diff --git a/cli.py b/cli.py
new file mode 100755
index 0000000..1fa45bb
--- /dev/null
+++ b/cli.py
@@ -0,0 +1,286 @@
+#!/usr/bin/env python3
+"""
+LED Bar Configuration CLI Tool
+
+Command-line interface for downloading, editing, and uploading settings.json
+to/from MicroPython devices via mpremote.
+"""
+
+import json
+import argparse
+import sys
+from typing import Dict, Any, List
+
+# Import functions from tool.py
+import tempfile
+import subprocess
+import os
+
+
+def _run_mpremote_copy(from_device: bool, device: str, temp_path: str) -> None:
+    """Run mpremote copy command."""
+    if from_device:
+        cmd = ["mpremote", "connect", device, "cp", ":/settings.json", temp_path]
+    else:
+        cmd = ["mpremote", "connect", device, "cp", temp_path, ":/settings.json"]
+
+    result = subprocess.run(cmd, capture_output=True, text=True, timeout=10)
+    if result.returncode != 0:
+        raise RuntimeError(f"mpremote error: {result.stderr.strip() or result.stdout.strip()}")
+
+
+def download_settings(device: str) -> dict:
+    """Download settings.json from the device using mpremote."""
+    temp_file = tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False)
+    temp_path = temp_file.name
+    temp_file.close()
+
+    try:
+        _run_mpremote_copy(from_device=True, device=device, temp_path=temp_path)
+        with open(temp_path, "r", encoding="utf-8") as f:
+            return json.load(f)
+    finally:
+        if os.path.exists(temp_path):
+            try:
+                os.unlink(temp_path)
+            except OSError:
+                pass
+
+
+def upload_settings(device: str, settings: dict) -> None:
+    """Upload settings.json to the device using mpremote and reset device."""
+    temp_file = tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False)
+    temp_path = temp_file.name
+
+    try:
+        json.dump(settings, temp_file, indent=2)
+        temp_file.close()
+
+        _run_mpremote_copy(from_device=False, device=device, temp_path=temp_path)
+
+        # Reset device (best effort)
+        try:
+            import serial  # type: ignore
+
+            with serial.Serial(device, baudrate=115200) as ser:
+                ser.write(b"\x03\x03\x04")
+        except Exception:
+            reset_cmd = [
+                "mpremote",
+                "connect",
+                device,
+                "exec",
+                "import machine; machine.reset()",
+            ]
+            try:
+                subprocess.run(reset_cmd, capture_output=True, text=True, timeout=5)
+            except subprocess.TimeoutExpired:
+                pass
+    finally:
+        if os.path.exists(temp_path):
+            try:
+                os.unlink(temp_path)
+            except OSError:
+                pass
+
+
+def parse_colors(color_string: str) -> List[tuple]:
+    """
+    Parse color string into list of RGB tuples.
+    Format: "r,g,b" or "r,g,b;r2,g2,b2" for multiple colors
+    """
+    colors = []
+    for color_part in color_string.split(";"):
+        parts = color_part.strip().split(",")
+        if len(parts) == 3:
+            try:
+                r = int(parts[0].strip())
+                g = int(parts[1].strip())
+                b = int(parts[2].strip())
+                colors.append((r, g, b))
+            except ValueError:
+                raise ValueError(f"Invalid color format: {color_part}. Expected 'r,g,b'")
+        else:
+            raise ValueError(f"Invalid color format: {color_part}. Expected 'r,g,b'")
+    return colors
+
+
+def print_settings(settings: Dict[str, Any]) -> None:
+    """Pretty print settings dictionary."""
