Nakama C/C++ Client SDK

General C/C++ client for Nakama server.

Nakama is an open-source server designed to power modern games and apps. Features include user accounts, chat, social, matchmaker, realtime multiplayer, and much more.

This client implements the full API and socket options with the server. It's written in C and C++11 with minimal dependencies to support Cocos2d-x, Unreal and other custom engines and frameworks.

If you experience any issues with the client, it can be useful to enable debug logs (see Logging section) and open an issue.

Full documentation is online - https://heroiclabs.com/docs

Getting Started

You'll need to setup the server and database before you can connect with the client. The simplest way is to use Docker but have a look at the server documentation for other options.

1. Install and run the servers. Follow these instructions.
2. Nakama C/C++ SDK is released with prebuilt libraries for following platforms and architectures:

• Windows - 7+, Visual Studio 2015, 2017, 2019 (x86, x64, Debug, Release)
• Android - Android 4.1 (armeabi-v7a, arm64-v8a, x86, x86_64)
• Linux - Ubuntu 18.04 x64
• Mac - 10.10+
• iOS - 8.0+ (arm64, armv7, armv7s, x86_64), Bitcode is off

In theory any platform that meets the requirement for cpprest and boost is also supported. The client is compiled with C++11.

1. Download the client from the releases page. You can also build from source.
2. Integrate the client library into your project:

When you've downloaded the Nakama C++ archive and extracted it to NAKAMA_CPP_SDK folder, you should include it in your project.

We don't recommend to copy Nakama C++ SDK to your project because it's quite big in size (~1 Gb).

Setup for Mac and iOS projects

1. Add NAKAMA_CPP_SDK/include in Build Settings > Header Search Paths
2. Add libs folder in Build Settings > Library Search Paths:
   • NAKAMA_CPP_SDK/libs/ios - for iOS
   • NAKAMA_CPP_SDK/libs/mac - for Mac
3. In General > Frameworks, Libraries, and Embedded Content add following:
   • all .a files located in libs folder
   • foundation and security frameworks

Setup for Android projects

If you use CMake then see Setup for CMake projects section.

If you use ndk-build then add following to your Android.mk file:

# add this to your module
LOCAL_STATIC_LIBRARIES += nakama-cpp
 
# add this at bottom of Android.mk file
$(call import-add-path, NAKAMA_CPP_SDK)
$(call import-module, nakama-cpp-android)

Initialize Nakama SDK

For most NativeActivity projects, if you have an entry point like:

void android_main(struct android_app* state) {

Add include:

#include "nakama-cpp/platform/android/android.h"

Add the following code at the top of the android_main function:

Nakama::init(state->activity->vm);

Shared library size

Don't be afraid that nakama shared library are near 100 Mb in size. After building final apk it will be just few Mb.

Android permissions

Android uses a permissions system which determines which platform services the application will request to use and ask permission for from the user. The client uses the network to communicate with the server so you must add the "INTERNET" permission.

<uses-permission android:name="android.permission.INTERNET"/>

Setup for CMake projects

To link Nakama's static lib add following to your CMakeLists.txt file:

add_subdirectory(NAKAMA_CPP_SDK ${CMAKE_CURRENT_BINARY_DIR}/nakama-cpp)
target_link_libraries(${APP_NAME} ext_nakama-cpp)

To link Nakama's shared lib add following to your CMakeLists.txt file:

set(NAKAMA_SHARED_LIBRARY TRUE)
add_subdirectory(NAKAMA_CPP_SDK ${CMAKE_CURRENT_BINARY_DIR}/nakama-cpp)
target_link_libraries(${APP_NAME} ext_nakama-cpp)
CopyNakamaSharedLib(${APP_NAME})

Setup for Visual Studio projects

In Project Settings add following:

