TL;DR

Here is the issue on Apple Stack Exchange link

hidutil property --set '{"UserKeyMapping":[
    {
        "HIDKeyboardModifierMappingSrc": 0x700000065,
        "HIDKeyboardModifierMappingDst": 0x7000000E6
    }
]}'

Problem

Recently I have started using MacOS. And with all this comfort connected with it, there also came a problem. Writing polish signs on my Bluetooth Keyboard (Microsoft Sculpture).

As you can see on the picture below, right to the spacebar there is an Alt key, which i used to click when I wanted to type polish sings e.g. ą, ę.

Right Alt is used in MacOS as command, but what I wanted is option. And yes, there is an easy way: you can swap option with command in System Setting for any keyboard, but…

I wanted a full MacOS experience, and “unify” my muscle memory, because switching from macbook keyboard to bluetooth would become hell. Not to mention remapping the macbook’s keyboard keys, that is not what I wanted.

I decided to remap the ≣ Menu button to ⌥ Right option

Solution

Net-enjoyer truly I am, so I asked google and got the answer.

At first I tried karabiner-elements, but it neither helped me (did not support menu button), nor did I liked it (privacy issue, 3rd party listening to my keyboard).

So I went for the second answer, more low level one, using CLI tool called hidutil introduced in MacOS 10.12.

Steps I needed to take:

1. Identify which keys to change cheatsheet

   • source: ≣ Menu - Application (0x65)
   • destination: ⌥ Right option - Right Alt (0xE6)

2. Run hidutil to test that it works:

hidutil property --set '{"UserKeyMapping":[
    {
        "HIDKeyboardModifierMappingSrc": 0x700000065,
         "HIDKeyboardModifierMappingDst": 0x7000000E6
    }
]}' 

3. Use launchd agent to run this sript on system startup

   • create file ~/Library/LaunchAgents/remap.plist
   • fill the file with the following code

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.local.KeyRemapping</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/bin/hidutil</string>
        <string>property</string>
        <string>--set</string>
        <string>{"UserKeyMapping":[
            {
                "HIDKeyboardModifierMappingSrc": 0x700000065,
                "HIDKeyboardModifierMappingDst": 0x7000000E6
            }
        ]}</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

It works !!! Proof: ćąłóę