diff --git a/keyboards/kprepublic/cstc40/config.h b/keyboards/kprepublic/cstc40/config.h
new file mode 100644
index 00000000000..c4309868952
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/config.h
@@ -0,0 +1,59 @@
+// Copyright 2022 Var (@itsvar8)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#define I2C1_SDA_PIN B9
+#define I2C1_SCL_PIN B8
+#define DRIVER_ADDR_1 0b1010000
+#define DRIVER_COUNT 1
+#define RGB_MATRIX_LED_COUNT 47
+
+#define RGB_MATRIX_FRAMEBUFFER_EFFECTS
+#define RGB_MATRIX_KEYPRESSES
+
+#define ENABLE_RGB_MATRIX_ALPHAS_MODS
+#define ENABLE_RGB_MATRIX_GRADIENT_UP_DOWN
+#define ENABLE_RGB_MATRIX_GRADIENT_LEFT_RIGHT
+#define ENABLE_RGB_MATRIX_BREATHING
+#define ENABLE_RGB_MATRIX_BAND_SAT
+#define ENABLE_RGB_MATRIX_BAND_VAL
+#define ENABLE_RGB_MATRIX_BAND_PINWHEEL_SAT
+#define ENABLE_RGB_MATRIX_BAND_PINWHEEL_VAL
+#define ENABLE_RGB_MATRIX_BAND_SPIRAL_SAT
+#define ENABLE_RGB_MATRIX_BAND_SPIRAL_VAL
+#define ENABLE_RGB_MATRIX_CYCLE_ALL
+#define ENABLE_RGB_MATRIX_CYCLE_LEFT_RIGHT
+#define ENABLE_RGB_MATRIX_CYCLE_UP_DOWN
+#define ENABLE_RGB_MATRIX_RAINBOW_MOVING_CHEVRON
+#define ENABLE_RGB_MATRIX_CYCLE_OUT_IN
+#define ENABLE_RGB_MATRIX_CYCLE_OUT_IN_DUAL
+#define ENABLE_RGB_MATRIX_CYCLE_PINWHEEL
+#define ENABLE_RGB_MATRIX_CYCLE_SPIRAL
+#define ENABLE_RGB_MATRIX_DUAL_BEACON
+#define ENABLE_RGB_MATRIX_RAINBOW_BEACON
+#define ENABLE_RGB_MATRIX_RAINBOW_PINWHEELS
+#define ENABLE_RGB_MATRIX_RAINDROPS
+#define ENABLE_RGB_MATRIX_JELLYBEAN_RAINDROPS
+#define ENABLE_RGB_MATRIX_HUE_BREATHING
+#define ENABLE_RGB_MATRIX_HUE_PENDULUM
+#define ENABLE_RGB_MATRIX_HUE_WAVE
+#define ENABLE_RGB_MATRIX_PIXEL_FRACTAL
+#define ENABLE_RGB_MATRIX_PIXEL_FLOW
+#define ENABLE_RGB_MATRIX_PIXEL_RAIN
+#define ENABLE_RGB_MATRIX_TYPING_HEATMAP
+#define ENABLE_RGB_MATRIX_DIGITAL_RAIN
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_SIMPLE
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_WIDE
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_MULTIWIDE
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_CROSS
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_MULTICROSS
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_NEXUS
+#define ENABLE_RGB_MATRIX_SOLID_REACTIVE_MULTINEXUS
+#define ENABLE_RGB_MATRIX_SPLASH
+#define ENABLE_RGB_MATRIX_MULTISPLASH
+#define ENABLE_RGB_MATRIX_SOLID_SPLASH
+#define ENABLE_RGB_MATRIX_SOLID_MULTISPLASH
+
+#define RGB_DISABLE_WHEN_USB_SUSPENDED
diff --git a/keyboards/kprepublic/cstc40/daughterboard/daughterboard.c b/keyboards/kprepublic/cstc40/daughterboard/daughterboard.c
new file mode 100644
index 00000000000..39d3d7ff528
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/daughterboard/daughterboard.c
@@ -0,0 +1,71 @@
+/* Copyright 2022 bdtc123
+ *
+ * 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 .
