nips/83.md

NIP-83
======

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

`draft` `optional` `author:arcbtc` `author:blackcoffeexbt`

Useful for clients wanting to intergrate wallet features, could be custodial or non-custodial or both.

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

## Motivation

All bitcoin lightning wallet clients connected to nodes use http, they should also be able to use nostr.

Simple plugins/middleware/libraries could be easily made for existing nodes and lightning wallet software.

## 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`: Connected to the funding source.

2. `service client`: Built into service/client that wants wallet functions.

### Permissions

In `funding source client` nostr pubkeys used by `service client` are given and permissions granted (such as `read`/`create_invoice_only`/`pay_invoices`)

### 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]>"
   }
}
```

`funding source client` checks the pubkey has permission and attempts to pay the invoice.

### 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>"
   }
}
```