@appmonster/mcp-japan-bridge

@appmonster/mcp-japan-bridge

MCP server that turns an agent into a 일본구매대행 sourcing assistant: search Japanese marketplaces, compute the real Korea landed cost and a selling price, and draft the Smart Store listing — including the disclosures Korean consumer law requires for overseas buying-agent sales.

Built from running an actual Japan buying-agent store on Naver Smart Store. Pair it with @appmonster/mcp-naver-commerce (post the draft) or @appmonster/mcp-coupang.

Tools

Tool	What it does
jp_search_rakuten	楽天市場 keyword search — price, shop, image, reviews, stock, 送料 flag
jp_search_yahoo	Yahoo! JAPAN Shopping search — same shape, 1 req/sec
jp_fx_rate	JPY→KRW, USD→KRW mid-market rates (no key)
jp_landed_cost	Full landed cost + suggested price: FX → forwarder shipping → customs (USD 150 목록통관, 간이세율 20% or 관세+부가세) → marketplace fee → target margin. Every step explained
jp_listing_draft	Naver originProduct draft with origin 일본, lead time, 개인통관고유부호 / 관부가세 / 반품 제한 notices, and a pre-publish checklist

All tools are read-only; nothing is posted anywhere.

Example flow (agent)

• jp_search_rakuten {keyword: "ポケモン ぬいぐるみ", sort: "-reviewCount"}
• jp_fx_rate
• jp_landed_cost {priceJpy: 2980, weightKg: 0.4, jpyToKrw: 9.1, usdToKrw: 1380, targetMarginRate: 0.25} → landedCostKrw 47,000 · dutyFree true · suggestedPriceKrw 68,200 · marginKrw 17,100
• Agent writes the Korean title/description → jp_listing_draft → review → naver_create_product (naver-commerce server, coming) or paste into 스마트스토어센터.

Setup

{
  "mcpServers": {
    "japan-bridge": {
      "command": "npx",
      "args": ["-y", "@appmonster/mcp-japan-bridge"],
      "env": {
        "RAKUTEN_APP_ID": "…",         "RAKUTEN_ACCESS_KEY": "…",
        "YAHOO_JP_APP_ID": "…",
        "BRIDGE_SHIPPING_BASE_JPY": "700",
        "BRIDGE_SHIPPING_PER_KG_JPY": "1500",
        "BRIDGE_PLATFORM_FEE_RATE": "0.06"
      }
    }
  }
}

• Rakuten: free app at https://webservice.rakuten.co.jp (app id + access key).
• Yahoo! JAPAN: free Client ID at https://e.developer.yahoo.co.jp.
• BRIDGE_SHIPPING_*: your forwarder's (배대지) tariff. The defaults are rough placeholders — set yours.
• BRIDGE_PLATFORM_FEE_RATE: Smart Store commission + PG ≈ 5.5–6.5% depending on channel; Coupang is higher.

Customs rules encoded (adjust via inputs)

• 소액면세: goods value ≤ USD 150 per shipment → no duty/VAT (목록통관). dutyFreeUsd adjustable.
• Above: simple mode applies 간이세율 (default 20%) on 과세가격 = goods + shipping; general mode applies HS-code dutyRate then 10% VAT on (과세가격 + duty).
• The tool warns about 합산과세 when splitting quantities.

These are estimates for pricing decisions; customs uses its own weekly exchange rate and final classification.

Development

pnpm --filter @appmonster/mcp-japan-bridge test