jpyc-dev-reference
Developer reference for JPYC, a JPY-pegged stablecoin (日本円ステーブルコイン) deployed on Ethereum, Polygon, and Avalanche. Provides contract addresse
Open source Repository Open in the app JSON README (API)
About
Developer reference for JPYC, a JPY-pegged stablecoin (日本円ステーブルコイン) deployed on Ethereum, Polygon, and Avalanche. Provides contract addresses, ERC20 functions, EIP-3009 gasless transfer signatures, EIP-2612 permit, admin/role operations (mint, burn, pause, blocklist), EIP712 domain configuration, type hashes, error messages, and TypeScript/viem code examples.
Details
- Kind
- Plugins
- Topic
- Finance & crypto
- Publisher
- mameta29
- Origin
- marketplace
- Category
- ferramentas
- Stars
- 2
- Last push
- 2026-08-19T00:18:15Z
- Repository state
- ativo
- Language
- TypeScript
- License
- MIT
- Added
- 2026-08-30 01:48:58
- Updated
- 2026-08-30 01:48:58
- Origin id
mameta29/jpyc-skill/jpyc-dev-reference
README
# jpyc-skill
AI agent tooling for the **JPYC EC Platform** ([ec.jpyc-service.com](https://ec.jpyc-service.com)) — buy products with JPYC stablecoin via the **x402** payment protocol, no gas fees, no accounts.
This repo ships two complementary pieces:
| Path | What it is | Use it from |
| ---- | ---------- | ----------- |
| [`skills/jpyc-ec-purchase/`](./skills/jpyc-ec-purchase) | Claude Code [Skill](https://docs.anthropic.com/en/docs/claude-code/plugins) — markdown reference describing the EC API and x402 flow | Claude Code (CLI / Desktop) |
| [`mcp-servers/jpyc-ec-purchase/`](./mcp-servers/jpyc-ec-purchase) | Model Context Protocol server — invokable tools (`list_shops`, `get_product`, `purchase_cart`, …) for any MCP-capable agent | Claude Desktop, Cursor, OpenAI Agents SDK, and any MCP host |
Both target the same surface: the JPYC EC Platform's public `/api/v1` routes plus the x402 v2 checkout endpoint.
---
## Why this exists
[x402](https://x402.org) is an open standard (Coinbase, December 2025) that embeds payments into HTTP using the long-dormant `402 Payment Required` status code. JPYC implements EIP-3009 natively, so an AI agent can:
1. Discover a product on the JPYC EC Platform
2. Sign an EIP-712 authorization with its wallet (zero gas)
3. POST it back — the platform's facilitator settles on-chain in one round trip
4. Receive an order number + transaction hash
This repo is the agent-side ergonomics layer for that flow.
---
## Skill (`skills/jpyc-ec-purchase/`)
Markdown documentation Claude Code reads as context. Two files:
- **`SKILL.md`** — The TypeScript / SDK-flavoured reference. Decision tree (when to ask for shipping, when to ask for variants), full request/response shapes for every `/api/v1` route, complete error matrix, sample TypeScript implementation using viem.
- **`SKILL-acli.md`** — The same content rewritten as `curl` + `jq` recipes. Useful for shell-based agents and direct debugging.
### Install (Claude Code)
```bash
git clone https://github.com/Mameta29/jpyc-skill.git
mkdir -p ~/.claude/skills/jpyc-ec-purchase
cp -r jpyc-skill/skills/jpyc-ec-purchase/* ~/.claude/skills/jpyc-ec-purchase/
```
Claude Code will then automatically use the skill whenever you ask it to interact with the JPYC EC Platform — e.g. "list shops on stg-ec.jpyc-service.com" or "buy product X with my testnet wallet".
---
## MCP server (`mcp-servers/jpyc-ec-purchase/`)
A standalone MCP server exposing eight tools:
| Tool | EC API endpoint |
| ---- | --------------- |
| `list_shops` | `GET /api/v1/shops` |
| `list_products_in_shop` | `GET /api/v1/shops/:slug/products` |
| `get_product` | `GET /api/v1/products/:id` |
| `get_product_reviews` | `GET /api/v1/products/:id/reviews` |
| `get_nft_discounts` | `GET /api/v1/shops/:slug/nft-discounts` |
| `get_categories` | `GET /api/v1/categories` |
| `get_order_status` | `GET /api/v1/orders?customer_address=` |
| `purchase_cart` | `POST /api/v1/checkout` (x402, called twice) |
| `purchase_product` | `POST /api/v1/checkout` (x402, called twice — single-item shim over `purchase_cart`) |
`purchase_cart` runs the full x402 dance: fetches the 402 challenge, signs an
EIP-3009 `transferWithAuthorization` with the agent's wallet, submits the
signed payload, returns the finalized order. `purchase_product` is a thin
single-item wrapper over it. Both accept an optional `max_amount_atomic`
budget cap so a misbehaving (or hijacked) agent can't overspend.
> Both purchase tools target the unified `POST /api/v1/checkout` endpoint.
> The older single-product `POST /api/v1/products/:id/checkout` route was
> removed on the platform — human shoppers and AI agents now share one
> checkout endpoint.
### Configure (Claude Desktop)
```json
{
"mcpServers": {
"jpyc-ec-purchase": {
"command": "npx",
"args": ["-y", "@jpyc-skill/ec-purchase-mcp"],
"env": {
"BUYER_PRIVATE_KEY": "0x...",
"EC_API_URL": "https://ec.jpyc-service.com"
}
}
}
}
```
For Cursor / OpenAI Agents SDK, the same stdio launcher works — both accept arbitrary MCP servers.
### Run from source
```bash
cd jpyc-skill/mcp-servers/jpyc-ec-purchase
npm install && npm run build
BUYER_PRIVATE_KEY=0x... EC_API_URL=https://stg-ec.jpyc-service.com node dist/bin.js
```
See [`mcp-servers/jpyc-ec-purchase/README.md`](./mcp-servers/jpyc-ec-purchase/README.md) for the full setup walkthrough.
---
## What this repo is NOT
- It is **not** a JPYC contract reference. EIP-3009 / EIP-2612 / admin docs for the JPYC token itself live elsewhere.
- It is **not** a generic x402 facilitator. The hosted facilitator the platform uses (`facilitator.jpyc-service.com`) is operated separately at [`Mameta29/jpyc-x402-facilitator`](https://github.com/Mameta29/jpyc-x402-facilitator).
- It is **not** affiliated with JPYC株式会社 or Coinbase.
---
## Related
- [jpyc-ec-platform](https://github.com/Mameta29/jpyc-ec-platform) — The EC platform whose API these tools target.
- [jpyc-x402-facilitator](https://github.com/Mameta29/jpyc-x402-facilitator) — The x402 facilitator the EC platform delegates settlement to.
- [coinbase/x402](https://github.com/coinbase/x402) — Protocol specification.
## License
MIT