lntip/README.md

# LnMe - your friendly ⚡ payment page

LnMe is a personal Bitcoin Lightning payment website and payment widget.

![demo](./lnme-demo.gif)

It is a small service written in Go that connects to a [lnd node](https://github.com/lightningnetwork/lnd/blob/master/docs/INSTALL.md) and exposes a simple HTTP JSON API to create and monitor invoices. 
It comes with a configurable personal payment website and offers a JavaScript widget to integrate in existing websites.

If [webln](https://github.com/wbobeirne/webln) is available the widget automatically use webln to request the payment; 
otherwise an overlay will be shown with the payment request and a QR code.

## Motivation

I wanted a simple way for people to send Lightning payments using my own lightning node.

BTCPay Server is too big and hard to run for that and I do not need most of its features.


## Installation

LnMe connects to your [LND node](https://github.com/lightningnetwork/lnd/blob/master/docs/INSTALL.md), so a running LND node is required. 
LnMe can easily run next to LND on the same system.

1. Download the latest [release](https://github.com/bumi/lnme/releases)
2. Run `lnme`
3. Done.

### Build from source

1. `$ git clone https://github.com/bumi/lnme.git && cd lnme`
2. `$ go install`
3. `$ rice embed-go && go build`
4. `$ ./lnme`

### Configuration

#### LND configuration

To connect to the lnd node the cert, macaroon and address of the lnd node has to be configured. LnMe uses the LND defaults.

* `lnd-address`: Host and port of the LND gRPC service. default: localhost:10009
* `lnd-cert-path`: Path to the LND TLS cert file. default: ~/.lnd/tls.cert
* `lnd-macaroon-path`: Path to the LND macaroon file. default: ~/.lnd/data/chain/bitcoin/mainnet/invoice.macaroon (invoice.macaroon is recommended)

Instead of the path to the macaroon and cert files you can also provide the hex strings:

* `lnd-cert`: LND TLS cert as HEX string.
* `lnd-macaroon`: LND macaroon file. (invoice.macaroon is recommended)

#### Other configuration

* `static-path`: Path to a folder that you want to serve with LnMe (e.g. /home/bitcoin/lnme/website). Use this if you want to customize your ⚡website. default: disabled
* `disable-website`: Disable the default LnMe website. Disable the website if you only want to embed the LnMe widget on your existing website.
* `disable-cors`: Disable CORS headers. (default: false)
* `port`: Port to listen on. (default: 1323)
* `request-limit`: Limit the allowed requests per second. (default: 5)

Depending on your deployment needs LnMe can be configured using the following options:

1. Command line flags
2. Environment variables
3. Config TOML file

#### Examples:

##### Command line flags:

    $ lnme --help
    $ lnme --lnd-address=lndhost.com:10009 --port=4711
    $ lnme --disable-website

##### TOML config file

See [config.toml.example](./toml.config.example) for an example file.

    $ lnme --config=/path/to/config.toml

##### Environment variables

All environment variables must be prefixed by `LNME_` use `_` instead of `-`

    $ LNME_LND_ADDRESS=127.0.0.1:10005 lnme


### Deployment

To run LnMe as systemd service have a look at the [systemd service example config](https://github.com/bumi/lnme/blob/master/examples/lnme.service)

I am running LnMe behind a reverse proxy using [caddy](https://caddyserver.com/) which comes with [fully-managed HTTPS](https://caddyserver.com/docs/quick-starts/https) via [letsencrypt](https://letsencrypt.org/).

Example Caddyfile:
```
lnme.michaelbumann.com {
  reverse_proxy 127.0.0.1:1323
}
```
`$ caddy  --config /etc/caddy/Caddyfile`


### Customize your ⚡ website

LnMe comes with a default website but you can easily configure and build your own using the the LnMe JavaScript widget or JSON API.

Take a look at the [embedded default website](https://github.com/bumi/lnme/blob/master/files/root/index.html) for an example and use the `--static-path` option to configure LnMe to serve your static file.

1. Create a new folder (e.g. /home/satoshi/my-ln-page)
2. Create your index.html
3. Run lnme: `lnme --static-path=/home/satoshi/my-ln-page


### JavaScript Widget integration

You can integrate the LnMe widget in your existing website.

#### 1. Add the LnMe JavaScript files

```html
<script data-lnme-base-url="https://your-lnme-host.com:1323" src="https://your-lnme-host.com/lnme/lnme.js"></script>
```

#### 2. Usage

To request a lightning payment simply call `request()` on a `new LnMe({value: value, memo: memo})`:

```js
var lnme = new LnMe({ value: 1000, memo: 'high5' });
lnme.request();
```

Use it from a plain HTML link:

```html
<a href="#" onclick="javascript:new LnMe({ value: 1000, memo: 'high5' }).request();return false;">Tip me</a>
```

##### More advanced JS API:

```js
let lnme = new LnMe({ value: 1000, memo: 'high5' });

// get a new invoice and watch for a payment
// promise resolves if the invoice is settled
lnme.requestPayment().then(invoice => {
  alert('YAY, thanks!');
});

// create a new invoice
lnme.addInvoice().then(invoice => {
  console.log(invoice.PaymentRequest)
});

// periodically watch if an invoice is settled
lnme.watchPayment().then(invoice => {
  alert('YAY, thanks!');
});

```

## Development

Use `go run` to ron the service locally:

    $ go run lnme.go --address=127.0.0.1:10009 --cert=/home/bitcoin/lightning/tls.cert --macaroon=/home/bitcoin/lightning/invoice.macaroon

## Build

LnMe uses [go.rice](https://github.com/GeertJohan/go.rice) to embed assets (HTML, JS, and CSS files). run `rice embed-go`

    $ rice embed-go
    $ go build

## Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/bumi/lnme

## License

Available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).