1. Add NAKAMA_CPP_SDK/include in C/C++ > General > Additional Include Directories
2. Add libs folder in Linker > General > Additional Library Directories:
   • NAKAMA_CPP_SDK/libs/win32/v140 - for VS 2015 x86
   • NAKAMA_CPP_SDK/libs/win64/v140 - for VS 2015 x64
   • NAKAMA_CPP_SDK/libs/win32/v141 - for VS 2017 x86
   • NAKAMA_CPP_SDK/libs/win64/v141 - for VS 2017 x64
   • NAKAMA_CPP_SDK/libs/win32/v142 - for VS 2019 x86
   • NAKAMA_CPP_SDK/libs/win64/v142 - for VS 2019 x64
3. Add the .lib files in your Debug libs folder to Linker > Input > Additional Dependencies for your Debug configuration. Do the same for your Release libs and configuration.

Custom setup

• add define:
  • NLOGS_ENABLED - define it if you want to use Nakama logger. See Logging section
• add include directory: /include
• add link directory: /libs/{platform}/{ABI}
• add all libraries for linking from link directory

Threading model

Nakama C++ is designed to use in one thread only.

Usage

Use as static library

Include nakama header and use nakama namespace.

#include "nakama-cpp/Nakama.h"
 
using namespace NAKAMA_NAMESPACE;

Use as dynamic library

Include nakama header and use nakama namespace.

#include "nakama-cpp-c-wrapper/NakamaWrapper.h"
 
using namespace NAKAMA_NAMESPACE;

Include following header only once in some source file e.g. in main.cpp:

#include "nakama-cpp-c-wrapper/NakamaWrapperImpl.h"

This header includes implementation of Nakama C++ wrapper. It uses C interface to communicate with Nakama shared library (DLL).

Client

The client object has many methods to execute various features in the server or open realtime socket connections with the server.

Use the connection credentials to build a client object.

NClientParameters parameters;
parameters.serverKey = "defaultkey";
parameters.host = "127.0.0.1";
parameters.port = DEFAULT_PORT;
NClientPtr client = createDefaultClient(parameters);

The createDefaultClient will create HTTP/1.1 client to use REST API.

Tick

The tick method pumps requests queue and executes callbacks in your thread. You must call it periodically (recommended every 50ms) in your thread.

client->tick();
if (rtClient)
    rtClient->tick();

Without this the default client and realtime client will not work, and you will not receive responses from the server.

Authenticate

There's a variety of ways to authenticate with the server. Authentication can create a user if they don't already exist with those credentials. It's also easy to authenticate with a social profile from Google Play Games, Facebook, Game Center, etc.

string email = "super@heroes.com";
string password = "batsignal";
 
auto successCallback = [](NSessionPtr session)
{
    std::cout << "session token: " << session->getAuthToken() << std::endl;
};
 
auto errorCallback = [](const NError& error)
{
};
 
client->authenticateEmail(email, password, "", false, {}, successCallback, errorCallback);

Sessions

When authenticated the server responds with an auth token (JWT) which contains useful properties and gets deserialized into a NSession object.

std::cout << session->getAuthToken() << std::endl; // raw JWT token
std::cout << session->getUserId() << std::endl;
std::cout << session->getUsername() << std::endl;
std::cout << "Session has expired: " << session->isExpired() << std::endl;
std::cout << "Session expires at: " << session->getExpireTime() << std::endl;

It is recommended to store the auth token from the session and check at startup if it has expired. If the token has expired you must reauthenticate. The expiry time of the token can be changed as a setting in the server.

string authtoken = "restored from somewhere";
NSessionPtr session = restoreSession(authtoken);
if (session->isExpired()) {
    std::cout << "Session has expired. Must reauthenticate!" << std::endl;
}

Requests

The client includes lots of builtin APIs for various features of the game server. These can be accessed with the async methods. It can also call custom logic as RPC functions on the server. These can also be executed with a socket object.

