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Building wolfMQTT

wolfMQTT was written with portability in mind, and should generally be easy to build on most systems. If you have difficulty building, please don’t hesitate to seek support through our support forums or contact us directly at . This chapter explains how to build wolfMQTT on Unix and Windows, and provides guidance for building in a non-standard environment.

When using the autoconf / automake system to build, wolfMQTT uses a single Makefile to build all parts and examples of the library, which is both simpler and faster than using Makefiles recursively. If using the TLS features or the Firmware/Azure IoT Hub examples you’ll need to have wolfSSL installed. For wolfSSL and wolfMQTT we recommend using config options below

./configure  --enable-ecc  --enable-supportedcurves  --enable-base64encode. 

For wolfSSL use make && sudo make install. If you get an error locating the, run sudo ldconfig from the wolfSSL directory.

Getting the Source Code

The most recent version of wolfMQTT can be downloaded from the wolfSSL downloads page here

Or from Github with the command:

git clone

Building on *nix/Mac

When building on Linux, BSD, OS X, Solaris, or other nix-like systems, use the autoconf system. If cloned from github, run the following three commands:


Otherwise, just run these two commands:


You can append any number of build options to ./configure. For a list of available build options, run the command below:

./configure --help

To build wolfMQTT, run:


To install wolfMQTT run:

make install

You may need superuser privileges to install, in which case precede the command with sudo:

sudo make install

Notes: * If wolfssl was recently installed, run sudo ldconfig to update the linker cache. * Debug messages can be enabled using --enable-debug or --enable-debug=verbose (for extra logging). * For a list of build options run ./configure --help. * The build options are generated in a file here: wolfmqtt/options.h.

To test the build, run the mqttclient program from the root wolfMQTT source directory:


If you want to build only the wolfMQTT library and not the additional items (examples), you can run the following command from the wolfMQTT root directory:

make src/

Building on Windows

Visual Studio :

For building wolfMQTT with TLS support in Visual Studio:

  1. Open the <wolfssl-root>/wolfssl64.sln.
  2. Re-target for your Visual Studio version (right-click on solution and choose Retarget solution).
  3. Make sure the Debug DLL or Release DLL configuration is selected. Make note if you are building 32-bit x86 or 64-bit x64.
  4. Build the wolfSSL solution.
  5. Copy the wolfssl.lib and wolfssl.dll files into <wolfmqtt-root>.
  6. For DLL Debug with x86 the files are in: DLL Debug.
  7. For DLL Release with x86 the files are in: DLL Release.
  8. For DLL Debug with x64 the files are in: x64/DLL Debug.
  9. For DLL Release with x64 the files are in: x64/DLL Release.
  10. Open the <wolfmqtt-root>/wolfmqtt.sln solution.
  11. Make sure you have the same architecture (x86 or x64 selected) as used in wolfSSL above.
  12. By default the include path for the wolfssl headers is ./../wolfssl/. If your wolfssl root location is different you can go into the project settings and adjust this in C/C++ -> General -> Additional Include Directories.
  13. Configure your Visual Studio build settings using wolfmqtt/vs_settings.h.
  14. Build the wolfMQTT solution.

The wolfmqtt.sln solution is included for Visual Studio 2015 in the root directory of the install. To test each build, choose “Build All” from the Visual Studio menu and then run the mqttclient program. To edit build options in the Visual Studio project, select your desired project (wolfmqtt, mqttclient) and browse to the “Properties” panel.

For instructions on building the required wolfssl.dll see here. When done copy the wolfssl.dll and wolfssl.lib into the wolfMQTT root. The project also assumes the wolfSSL headers are located ../wolfssl/.

Cygwin : If using Cygwin, or other toolsets for Windows that provides nix-like commands and functionality, please follow the instructions in Section 2.2, above, for “Building on nix”. If building wolfMQTT for Windows on a Windows development machine, we recommend using the included Visual Studio project files to build wolfMQTT.