+    print(json.dumps(settings, indent=2))
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="LED Bar Configuration CLI Tool",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+  # Download and print current settings
+  %(prog)s
+
+  # Download, edit device name and brightness, then upload
+  %(prog)s -n "LED-Strip-1" -b 128
+
+  # Set colors (format: r,g,b or r,g,b;r2,g2,b2 for multiple)
+  %(prog)s -c "255,0,0;0,255,0;0,0,255"
+
+  # Set multiple parameters
+  %(prog)s -n "MyLED" -b 200 --preset "rainbow" -n1 10 -n2 20
+
+  # Set number of LEDs, color order, and debug mode
+  %(prog)s -l 60 -o rgb -d 1
+        """
+    )
+
+    parser.add_argument(
+        "-p", "--port",
+        default="/dev/ttyACM0",
+        help="Serial port/device path (default: /dev/ttyACM0)"
+    )
+
+    parser.add_argument(
+        "-n", "--name",
+        help="Device name"
+    )
+
+    parser.add_argument(
+        "-b", "--brightness",
+        type=int,
+        help="Brightness (0-255)"
+    )
+
+    parser.add_argument(
+        "-l", "--leds",
+        type=int,
+        help="Number of LEDs"
+    )
+
+    parser.add_argument(
+        "-d", "--debug",
+        type=int,
+        choices=[0, 1],
+        help="Debug mode (0 or 1)"
+    )
+
+    parser.add_argument(
+        "-o", "--color-order",
+        choices=["rgb", "rbg", "grb", "gbr", "brg", "bgr"],
+        help="Color order (rgb, rbg, grb, gbr, brg, bgr)"
+    )
+
+    parser.add_argument(
+        "--preset",
+        help="Pattern preset name"
+    )
+
+    parser.add_argument(
+        "-c", "--colors",
+        help="Colors in format 'r,g,b' or 'r,g,b;r2,g2,b2' for multiple colors"
+    )
+
+    # Add n1 through n8 parameters
+    for i in range(1, 9):
+        parser.add_argument(
+            f"-n{i}",
+            type=int,
+            help=f"N{i} parameter"
+        )
+
+    parser.add_argument(
+        "--no-upload",
+        action="store_true",
+        help="Don't upload settings after editing (only download and print)"
+    )
+
+    parser.add_argument(
+        "--no-download",
+        action="store_true",
+        help="Don't download settings first (use empty settings)"
+    )
+
+    args = parser.parse_args()
+
+    # Collect all edit parameters
+    edits: Dict[str, Any] = {}
+
+    if args.name is not None:
+        edits["name"] = args.name
+
+    if args.brightness is not None:
+        edits["brightness"] = args.brightness
+
+    if args.leds is not None:
+        edits["num_leds"] = args.leds
+
+    if args.debug is not None:
+        edits["debug"] = bool(args.debug)
+
+    if args.color_order is not None:
+        edits["color_order"] = args.color_order
+
+    if args.preset is not None:
+        edits["pattern"] = args.preset
+
+    if args.colors is not None:
+        colors = parse_colors(args.colors)
+        edits["colors"] = colors
+
+    # Add n1-n8 parameters
+    for i in range(1, 9):
+        attr_name = f"n{i}"
+        value = getattr(args, attr_name, None)
+        if value is not None:
+            edits[attr_name] = value
+
+    # Download current settings (unless --no-download is specified)
+    if args.no_download:
+        settings = {}
+    else:
+        try:
+            print(f"Downloading settings from {args.port}...", file=sys.stderr)
+            settings = download_settings(args.port)
+            print("Settings downloaded successfully.", file=sys.stderr)
+        except FileNotFoundError:
+            print("Error: mpremote not found. Install with: pip install mpremote", file=sys.stderr)
+            sys.exit(1)
+        except subprocess.TimeoutExpired:
+            print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
+            sys.exit(1)
+        except Exception as e:
+            print(f"Error downloading settings: {e}", file=sys.stderr)
+            sys.exit(1)
+
+    # Apply edits
+    if edits:
+        print(f"Applying {len(edits)} edit(s)...", file=sys.stderr)
+        settings.update(edits)
+        # Handle colors specially - convert list of tuples to format expected by device
+        if "colors" in edits:
+            # Store colors as list of lists for JSON serialization
+            settings["colors"] = [list(c) for c in edits["colors"]]
+
+    # Print settings
+    print_settings(settings)
+
+    # Upload if edits were made and --no-upload is not specified
+    if edits and not args.no_upload:
+        try:
+            print(f"\nUploading settings to {args.port}...", file=sys.stderr)
+            upload_settings(args.port, settings)
+            print("Settings uploaded successfully. Device will reset.", file=sys.stderr)
+        except FileNotFoundError:
+            print("Error: mpremote not found. Install with: pip install mpremote", file=sys.stderr)
+            sys.exit(1)
+        except subprocess.TimeoutExpired:
+            print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
+            sys.exit(1)
+        except Exception as e:
+            print(f"Error uploading settings: {e}", file=sys.stderr)
+            sys.exit(1)
+    elif edits and args.no_upload:
+        print("\nSettings modified but not uploaded (--no-upload specified).", file=sys.stderr)
+
+
+if __name__ == "__main__":
+    main()