Mosquitto is a BSD licensed message broker that implements the MQ Telemetry Transport protocol versions 3.1 and 3.1.1.

Mosquitto is a lightweight broker and it is available in binary form for most used platforms like Windows, Linux and Mac OS X.

In a previous post I shown how to install mosquitto, on Raspberry Pirunning raspbian, from source code.

On Mac OS X you could have some error because you should build all the environment for compiling.

Instead you could use brew.

Install brew.

from a terminal run the following commands:

$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
$ brew doctor
$ brew prune

Install mosquitto from brew:

$ brew install mosquitto

Prepare mosquitto for launchd

$ ln -sfv /usr/local/opt/mosquitto/*.plist ~/Library/LaunchAgents

Run mosquitto

$ launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mosquitto.plist

Now let’s try the broker, in the terminal launch the subscriber client:

$ mosquitto_sub -h 127.0.0.1 -t topic

In another terminal launch the publisher client

$ mosquitto_pub -h 127.0.0.1 -t topic -m "Hello world!"

in the first terminal you should see the Hello world! message.

Gg1