# kaisha-mcp

MCP server for the **[Kaisha API](https://kaisha-api.hp-vladic.workers.dev)** — official Japanese company-registry data for AI agents, paid per call with [x402](https://x402.org) (USDC on Base or Solana). **No API keys, no signup** — the paying wallet is the account.

Data comes from Japan's National Tax Agency open datasets: all ~5.8M registered corporations (法人番号) and ~5M qualified-invoice registrations (適格請求書). Individual proprietors' names are never returned.

## Install

Add it to any MCP client (Claude Code, Cursor, OpenClaw, …) in one line:

```bash
claude mcp add kaisha -e EVM_PRIVATE_KEY=0x<base-wallet-with-usdc> -- npx -y kaisha-mcp
```

Or run it directly:

```bash
EVM_PRIVATE_KEY=0x... npx -y kaisha-mcp
```

## Configuration

Set **at least one** signing key — a wallet holding a small amount of USDC (calls cost $0.002–$0.01):

| Env var | Meaning |
|---|---|
| `EVM_PRIVATE_KEY` | Base wallet private key holding USDC (`0x…`) |
| `SVM_PRIVATE_KEY` | Solana wallet private key holding USDC (base58) |
| `EVM_RPC_URL` | *(optional)* Base RPC, default `https://mainnet.base.org` |
| `KAISHA_BASE_URL` | *(optional)* API base, default `https://kaisha-api.hp-vladic.workers.dev` |

> Keep your private key in your MCP client's env config — never commit it.

## Tools

| Tool | Description | Price |
|---|---|---|
| `resolve_japanese_company` | Company name (fuzzy) or 13-digit corporate number → canonical name, address, entity type, active/closed | $0.005 |
| `verify_japan_invoice_number` | Qualified-invoice number (`T`+13 digits) → active / cancelled / not-found, registration date, name | $0.01 |
| `japan_new_companies` | Daily feed of newly registered companies (新設法人), closures, moves, renames, mergers from NTA diff data | $0.01 |
| `japan_business_days` | Business-day check / add N days / count a range (weekends + national holidays) | $0.002 |
| `japan_holidays` | Japanese national holidays for a year (1955–2027) | $0.002 |
| `kaisha_catalog` | Machine-readable catalog of endpoints, prices, and payment networks | free |

## How payment works

Each priced call triggers the x402 flow automatically: the API replies `402 Payment Required` with a price, your wallet signs a USDC payment, the request is retried, and the data comes back with an on-chain settlement proof. Every challenge offers both **Base** (`eip155:8453`) and **Solana** mainnet.

## Links

- API & docs: https://kaisha-api.hp-vladic.workers.dev
- npm: https://www.npmjs.com/package/kaisha-mcp
- Catalog (free): https://kaisha-api.hp-vladic.workers.dev/catalog

## License

MIT