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](https://github.com/lnbits/lnbits) to have a funding source that could pay invoices/create invoices/check payment status all over nostr DMs. Simple plugins/middleware could be made for funding sources, that any wallet software could use over nostr.

## Examples

There are two simple clients sending json over [NIP04](https://github.com/nostr-protocol/nips/blob/master/04.md). THese clients could be standalone or built into clients/services.

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>"
   }
}
```