diff --git a/libs/python/mcp-server/build-extension.py b/libs/python/mcp-server/build-extension.py
index 10c00646..0ea644ca 100755
--- a/libs/python/mcp-server/build-extension.py
+++ b/libs/python/mcp-server/build-extension.py
@@ -15,6 +15,7 @@ Usage:
 
 import os
 import shutil
+import subprocess
 import sys
 import tempfile
 import zipfile
@@ -37,7 +38,7 @@ def main():
     # Required files to copy
     files_to_copy = {
         "manifest.json": output_dir / "manifest.json",
-        "logo_black.png": output_dir / "logo_black.png",
+        "desktop_extension.png": output_dir / "desktop_extension.png",
         "requirements.txt": output_dir / "requirements.txt",
         "run_server.sh": output_dir / "run_server.sh",
         "setup.py": output_dir / "setup.py",
@@ -106,6 +107,59 @@ def main():
         print(f"✓ Build complete: {output_file}")
         print(f"  Archive size: {output_file.stat().st_size / 1024:.1f} KB")
 
+        # Set custom file icon based on platform
+        icon_file = output_dir / "desktop_extension.png"
+        if sys.platform == "darwin":
+            _set_icon_macos(output_file, icon_file)
+        elif sys.platform == "win32":
+            _set_icon_windows(output_file, icon_file)
+        elif sys.platform.startswith("linux"):
+            _set_icon_linux(output_file, icon_file)
+
+
+def _set_icon_macos(output_file: Path, icon_file: Path):
+    """Set custom file icon on macOS."""
+    try:
+        # Check if fileicon is installed
+        result = subprocess.run(["which", "fileicon"], capture_output=True, text=True)
+        if result.returncode == 0:
+            # Use the logo as the file icon
+            if icon_file.exists():
+                print("  Setting custom file icon (macOS)...")
+                subprocess.run(
+                    ["fileicon", "set", str(output_file), str(icon_file)],
+                    check=False,
+                    capture_output=True,
+                )
+                print("    ✓ File icon set")
+            else:
+                print(f"    ⚠ Icon file not found: {icon_file}")
+        else:
+            print("  ⚠ fileicon not installed (optional - for custom file icon)")
+            print("    Install with: brew install fileicon")
+    except Exception as e:
+        print(f"  ⚠ Could not set file icon: {e}")
+
+
+def _set_icon_windows(output_file: Path, icon_file: Path):
+    """Set custom file icon on Windows."""
+    try:
+        # Windows uses a desktop.ini approach, which is complex
+        # For simplicity, we'll skip this for now
+        print("  ⚠ Custom file icons not supported on Windows yet")
+    except Exception as e:
+        print(f"  ⚠ Could not set file icon: {e}")
+
+
+def _set_icon_linux(output_file: Path, icon_file: Path):
+    """Set custom file icon on Linux."""
+    try:
+        # Linux uses .desktop files and thumbnail generation
+        # This is complex and depends on the desktop environment
+        print("  ⚠ Custom file icons not supported on Linux yet")
+    except Exception as e:
+        print(f"  ⚠ Could not set file icon: {e}")
+
 
 if __name__ == "__main__":
     main()
diff --git a/libs/python/mcp-server/desktop-extension/README.md b/libs/python/mcp-server/desktop-extension/README.md
index 42b1f92b..b03861ee 100644
--- a/libs/python/mcp-server/desktop-extension/README.md
+++ b/libs/python/mcp-server/desktop-extension/README.md
@@ -16,6 +16,9 @@ This will:
 1. Copy the MCP server code from `mcp_server/` directory
 2. Copy static files (manifest, icons, scripts)
 3. Create a `.mcpb` zip archive in `desktop-extension/cua-extension.mcpb`
+4. Set custom file icon (platform-specific):
+   - macOS: Uses `fileicon` (install with `brew install fileicon`)
+   - Windows/Linux: Not yet supported
 
 ## Directory Structure
 
@@ -23,11 +26,11 @@ This will:
 desktop-extension/
 ├── README.md              # This file
 ├── manifest.json          # Extension manifest
-├── logo_black.png         # Extension icon
+├── desktop_extension.png  # Extension icon
 ├── requirements.txt       # Python dependencies
 ├── run_server.sh          # Server launcher script
 ├── setup.py               # Dependency installer
-└── cua-extension.mcpb     # Generated extension archive (gitignored)
+└── cua-extension.mcpb     # Generated extension archive
 ```
 
 ## Source Files
@@ -42,7 +45,7 @@ The actual MCP server code lives in `../mcp_server/`:
 These files are maintained in this directory:
 
 - `manifest.json` - Extension metadata and configuration
-- `logo_black.png` - Extension icon
+- `desktop_extension.png` - Extension icon
 - `requirements.txt` - Python package dependencies
 - `run_server.sh` - Shell script to launch the server
 - `setup.py` - Python script to install dependencies
diff --git a/libs/python/mcp-server/desktop-extension/cua-extension.mcpb b/libs/python/mcp-server/desktop-extension/cua-extension.mcpb
index 5ff52e5a..731c00dd 100644
Binary files a/libs/python/mcp-server/desktop-extension/cua-extension.mcpb and b/libs/python/mcp-server/desktop-extension/cua-extension.mcpb differ
diff --git a/libs/python/mcp-server/desktop-extension/desktop_extension.png b/libs/python/mcp-server/desktop-extension/desktop_extension.png
new file mode 100644
index 00000000..c2bbf0fc
Binary files /dev/null and b/libs/python/mcp-server/desktop-extension/desktop_extension.png differ
diff --git a/libs/python/mcp-server/desktop-extension/logo_black.png b/libs/python/mcp-server/desktop-extension/logo_black.png
deleted file mode 100644
index 875ac79f..00000000
Binary files a/libs/python/mcp-server/desktop-extension/logo_black.png and /dev/null differ
diff --git a/libs/python/mcp-server/desktop-extension/manifest.json b/libs/python/mcp-server/desktop-extension/manifest.json
index 2a43970b..617a1bc0 100644
--- a/libs/python/mcp-server/desktop-extension/manifest.json
+++ b/libs/python/mcp-server/desktop-extension/manifest.json
@@ -17,7 +17,7 @@
   "homepage": "https://trycua.com",
   "documentation": "https://docs.trycua.com",
   "support": "https://github.com/trycua/cua/issues",
-  "icon": "logo_black.png",
+  "icon": "desktop_extension.png",
   "server": {
     "type": "python",
     "entry_point": "server.py",