+ */
+#include "quantum.h"
+
+#ifdef RGB_MATRIX_ENABLE
+const is31_led g_is31_leds[RGB_MATRIX_LED_COUNT] = {
+ { 0, L_1, K_1, J_1 },
+ { 0, L_2, K_2, J_2 },
+ { 0, L_3, K_3, J_3 },
+ { 0, L_4, K_4, J_4 },
+ { 0, L_5, K_5, J_5 },
+ { 0, L_6, K_6, J_6 },
+ { 0, L_7, K_7, J_7 },
+ { 0, L_8, K_8, J_8 },
+ { 0, L_9, K_9, J_9 },
+ { 0, L_10, K_10, J_10 },
+ { 0, L_11, K_11, J_11 },
+ { 0, L_12, K_12, J_12 },
+
+ { 0, I_1, H_1, G_1 },
+ { 0, I_2, H_2, G_2 },
+ { 0, I_3, H_3, G_3 },
+ { 0, I_4, H_4, G_4 },
+ { 0, I_5, H_5, G_5 },
+ { 0, I_6, H_6, G_6 },
+ { 0, I_7, H_7, G_7 },
+ { 0, I_8, H_8, G_8 },
+ { 0, I_9, H_9, G_9 },
+ { 0, I_10, H_10, G_10 },
+ { 0, I_11, H_11, G_11 },
+ { 0, I_12, H_12, G_12 },
+
+ { 0, F_1, E_1, D_1 },
+ { 0, F_2, E_2, D_2 },
+ { 0, F_3, E_3, D_3 },
+ { 0, F_4, E_4, D_4 },
+ { 0, F_5, E_5, D_5 },
+ { 0, F_6, E_6, D_6 },
+ { 0, F_7, E_7, D_7 },
+ { 0, F_8, E_8, D_8 },
+ { 0, F_9, E_9, D_9 },
+ { 0, F_10, E_10, D_10 },
+ { 0, F_11, E_11, D_11 },
+ { 0, F_12, E_12, D_12 },
+
+ { 0, C_1, B_1, A_1 },
+ { 0, C_2, B_2, A_2 },
+ { 0, C_3, B_3, A_3 },
+ { 0, C_4, B_4, A_4 },
+ { 0, C_5, B_5, A_5 },
+ { 0, C_6, B_6, A_6 },
+ { 0, C_8, B_8, A_8 },
+ { 0, C_9, B_9, A_9 },
+ { 0, C_10, B_10, A_10 },
+ { 0, C_11, B_11, A_11 },
+ { 0, C_12, B_12, A_12 }
+};
+#endif
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/daughterboard/info.json b/keyboards/kprepublic/cstc40/daughterboard/info.json
new file mode 100644
index 00000000000..cdba7942df8
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/daughterboard/info.json
@@ -0,0 +1,6 @@
+{
+ "matrix_pins": {
+ "cols": ["B15", "B14", "B13", "B10", "B12", "A5", "C4", "A7", "A15", "C10", "C11", "C0"],
+ "rows": ["B1", "B0", "C5", "A6"]
+ }
+}
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/daughterboard/rules.mk b/keyboards/kprepublic/cstc40/daughterboard/rules.mk
new file mode 100644
index 00000000000..7ff128fa692
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/daughterboard/rules.mk
@@ -0,0 +1 @@
+# This file intentionally left blank
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/halconf.h b/keyboards/kprepublic/cstc40/halconf.h
new file mode 100644
index 00000000000..0f279040aae
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/halconf.h
@@ -0,0 +1,20 @@
+/* Copyright 2020 Nick Brassel (tzarc)
+ *
+ * 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 3 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 .