All requests are sent with a session object which authorizes the client.

auto successCallback = [](const NAccount& account)
{
    std::cout << "user id : " << account.user.id << std::endl;
    std::cout << "username: " << account.user.username << std::endl;
    std::cout << "wallet  : " << account.wallet << std::endl;
};
 
client->getAccount(session, successCallback, errorCallback);

Realtime client

The client can create one or more realtime clients with the server. Each realtime client can have it's own events listener registered for responses received from the server.

bool createStatus = true; // if the socket should show the user as online to others.
// define realtime client in your class as NRtClientPtr rtClient;
rtClient = client->createRtClient(DEFAULT_PORT);
// define listener in your class as NRtDefaultClientListener listener;
listener.setConnectCallback([]()
{
    std::cout << "Socket connected" << std::endl;
});
rtClient->setListener(&listener);
rtClient->connect(session, createStatus);

Don't forget to call tick method. See Tick section for details.

Logging

Initializing Logger

Client logging is off by default.

To enable logs output to console with debug logging level:

NLogger::initWithConsoleSink(NLogLevel::Debug);

To enable logs output to custom sink with debug logging level:

NLogger::init(sink, NLogLevel::Debug);

Using Logger

To log string with debug logging level:

NLOG_DEBUG("debug log");

formatted log:

NLOG(NLogLevel::Info, "This is string: %s", "yup I'm string");
NLOG(NLogLevel::Info, "This is int: %d", 5);

Changing logging level boundary:

NLogger::setLevel(NLogLevel::Debug);

NLogger behaviour depending on logging level boundary:

• Debug writes all logs.
• Info writes logs with Info, Warn, Error and Fatal logging level.
• Warn writes logs with Warn, Error and Fatal logging level.
• Error writes logs with Error and Fatal logging level.
• Fatal writes only logs with Fatal logging level.

Note: to use logging macroses you have to define NLOGS_ENABLED.

Websockets transport

Nakama C++ client has built-in support for WebSocket. This is available on all supported platforms.

Client will default to use the Websocket transport provided by C++ REST SDK.

You can use a custom Websocket transport by implementing the NRtTransportInterface:

rtClient = client->createRtClient(port, websockets_transport);

For more code examples, have a look at:

• NWebsocketCppRest
• NCocosWebSocket

Activity timeout

Built-in websocket transport supports "Activity timeout" feature - if no any message received from server during "Activity timeout" then connection will be closed. Set 0 to disable this feature (default value).

rtClient->getTransport()->setActivityTimeout(20000); // 20 sec

You can change ping period on server - ping_period_ms parameter:

https://heroiclabs.com/docs/install-configuration/#socket

Contribute

The development roadmap is managed as GitHub issues and pull requests are welcome. If you're interested to enhance the code please open an issue to discuss the changes or drop in and discuss it in the community forum.

Source Builds

Clone the Nakama C++ repository:

git clone --recurse-submodules -j8 git://github.com/heroiclabs/nakama-cpp.git

To update all submodules:

git submodule update --init --recursive

Change submodule branch:

• edit .gitmodules
• git submodule update --remote

Build Prerequisites

• git
• python 2.7 or 3.x
• CMake 3.15+
• go
• perl
• Visual Studio 2015, 2017 or 2019 - for Windows only

Third party libraries:

• boost 1.69 - must be installed in system and set path to BOOST_ROOT system variable. Used by cpprest library on Windows, Mac and Linux.
• grpc - in source control as git submodule
• optional-lite - in source control
• cpprestsdk - in source control
• rapidjson - in source control

Build Configuration

Build configuration is located here:

build/build_config.py

In the build configuration you can enable components depending on your needs.

There are following components:

• REST client (HTTP/1.1)
• gRPC client
• HTTP transport using C++ REST SDK
• Websocket transport using C++ REST SDK
• C API
• Tests

In the config you can also set whenever you need to build nakama-cpp as static, dynamic library or both version.

