Nostr client using async websockets

client.rb

require 'async'
require 'async/barrier'
require 'async/http/endpoint'
require 'async/websocket/client'

require 'nostrb/source'

module Nostrb
  class Client
    def initialize(relay_url)
      @url = relay_url
      @endpoint = Async::HTTP::Endpoint.parse(@url)
    end

    def publish(signed_event)
      barrier = Async::Barrier.new
      resp = nil
      Sync do |task|
        task.async do
          conn = Async::WebSocket::Client.connect(@endpoint)
          conn.write(Nostrb.json(Nostrb::Source.publish(signed_event)))
          conn.flush
          resp = conn.read
          conn.shutdown
        end.wait
      ensure
        barrier.stop
      end
      Nostrb.parse(resp.buffer)[2] if resp
    end
  end
end

config.ru

# path/to/falcon serve \
#   --bind wss://localhost:7070 \
#   --config examples/config.ru \

require 'async/websocket/adapters/rack'
require 'nostrb/relay'

relay = Nostrb::Server.new
Adapter = Async::WebSocket::Adapters::Rack

app = lambda do |env|
  Adapter.open(env, protocols: ['ws', 'wss']) do |conn|
    puts "New connection: #{conn}"
    reqs, resps = 0, 0
    while req = conn.read
      reqs += 1
      puts req.buffer
      relay.ingest(req.buffer).each { |resp|
        resps += 1
        conn.write Nostrb.json(resp)
      }
    end
    puts "Closed after #{reqs} requests and #{resps} responses"
  end
end

run app

irb_session.txt

[rwh@nixos:~/git/nostrb]$ irb -rnostrb/client
irb(main):001> c = Nostrb::Client.new('wss://localhost:7070')
=>
#<Nostrb::Client:0x00007f5989ad2750
...
irb(main):002> sk, pk = SchnorrSig.keypair
=> ["\xADl\x84\xD8W\xAA\xCB\x91\x8FJ\x83Y\x93T\xA2u5\xB9\x94\x9E\xF4\xD1\x7...
irb(main):003> src = Nostrb::Source.new(pk)
=>
#<Nostrb::Source:0x00007f5989ad5ce8
...
irb(main):004> e = src.text_note('hi').sign(sk)
=>
#<Nostrb::SignedEvent:0x00007f5989b26918
...
irb(main):005> c.publish(e)

# ... never returns ...