+ */
+#pragma once
+
+#define HAL_USE_I2C TRUE
+
+#include_next
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/info.json b/keyboards/kprepublic/cstc40/info.json
new file mode 100644
index 00000000000..4ccd8389e88
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/info.json
@@ -0,0 +1,130 @@
+{
+ "manufacturer": "kprepublic",
+ "keyboard_name": "cstc40",
+ "maintainer": "itsvar8",
+ "bootloader": "stm32-dfu",
+ "diode_direction": "ROW2COL",
+ "debounce": 2,
+ "features": {
+ "bootmagic": true,
+ "command": false,
+ "console": false,
+ "extrakey": true,
+ "mousekey": true,
+ "nkro": true,
+ "rgb_matrix": true
+ },
+ "processor": "STM32F401",
+ "url": "",
+ "usb": {
+ "device_version": "1.0.0",
+ "pid": "0x0040",
+ "vid": "0x586A"
+ },
+ "layouts": {
+ "LAYOUT_planck_mit": {
+ "layout": [
+ { "matrix": [0, 0], "x": 0, "y": 0 },
+ { "matrix": [0, 1], "x": 1, "y": 0 },
+ { "matrix": [0, 2], "x": 2, "y": 0 },
+ { "matrix": [0, 3], "x": 3, "y": 0 },
+ { "matrix": [0, 4], "x": 4, "y": 0 },
+ { "matrix": [0, 5], "x": 5, "y": 0 },
+ { "matrix": [0, 6], "x": 6, "y": 0 },
+ { "matrix": [0, 7], "x": 7, "y": 0 },
+ { "matrix": [0, 8], "x": 8, "y": 0 },
+ { "matrix": [0, 9], "x": 9, "y": 0 },
+ { "matrix": [0, 10], "x": 10, "y": 0 },
+ { "matrix": [0, 11], "x": 11, "y": 0 },
+ { "matrix": [1, 0], "x": 0, "y": 1 },
+ { "matrix": [1, 1], "x": 1, "y": 1 },
+ { "matrix": [1, 2], "x": 2, "y": 1 },
+ { "matrix": [1, 3], "x": 3, "y": 1 },
+ { "matrix": [1, 4], "x": 4, "y": 1 },
+ { "matrix": [1, 5], "x": 5, "y": 1 },
+ { "matrix": [1, 6], "x": 6, "y": 1 },
+ { "matrix": [1, 7], "x": 7, "y": 1 },
+ { "matrix": [1, 8], "x": 8, "y": 1 },
+ { "matrix": [1, 9], "x": 9, "y": 1 },
+ { "matrix": [1, 10], "x": 10, "y": 1 },
+ { "matrix": [1, 11], "x": 11, "y": 1 },
+ { "matrix": [2, 0], "x": 0, "y": 2 },
+ { "matrix": [2, 1], "x": 1, "y": 2 },
+ { "matrix": [2, 2], "x": 2, "y": 2 },
+ { "matrix": [2, 3], "x": 3, "y": 2 },
+ { "matrix": [2, 4], "x": 4, "y": 2 },
+ { "matrix": [2, 5], "x": 5, "y": 2 },
+ { "matrix": [2, 6], "x": 6, "y": 2 },
+ { "matrix": [2, 7], "x": 7, "y": 2 },
+ { "matrix": [2, 8], "x": 8, "y": 2 },
+ { "matrix": [2, 9], "x": 9, "y": 2 },
+ { "matrix": [2, 10], "x": 10, "y": 2 },
+ { "matrix": [2, 11], "x": 11, "y": 2 },
+ { "matrix": [3, 0], "x": 0, "y": 3 },
+ { "matrix": [3, 1], "x": 1, "y": 3 },
+ { "matrix": [3, 2], "x": 2, "y": 3 },
+ { "matrix": [3, 3], "x": 3, "y": 3 },
+ { "matrix": [3, 4], "x": 4, "y": 3 },
+ { "matrix": [3, 5], "w": 2, "x": 5, "y": 3 },
+ { "matrix": [3, 7], "x": 7, "y": 3 },
+ { "matrix": [3, 8], "x": 8, "y": 3 },
+ { "matrix": [3, 9], "x": 9, "y": 3 },
+ { "matrix": [3, 10], "x": 10, "y": 3 },
+ { "matrix": [3, 11], "x": 11, "y": 3 }
+ ]
+ }
+ },
+ "rgb_matrix": {
+ "driver": "is31fl3733",
+ "layout": [
+ {"matrix": [0, 0], "x": 0, "y": 0, "flags": 1},
+ {"matrix": [0, 1], "x": 20, "y": 0, "flags": 4},
