omniauth-lightning

This gem implements an Omniauth strategy to login via the Lightning Network. It uses LNPay.co as the backend.

Once integrated, users of your application can submit an invoice from their own node, this gem will decode the invoice to extract the pubkey of the user's node and use that pubkey as the UID of the user.

Note that the user will submit Lightning Network invoices to your application, but your application won't need to pay them.

Installation

Add to your Gemfile:

gem 'omniauth-lightning'

and run bundle install.

Integration

Next, tell OmniAuth about this provider. For a Rails app, your config/initializers/omniauth.rb file should look like this:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :lightning,
    invoice_sats_amount: 1,
    validating_text: 'my-app-auth-string',
    lnpay_key: 'my-lnpay-key' # secret api key from https://lnpay.co/dashboard/developers
end

This configuration will make the strategy require a 1 sat invoice that includes the text my-app-auth-string to validate the invoice.

Configuration

The following settings are available:

:title                      # title of the rendered form that prompts user to submit their invoice
:sats_amount                # amount of sats that the invoice should include
:validating_text            # text that should be included in the invoice's description
:invoice_max_age_in_seconds # maximum age of invoices that are accepted in seconds
:lnpay_key                  # Key from LNPay.co to use to decode invoices

Error keys

The following errors might be returned from the gem; you might want to handle them on your application to display errors:

:invalid_invoice                 # invoice invalid
:invoice_without_required_amount # invoice wasn't for the amount specified on :sats_amount
:invoice_without_required_text   # invoice didn't include the required text specified on :validating_text
:old_invoice                     # invoice is older than :invoice_max_age_in_seconds
:custodial_wallet                # invoice was generated by a custodial wallet

Customizing Invoice Form

To use your own custom invoice form, create a form that POSTs to '/auth/lightning/callback' with invoice.

<%= form_tag '/auth/lightning/callback' do |f| %>
  <h1>Submit your invoice</h1>
  <%= text_field_tag :invoice %>
  <%= submit_tag %>
<% end %>

Example app

If you want to see an app using this gem, checkout bitcoiners-best. To see a live version of this, checkout https://bitcoiners.best/

Author

Written by @pablof7z.