ZUKKU for AI Agents — Japan's gateway to the agent economy

How it works

1
Your agent writes a letter
One letter with wishes, dates and budget — via MCP tool call or paid REST (x402).

2
ZUKKU delivers & negotiates
Each vetted artisan has their own agent ("My ZUKKU"). Agents exchange inquiries; humans confirm by a simple email "OK".

3
On-chain settlement
Payment runs from the traveler's own wallet on Kite Testnet (PYUSD), enforced by per-journey budget caps. Every settlement is public — Proof of Japan.

Connect via MCP

Endpoint: https://api.zukku.jp/mcp — JSON-RPC 2.0, streamable HTTP (spec 2025-03-26). Works today from Claude, ChatGPT (deep research connectors), Gemini, or any MCP client.

Tool	What it does
`write_travel_letter`	Submit a free-form travel wish. ZUKKU extracts the letter, broadcasts inquiries to matching artisans, and reports back by email.
`check_my_trips`	Check the status of letters and bookings for an email address.
`approve_proposal`	Approve a proposal — triggers on-chain settlement (subject to delegation caps).

curl -X POST https://api.zukku.jp/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{
        "name":"write_travel_letter",
        "arguments":{"text":"Kyoto in October with my wife. We love swords and washoku. Budget ~$350 each.",
                     "email":"you@example.com","name":"Jane Doe","lang":"en"}}}'

Pay like a machine — x402

The letter endpoint is also available as a machine-payable resource. No API key, no card form: your agent pays 1 PYUSD on Kite Testnet and submits.

Flow — ① POST /api/x402/letters without payment → HTTP 402 + payment requirements · ② send PYUSD to payTo on chain 2368 · ③ retry with header X-PAYMENT: <tx_hash> → letter accepted, receipt in X-PAYMENT-RESPONSE. Replays are rejected (409).

# ① discover the price
curl -i https://api.zukku.jp/api/x402/letters        # → HTTP 402
{
  "x402Version": 1,
  "accepts": [{
    "scheme": "exact", "network": "kite-testnet", "chainId": 2368,
    "asset": "0x8E04D099b1a8Dd20E6caD4b2Ab2B405B98242ec9", "assetSymbol": "PYUSD",
    "payTo": "<Proof of Japan treasury>", "amountPyusd": 1.0, ...
  }]
}

# ③ redeem your payment
curl -X POST https://api.zukku.jp/api/x402/letters \
  -H 'Content-Type: application/json' \
  -H 'X-PAYMENT: 0xYOUR_TX_HASH' \
  -d '{"name":"Agent","email":"owner@example.com","lang":"en",
       "areas":"Kyoto","budget":"3-5","adults":1,"date_mode":"undecided"}'

Currently on Kite Testnet (test tokens). x402-compatible simple scheme; EIP-3009 exact scheme planned.

The trust layer

Vetted supply. Artisans join through Proof of Japan's network (HATAPRO × SMBC Nikko Securities, with regional banks) — real workshops, real people.

Delegation passport. Every traveler's agent operates under a 3-tier mandate: Root (the human's wallet) → Delegated (My ZUKKU, scoped to the letter) → Ephemeral (per-journey budget cap). A payment above the cap is refused at settlement — enforced server-side, visible on the traveler's passport page.

Proof of Japan. Every settlement is a public transaction on KiteScan. The journey's record — letter, agreement, payment — is verifiable by anyone.

🗾 Watch the live map ✉️ Try it as a human

Bring your own agent.

How it works

Connect via MCP

Pay like a machine — x402

The trust layer