+ {"matrix": [0, 2], "x": 40, "y": 0, "flags": 4},
+ {"matrix": [0, 3], "x": 61, "y": 0, "flags": 4},
+ {"matrix": [0, 4], "x": 81, "y": 0, "flags": 4},
+ {"matrix": [0, 5], "x": 101, "y": 0, "flags": 4},
+ {"matrix": [0, 6], "x": 122, "y": 0, "flags": 4},
+ {"matrix": [0, 7], "x": 142, "y": 0, "flags": 4},
+ {"matrix": [0, 8], "x": 162, "y": 0, "flags": 4},
+ {"matrix": [0, 9], "x": 183, "y": 0, "flags": 4},
+ {"matrix": [0, 10], "x": 203, "y": 0, "flags": 4},
+ {"matrix": [0, 11], "x": 224, "y": 0, "flags": 1},
+ {"matrix": [1, 0], "x": 0, "y": 21, "flags": 1},
+ {"matrix": [1, 1], "x": 20, "y": 21, "flags": 4},
+ {"matrix": [1, 2], "x": 40, "y": 21, "flags": 4},
+ {"matrix": [1, 3], "x": 61, "y": 21, "flags": 4},
+ {"matrix": [1, 4], "x": 81, "y": 21, "flags": 4},
+ {"matrix": [1, 5], "x": 101, "y": 21, "flags": 4},
+ {"matrix": [1, 6], "x": 122, "y": 21, "flags": 4},
+ {"matrix": [1, 7], "x": 142, "y": 21, "flags": 4},
+ {"matrix": [1, 8], "x": 162, "y": 21, "flags": 4},
+ {"matrix": [1, 9], "x": 183, "y": 21, "flags": 4},
+ {"matrix": [1, 10], "x": 203, "y": 21, "flags": 4},
+ {"matrix": [1, 11], "x": 224, "y": 21, "flags": 1},
+ {"matrix": [2, 0], "x": 0, "y": 42, "flags": 1},
+ {"matrix": [2, 1], "x": 20, "y": 42, "flags": 4},
+ {"matrix": [2, 2], "x": 40, "y": 42, "flags": 4},
+ {"matrix": [2, 3], "x": 61, "y": 42, "flags": 4},
+ {"matrix": [2, 4], "x": 81, "y": 42, "flags": 4},
+ {"matrix": [2, 5], "x": 101, "y": 42, "flags": 4},
+ {"matrix": [2, 6], "x": 122, "y": 42, "flags": 4},
+ {"matrix": [2, 7], "x": 142, "y": 42, "flags": 4},
+ {"matrix": [2, 8], "x": 162, "y": 42, "flags": 4},
+ {"matrix": [2, 9], "x": 183, "y": 42, "flags": 4},
+ {"matrix": [2, 10], "x": 203, "y": 42, "flags": 4},
+ {"matrix": [2, 11], "x": 224, "y": 42, "flags": 1},
+ {"matrix": [3, 0], "x": 0, "y": 64, "flags": 1},
+ {"matrix": [3, 1], "x": 20, "y": 64, "flags": 1},
+ {"matrix": [3, 2], "x": 40, "y": 64, "flags": 1},
+ {"matrix": [3, 3], "x": 61, "y": 64, "flags": 1},
+ {"matrix": [3, 4], "x": 81, "y": 64, "flags": 1},
+ {"matrix": [3, 5], "x": 111, "y": 64, "flags": 1},
+ {"matrix": [3, 7], "x": 142, "y": 64, "flags": 1},
+ {"matrix": [3, 8], "x": 162, "y": 64, "flags": 1},
+ {"matrix": [3, 9], "x": 183, "y": 64, "flags": 1},
+ {"matrix": [3, 10], "x": 203, "y": 64, "flags": 1},
+ {"matrix": [3, 11], "x": 224, "y": 64, "flags": 1}
+ ],
+ "max_brightness": 200
+ }
+}
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/keymaps/default/keymap.c b/keyboards/kprepublic/cstc40/keymaps/default/keymap.c
new file mode 100644
index 00000000000..e47ff226a93
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/keymaps/default/keymap.c
@@ -0,0 +1,94 @@
+/* Copyright 2023
+ *
+ * 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 .
+ */
+
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+/* Qwerty
+ * ,-----------------------------------------------------------------------------------.
