nips/83.md

NIP-83
======

Wallet connect/bridge
--------------

`draft` `optional` `author:arcbtc`

Useful for clients wanting to intergrate non-custodal wallet features.

> Intended for use with bitcoin, but could be used with any invoice payment system that can pay invoices/create invoices/check payment status.

## Motivation

We wanted LNbits to have a funding source that pay invoices/create invoices/check payment status, all over nostr DMs. Simple plugins/middleware coud be made for lightning nodes that connect to the funding source.

## Examples

There are two simple clients sending json over [NIP04](https://github.com/nostr-protocol/nips/blob/master/04.md).

1. `funding source client`: Attached to the funding source, the other built into another service/client.

2. `service client`: Built into a service.

### Creating an invoice

`service client` sends `create_invoice` event:

```json
{ "create_invoice": {
        "amount": int,
        "memo": "<Optional[str]>",
        "description_hash": "<Optional[bytes]>"
}
}
```

`funding source client` checks the pubkey has permission and sends `generated_invoice` event:

```json
{ "generated_invoice": {
    "payment_hash": "<string>", 
    "payment_request": "<string>"
  }
}
```

### Paying an invoice

`service client` sends `pay_invoice` event:

```json
{ "pay_invoice": {
        "invoice":  "<string>",
        "note": "<Optional[str]>"
}
}
```

### Checking a payment in/out

`service client` sends `check_payment` event:

```json
{ "check_payment": {
    "payment_hash": "<string>"
  }
}

```

`funding source client` checks the pubkey has permission, checks the payment status and sends `payment_status` event:

```json
{ "payment_status": {
    "paid": "<bool>"
  }
}
```