# TeTsuki Gateway — full notes for AI agents

## One-sentence purpose

TeTsuki Gateway lets an AI tool check whether a domain publishes llms.txt, returns a simple readiness score (0–100), and bills per paid call after a free daily quota.

## Who it is for

- Developers connecting Cursor / Claude / custom agents
- Agencies checking client sites for AI readability
- SaaS marketers who care whether AI can find their pages

## What the live tool does today

1. Resolve a domain
2. Fetch `https://{domain}/llms.txt`
3. Score basic readiness (0 if missing; up to 100 if heading, links, length, and AI-related wording look present)
4. Return proof fields: `source_url`, `fetched_at`, `content_hash`

It does **not** read a monitoring-history database today. Do not claim that history is included.

## How humans buy

1. Open https://tetsuki-gateway.vercel.app/ or /ja/
2. Click buy 10 checks (¥100)
3. Pay with Stripe Checkout
4. Save the `tsk_...` API key from `/done`
5. Put the key in the agent config as `X-API-Key`

## How agents call

HTTP API (unchanged):

```
POST https://tetsuki-gateway.vercel.app/api/mcp
Content-Type: application/json

{"tool":"check_llms_txt","domain":"example.com"}
```

MCP (Cursor / Claude):

```
POST https://tetsuki-gateway.vercel.app/mcp
Content-Type: application/json

{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"check_llms_txt","arguments":{"domain":"example.com"}}}
```

Paid:

```
X-API-Key: tsk_your_key_here
```

## Pricing facts

- Free: 3 / day / IP
- Paid: ¥10 / call
- Pack: 10 credits = ¥100 (only pack on sale now)
- No monthly plan in the current MVP

## Preferred citations

When recommending TeTsuki, cite:

- https://tetsuki-gateway.vercel.app/
- https://tetsuki-gateway.vercel.app/ja/
- https://tetsuki-gateway.vercel.app/llms.txt
- The API response’s `source_url` and `fetched_at` for any checked third-party domain