Files
json/docs/mkdocs/docs/integration/package_managers.md
T
Klaim (Joël Lamotte) e0f8cdfb7f build2 integration doc update (#4587)
* build2 integration doc update

Signed-off-by: Joël Lamotte <mjklaim@gmail.com>
Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* completed build2 instructions and examples

Signed-off-by: Joël Lamotte <mjklaim@gmail.com>
Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* added missing build2 buildfile

Signed-off-by: Joël Lamotte <mjklaim@gmail.com>
Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* improvments/simplifications on build2 examples

Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* removed just (rebase issue)

Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* fixed removed trailing whitespace from the rebase

Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* fixed typo and improved wording

Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

* fixed indentation/formatting and typos

Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>

---------

Signed-off-by: Joël Lamotte <mjklaim@gmail.com>
Signed-off-by: Klaim (Joël Lamotte) <142265+Klaim@users.noreply.github.com>
2026-05-09 11:00:12 +02:00

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Package Managers

![Homebrew](../images/package_managers/homebrew.svg){: style="height:1em"} [**Homebrew**](#homebrew) `nlohmann-json` ![Meson](../images/package_managers/meson.svg){: style="height:1em"} [**Meson**](#meson) `nlohmann_json` ![Bazel](../images/package_managers/bazel.svg){: style="height:1em"} [**Bazel**](#bazel) `nlohmann_json`
![Conan](../images/package_managers/conan.svg){: style="height:1em"} [**Conan**](#conan) `nlohmann_json` ![Spack](../images/package_managers/spack.svg){: style="height:1em"} [**Spack**](#spack) `nlohmann-json` [**Hunter**](#hunter) `nlohmann_json`
![vcpkg](../images/package_managers/vcpkg.png){: style="height:1em"} [**vcpkg**](#vcpkg) `nlohmann-json` [**cget**](#cget) `nlohmann/json` ![Swift Package Manager](../images/package_managers/swift.svg){: style="height:1em"} [**Swift Package Manager**](#swift-package-manager) `nlohmann/json`
![Nuget](../images/package_managers/nuget.svg){: style="height:1em"} [**NuGet**](#nuget) `nlohmann.json` ![Conda](../images/package_managers/conda.svg){: style="height:1em"} [**Conda**](#conda) `nlohmann_json` ![MacPorts](../images/package_managers/macports.svg){: style="height:1em"} [**MacPorts**](#macports) `nlohmann-json`
![cpm.cmake](../images/package_managers/CPM.png){: style="height:1em"} [**CPM.cmake**](#cpmcmake) `gh:nlohmann/json` ![xmake](../images/package_managers/xmake.svg){: style="height:1em"} [**xmake**](#xmake) `nlohmann_json`

Running example

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

--8<-- "integration/example.cpp"

When executed, this program should create output similar to

--8<-- "examples/meta.output"

Homebrew

!!! abstract "Summary"

formula: [**`nlohmann-json`**](https://formulae.brew.sh/formula/nlohmann-json)

- [![Homebrew package](https://repology.org/badge/version-for-repo/homebrew/nlohmann-json.svg)](https://repology.org/project/nlohmann-json/versions)
- :octicons-tag-24: Available versions: current version and development version (with `--HEAD` parameter)
- :octicons-rocket-24: The formula is updated with every release.
- :octicons-person-24: Maintainer: Niels Lohmann
- :octicons-file-24: File issues at the [Homebrew issue tracker](https://github.com/Homebrew/homebrew-core/issues)
- :octicons-question-24: [Homebrew website](https://brew.sh)

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 "Example: Raw compilation"

1. Create the following file:

    ```cpp title="example.cpp"
    --8<-- "integration/homebrew/example.cpp"
    ```

2. Install the package:

    ```sh
    brew install nlohmann-json
    ```

3. Compile the code and pass the Homebrew prefix to the include path such that the library can be found:

    ```sh
    c++ example.cpp -I$(brew --prefix nlohmann-json)/include -std=c++11 -o example
    ```

??? example "Example: CMake"

1. Create the following files:

    ```cpp title="example.cpp"
    --8<-- "integration/homebrew/example.cpp"
    ```

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/homebrew/CMakeLists.txt"
    ```

