diff --git a/keyboards/ai03/altair_x/config.h b/keyboards/ai03/altair_x/config.h
new file mode 100644
index 000000000000..c54b35498b50
--- /dev/null
+++ b/keyboards/ai03/altair_x/config.h
@@ -0,0 +1,12 @@
+/* Copyright 2024 ai03 Design Studio */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+/* VBUS-routed pin for upstream detection */
+#define USB_VBUS_PIN GP0
+
+/* RP2040- and hardware-specific config */
+#define RP2040_BOOTLOADER_DOUBLE_TAP_RESET
+#define RP2040_BOOTLOADER_DOUBLE_TAP_RESET_TIMEOUT 500U
+#define PICO_XOSC_STARTUP_DELAY_MULTIPLIER 64
diff --git a/keyboards/ai03/altair_x/keyboard.json b/keyboards/ai03/altair_x/keyboard.json
new file mode 100644
index 000000000000..d1448ab8c2f0
--- /dev/null
+++ b/keyboards/ai03/altair_x/keyboard.json
@@ -0,0 +1,104 @@
+{
+    "manufacturer": "ai03 Design Studio",
+    "keyboard_name": "Altair-X",
+    "maintainer": "ai03_2725",
+    "bootloader": "rp2040",
+    "build": {
+        "debounce_type": "asym_eager_defer_pk"
+    },
+    "diode_direction": "COL2ROW",
+    "dynamic_keymap": {
+        "layer_count": 6
+    },
+    "features": {
+        "bootmagic": true,
+        "command": false,
+        "console": false,
+        "extrakey": true,
+        "mousekey": true,
+        "nkro": true
+    },
+    "matrix_pins": {
+        "cols": ["GP20", "GP19", "GP18", "GP17", "GP16", "GP21", "GP9"],
+        "rows": ["GP26", "GP27", "GP28", "GP10"]
+    },
+    "processor": "RP2040",
+    "split": {
+        "bootmagic": {
+            "matrix": [4, 0]
+        },
+        "enabled": true,
+        "handedness": {
+            "pin": "GP8"
+        },
+        "matrix_pins": {
+            "right": {
+                "cols": ["GP15", "GP21", "GP9", "GP13", "GP10", "GP11", "GP12"],
+                "rows": ["GP16", "GP20", "GP28", "GP14"]
+            }
+        },
+        "soft_serial_pin": "GP29"
+    },
+    "url": "https://ai03.com/",
+    "usb": {
+        "device_version": "0.0.1",
+        "pid": "0x0023",
+        "vid": "0xA103"
+    },
+    "layouts": {
+        "LAYOUT": {
+            "layout": [
+                {"matrix": [0, 0], "x": 0, "y": 0.38},
+                {"matrix": [0, 1], "x": 1, "y": 0.38},
+                {"matrix": [0, 2], "x": 2, "y": 0.13},
+                {"matrix": [0, 3], "x": 3, "y": 0},
+                {"matrix": [0, 4], "x": 4, "y": 0.13},
+                {"matrix": [0, 5], "x": 5, "y": 0.25},
+                {"matrix": [0, 6], "x": 6, "y": 0.5},
+                {"matrix": [4, 0], "x": 7.75, "y": 0.5},
+                {"matrix": [4, 1], "x": 8.75, "y": 0.25},
+                {"matrix": [4, 2], "x": 9.75, "y": 0.13},
+                {"matrix": [4, 3], "x": 10.75, "y": 0},
+                {"matrix": [4, 4], "x": 11.75, "y": 0.13},
+                {"matrix": [4, 5], "x": 12.75, "y": 0.38},
+                {"matrix": [4, 6], "x": 13.75, "y": 0.38},
+                {"matrix": [1, 0], "x": 0, "y": 1.38},
+                {"matrix": [1, 1], "x": 1, "y": 1.38},
+                {"matrix": [1, 2], "x": 2, "y": 1.13},
+                {"matrix": [1, 3], "x": 3, "y": 1},
+                {"matrix": [1, 4], "x": 4, "y": 1.13},
+                {"matrix": [1, 5], "x": 5, "y": 1.25},
+                {"matrix": [1, 6], "x": 6, "y": 1.5},
+                {"matrix": [5, 0], "x": 7.75, "y": 1.5},
+                {"matrix": [5, 1], "x": 8.75, "y": 1.25},