+ * | Tab | Q | W | E | R | T | Y | U | I | O | P | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Esc | A | S | D | F | G | H | J | K | L | ; | " |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Shift| Z | X | C | V | B | N | M | , | . | / |Enter |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | BLTog| Ctrl | Alt | GUI |Lower | Space |Raise | Left | Down | Up |Right |
+ * `-----------------------------------------------------------------------------------'
+ */
+[0] = LAYOUT_planck_mit(
+ KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_BSPC,
+ KC_ESC, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT,
+ KC_LSFT, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_ENT ,
+ RGB_TOG, KC_LCTL, KC_LALT, KC_LGUI, TL_LOWR, KC_SPC, TL_UPPR, KC_LEFT, KC_DOWN, KC_UP, KC_RGHT
+),
+
+/* Lower
+ * ,-----------------------------------------------------------------------------------.
+ * | ~ | ! | @ | # | $ | % | ^ | & | * | ( | ) | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Del | F1 | F2 | F3 | F4 | F5 | F6 | _ | + | { | } | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | F7 | F8 | F9 | F10 | F11 | F12 |ISO ~ |ISO | | Home | End | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[1] = LAYOUT_planck_mit(
+ KC_TILD, KC_EXLM, KC_AT, KC_HASH, KC_DLR, KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_BSPC,
+ KC_DEL, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_UNDS, KC_PLUS, KC_LCBR, KC_RCBR, KC_PIPE,
+ _______, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, S(KC_NUHS), S(KC_NUBS), KC_HOME, KC_END, _______,
+ _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY
+),
+
+/* Raise
+ * ,-----------------------------------------------------------------------------------.
+ * | ` | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Del | F1 | F2 | F3 | F4 | F5 | F6 | - | = | [ | ] | \ |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | F7 | F8 | F9 | F10 | F11 | F12 |ISO # |ISO / |Pg Up |Pg Dn | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[2] = LAYOUT_planck_mit(
+ KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_BSPC,
+ KC_DEL, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_MINS, KC_EQL, KC_LBRC, KC_RBRC, KC_BSLS,
+ _______, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_NUHS, KC_NUBS, KC_PGUP, KC_PGDN, _______,
+ _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY
+),
+
+/* Adjust (Lower + Raise)
+ * v------------------------RGB CONTROL--------------------v
+ * ,-----------------------------------------------------------------------------------.
+ * | | Reset|Debug | RGB |RGBMOD| HUE+ | HUE- | SAT+ | SAT- |BRGTH+|BRGTH-| Del |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | |
+ * `-----------------------------------------------------------------------------------'
+ */
+[3] = LAYOUT_planck_mit(
+ _______, QK_BOOT, DB_TOGG, RGB_TOG, RGB_MOD, RGB_HUI, RGB_HUD, RGB_SAI, RGB_SAD, RGB_VAI, RGB_VAD, KC_DEL,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______
+)
+
+};
diff --git a/keyboards/kprepublic/cstc40/keymaps/default/rules.mk b/keyboards/kprepublic/cstc40/keymaps/default/rules.mk
new file mode 100644
index 00000000000..7c9bf212a6f
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/keymaps/default/rules.mk
@@ -0,0 +1 @@
+TRI_LAYER_ENABLE = yes
diff --git a/keyboards/kprepublic/cstc40/keymaps/via/keymap.c b/keyboards/kprepublic/cstc40/keymaps/via/keymap.c
new file mode 100644
index 00000000000..e47ff226a93
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/keymaps/via/keymap.c
@@ -0,0 +1,94 @@
+/* Copyright 2023
+ *
+ * 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 .
+ */
+
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+/* Qwerty
+ * ,-----------------------------------------------------------------------------------.
+ * | Tab | Q | W | E | R | T | Y | U | I | O | P | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Esc | A | S | D | F | G | H | J | K | L | ; | " |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Shift| Z | X | C | V | B | N | M | , | . | / |Enter |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | BLTog| Ctrl | Alt | GUI |Lower | Space |Raise | Left | Down | Up |Right |
+ * `-----------------------------------------------------------------------------------'
+ */
+[0] = LAYOUT_planck_mit(
+ KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_BSPC,
+ KC_ESC, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT,
+ KC_LSFT, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_ENT ,
+ RGB_TOG, KC_LCTL, KC_LALT, KC_LGUI, TL_LOWR, KC_SPC, TL_UPPR, KC_LEFT, KC_DOWN, KC_UP, KC_RGHT
+),
+
+/* Lower
+ * ,-----------------------------------------------------------------------------------.