Building on Arduino

Reformatting wolfMQTT as a compatible Arduino Library is a shell script that will re-organize the wolfMQTT library to be compatible with Arduino projects. The Arduino IDE requires a library's source files to be in the library's root directory with a header file in the name of the library. This script copies all source files to the IDE/ARDUINO/wolfMQTT directory and creates a stub header file called wolfMQTT.h.

To configure wolfMQTT with Arduino, enter the following from within the IDE/ARDUINO directory:


Including wolfMQTT in Arduino Libraries (for Arduino version 1.8.2)

  1. In the Arduino IDE:
    • In Sketch -> Include Library -> Add .ZIP Library... and choose the IDE/ARDUNIO/wolfMQTT folder.
    • In Sketch -> Include Library choose wolfMQTT.

To enable TLS support, add #define ENABLE_MQTT_TLS in IDE/ARDUNIO/wolfMQTT/wolfmqtt/options.h. Note: If using wolfSSL TLS then you'll need to do this for wolfSSL as well. See <wolfssl-root>/IDE/ARDUINO/ for instructions.

An example wolfMQTT client INO sketch exists here: wolfmqtt_client/wolfmqtt_client.ino to demonstrate using the wolfMQTT library.

Building with MinGW

After downloading both wolfSSL and wolfMQTT, run the script below to build then install both:

export PATH="/opt/mingw-w32-bin_i686-darwin/bin:$PATH"
export PREFIX=$PWD/build

# wolfSSL
cd wolfssl
./configure --host=i686 CC=i686-w64-mingw32-gcc LD=i686-w64-mingw32-ld CFLAGS="-DWIN32 -DMINGW -D_WIN32_WINNT=0x0600" LIBS="-lws2_32 -L$PREFIX/lib -lwolfssl" --prefix=$PREFIX
make install

# wolfMQTT
cd ../wolfmqtt
./configure --host=i686 CC=i686-w64-mingw32-gcc LD=i686-w64-mingw32-ld CFLAGS="-DWIN32 -DMINGW -D_WIN32_WINNT=0x0600 -DBUILDING_WOLFMQTT -I$PREFIX/include" LDFLAGS="-lws2_32 -L$PREFIX/lib -lwolfssl" --prefix=$PREFIX --disable-examples

Building in a non-standard environment

While not officially supported, we try to help users wishing to build wolfMQTT in a non-standard environment, particularly with embedded and cross-compilation systems. Below are some notes on getting started with this.

  1. The source and header files need to remain in the same directory structure as they are in the wolfMQTT download package.
  2. Some build systems will want to explicitly know where the wolfMQTT header files are located, so you may need to specify that. They are located in the <wolfmqtt_root>/wolfmqtt directory. Typically, you can add the directory to your include path to resolve header problems.
  3. wolfMQTT defaults to a little endian system unless the configure process detects big endian. Since users building in a non-standard environment aren't using the configure process, BIG_ENDIAN_ORDER will need to be defined if using a big endian system.
  4. Try to build the library, and let us know if you run into any problems. If you need help, contact us at .

Cross Compiling

Many users on embedded platforms cross compile for their environment. The easiest way to cross compile the library is to use the ./configure system. It will generate a Makefile which can then be used to build wolfMQTT. When cross compiling, you’ll need to specify the host to ./configure, such as:

./configure --host=arm-linux

You may also need to specify the compiler, linker, etc. that you want to use:

./configure --host=arm-linux CC=arm-linux-gcc AR=arm-linux-ar RANLIB=arm-linux

After correctly configuring wolfMQTT for cross-compilation, you should be able to follow standard autoconf practices for building and installing the library:

sudo make install

If you have any additional tips or feedback about cross compiling wolfMQTT, please let us know at

Install to Custom Directory

To setup a custom install directory for wolfSSL and specify the custom wolfSSL lib/include directories for wolfMQTT, use the following:

In wolfSSL:

./configure  --prefix=~/wolfssl
make install

This will place the libs in ~/wolfssl/lib and includes in ~/wolfssl/include.

In wolfMQTT:

./configure --prefix=~/wolfmqtt  --libdir=~/wolfssl/lib  --includedir=~/wolfssl/include
make install

Make sure the paths above match your actual location.