MCGA - My Clipboard Guard Assistant

Clipboard parser for macOS and Windows. MCGA watches the clipboard, runs built-in and custom parsers, then shows parsed results in a popover and an auto popup.

Features

• macOS 15+ menu bar app, no Dock icon.
• Windows notification area app with auto popup, settings, single-instance replacement, and optional start at login.
• Clipboard auto-detection with hover-preserved popup.
• Current result and history in the menu bar popover.
• Copy parsed result content without copying parser titles.
• Parser settings window with Chinese / English UI, light / dark theme, and per-parser toggles.
• Built-in parsers for UUID, ObjectID, hash, CIDR, IPv4/IPv6, timestamp, HTTP status, number base, Cron, URL, JSON, JSON5, XML, TOML, YAML, HTML entity, Base64, DNS, and keyword generators.
• Custom command parsers from local scripts.

Screenshots

Popover

Settings

Windows

Installation

Download the latest DMG from the Releases page. Open the DMG and drag MCGA.app to your Applications folder.

Note: Because MCGA is an open-source tool and not signed with an Apple Developer certificate, macOS Gatekeeper may show a warning that the app "is damaged and can't be opened." You must manually remove the quarantine attribute before running it for the first time.

Open Terminal and run:

sudo xattr -rd com.apple.quarantine /Applications/MCGA.app

Enter your password when prompted. You can then open MCGA normally from Launchpad or your Applications folder.

Build

macOS

Requirements:

• macOS 15+
• Swift 6 / Xcode Command Line Tools

First, enter the macOS directory:

cd macos

Verify core parsers:

swift run MCGASmokeTests

Build the executable:

swift build --product MCGA

Package .build/MCGA.app:

bash scripts/build-macos-app.sh

Open the app:

open .build/MCGA.app

If an old version is running:

pkill MCGA
open .build/MCGA.app

After launch, click the MCGA menu bar item to view current results and history. Copy a supported value such as JSON, UUID, IP, timestamp, CIDR, HTTP status code, URL, HTML entities, XML, TOML, Base64, Cron, YAML, or a domain to trigger parsing.

Windows

Requirements:

• Windows 10/11
• .NET 8 SDK

Build and publish a self-contained single-file executable:

dotnet publish windows\MCGA.csproj -c Release -r win-x64 --self-contained true

The published executable is generated at:

windows\bin\Release\net8.0-windows\win-x64\publish\MCGA.exe

MCGA runs in the Windows notification area. If the icon is hidden under ^, pin it from Windows taskbar settings or drag it next to the other system tray icons. Start-at-login writes the current executable path to the current user's HKCU\Software\Microsoft\Windows\CurrentVersion\Run registry key.

Windows behavior:

• Closing MCGA panels hides the window; it does not quit the app.
• To quit MCGA, use Quit from the notification area icon menu.
• Starting a new MCGA process replaces the old running process.
• Enabling start at login registers the exact executable path currently running.

Custom Command Parsers

Custom parsers are loaded from:

~/.config/mcga/custom_parsers.json

Only command parsers are supported. MCGA executes the configured command, writes the clipboard text to stdin, and reads stdout:

• exit code 0 means success
• empty stdout means no result
• the first stdout line is shown as the parsed value
• multi-line stdout is preserved as result details
• stderr is ignored
• command paths support absolute paths, ~, $HOME, and ${HOME}
• commands must be executable files
• timeoutMs is clamped to 50-3000 ms, default 500 ms

Example:

{
  "parsers": [
    {
      "name": "Demo Command",
      "kind": "command",
      "description": {
        "zh": "执行本地命令解析 demo: 开头的剪切板内容。",
        "en": "Runs a local command for clipboard text starting with demo:."
      },
      "examples": [
        {
          "input": "demo:123",
          "expected": {
            "zh": "命令 stdout 的第一行会显示为解析结果。",
            "en": "The first stdout line is shown as the parsed result."
          }
        }
      ],
      "match": "^demo:",
      "command": "$HOME/.config/mcga/parsers/demo.sh",
      "args": [],
      "timeoutMs": 500,
      "enabled": true
    }
  ]
}

Example script:

#!/usr/bin/env bash
set -euo pipefail
input="$(cat)"
printf 'Parsed %s\n' "$input"
printf 'Original clipboard: %s\n' "$input"

License

MIT