to.from_event

This feature is available since Karabiner-Elements 15.9.13 (beta).

Specifying to.from_event lets you send the key defined in from as-is. With this, using a rule like the one below, you can disable changes from other Complex Modifications when you enable pass-through mode with fn+p.

This uses the property that in Complex Modifications, once an event is modified, it is no longer subject to subsequent rules. In other words, by handling events early with from.any and to.from_event, later rules are effectively disabled.

Relationship with Simple Modifications

Note that Simple Modifications are applied before Complex Modifications are evaluated, so this setting does not disable them. If you also want to disable Simple Modifications, do the same configuration in Complex Modifications instead of using Simple Modifications, and place it after the disable complex modifications setting. In other words, in Complex Modifications it should look like this:

Disable Complex Modifications in Windows App
Rules migrated from Simple Modifications

Toggle Pass-Through Mode by fn+p
Rules migrated from Simple Modifications

Examples

Disable Complex Modifications in Windows App

💡 How to use this example

{
    "description": "Disable Complex Modifications in Windows App",
    "manipulators": [
        {
            "type": "basic",
            "from": {
                "any": "key_code",
                "modifiers": {
                    "optional": ["any"]
                }
            },
            "to": [
                {
                    "from_event": true
                }
            ],
            "conditions": [
                {
                    "type": "frontmost_application_if",
                    "bundle_identifiers": ["^com\\.microsoft\\.rdc\\.macos"]
                }
            ]
        }
    ]
}

Pass-Through Mode

💡 How to use this example

{
    "description": "Toggle Pass-Through Mode by fn+p",
    "manipulators": [
        // fn+p
        {
            "type": "basic",
            "from": {
                "key_code": "p",
                "modifiers": {
                    "mandatory": ["fn"],
                    "optional": ["caps_lock"]
                }
            },
            "to": [
                {
                    // If it's off now, it will turn on, so display a message.
                    "set_notification_message": {
                        "id": "pass_through_mode",
                        "text": "Pass-Through Mode"
                    },
                    "conditions": [
                        {
                            "type": "variable_if",
                            "name": "pass_through_mode",
                            "value": 0
                        }
                    ]
                },
                {
                    // If it's on now, it will turn off, so hide the message.
                    "set_notification_message": {
                        "id": "pass_through_mode",
                        "text": ""
                    },
                    "conditions": [
                        {
                            "type": "variable_if",
                            "name": "pass_through_mode",
                            "value": 1
                        }
                    ]
                },
                {
                    "set_variable": {
                        "name": "pass_through_mode",
                        // pass_through_mode is 0 or 1.
                        "expression": "pass_through_mode != 0 ? 0 : 1"
                    }
                }
            ]
        },
        // pass through any key events
        {
            "type": "basic",
            "from": {
                "any": "key_code",
                "modifiers": {
                    "optional": ["any"]
                }
            },
            "to": [
                {
                    "from_event": true
                }
            ],
            "conditions": [
                {
                    "type": "variable_if",
                    "name": "pass_through_mode",
                    "value": 1
                }
            ]
        }
    ]
}