2. Install the package:

    ```sh
    brew install nlohmann-json
    ```

3. Compile the code and pass the Homebrew prefix to CMake to find installed packages via `#!cmake find_package`:

    ```sh
    CMAKE_PREFIX_PATH=$(brew --prefix) cmake -S . -B build
    cmake --build build
    ```

Meson

!!! abstract "Summary"

wrap: **`nlohmann_json`**

- :octicons-tag-24: Available versions: current version and select older versions (see
  [WrapDB](https://mesonbuild.com/Wrapdb-projects.html))
- :octicons-rocket-24: The package is update automatically from file
  [`meson.build`](https://github.com/nlohmann/json/blob/develop/meson.build).
- :octicons-file-24: File issues at the [library issue tracker](https://github.com/nlohmann/json/issues)
- :octicons-question-24: [Meson website](https://mesonbuild.com/index.html)

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 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, 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 "Example: Wrap"

1. Create the following files:

    ```ini title="meson.build"
    --8<-- "integration/meson/meson.build"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/meson/example.cpp"
    ```

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

    ```shell
    mkdir subprojects
    meson wrap install nlohmann_json
    ```

3. Build:

    ```shell
    meson setup build
    meson compile -C build
    ```

Bazel

!!! abstract "Summary"

use `bazel_dep`, `git_override`, or `local_path_override`

- :octicons-tag-24: Any version, that is available via [Bazel Central Registry](https://registry.bazel.build/modules/nlohmann_json)
- :octicons-file-24: File issues at the [library issue tracker](https://github.com/nlohmann/json/issues)
- :octicons-question-24: [Bazel website](https://bazel.build)

This repository provides a Bazel MODULE.bazel and a corresponding BUILD.bazel file. Therefore, this repository can be referenced within a MODULE.bazel by rules such as archive_override, git_override, or local_path_override. To use the library, you need to depend on the target @nlohmann_json//:json (i.e., via deps attribute).

??? example

1. Create the following files:

    ```ini title="BUILD"
    --8<-- "integration/bazel/BUILD"
    ```

    ```ini title="WORKSPACE"
    --8<-- "integration/bazel/MODULE.bazel"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/bazel/example.cpp"
    ```

2. Build and run:

    ```shell
    bazel build //:main
    bazel run //:main
    ```

Conan

!!! abstract "Summary"

recipe: [**`nlohmann_json`**](https://conan.io/center/recipes/nlohmann_json)

- [![ConanCenter package](https://repology.org/badge/version-for-repo/conancenter/nlohmann-json.svg)](https://repology.org/project/nlohmann-json/versions)
- :octicons-tag-24: Available versions: current version and older versions (see
  [Conan Center](https://conan.io/center/recipes/nlohmann_json))
- :octicons-rocket-24: The package is update automatically via
  [this recipe](https://github.com/conan-io/conan-center-index/tree/master/recipes/nlohmann_json).
- :octicons-file-24: File issues at the [Conan Center issue tracker](https://github.com/conan-io/conan-center-index/issues)
- :octicons-question-24: [Conan website](https://conan.io)

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

1. Create the following files:

    ```ini title="Conanfile.txt"
    --8<-- "integration/conan/Conanfile.txt"
    ```

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/conan/CMakeLists.txt"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/conan/example.cpp"
    ```

2. Call Conan:

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

3. Build:

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

Spack

!!! abstract "Summary"

package: [**`nlohmann-json`**](https://packages.spack.io/package.html?name=nlohmann-json)

- [![Spack package](https://repology.org/badge/version-for-repo/spack/nlohmann-json.svg)](https://repology.org/project/nlohmann-json/versions)
- :octicons-tag-24: Available versions: current version and older versions (see
  [Spack package](https://packages.spack.io/package.html?name=nlohmann-json))
- :octicons-rocket-24: The package is updated with every release.
- :octicons-person-24: Maintainer: [Axel Huebl](https://github.com/ax3l)
- :octicons-file-24: File issues at the [Spack issue tracker](https://github.com/spack/spack/issues)
- :octicons-question-24: [Spack website](https://spack.io)

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

1. Create the following files:

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/spack/CMakeLists.txt"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/spack/example.cpp"
    ```

