diff --git a/keyboards/atreus/keymaps/via/keymap.c b/keyboards/atreus/keymaps/via/keymap.c
new file mode 100644
index 00000000000..980eaf32ad7
--- /dev/null
+++ b/keyboards/atreus/keymaps/via/keymap.c
@@ -0,0 +1,65 @@
+/* Copyright 2021 Leonardus Dipa
+ * 
+ * This program is free software: you can redistribute it and/or modify 
+ * it under the terms of the GNU General Public License as published by 
+ * the Free Software Foundation, either version 2 of the License, or 
+ * (at your option) any later version. 
+ * 
+ * This program is distributed in the hope that it will be useful, 
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * GNU General Public License for more details. 
+ * 
+ * You should have received a copy of the GNU General Public License 
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. 
+ */
+#include QMK_KEYBOARD_H
+
+// Each layer gets a name for readability, which is then used in the keymap matrix below.
+// The underscores don't mean anything - you can have a layer called STUFF or any other name.
+// Layer names don't all need to be of the same length, obviously, and you can also skip them
+// entirely and just use numbers.
+enum custom_layers {
+    _QW,
+    _RS,
+    _LW,
+    _EM,
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+  [_QW] = LAYOUT( /* Qwerty */
+    KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,                      KC_Y,    KC_U,    KC_I,    KC_O,    KC_P    ,
+    KC_A,    KC_S,    KC_D,    KC_F,    KC_G,                      KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN ,
+    KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,                      KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH ,
+    KC_ESC, KC_TAB, KC_LGUI,  KC_LSFT, KC_BSPC,  KC_LCTL, KC_LALT, KC_SPC,  MO(_RS), KC_MINS, KC_QUOT, KC_ENT
+  ),
+
+  /*
+   *  !       @     up     {    }        ||     pgup    7     8     9    *
+   *  #     left   down  right  $        ||     pgdn    4     5     6    +
+   *  [       ]      (     )    &        ||       `     1     2     3    \
+   * lower  insert super shift bksp ctrl || alt space   fn    .     0    =
+   */
+  [_RS] = LAYOUT( /* [> RAISE <] */
+    KC_EXLM, KC_AT,   KC_UP,   KC_LCBR, KC_RCBR,                   KC_PGUP, KC_7,    KC_8,   KC_9, KC_ASTR ,
+    KC_HASH, KC_LEFT, KC_DOWN, KC_RGHT, KC_DLR,                    KC_PGDN, KC_4,    KC_5,   KC_6, KC_PLUS ,
+    KC_LBRC, KC_RBRC, KC_LPRN, KC_RPRN, KC_AMPR,                   KC_GRV,  KC_1,    KC_2,   KC_3, KC_BSLS ,
+    TG(_LW), KC_INS,  KC_LGUI, KC_LSFT, KC_BSPC, KC_LCTL, KC_LALT, KC_SPC,  KC_TRNS, KC_DOT, KC_0, KC_EQL  ),
+  /*
+   * insert home   up  end   pgup       ||      up     F7    F8    F9   F10
+   *  del   left  down right pgdn       ||     down    F4    F5    F6   F11
+   *       volup             reset      ||             F1    F2    F3   F12
+   *       voldn  super shift bksp ctrl || alt space   L0  prtsc scroll pause
+   */
+  [_LW] = LAYOUT( /* [> LOWER <] */
+    KC_INS,  KC_HOME, KC_UP,   KC_END,  KC_PGUP,                   KC_UP,   KC_F7,   KC_F8,   KC_F9,   KC_F10  ,
+    KC_DEL,  KC_LEFT, KC_DOWN, KC_RGHT, KC_PGDN,                   KC_DOWN, KC_F4,   KC_F5,   KC_F6,   KC_F11  ,
+    KC_NO,   KC_VOLU, KC_NO,   KC_NO,   RESET,                     KC_NO,   KC_F1,   KC_F2,   KC_F3,   KC_F12  ,
+    KC_NO,   KC_VOLD, KC_LGUI, KC_LSFT, KC_BSPC, KC_LCTL, KC_LALT, KC_SPC,  TO(_QW), KC_PSCR, KC_SLCK, KC_PAUS ),
+
+  [_EM] = LAYOUT( /* [> EMPTY <] */
+    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS  ,
+    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS  ,
+    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS  ,
+    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS  )
+};
diff --git a/keyboards/atreus/keymaps/via/rules.mk b/keyboards/atreus/keymaps/via/rules.mk
new file mode 100644
index 00000000000..f75f41cf50e
--- /dev/null
+++ b/keyboards/atreus/keymaps/via/rules.mk
@@ -0,0 +1,4 @@
+LTO_ENABLE=yes
+VIA_ENABLE = yes
+
+MOUSEKEY_ENABLE = no
diff --git a/keyboards/atreus/promicro/config.h b/keyboards/atreus/promicro/config.h
index 03b63f6ff32..a4ed1c642da 100644
--- a/keyboards/atreus/promicro/config.h
+++ b/keyboards/atreus/promicro/config.h
@@ -28,6 +28,8 @@
  *                  ROW2COL = ROW = Anode (+), COL = Cathode (-, marked on diode)
  *
 */
+
+/* key matrix pins */
 #define MATRIX_ROW_PINS { F4, B2, B4, B5 }
 #if defined(PCBDOWN)
   #define MATRIX_COL_PINS { D0, D4, C6, D7, E6, B6, B3, B1, F7, F6, F5 }