+                {"matrix": [5, 2], "x": 9.75, "y": 1.13},
+                {"matrix": [5, 3], "x": 10.75, "y": 1},
+                {"matrix": [5, 4], "x": 11.75, "y": 1.13},
+                {"matrix": [5, 5], "x": 12.75, "y": 1.38},
+                {"matrix": [5, 6], "x": 13.75, "y": 1.38},
+                {"matrix": [2, 0], "x": 0, "y": 2.38},
+                {"matrix": [2, 1], "x": 1, "y": 2.38},
+                {"matrix": [2, 2], "x": 2, "y": 2.13},
+                {"matrix": [2, 3], "x": 3, "y": 2},
+                {"matrix": [2, 4], "x": 4, "y": 2.13},
+                {"matrix": [2, 5], "x": 5, "y": 2.25},
+                {"matrix": [2, 6], "x": 6, "y": 2.5},
+                {"matrix": [6, 0], "x": 7.75, "y": 2.5},
+                {"matrix": [6, 1], "x": 8.75, "y": 2.25},
+                {"matrix": [6, 2], "x": 9.75, "y": 2.13},
+                {"matrix": [6, 3], "x": 10.75, "y": 2},
+                {"matrix": [6, 4], "x": 11.75, "y": 2.13},
+                {"matrix": [6, 5], "x": 12.75, "y": 2.38},
+                {"matrix": [6, 6], "x": 13.75, "y": 2.38},
+                {"matrix": [3, 3], "x": 2.71, "y": 3.13},
+                {"matrix": [3, 4], "x": 3.73, "y": 3.16},
+                {"matrix": [3, 5], "x": 4.74, "y": 3.36},
+                {"matrix": [3, 6], "x": 5.75, "y": 3.72},
+                {"matrix": [7, 0], "x": 8, "y": 3.72},
+                {"matrix": [7, 1], "x": 9.02, "y": 3.36},
+                {"matrix": [7, 2], "x": 10.03, "y": 3.18},
+                {"matrix": [7, 3], "x": 11.05, "y": 3.13}
+            ]
+        }
+    }
+}
diff --git a/keyboards/ai03/altair_x/keymaps/default/keymap.c b/keyboards/ai03/altair_x/keymaps/default/keymap.c
new file mode 100644
index 000000000000..8eb350993da3
--- /dev/null
+++ b/keyboards/ai03/altair_x/keymaps/default/keymap.c
@@ -0,0 +1,29 @@
+/* Copyright 2024 ai03 Design Studio */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+    [0] = LAYOUT(
+        KC_ESC,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    XXXXXXX, XXXXXXX, KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_BSPC,
+        KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    XXXXXXX, XXXXXXX, KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT,
+        KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    XXXXXXX, XXXXXXX, KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_ENT,
+                                   KC_LGUI, KC_LALT, MO(1),   KC_SPC,  KC_SPC,  MO(2),   KC_TAB,  KC_DEL
+    ),
+
+    [1] = LAYOUT(
+        _______, KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    _______, _______, KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    _______,
+        _______, KC_GRV,  KC_LBRC, KC_LCBR, KC_LPRN, KC_MINS, _______, _______, KC_EQL,  KC_RPRN, KC_RCBR, KC_RBRC, KC_BSLS, _______,
+        _______, KC_TILD, _______, _______, _______, KC_UNDS, _______, _______, KC_PLUS, _______, _______, _______, KC_PIPE, _______,
+                                   _______, _______, _______, _______, _______, _______, _______, _______
+    ),
+
+    [2] = LAYOUT(
+        _______, _______, _______, KC_PGUP, _______, _______, _______, _______, _______, _______, KC_UP,   _______, _______, _______,
+        _______, _______, KC_HOME, KC_PGDN, KC_END,  _______, _______, _______, _______, KC_LEFT, KC_DOWN, KC_RGHT, _______, _______,