+ * | ~ | ! | @ | # | $ | % | ^ | & | * | ( | ) | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Del | F1 | F2 | F3 | F4 | F5 | F6 | _ | + | { | } | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | F7 | F8 | F9 | F10 | F11 | F12 |ISO ~ |ISO | | Home | End | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[1] = LAYOUT_planck_mit(
+ KC_TILD, KC_EXLM, KC_AT, KC_HASH, KC_DLR, KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_BSPC,
+ KC_DEL, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_UNDS, KC_PLUS, KC_LCBR, KC_RCBR, KC_PIPE,
+ _______, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, S(KC_NUHS), S(KC_NUBS), KC_HOME, KC_END, _______,
+ _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY
+),
+
+/* Raise
+ * ,-----------------------------------------------------------------------------------.
+ * | ` | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Del | F1 | F2 | F3 | F4 | F5 | F6 | - | = | [ | ] | \ |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | F7 | F8 | F9 | F10 | F11 | F12 |ISO # |ISO / |Pg Up |Pg Dn | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[2] = LAYOUT_planck_mit(
+ KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_BSPC,
+ KC_DEL, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_MINS, KC_EQL, KC_LBRC, KC_RBRC, KC_BSLS,
+ _______, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_NUHS, KC_NUBS, KC_PGUP, KC_PGDN, _______,
+ _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY
+),
+
+/* Adjust (Lower + Raise)
+ * v------------------------RGB CONTROL--------------------v
+ * ,-----------------------------------------------------------------------------------.
+ * | | Reset|Debug | RGB |RGBMOD| HUE+ | HUE- | SAT+ | SAT- |BRGTH+|BRGTH-| Del |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | | | | | | | | | | |
+ * `-----------------------------------------------------------------------------------'
+ */
+[3] = LAYOUT_planck_mit(
+ _______, QK_BOOT, DB_TOGG, RGB_TOG, RGB_MOD, RGB_HUI, RGB_HUD, RGB_SAI, RGB_SAD, RGB_VAI, RGB_VAD, KC_DEL,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
+ _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______
+)
+
+};
diff --git a/keyboards/kprepublic/cstc40/keymaps/via/rules.mk b/keyboards/kprepublic/cstc40/keymaps/via/rules.mk
new file mode 100644
index 00000000000..1e5b99807cb
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/keymaps/via/rules.mk
@@ -0,0 +1 @@
+VIA_ENABLE = yes
diff --git a/keyboards/kprepublic/cstc40/mcuconf.h b/keyboards/kprepublic/cstc40/mcuconf.h
new file mode 100644
index 00000000000..a56e52fb8da
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/mcuconf.h
@@ -0,0 +1,21 @@
+/* Copyright 2020 Nick Brassel (tzarc)
+ *
+ * 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 3 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 .
+ */
+#pragma once
+
+#include_next
+
+#undef STM32_I2C_USE_I2C1
+#define STM32_I2C_USE_I2C1 TRUE
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/readme.md b/keyboards/kprepublic/cstc40/readme.md
new file mode 100644
index 00000000000..211c078cc2e
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/readme.md
@@ -0,0 +1,26 @@
+# cstc40
+
+A 40% hotswap ortholinear RGB keyboard from KP Republic.
+
+* Keyboard Maintainer: [Var](https://github.com/itsvar8)
+* Hardware Supported: CSTC40
+* Hardware Availability: kprepublic.com
+
+The differences between the two versions are just the rows and columns pins and the additional small pcb for the daughterboard version.
+
+Make example for this keyboard (after setting up your build environment):
+
+ for daughterboard version: make kprepublic/cstc40/daughterboard:default
+ for single pcb version: make kprepublic/cstc40/single_pcb:default
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).
