Package Managers¶

Throughout this page, we will describe how to compile the example file example.cpp below.

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

When executed, this program should create output similar to

{
    "compiler": {
        "c++": "201103",
        "family": "gcc",
        "version": "12.3.0"
    },
    "copyright": "(C) 2013-2022 Niels Lohmann",
    "name": "JSON for Modern C++",
    "platform": "apple",
    "url": "https://github.com/nlohmann/json",
    "version": {
        "major": 3,
        "minor": 11,
        "patch": 3,
        "string": "3.11.3"
    }
}

Homebrew¶

Summary

formula: nlohmann-json

Availalbe versions: current version and development version (with --HEAD parameter)
The formula is updated with every release.
Maintainer: Niels Lohmann
File issues at the Homebrew issue tracker
Homebrew website

If you are using Homebrew, you can install the library with

brew install nlohmann-json

The header can be used directly in your code or via CMake.

Example: Raw compilation

Create the following file:

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Install the package:
```
brew install nlohmann-json
```
Compile the code and pass the Homebrew prefix to the include path such that the library can be found:
```
c++ example.cpp -I$(brew --prefix nlohmann-json)/include -std=c++11 -o example
```

Example: CMake

Create the following files:

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(json_example)

find_package(nlohmann_json CONFIG REQUIRED)

add_executable(json_example example.cpp)
target_link_libraries(json_example PRIVATE nlohmann_json::nlohmann_json)

Install the package:
```
brew install nlohmann-json
```
Compile the code and pass the Homebrew prefix to CMake to find installed packages via find_package:
```
CMAKE_PREFIX_PATH=$(brew --prefix) cmake -S . -B build
cmake --build build
```

Meson¶

Summary

wrap: nlohmann_json

Availalbe versions: current version and select older versions (see WrapDB)
The package is update automatically from file meson.build.
File issues at the library issue tracker
Meson website

If you are using the Meson Build System, add this source tree as a meson subproject. You may also use the include.zip published in this project's Releases to reduce the size of the vendored source tree. Alternatively, you can get a wrap file by downloading it from Meson WrapDB, or simply use

meson wrap install nlohmann_json

Please see the Meson project for any issues regarding the packaging.

The provided meson.build can also be used as an alternative to CMake for installing nlohmann_json system-wide in which case a pkg-config file is installed. To use it, simply have your build system require the nlohmann_json pkg-config dependency. In Meson, it is preferred to use the dependency() object with a subproject fallback, rather than using the subproject directly.

Example: Wrap

Create the following files:

meson.build

project('json_example', 'cpp',
  version: '1.0',
  default_options: ['cpp_std=c++11']
)

dependency_json = dependency('nlohmann_json', required: true)

executable('json_example',
  sources: ['example.cpp'],
  dependencies: [dependency_json],
  install: true
)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Use the Meson WrapDB to fetch the nlohmann/json wrap:

mkdir subprojects
meson wrap install nlohmann_json

Build:

meson setup build
meson compile -C build

Bazel¶

Summary

use http_archive, git_repository, or local_repository

Any version, as version is specified in WORKSPACE file
File issues at the library issue tracker
Bazel website

This repository provides a Bazel WORKSPACE.bazel and a corresponding BUILD.bazel file. Therefore, this repository can be referenced by workspace rules such as http_archive, git_repository, or local_repository from other Bazel workspaces. To use the library you only need to depend on the target @nlohmann_json//:json (e.g., via deps attribute).

Example

Create the following files:

BUILD

cc_binary(
    name = "main",
    srcs = ["example.cpp"],
    deps = ["@nlohmann_json//:json"],
)

WORKSPACE

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "nlohmann_json",
    urls = ["https://github.com/nlohmann/json/archive/refs/tags/v3.11.3.tar.gz"],
    strip_prefix = "json-3.11.3",
)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Build and run:
```
bazel build //:main
bazel run //:main
```

Conan¶

Summary

recipe: nlohmann_json

Availalbe versions: current version and older versions (see Conan Center)
The package is update automatically via this recipe.
File issues at the Conan Center issue tracker
Conan website

If you are using Conan to manage your dependencies, merely add nlohmann_json/x.y.z to your conanfile's requires, where x.y.z is the release version you want to use.

Example

Create the following files:

Conanfile.txt

[requires]
nlohmann_json/3.11.3

[generators]
CMakeToolchain
CMakeDeps

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(json_example)

find_package(nlohmann_json REQUIRED)

add_executable(json_example example.cpp)
target_link_libraries(json_example PRIVATE nlohmann_json::nlohmann_json)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Call Conan:

conan install . --output-folder=build --build=missing

Build:

cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE="conan_toolchain.cmake" -DCMAKE_BUILD_TYPE=Release
cmake --build build

Spack¶

Summary

package: nlohmann-json

Availalbe versions: current version and older versions (see Spack package)
The formula is updated with every release.
Maintainer: Axel Huebl
File issues at the Spack issue tracker
Spack website

If you are using Spack to manage your dependencies, you can use the nlohmann-json package via

spack install nlohmann-json

Please see the Spack project for any issues regarding the packaging.