+        _______, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  _______,
+                                   _______, _______, _______, _______, _______, _______, _______, _______
+    )
+
+};
diff --git a/keyboards/ai03/altair_x/keymaps/via/keymap.c b/keyboards/ai03/altair_x/keymaps/via/keymap.c
new file mode 100644
index 000000000000..8eb350993da3
--- /dev/null
+++ b/keyboards/ai03/altair_x/keymaps/via/keymap.c
@@ -0,0 +1,29 @@
+/* Copyright 2024 ai03 Design Studio */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+    [0] = LAYOUT(
+        KC_ESC,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    XXXXXXX, XXXXXXX, KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_BSPC,
+        KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    XXXXXXX, XXXXXXX, KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT,
+        KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    XXXXXXX, XXXXXXX, KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_ENT,
+                                   KC_LGUI, KC_LALT, MO(1),   KC_SPC,  KC_SPC,  MO(2),   KC_TAB,  KC_DEL
+    ),
+
+    [1] = LAYOUT(
+        _______, KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    _______, _______, KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    _______,
+        _______, KC_GRV,  KC_LBRC, KC_LCBR, KC_LPRN, KC_MINS, _______, _______, KC_EQL,  KC_RPRN, KC_RCBR, KC_RBRC, KC_BSLS, _______,
+        _______, KC_TILD, _______, _______, _______, KC_UNDS, _______, _______, KC_PLUS, _______, _______, _______, KC_PIPE, _______,
+                                   _______, _______, _______, _______, _______, _______, _______, _______
+    ),
+
+    [2] = LAYOUT(
+        _______, _______, _______, KC_PGUP, _______, _______, _______, _______, _______, _______, KC_UP,   _______, _______, _______,
+        _______, _______, KC_HOME, KC_PGDN, KC_END,  _______, _______, _______, _______, KC_LEFT, KC_DOWN, KC_RGHT, _______, _______,
+        _______, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  _______,
+                                   _______, _______, _______, _______, _______, _______, _______, _______
+    )
+
+};
diff --git a/keyboards/ai03/altair_x/keymaps/via/rules.mk b/keyboards/ai03/altair_x/keymaps/via/rules.mk
new file mode 100644
index 000000000000..1e5b99807cb7
--- /dev/null
+++ b/keyboards/ai03/altair_x/keymaps/via/rules.mk
@@ -0,0 +1 @@
+VIA_ENABLE = yes
diff --git a/keyboards/ai03/altair_x/readme.md b/keyboards/ai03/altair_x/readme.md
new file mode 100644
index 000000000000..221a46155626
--- /dev/null
+++ b/keyboards/ai03/altair_x/readme.md
@@ -0,0 +1,19 @@
+# Altair-X
+
+![altair-x](https://i.imgur.com/regfKQC.png)
+
+ai03's third-generation ergonomic keyboard, 4-row variant  
+
+* Keyboard Maintainer: [ai03](https://github.com/ai03-2725)
+* Hardware Supported: Altair-X keyboard PCB
+* Hardware Availability: Group buy
+
+Make example for this keyboard (after setting up your build environment):
+
+    make ai03/altair_x:default
+
+Flashing example for this keyboard:
+
+    make ai03/altair_x:default:flash
+
+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).
diff --git a/keyboards/ai03/altair_x/rules.mk b/keyboards/ai03/altair_x/rules.mk
new file mode 100644
index 000000000000..161ec22b16e2
--- /dev/null
+++ b/keyboards/ai03/altair_x/rules.mk
@@ -0,0 +1 @@
+SERIAL_DRIVER = vendor