MCPal

Lightweight MCP server for native desktop notifications with action buttons, text replies, and LLM-aware icons.
Compatible with any MCP client.

Usage

Add to your MCP Config manually:

// JSON
{
  "mcpServers": {
    "mcpal": {
      "command": "npx",
      "args": ["mcpal@latest"]
    }
  }
}

Or TOML (Codex):

// TOML
[mcp_servers.mcpal]
command = "npx"
args = ["-y", "mcpal@latest"]

Codex CLI

Add MCPal directly via the CLI:

codex mcp add mcpal -- npx -y mcpal@latest

Claude Code

Add MCPal directly via the CLI:

# Project scope (current project only)
claude mcp add mcpal -- npx -y mcpal@latest

# User scope (available in all projects)
claude mcp add mcpal --scope user -- npx -y mcpal@latest

Configuring Proactive Notifications

MCPal includes built-in MCP instructions that tell clients how to use notifications. To configure when your assistant should proactively notify you, add this to your client instruction file. This should either be AGENTS.md or CLAUDE.md based on your model:

## Post Task Completion Hook

ALWAYS use MCPal MCP tool (if available) to notify me when you finish any tasks (this includes reading files, investigating, coding). You should use this tool before you terminate conversations. Refer to tool instructions precisely to craft your response.

Customize this based on your preferences - some users want frequent updates, others only want notifications for important decisions.

Other MCP Clients

MCPal works with any MCP-compatible client (Cursor, VS Code with MCP extensions, etc.). The setup varies by client - refer to your client's documentation for adding MCP servers.

Tool: send_notification

Send native notifications with optional features.

Parameters

Parameter	Type	Required	Description
message	string	Yes	The notification body text
title	string	No	The notification title (default: "MCPal")
actions	string[]	No	Action buttons (e.g., ["Yes", "No", "Maybe"])
dropdownLabel	string	No	Label for actions dropdown (required for multiple actions)
reply	boolean	No	Enable text reply input

Examples

Simple notification:

{
  "message": "Build complete!",
  "title": "CI/CD"
}

With actions:

{
  "message": "Deploy to production?",
  "title": "Deployment",
  "actions": ["Deploy", "Cancel"],
  "dropdownLabel": "Choose"
}

With reply:

{
  "message": "What should I name this file?",
  "title": "Question",
  "reply": true
}

You can reply directly from the notification without switching apps:

Tool Result Contract

send_notification now returns a dual contract:

• Canonical machine output via structuredContent (recommended for parsing)
• Backward-compatible text output in content[0].text

Structured fields:

• status: "sent" or "error"
• title?: Notification title
• message?: Message actually sent after sanitization
• response?: Notification response ("timeout", clicked action, etc.)
• activationType?: Activation source ("replied", "actionClicked", etc.)
• reply?: User free-form reply
• error?: Error message when status is "error"
• sanitized?: true when MCPal had to sanitize or truncate inputs

Legacy text is still line-based, but each value is JSON-encoded on a single line for parser safety, for example:

status: "sent"
title: "MCPal"
message: "Line 1\nLine 2"
response: "timeout"

Input Sanitization

Before delivery, MCPal applies best-effort sanitization to reduce notifier/parser failures:

• Normalize line endings: \r\n / \r -> \n
• Remove unsafe control chars (keeps \n and \t)
• Truncate limits:
  • title: 256 chars
  • message: 4000 chars
  • actions: max 3 items, each 64 chars
  • dropdownLabel: 64 chars

LLM-Aware Icons

MCPal detects which MCP client is calling the tool and displays the appropriate icon in notifications.

Client	Icon
Claude Desktop / Claude Code / Opus	Claude logo
Codex / OpenAI / ChatGPT	OpenAI logo
Cursor	Cursor logo
VS Code	VS Code logo
Unknown	No icon

This works via the MCP protocol's client identification - each client sends its name during initialization.

Adding New Client Icons

To add support for a new LLM client, add a PNG to src/assets/clients/ and update the mapping in src/notify.config.ts.

Icon Specifications:

Property	Requirement
Format	PNG with transparency (RGBA)
Dimensions	128×128 pixels
File size	<10KB (use pngquant for compression)

# Optimize a new icon
convert input.png -resize 128x128 -background none -gravity center -extent 128x128 temp.png
pngquant --quality=65-80 --output src/assets/clients/newclient.png temp.png
rm temp.png

Custom App Icon

The package includes a custom notification icon that replaces the default Terminal icon on desktop. This is automatically configured during installation via the postinstall script.

Notification Permissions

After the first notification, your system may prompt you to allow notifications from "MCPal". You can manage this in:

System Settings > Notifications > MCPal

Development

# Install dependencies
pnpm install

# Build (required after clone - sets up desktop notification app)
pnpm run build

# Type check
pnpm run typecheck

# Lint
pnpm run lint:fix

# Format
pnpm run format:fix

MCP Inspector

Test the MCP server interactively using the official inspector:

pnpx @modelcontextprotocol/inspector node dist/index.js

This opens a web UI where you can:

• View available tools and their schemas
• Send test notifications with different parameters
• See raw MCP protocol messages

Local Dev Troubleshooting

If you run a local build directly from dist/index.js and notifications are not working, make sure the entrypoint is executable:

chmod +x dist/index.js

Testing Notifications

Test the notification system directly without running the MCP server:

# Simple notification (default)
pnpm run test:notification

# With action buttons
pnpm run test:notification actions

# With reply input
pnpm run test:notification reply

# Run all tests
pnpm run test:notification all

License

Code: MIT License

MCPal Icon & Branding: © 2025 All Rights Reserved. The MCPal logo and icon designs may not be used without permission.