Example

Create the following files:

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(json_example)

find_package(nlohmann_json REQUIRED)

add_executable(json_example example.cpp)
target_link_libraries(json_example PRIVATE nlohmann_json::nlohmann_json)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Install the library:
```
spack install nlohmann-json
```
Load the environment for your Spack-installed packages:
```
spack load nlohmann-json
```

Build the project with CMake:

cmake -S . -B build -DCMAKE_PREFIX_PATH=$(spack location -i nlohmann-json)
cmake --build build

Hunter¶

Summary

package: nlohmann_json

Availalbe versions: current version and older versions (see Hunter package)
The formula is updated with every release.
File issues at the Hunter issue tracker
Hunter website

If you are using Hunter on your project for external dependencies, then you can use the nlohmann_json package via

hunter_add_package(nlohmann_json)

Please see the Hunter project for any issues regarding the packaging.

Example

Create the following files:

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)

include("cmake/HunterGate.cmake")
HunterGate(
    URL "https://github.com/cpp-pm/hunter/archive/v0.23.297.tar.gz"
    SHA1 "3319fe6a3b08090df7df98dee75134d68e2ef5a3"
)

project(json_example)

hunter_add_package(nlohmann_json)
find_package(nlohmann_json CONFIG REQUIRED)

add_executable(json_example example.cpp)
target_link_libraries(json_example PRIVATE nlohmann_json::nlohmann_json)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Download required files

mkdir cmake
wget https://raw.githubusercontent.com/cpp-pm/gate/master/cmake/HunterGate.cmake -O cmake/HunterGate.cmake

Build the project with CMake:

cmake -S . -B build
cmake --build build

Buckaroo¶

If you are using Buckaroo, you can install this library's module with buckaroo add github.com/buckaroo-pm/nlohmann-json. There is a demo repo here.

Warning

The module is outdated as the respective repository has not been updated in years.

vcpkg¶

Summary

package: nlohmann-json

Availalbe versions: current version
The formula is updated with every release.
File issues at the vcpkg issue tracker
vcpkg website

If you are using vcpkg on your project for external dependencies, then you can install the nlohmann-json package with

vcpkg install nlohmann-json

and follow the then displayed descriptions. Please see the vcpkg project for any issues regarding the packaging.

Example

Create the following files:

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(json_example)

find_package(nlohmann_json CONFIG REQUIRED)

add_executable(json_example example.cpp)
target_link_libraries(json_example PRIVATE nlohmann_json::nlohmann_json)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Install package:
```
vcpkg install nlohmann-json
```

Build:

cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=$VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake
cmake --build build

cget¶

Summary

package: nlohmann/json

Availalbe versions: current version and older versions
The formula is updated with every release.
File issues at the cget issue tracker
cget website

If you are using cget, you can install the latest master version with

cget install nlohmann/json

A specific version can be installed with cget install nlohmann/json@v3.11.3. Also, the multiple header version can be installed by adding the -DJSON_MultipleHeaders=ON flag (i.e., cget install nlohmann/json -DJSON_MultipleHeaders=ON).

Example

Create the following files:

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(json_example)

find_package(nlohmann_json CONFIG REQUIRED)

add_executable(json_example example.cpp)
target_link_libraries(json_example PRIVATE nlohmann_json::nlohmann_json)

example.cpp

#include <nlohmann/json.hpp>
#include <iostream>
#include <iomanip>

using json = nlohmann::json;

int main()
{
    std::cout << std::setw(4) << json::meta() << std::endl;
}

Initialize cget
```
cget init
```
Install the library
```
cget install nlohmann/json
```

Build

cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=cget/cget/cget.cmake
cmake --build build

CocoaPods¶

If you are using CocoaPods, you can use the library by adding pod "nlohmann_json", '~>3.1.2' to your podfile (see an example). Please file issues here.

NuGet¶

If you are using NuGet, you can use the package nlohmann.json. Please check this extensive description on how to use the package. Please file issues here.

Conda¶

If you are using conda, you can use the package nlohmann_json from conda-forge executing conda install -c conda-forge nlohmann_json. Please file issues here.

MSYS2¶

If you are using MSYS2, you can use the mingw-w64-nlohmann-json package, just type pacman -S mingw-w64-i686-nlohmann-json or pacman -S mingw-w64-x86_64-nlohmann-json for installation. Please file issues here if you experience problems with the packages.

The package is updated automatically.

MacPorts¶

If you are using MacPorts, execute sudo port install nlohmann-json to install the nlohmann-json package.

The package is updated automatically.

build2¶

If you are using build2, you can use the nlohmann-json package from the public repository http://cppget.org or directly from the package's sources repository. In your project's manifest file, just add depends: nlohmann-json (probably with some version constraints). If you are not familiar with using dependencies in build2, please read this introduction. Please file issues here if you experience problems with the packages.

The package is updated automatically.

wsjcpp¶

If you are using wsjcpp, you can use the command wsjcpp install "https://github.com/nlohmann/json:develop" to get the latest version. Note you can change the branch ":develop" to an existing tag or another branch.

wsjcpp reads directly from the GitHub repository and is always up-to-date.

CPM.cmake¶

If you are using CPM.cmake, you can check this example. After adding CPM script to your project, implement the following snippet to your CMake:

CPMAddPackage("gh:nlohmann/json@3.11.3")

Example

Download CPM.cmake

mkdir -p cmake
wget -O cmake/CPM.cmake https://github.com/cpm-cmake/CPM.cmake/releases/latest/download/get_cpm.cmake

Build

cmake -S . -B build
cmake --build build