# Lnrpc - ruby gRPC client for LND

a [gRPC](https://grpc.io/) client for [LND, the Lightning Network Daemon](https://github.com/lightningnetwork/lnd/) packed as ruby gem. 


## Installation

Add this line to your application's Gemfile:

```ruby
gem 'lnrpc'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install lnrpc

## Usage

This gem makes the gRPC client classes created from the [LND service defintions](https://github.com/lightningnetwork/lnd/tree/master/lnrpc) available.  

```ruby
require "lnrpc"

# the gRPC client is available under the Lnrpc namespace, e.g. 

Lnrpc::Lightning::Stub
Lnrpc::GetInfoRequest
```

Learn more about [gRPC](https://grpc.io/) on [gRPC.io](https://grpc.io/).

The LND API reference can be found here: [https://api.lightning.community/](https://api.lightning.community/)

### Example

```ruby
require "lnrpc"

credentials = File.read("/path/to/tls.cert") 
macaroon = File.read("/path/to/readonly.macaroon").unpack("H*")

# initialize a new client
client = Lnrpc::Lightning::Stub.new("localhost:10009", GRPC::Core::ChannelCredentials.new(self.credentials))

# perform a request
request = Lnrpc::GetInfoRequest.new
response = client.get_info(request, { metadata: { macaroon: macaroon } }) #=> Lnrpc::GetInfoResponse
puts response.alias 
```

### Client wrapper

An optional client wrapper ([Lnrpc::Client](https://github.com/bumi/lnrpc/blob/master/lib/lnrpc/client.rb")) makes 
initializing the gRPC client easier and removes the need for some boilerplate code for calling RPC methods.

#### Example
```ruby
lnd = Lnrpc::Client.new({credentials_path: '/path/to.cert.cls', macaroon_path: '/path/to/admin.macaroon'})
lnd.get_info
```

#### Initializing a new client

The Lnrpc::Client constructor allows the following options: 

* credentials: 
  - `credentials` : the credentials data as string
  - `credentials_path` : the path to a credentials file (tls.cert) as string
* macaroon: 
  - `macaroon` : the macaroon as hex string
  - `macaroon_path` : the path to the macaroon file created by lnd as string
* address:
  - `address` : lnd address as string. format: address:port, e.g. default: localhost:10009


```ruby
require 'lnrpc'

lnd = Lnrpc::Client.new({
  credentials_path: '/path/to.cert.cls', 
  macaroon_path: '/path/to/admin.macaroon',
  address: 'host:port'
})

# the actual gRPC client is available through:
lnd.grpc_client
```

#### Calling RPC methods

The client wrapper passes any supported RPC method call to the gRPC client applying the following conventions:

If the first parameter is a hash or blank a new request instance of `Lnrpc::[capitalized method name]Request` will be used as request paramter.

If the second paramter is blank the macaroon will be passed as metadata. (`{ metadata: { macaroon: self.macaroon } }`)

Example:

```ruby
client.get_info
# is the same as: 
client.grpc_client.get_info(Lnrpc::GetInfoRequest.new, { metadata: { macaroon: macaroon } })

client.add_invoice(value: 1000, memo: 'I :heart: ruby')
# is the same as: 
invoice_request = Lnrpc::AddInvoiceRequest(value: 1000, memo: 'I :heart: ruby')
client.grpc_client.add_invoice(invoice_request, { metadata: { macaroon: macaroon } })
```


## Versioning

This gem follows the LND versions and will update the gRPC service definitions accordingly. 
e.g. gem version 0.5.2 includes the gRPC service definitions from LND v0.5.2


## Other resources

* [LND gRPC API Reference](https://api.lightning.community)
* [LND Developer Site](https://dev.lightning.community/)
* [gRPC Ruby quick start](https://grpc.io/docs/quickstart/ruby.html)

## Contributing

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

## License

The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).