Building for Windows

cd build\windows
python build_windows.py -m Mode -a Arch -t Toolset --dll

Where Mode is build mode: Debug or Release

Where Arch is architecture: x86 or x64

Where Toolset is platform toolset:

• v140 - Visual Studio 2015
• v141 - Visual Studio 2017
• v142 - Visual Studio 2019

--dll is optional parameter. If set then Nakama will be built as DLL otherwise as static library.

It builds and copies nakama lib to release folder.

To build for all modes, architectures and toolsets:

cd build\windows
python build_windows_all.py

Building for Mac

Prerequisites:

sudo xcode-select --install
brew install autoconf automake libtool shtool
brew install gflags
brew install cmake ninja boost

Build:

cd build/mac
python build_mac.py --dylib

--dylib is optional parameter. If set then Nakama will be built as dynamic library otherwise as static.

It builds in Release mode and copies nakama lib to release folder.

Building for iOS

To build for one architecture:

cd build/ios
python build_ios.py Arch --dylib

Where Arch is architecture: arm64, armv7, armv7s or x86_64.

--dylib is optional parameter. If set then Nakama will be built as dynamic library otherwise as static.

It builds in Release mode.

To build for all architectures arm64, armv7, armv7s and x86_64:

cd build/ios
python build_ios_all.py

It builds in Release mode, creates universal libraries and copies them to release folder.

Building for Linux

We use Ubuntu 18.04 amd64.

Prerequisites:

To automatically install all dependencies call:

build/linux/install_deps.sh

It will install all needed packages, will download and build boost and CMake.

Execute command which will be printed at end.

To manually install dependencies:

• sudo apt-get install build-essential autoconf libtool pkg-config
• sudo apt-get install libgflags-dev libgtest-dev
• sudo apt-get install clang libc++-dev golang perl

• download boost 1.69 sources and build them:

  ./bootstrap.sh --with-libraries=system,chrono,thread

  ./b2

  set BOOST_ROOT env var to boost folder:

  export BOOST_ROOT={path to boost}

• download CMake 3.15+ sources and build them:

  ./bootstrap && make && make install

To build as static or shared object library:

cd build/linux
python build_linux.py --so

--so is optional parameter. If set then Nakama will be built as shared library otherwise as static.

It builds in Release mode and copies nakama lib to release folder.

To build both static and shared object library (see Build Configuration):

cd build/linux
python build_linux_all.py

Building for Android

Currently buid for Android is supported on Mac OS and Linux.

Set ANDROID_NDK or NDK_ROOT system variable to Android NDK folder.

To build for one ABI:

cd build/android
python build_android.py ABI --so

Where ABI is Android ABI e.g. armeabi-v7a, arm64-v8a, x86 or x86_64

--so is optional parameter. If set then Nakama will be built as shared library otherwise as static.

It builds for Andoid API level 16 in Release mode.

To build for all ABIs armeabi-v7a, arm64-v8a, x86 and x86_64:

cd build/android
python build_android_all.py

Tests

Tests are built when you build Nakama C++ SDK for desktop OS (Windows, Mac or Linux).

By default tests connect to local server by 127.0.0.1. To use another IP of your server, edit test/test_serverConfig.h file.

Prerequisites

Tests require lua modules: download them from https://github.com/heroiclabs/nakama/tree/master/data/modules and put to <nakama-server>/data/modules.

Restart server.

Run tests

Run tests executable (console application):

build/{platform}/build/test/Debug/nakama-test

Full C++ Client example

You can find the C++ Client example here

C language support

Please follow README-C

Generate Docs

API docs are generated with Doxygen and deployed to GitHub pages.

When changing the API comments, rerun Doxygen and commit the changes in docs/*.

To run Doxygen:

brew install doxygen
cd docs/
doxygen

License

This project is licensed under the Apache-2 License.

Special Thanks

Thanks to @dimon4eg for this excellent support on developing Nakama C/C++, Cocos2d-x and Unreal client libraries.