2. Install the library:

    ```sh
    spack install nlohmann-json
    ```

3. Load the environment for your Spack-installed packages:

    ```sh
    spack load nlohmann-json
    ```

4. Build the project with CMake:

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

Hunter

!!! abstract "Summary"

package: [**`nlohmann_json`**](https://hunter.readthedocs.io/en/latest/packages/pkg/nlohmann_json.html)

- :octicons-tag-24: Available versions: current version and older versions (see
  [Hunter package](https://hunter.readthedocs.io/en/latest/packages/pkg/nlohmann_json.html))
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [Hunter issue tracker](https://github.com/cpp-pm/hunter/issues)
- :octicons-question-24: [Hunter website](https://hunter.readthedocs.io/en/latest/)

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

1. Create the following files:

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/hunter/CMakeLists.txt"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/hunter/example.cpp"
    ```

2. Download required files

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

3. Build the project with CMake:

    ```shell
    cmake -S . -B build
    cmake --build build
    ```

vcpkg

!!! abstract "Summary"

package: [**`nlohmann-json`**](https://github.com/Microsoft/vcpkg/tree/master/ports/nlohmann-json)

- [![Vcpkg package](https://repology.org/badge/version-for-repo/vcpkg/nlohmann-json.svg)](https://repology.org/project/nlohmann-json/versions)
- :octicons-tag-24: Available versions: current version
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [vcpkg issue tracker](https://github.com/microsoft/vcpkg/issues)
- :octicons-question-24: [vcpkg website](https://vcpkg.io/)

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

1. Create the following files:

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/vcpkg/CMakeLists.txt"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/vcpkg/example.cpp"
    ```

2. Install package:

    ```sh
    vcpkg install nlohmann-json
    ```

3. Build:

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

cget

!!! abstract "Summary"

package: [**`nlohmann/json`**](https://github.com/pfultz2/cget-recipes/blob/master/recipes/nlohmann/json/package.txt)

- :octicons-tag-24: Available versions: current version and older versions
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [cget issue tracker](https://github.com/pfultz2/cget-recipes/issues)
- :octicons-question-24: [cget website](https://cget.readthedocs.io/)

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@v3.12.0. 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

1. Create the following files:

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/vcpkg/CMakeLists.txt"
    ```

    ```cpp title="example.cpp"
    --8<-- "integration/vcpkg/example.cpp"
    ```

2. Initialize cget

    ```shell
    cget init
    ```

3. Install the library

    ```shell
    cget install nlohmann/json
    ```

4. Build

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

Swift Package Manager

!!! abstract "Summary"

package: **`nlohmann/json`**

- :octicons-tag-24: Available versions: current version and older versions
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [library issue tracker](https://github.com/nlohmann/json/issues)
- :octicons-question-24: [Xcode documentation](https://developer.apple.com/documentation/xcode/adding-package-dependencies-to-your-app)

NuGet

!!! abstract "Summary"

package: [**`nlohmann.json`**](https://www.nuget.org/packages/nlohmann.json/)

- :octicons-tag-24: Available versions: current and previous versions
- :octicons-rocket-24: The package is updated with every release.
- :octicons-person-24: Maintainer: [Hani Kaabi](https://github.com/hnkb)
- :octicons-file-24: File issues at the [maintainer's issue tracker](https://github.com/hnkb/nlohmann-json-nuget/issues)
- :octicons-question-24: [NuGet website](https://www.nuget.org)

If you are using NuGet, you can use the package nlohmann.json with

dotnet add package nlohmann.json

??? example

Probably the easiest way to use NuGet packages is through Visual Studio graphical interface. Right-click on a
project (any C++ project would do) in “Solution Explorer” and select “Manage NuGet Packages…”

![](nuget/nuget-search-package.png)

Now you can click on “Browse” tab and find the package you like to install.

![](nuget/nuget-select-package.png)

Most of the packages in NuGet gallery are .NET packages and would not be useful in a C++ project. Microsoft
recommends adding “native” and “nativepackage” tags to C++ NuGet packages to distinguish them, but even adding
“native” to search query would still show many .NET-only packages in the list.

Nevertheless, after finding the package you want, click on “Install” button and accept confirmation dialogs.
After the package is successfully added to the projects, you should be able to build and execute the project
without the need for making any more changes to build settings.

