your_target_name PRIVATE cpr::cpr)

Packages for Linux Distributions

Alternatively, you may install a package specific to your Linux distribution. Since so few distributions currently have a package for cpr, most users will not be able to run your program with this approach.

Currently, we are aware of packages for the following distributions:

• Arch Linux (AUR)

If there's no package for your distribution, try making one! If you do, and it is added to your distribution's repositories, please submit a pull request to add it to the list above. However, please only do this if you plan to actively maintain the package.

NuGet Package

For Windows, there is also a libcpr NuGet package available. Currently, x86 and x64 builds are supported with release and debug configuration.

The package can be found here: NuGet.org

Requirements

The only explicit requirements are:

• a C++17 compatible compiler such as Clang or GCC. The minimum required version of GCC is unknown, so if anyone has trouble building this library with a specific version of GCC, do let me know
• in case you only have a C++11 compatible compiler available, all versions below cpr 1.9.x are for you. With the upcoming release of cpr 1.10.0, we are switching to C++17 as a requirement.
• If you would like to perform https requests OpenSSL and its development libraries are required.

Building cpr - Using vcpkg

You can download and install cpr using the vcpkg dependency manager:

git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg integrate install
./vcpkg install cpr

The cpr port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.

Building cpr - Using Conan

You can download and install cpr using the Conan package manager. Setup your CMakeLists.txt (see Conan documentation on how to use MSBuild, Meson and others). An example can be found here.

The cpr package in Conan is kept up to date by Conan contributors. If the version is out of date, please create an issue or pull request on the conan-center-index repository.