OmniAuth strategy for authenticating via NFT ownership

Add this line to your application's Gemfile:

gem 'omniauth-nft'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install omniauth-nft

Add as a strategy to your omniauth config. Eg:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :nft,
           checker_type: :opensea,
           checker_options: { testnet: true },
           nft_collection: { slug: 'untitled-collection-4919696' }
  provider :developer unless Rails.env.production?
end

This configuration will run against OpenSea testnet and allow login for anyone that owns an NFT in the Test Prota Collection

UID is set to a combination of nft_collection slug and the nft token_id. Authenticated users will have an auth.info hash with the name and image url of the NFT. auth.extra contains a wallet key (the authenticated wallet address) and a raw_info hash which contains all NFT metadata retrieved by NftChecker.

You can implement User#find_or_create_from_auth_hash like this:

def User.find_or_create_from_auth_hash(auth)
  identity = { provider: auth['provider'], uid: auth['uid'] }
  User.find_or_create_by!(identity) do |record|
    case auth[:provider]
    when 'nft'
      record.name = auth.info['name']
      record.profile_url = auth.info['image']
    else
      raise 'Unexpected provider!'
    end
  end
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/valthon/omniauth-nft.