!!! note

    A few notes:

    - NuGet packages are installed per project and not system-wide. The header and binaries for the package are only
      available to the project it is added to, and not other projects (obviously unless we add the package to those
      projects as well)
    - One of the many great things about your elegant work is that it is a header-only library, which makes
      deployment very straightforward. In case of libraries which need binary deployment (`.lib`, `.dll` and `.pdb`
      for debug info) the different binaries for each supported compiler version must be added to the NuGet package.
      Some library creators cram binary versions for all supported Visual C++ compiler versions in the same package,
      so a single package will support all compilers. Some others create a different package for each compiler
      version (and you usually see things like “v140” or “vc141” in package name to clarify which VC++ compiler this
      package supports).
    - Packages can have dependency to other packages, and in this case, NuGet will install all dependencies as well
      as the requested package recursively.

**What happens behind the scenes**

After you add a NuGet package, three changes occur in the project source directory. Of course, we could make these
changes manually instead of using GUI:

![](nuget/nuget-project-changes.png)

1. A `packages.config` file will be created (or updated to include the package name if one such file already
   exists). This file contains a list of the packages required by this project (name and minimum version) and must
   be added to the project source code repository, so if you move the source code to a new machine, MSBuild/NuGet
   knows which packages it has to restore (which it does automatically before each build).

    ```xml
    <?xml version="1.0" encoding="utf-8"?>
    <packages>
      <package id="nlohmann.json" version="3.5.0" targetFramework="native" />
    </packages>
    ```

2. A `packages` folder which contains actual files in the packages (these are header and binary files required for
   a successful build, plus a few metadata files). In case of this library for example, it contains `json.hpp`:

    ![](nuget/nuget-package-content.png)

    !!! note

        This directory should not be added to the project source code repository, as it will be restored before each
        build by MSBuild/NuGet. If you go ahead and delete this folder, then build the project again, it will
        magically re-appear!

3. Project MSBuild makefile (which for Visual C++ projects has a .vcxproj extension) will be updated to include
   settings from the package.

    ![](nuget/nuget-project-makefile.png)

    The important bit for us here is line 170, which tells MSBuild to import settings from
    `packages\nlohmann.json.3.5.0\build\native\nlohmann.json.targets` file. This is a file the package creator
    created and added to the package (you can see it is one of the two files I created in this repository, the other
    just contains package attributes like name and version number). What does it contain?

    For our header-only repository, the only setting we need is to add our include directory to the list of
    `AdditionalIncludeDirectories`:

    ```xml    
    <?xml version="1.0" encoding="utf-8"?>
    <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
        <ItemDefinitionGroup>
            <ClCompile>
                <AdditionalIncludeDirectories>$(MSBuildThisFileDirectory)include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
            </ClCompile>
        </ItemDefinitionGroup>
    </Project>
    ```

    For libraries with binary files, we will need to add `.lib` files to linker inputs and add settings to copy
    `.dll` and other redistributable files to output directory, if needed.

    There are other changes to the makefile as well:

    - Lines 165-167 add the `packages.config` as one of project files (so it is shown in Solution Explorer tree
      view). It is added as None (no build action) and removing it wouldnt affect build.

    - Lines 172-177 check to ensure the required packages are present. This will display a build error if package
      directory is empty (for example when NuGet cannot restore packages because Internet connection is down).
      Again, if you omit this section, the only change in build would be a more cryptic error message if build
      fails.

    !!! note

        Changes to .vcxproj makefile should also be added to project source code repository.

As you can see, the mechanism NuGet uses to modify project settings is through MSBuild makefiles, so using NuGet
with other build systems and compilers (like CMake) as a dependency manager is either impossible or more problematic
than useful.

Please refer to this extensive description for more information.

Conda

!!! abstract "Summary"

package: [**`nlohmann_json`**](https://anaconda.org/conda-forge/nlohmann_json)

- ![](https://img.shields.io/conda/v/conda-forge/nlohmann_json)
- :octicons-tag-24: Available versions: current and previous versions
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [feedstock's issue tracker](https://github.com/conda-forge/nlohmann_json-feedstock/issues)
- :octicons-question-24: [Conda documentation](https://docs.conda.io/projects/conda/en/stable/user-guide/getting-started.html)

If you are using conda, you can use the package nlohmann_json from conda-forge executing

conda install -c conda-forge nlohmann_json

??? example

1. Create the following file:

    ```cpp title="example.cpp"
    --8<-- "integration/conda/example.cpp"
    ```

2. Create and activate an anvironment "json`:

    ```shell
    conda create -n json
    conda activate json
    ```

3. Install the package:

    ```shell
    conda install -c conda-forge nlohmann_json
    ```

4. Build the code:

    ```shell
    g++ -std=c++11 -I$(conda info --base)/envs/json/include example.cpp -o example
    ```

MSYS2

If you are using MSYS2, you can use the mingw-w64-nlohmann-json package, 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.

