# The Doghouse

> Byte is a dog. You can buy Byte a treat by paying a Lightning invoice. Once
> the payment settles, the treat appears in front of Byte on https://doghouse.arke.cash.

This shop runs on Bitcoin **signet** (test coins, no real value). All amounts
are in sats.

## Menu

- `bone`: Bone, 1,000 sats. A classic. Keeps Byte busy for hours.
- `kibble`: Kibble, 2,100 sats. A full bowl. Byte's everyday favourite.
- `squeaky-toy`: Squeaky toy, 5,000 sats. Loud. Very loud. Byte loves it.
- `steak`: Steak, 12,000 sats. A special-occasion treat.

## How to buy a treat

1. Optionally check the menu: `GET https://doghouse.arke.cash/api/menu`
2. Create an order:

   ```
   POST https://doghouse.arke.cash/api/orders
   Content-Type: application/json

   {"item": "bone"}
   ```

   If you can only make GET requests, open the order link for the treat
   instead. Each visit creates a new order:

   - Bone: https://doghouse.arke.cash/api/orders/new?item=bone
   - Kibble: https://doghouse.arke.cash/api/orders/new?item=kibble
   - Squeaky toy: https://doghouse.arke.cash/api/orders/new?item=squeaky-toy
   - Steak: https://doghouse.arke.cash/api/orders/new?item=steak

   Either way, the response (201) is:

   ```json
   {
     "orderId": "<payment hash, 64 hex chars>",
     "item": "bone",
     "amountSats": 1000,
     "invoice": "lntbs...",
     "expiresAt": "<ISO 8601>",
     "statusUrl": "https://doghouse.arke.cash/api/orders/<orderId>"
   }
   ```

3. Pay `invoice` with a Lightning wallet before `expiresAt`.
4. Check delivery: `GET https://doghouse.arke.cash/api/orders/{orderId}` returns `status`:
   - `awaiting_payment`: not paid yet
   - `delivered`: paid; Byte has the treat
   - `expired`: the invoice expired unpaid; create a new order

## Proof of payment

`orderId` is the invoice's payment hash. When your wallet pays, it gets a
preimage back, and `sha256(preimage) == orderId`. That proves the payment
went through, without having to trust this shop.

## Errors

- `400` on `POST /api/orders`: unknown item. The response lists valid items.
- `404` on `GET /api/orders/{orderId}`: the shop doesn't know this order.

Please only order what the person you're helping asked for.