Curie

{
  "title": "Russian - English by Left - Right Shift keys",
  "rules": [
    {
      "description": "Change Left Shift to 'English - ABC Extended' if pressed alone",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "key_code": "left_shift",
            "modifiers": {
              "optional": [
                "any"
              ]
            }
          },
          "to": [
            {
              "key_code": "left_shift"
            }
          ],
          "to_if_alone": [
            {
               "select_input_source": {
                    "input_source_id": "com.apple.keylayout.US"
                }
            }
          ]
        }
      ]
    },
    {
      "description": "Change Left Shift to 'English - ABC' if pressed alone",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "key_code": "left_shift",
            "modifiers": {
              "optional": [
                "any"
              ]
            }
          },
          "to": [
            {
              "key_code": "left_shift"
            }
          ],
          "to_if_alone": [
            {
               "select_input_source": {
                    "input_source_id": "com.apple.keylayout.ABC"
                }
            }
          ]
        }
      ]
    },
    {
      "description": "Change Right Shift to 'Russian - PC' if pressed alone",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "key_code": "right_shift",
            "modifiers": {
              "optional": [
                "any"
              ]
            }
          },
          "to": [
            {
              "key_code": "right_shift"
            }
          ],
          "to_if_alone": [
            {
               "select_input_source": {
                    "input_source_id": "com.apple.keylayout.Russian"
                }
            }
          ]
        }
      ]
    }
  ]
}