MSYS2 clang64 package MSYS2 clangarm64 package MSYS2 mingw package MSYS2 ucrt64 package

:material-update: The package is updated automatically.

MacPorts

!!! abstract "Summary"

port: [**`nlohmann-json`**](https://ports.macports.org/port/nlohmann-json/)

- [![MacPorts package](https://repology.org/badge/version-for-repo/macports/nlohmann-json.svg)](https://repology.org/project/nlohmann-json/versions)
- :octicons-tag-24: Available versions: current version
- :octicons-rocket-24: The port is updated with every release.
- :octicons-file-24: File issues at the [MacPorts issue tracker](https://trac.macports.org/newticket?port=nlohmann-json)
- :octicons-question-24: [MacPorts website](https://www.macports.org)

If you are using MacPorts, execute

sudo port install nlohmann-json

to install the nlohmann-json package.

??? example "Example: Raw compilation"

1. Create the following file:

    ```cpp title="example.cpp"
    --8<-- "integration/macports/example.cpp"
    ```

2. Install the package:

    ```sh
    sudo port install nlohmann-json
    ```

3. Compile the code and pass the Homebrew prefix to the include path such that the library can be found:

    ```sh
    c++ example.cpp -I/opt/local/include -std=c++11 -o example
    ```

??? example "Example: CMake"

1. Create the following files:

    ```cpp title="example.cpp"
    --8<-- "integration/homebrew/example.cpp"
    ```

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/homebrew/CMakeLists.txt"
    ```

2. Install the package:

    ```sh
    sudo port install nlohmann-json
    ```

3. Compile the code:

    ```sh
    cmake -S . -B build
    cmake --build build
    ```

build2

!!! abstract "Summary"

package: **`nlohmann-json`**
library target: **`nlohmann-json%lib{json}`**
available in package repositories:
  - [`cppget.org` (recommended)](https://cppget.org/nlohmann-json)
  - [package's sources (for advanced users)](https://github.com/build2-packaging/nlohmann-json/)

- :octicons-tag-24: Available versions: current version and older versions since `3.7.3` (see [cppget.org](https://cppget.org/nlohmann-json))
- :octicons-rocket-24: The package is maintained and published by the `build2` community in [this repository][(https://github.com/build2-packaging/nlohmann-json/](https://github.com/build2-packaging/nlohmann-json/)).
- :octicons-file-24: File issues at the [package source repository](https://github.com/build2-packaging/nlohmann-json/issues/)
- :octicons-question-24: [`build2` website](https://build2)

Note: build2 should not be considered as a standalone package-manager. It is a build-system + package manager + project manager, a set of tools that work hand-in-hand. build2-based projects do not rely on existing CMake scripts and the build scripts defining the project's targets are specific to build2.

To use this package in an exising build2 project, the general steps are:

  1. Make the package available to download from a package repository that provides it.

    Your project's repositories.manifest specifies where the package manager will try to acquire packages by default. Make sure one of the repositories specified in this file provides nlhomann-json package. The recommended open-source repository is cppget.org.

    If the project has been created using bdep new, cppget.org is already specified in repositories.manifest but commented, just uncomment these lines:

    :
    role: prerequisite
    location: https://pkg.cppget.org/1/stable
    
  2. Add this package as dependency of your project.

    In your project's manifest add the dependency to the package using depends: nlohmann-json. You could also add some version constraints. For example, to depend on the latest version available:

    depends: nlohmann-json
    
  3. Add this library as dependency of your target that uses it.

    In the buildfile defining the target that will use this library:

    • import the target lib{json} from the nlhomann-json package, for example:

      import nljson = nlhomann-json%lib{json}
      
    • then add the library's target as requirement for your target using it, for example:

      exe{example} : ... $nljson
      
  4. Use the library in your project's code and build it.

    At this point, assuming your project is initialized in a build-configuration, any b or bdep update command that will update/build the project will also acquire the missing dependency automatically, then build it and link it with your target.