+
+## Bootloader
+
+Enter the bootloader in 3 ways:
+
+* **Bootmagic reset**: Hold down the key at (0,0) in the matrix (usually the top left key or Escape) and plug in the keyboard
+* **Physical reset button**: Briefly press the button on the back of the PCB - some may have pads you must short instead
+* **Keycode in layout**: Press the key mapped to `QK_BOOT` if it is available
+
+The single_pcb uses pin A10, which apparently is a design flaw that prevent the bootloader to start every time - https://docs.qmk.fm/#/platformdev_blackpill_f4x1?id=pins-to-be-avoided. There is a simple workaround that works most of the time - press the pin key (generally the letter R) during the boot.
diff --git a/keyboards/kprepublic/cstc40/single_pcb/info.json b/keyboards/kprepublic/cstc40/single_pcb/info.json
new file mode 100644
index 00000000000..330ada7bac5
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/single_pcb/info.json
@@ -0,0 +1,6 @@
+{
+ "matrix_pins": {
+ "cols": ["C7", "C8", "C9", "A8", "A10", "B10", "A15", "C13", "B6", "B5", "B4", "B3"],
+ "rows": ["C12", "C10", "C11", "B0"]
+ }
+}
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/single_pcb/rules.mk b/keyboards/kprepublic/cstc40/single_pcb/rules.mk
new file mode 100644
index 00000000000..7ff128fa692
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/single_pcb/rules.mk
@@ -0,0 +1 @@
+# This file intentionally left blank
\ No newline at end of file
diff --git a/keyboards/kprepublic/cstc40/single_pcb/single_pcb.c b/keyboards/kprepublic/cstc40/single_pcb/single_pcb.c
new file mode 100644
index 00000000000..39d3d7ff528
--- /dev/null
+++ b/keyboards/kprepublic/cstc40/single_pcb/single_pcb.c
@@ -0,0 +1,71 @@
+/* Copyright 2022 bdtc123
+ *
+ * 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 .
+ */
+#include "quantum.h"
+
+#ifdef RGB_MATRIX_ENABLE
+const is31_led g_is31_leds[RGB_MATRIX_LED_COUNT] = {
+ { 0, L_1, K_1, J_1 },
+ { 0, L_2, K_2, J_2 },
+ { 0, L_3, K_3, J_3 },
+ { 0, L_4, K_4, J_4 },
+ { 0, L_5, K_5, J_5 },
+ { 0, L_6, K_6, J_6 },
+ { 0, L_7, K_7, J_7 },
+ { 0, L_8, K_8, J_8 },
+ { 0, L_9, K_9, J_9 },
+ { 0, L_10, K_10, J_10 },
+ { 0, L_11, K_11, J_11 },
+ { 0, L_12, K_12, J_12 },
+
+ { 0, I_1, H_1, G_1 },
+ { 0, I_2, H_2, G_2 },
+ { 0, I_3, H_3, G_3 },
+ { 0, I_4, H_4, G_4 },
+ { 0, I_5, H_5, G_5 },
+ { 0, I_6, H_6, G_6 },
+ { 0, I_7, H_7, G_7 },
+ { 0, I_8, H_8, G_8 },
+ { 0, I_9, H_9, G_9 },
+ { 0, I_10, H_10, G_10 },
+ { 0, I_11, H_11, G_11 },
+ { 0, I_12, H_12, G_12 },
+
+ { 0, F_1, E_1, D_1 },
+ { 0, F_2, E_2, D_2 },
+ { 0, F_3, E_3, D_3 },
+ { 0, F_4, E_4, D_4 },
+ { 0, F_5, E_5, D_5 },
+ { 0, F_6, E_6, D_6 },
+ { 0, F_7, E_7, D_7 },
+ { 0, F_8, E_8, D_8 },
+ { 0, F_9, E_9, D_9 },
+ { 0, F_10, E_10, D_10 },
+ { 0, F_11, E_11, D_11 },
+ { 0, F_12, E_12, D_12 },
+
+ { 0, C_1, B_1, A_1 },
+ { 0, C_2, B_2, A_2 },
+ { 0, C_3, B_3, A_3 },
+ { 0, C_4, B_4, A_4 },
+ { 0, C_5, B_5, A_5 },
+ { 0, C_6, B_6, A_6 },
+ { 0, C_8, B_8, A_8 },
+ { 0, C_9, B_9, A_9 },
+ { 0, C_10, B_10, A_10 },
+ { 0, C_11, B_11, A_11 },
+ { 0, C_12, B_12, A_12 }
+};
+#endif
\ No newline at end of file