Japan Price Alert MCP

japan-price-alert-mcp

Japanese EC price-change monitoring and notification MCP server for AI agents.

Overview

Monitor product prices across major Japanese e-commerce platforms (Mercari, Yahoo Auctions, Rakuten, SUUMO, Kakaku.com) and receive instant alerts on price drops.

Built on the Kensho project's price monitoring engine.

Platforms

• Mercari Japan (メルカリ) - jp.mercari.com
• Yahoo! Auctions / Shopping (ヤフオク) - auctions.yahoo.co.jp, shopping.yahoo.co.jp
• Rakuten Ichiba (楽天市場) - item.rakuten.co.jp
• SUUMO (SUUMO) - suumo.jp
• Kakaku.com (価格.com) - kakaku.com
• Suruga-ya (駿河屋) - suruga-ya.jp

Tools

Tool	Description
create_price_watch	Register a new product URL for price monitoring
list_price_watches	List all registered watches
get_price_watch	Get details of a specific watch
update_price_watch	Update watch parameters (target price, interval, etc.)
delete_price_watch	Remove a watch
check_price_watch	Force immediate price check
run_due_price_checks	Batch check all due watches
get_price_history	Get historical price data
detect_platform_url	Detect platform from URL

Installation

Smithery (Recommended)

npx @smithery/cli install atushi1841/japan_price_alert_mcp

Manual

# Clone or extract the MCPB bundle
# Configure in your MCP client:
{
  "servers": {
    "japan-price-alert-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/bundle", "src/stdio_main.py"]
    }
  }
}

Configuration

Environment Variable	Description	Default
PRICE_WATCH_DB	Custom SQLite database path	<bundle>/data/price_watch.db
TELEGRAM_BOT_TOKEN	Telegram bot token (for notifications)	-
TELEGRAM_CHAT_ID	Telegram chat ID (for notifications)	-

Usage Examples

// Create a price watch
const result = await mcp.callTool("create_price_watch", {
  user_id: "user123",
  url: "https://www.mercari.com/us/item/m123456789/",
  target_price_jpy: 5000,
  notification_channel: "telegram",
  notification_destination: "123456789",
  check_interval_minutes: 30
});

// Check a specific watch
const check = await mcp.callTool("check_price_watch", {
  watch_id: "pw_abc123"
});

// List all watches
const list = await mcp.callTool("list_price_watches", {
  user_id: "user123"
});

Alert Conditions

• lte (default): Alert when price <= target_price_jpy
• any_drop: Alert on any price decrease
• percent_drop: Alert when price drops by >= drop_percentage%
• in_stock: Alert when item comes back in stock

Notification Channels

• log (default): Log to stderr
• telegram: Send to Telegram bot (requires token + chat_id)
• webhook: POST to specified URL
• email: Log email alert (SMTP not implemented)

Dependencies

• Python >=3.10
• fastmcp >=3.0.0
• stdlib only for scraping (no external dependencies beyond fastmcp)

License

MIT

Author

atushi1841

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Data & Store

• Apify Store: https://apify.com/fruitful_quintessence
• Gumroad datasets: https://atushi5.gumroad.com/l/kutuxe