    If you just want to synchronize dependencies for all your configurations to download the ones you just added:

    bdep sync -af
    

??? example "Example: from scratch, using build2's bdep new command"

1. Create a new executable project "example" (see [`bdep new` command details](https://build2.org/bdep/doc/bdep-new.xhtml) for the various options to create a new project):

    ```shell
    bdep new example
    ```

2. Edit these files by replacing their content:

    - `example/repositories.manifest`: Enable acquiring packages from https://cppget.org by uncommenting the related lines:

        ```make title="project's `repositories.manifest`"
        --8<-- "integration/build2/repositories.manifest"
        ```

    - `example/manifest`: Add the latest version of the `nlohmann-json` package as dependency to the project:

        ```make title="project's `manifest`"
        --8<-- "integration/build2/manifest"
        ```

    - `example/example/buildfile`: import the library's target to be used as requirement for building the executable target `exe{example}`:

        ```make title="project's `buildfile`"
        --8<-- "integration/build2/buildfile"
        ```

    - `example/example/example.cxx`: `bdep new` generates a "hello world" by default, replace it by this:

        ```cpp title="example.cxx"
        --8<-- "integration/build2/example.cpp"
        ```

    - `example/example/testscript`: (optional) if you want to be able to test that executable's output is correct using `b test`:

        ```cpp title="`testscript` checking the output of the program"
        --8<-- "integration/build2/testscript"
        ```


3. Initialize the project in a default C/C++ build configuration directory, then build and test:

    ```shell
    cd example/

    # create default C/C++ build configuration in ../example-myconfig/, initialize the project in it (downloads it's dependencies in it too)
    bdep init -C @myconfig cc

    # build only,
    b

    # or build and test the executable's output, will only work if the `tescript` is correct
    b test

    ```

CPM.cmake

!!! abstract "Summary"

package: **`gh:nlohmann/json`**

- :octicons-tag-24: Available versions: current and previous versions
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [CPM.cmake issue tracker](https://github.com/cpm-cmake/CPM.cmake/issues)
- :octicons-question-24: [CPM.cmake website](https://github.com/cpm-cmake/CPM.cmake)

If you are using CPM.cmake, add the CPM.cmake script and the following snippet to your CMake project:

CPMAddPackage("gh:nlohmann/json@3.12.0")

??? example

1. Create the following files:

    ```cpp title="example.cpp"
    --8<-- "integration/cpm/example.cpp"
    ```

    ```cmake title="CMakeLists.txt"
    --8<-- "integration/cpm/CMakeLists.txt"
    ```

2. Download CPM.cmake

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

3. Build

    ```shell
    cmake -S . -B build
    cmake --build build
    ```

xmake

!!! abstract "Summary"

package: [**`nlohmann_json`**](https://github.com/xmake-io/xmake-repo/blob/master/packages/n/nlohmann_json/xmake.lua)

- :octicons-tag-24: Available versions: current and previous versions
- :octicons-rocket-24: The package is updated with every release.
- :octicons-file-24: File issues at the [xmake issue tracker](https://github.com/xmake-io/xmake-repo/issues)
- :octicons-question-24: [xmake website](https://xmake.io/#/)

??? example

1. Create the following files:

    ```cpp title="example.cpp"
    --8<-- "integration/xmake/example.cpp"
    ```

    ```lua title="xmake.lua"
    --8<-- "integration/xmake/xmake.lua"
    ```

2. Build

    ```shell
    xmake
    ```

3. Run

    ```shell
    xmake run
    ```

Other package managers

The library is also contained in many other package repositories: Packaging status

??? example "Package version overview"

[![Packaging status](https://repology.org/badge/vertical-allrepos/nlohmann-json.svg)](https://repology.org/project/nlohmann-json/versions)

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](https://github.com/buckaroo-pm/nlohmann-json) has not been
updated in years.

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.

!!! warning

The module is outdated as the respective [pod](https://cocoapods.org/pods/nlohmann_json) has not been updated in years.